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kernel_linux
提交 63ac0cf9 编写于 作者: J Jonathan Corbet
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Merge branch 'sphinx-fixes-for-docs-next' of git://people.freedesktop.org/~jani/drm into test 

A set of PDF and other docs related fixes from Jani.
上级 ac72618f 07c7e30c
隐藏空白更改
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Showing with 7513 addition and 7494 deletion
Documentation/Makefile.sphinx
浏览文件 @ 63ac0cf9
...@@ -10,6 +10,8 @@ _SPHINXDIRS = $(patsubst $(srctree)/Documentation/%/conf.py,%,$(wildcard $(src ...@@ -10,6 +10,8 @@ _SPHINXDIRS = $(patsubst $(srctree)/Documentation/%/conf.py,%,$(wildcard $(src
SPHINX_CONF = conf.py SPHINX_CONF = conf.py
PAPER = PAPER =
BUILDDIR = $(obj)/output BUILDDIR = $(obj)/output
PDFLATEX = xelatex
LATEXOPTS = -interaction=batchmode
# User-friendly check for sphinx-build # User-friendly check for sphinx-build
HAVE_SPHINX := $(shell if which $(SPHINXBUILD) >/dev/null 2>&1; then echo 1; else echo 0; fi) HAVE_SPHINX := $(shell if which $(SPHINXBUILD) >/dev/null 2>&1; then echo 1; else echo 0; fi)
...@@ -29,7 +31,7 @@ else ifneq ($(DOCBOOKS),) ...@@ -29,7 +31,7 @@ else ifneq ($(DOCBOOKS),)
else # HAVE_SPHINX else # HAVE_SPHINX
# User-friendly check for pdflatex # User-friendly check for pdflatex
HAVE_PDFLATEX := $(shell if which xelatex >/dev/null 2>&1; then echo 1; else echo 0; fi) HAVE_PDFLATEX := $(shell if which $(PDFLATEX) >/dev/null 2>&1; then echo 1; else echo 0; fi)
# Internal variables. # Internal variables.
PAPEROPT_a4 = -D latex_paper_size=a4 PAPEROPT_a4 = -D latex_paper_size=a4
...@@ -51,7 +53,7 @@ loop_cmd = $(echo-cmd) $(cmd_$(1)) ...@@ -51,7 +53,7 @@ loop_cmd = $(echo-cmd) $(cmd_$(1))
# $5 reST source folder relative to $(srctree)/$(src), # $5 reST source folder relative to $(srctree)/$(src),
# e.g. "media" for the linux-tv book-set at ./Documentation/media # e.g. "media" for the linux-tv book-set at ./Documentation/media
quiet_cmd_sphinx = SPHINX $@ --> file://$(abspath $(BUILDDIR)/$3/$4); quiet_cmd_sphinx = SPHINX $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
cmd_sphinx = $(MAKE) BUILDDIR=$(abspath $(BUILDDIR)) $(build)=Documentation/media all;\ cmd_sphinx = $(MAKE) BUILDDIR=$(abspath $(BUILDDIR)) $(build)=Documentation/media all;\
BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \ BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \
$(SPHINXBUILD) \ $(SPHINXBUILD) \
...@@ -67,16 +69,19 @@ htmldocs: ...@@ -67,16 +69,19 @@ htmldocs:
@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var))) @$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var)))
latexdocs: latexdocs:
@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,latex,$(var),latex,$(var)))
ifeq ($(HAVE_PDFLATEX),0) ifeq ($(HAVE_PDFLATEX),0)
$(warning The 'xelatex' command was not found. Make sure you have it installed and in PATH to produce PDF output.)
pdfdocs:
$(warning The '$(PDFLATEX)' command was not found. Make sure you have it installed and in PATH to produce PDF output.)
@echo " SKIP Sphinx $@ target." @echo " SKIP Sphinx $@ target."
else # HAVE_PDFLATEX else # HAVE_PDFLATEX
@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,latex,$(var),latex,$(var)))
endif # HAVE_PDFLATEX
pdfdocs: latexdocs pdfdocs: latexdocs
ifneq ($(HAVE_PDFLATEX),0) $(foreach var,$(SPHINXDIRS), $(MAKE) PDFLATEX=$(PDFLATEX) LATEXOPTS="$(LATEXOPTS)" -C $(BUILDDIR)/$(var)/latex;)
$(foreach var,$(SPHINXDIRS), $(MAKE) PDFLATEX=xelatex LATEXOPTS="-interaction=nonstopmode" -C $(BUILDDIR)/$(var)/latex)
endif # HAVE_PDFLATEX endif # HAVE_PDFLATEX
epubdocs: epubdocs:
......
Documentation/admin-guide/devices.rst
浏览文件 @ 63ac0cf9
...@@ -56,3090 +56,8 @@ an unreasonable effort. ...@@ -56,3090 +56,8 @@ an unreasonable effort.
Your cooperation is appreciated. Your cooperation is appreciated.
:: .. include:: devices.txt
:literal:
0 Unnamed devices (e.g. non-device mounts)
0 = reserved as null device number
See block major 144, 145, 146 for expansion areas.
1 char Memory devices
1 = /dev/mem Physical memory access
2 = /dev/kmem Kernel virtual memory access
3 = /dev/null Null device
4 = /dev/port I/O port access
5 = /dev/zero Null byte source
6 = /dev/core OBSOLETE - replaced by /proc/kcore
7 = /dev/full Returns ENOSPC on write
8 = /dev/random Nondeterministic random number gen.
9 = /dev/urandom Faster, less secure random number gen.
10 = /dev/aio Asynchronous I/O notification interface
11 = /dev/kmsg Writes to this come out as printk's, reads
export the buffered printk records.
12 = /dev/oldmem OBSOLETE - replaced by /proc/vmcore
1 block RAM disk
0 = /dev/ram0 First RAM disk
1 = /dev/ram1 Second RAM disk
...
250 = /dev/initrd Initial RAM disk
Older kernels had /dev/ramdisk (1, 1) here.
/dev/initrd refers to a RAM disk which was preloaded
by the boot loader; newer kernels use /dev/ram0 for
the initrd.
2 char Pseudo-TTY masters
0 = /dev/ptyp0 First PTY master
1 = /dev/ptyp1 Second PTY master
...
255 = /dev/ptyef 256th PTY master
Pseudo-tty's are named as follows:
* Masters are "pty", slaves are "tty";
* the fourth letter is one of pqrstuvwxyzabcde indicating
the 1st through 16th series of 16 pseudo-ttys each, and
* the fifth letter is one of 0123456789abcdef indicating
the position within the series.
These are the old-style (BSD) PTY devices; Unix98
devices are on major 128 and above and use the PTY
master multiplex (/dev/ptmx) to acquire a PTY on
demand.
2 block Floppy disks
0 = /dev/fd0 Controller 0, drive 0, autodetect
1 = /dev/fd1 Controller 0, drive 1, autodetect
2 = /dev/fd2 Controller 0, drive 2, autodetect
3 = /dev/fd3 Controller 0, drive 3, autodetect
128 = /dev/fd4 Controller 1, drive 0, autodetect
129 = /dev/fd5 Controller 1, drive 1, autodetect
130 = /dev/fd6 Controller 1, drive 2, autodetect
131 = /dev/fd7 Controller 1, drive 3, autodetect
To specify format, add to the autodetect device number:
0 = /dev/fd? Autodetect format
4 = /dev/fd?d360 5.25" 360K in a 360K drive(1)
20 = /dev/fd?h360 5.25" 360K in a 1200K drive(1)
48 = /dev/fd?h410 5.25" 410K in a 1200K drive
64 = /dev/fd?h420 5.25" 420K in a 1200K drive
24 = /dev/fd?h720 5.25" 720K in a 1200K drive
80 = /dev/fd?h880 5.25" 880K in a 1200K drive(1)
8 = /dev/fd?h1200 5.25" 1200K in a 1200K drive(1)
40 = /dev/fd?h1440 5.25" 1440K in a 1200K drive(1)
56 = /dev/fd?h1476 5.25" 1476K in a 1200K drive
72 = /dev/fd?h1494 5.25" 1494K in a 1200K drive
92 = /dev/fd?h1600 5.25" 1600K in a 1200K drive(1)
12 = /dev/fd?u360 3.5" 360K Double Density(2)
16 = /dev/fd?u720 3.5" 720K Double Density(1)
120 = /dev/fd?u800 3.5" 800K Double Density(2)
52 = /dev/fd?u820 3.5" 820K Double Density
68 = /dev/fd?u830 3.5" 830K Double Density
84 = /dev/fd?u1040 3.5" 1040K Double Density(1)
88 = /dev/fd?u1120 3.5" 1120K Double Density(1)
28 = /dev/fd?u1440 3.5" 1440K High Density(1)
124 = /dev/fd?u1600 3.5" 1600K High Density(1)
44 = /dev/fd?u1680 3.5" 1680K High Density(3)
60 = /dev/fd?u1722 3.5" 1722K High Density
76 = /dev/fd?u1743 3.5" 1743K High Density
96 = /dev/fd?u1760 3.5" 1760K High Density
116 = /dev/fd?u1840 3.5" 1840K High Density(3)
100 = /dev/fd?u1920 3.5" 1920K High Density(1)
32 = /dev/fd?u2880 3.5" 2880K Extra Density(1)
104 = /dev/fd?u3200 3.5" 3200K Extra Density
108 = /dev/fd?u3520 3.5" 3520K Extra Density
112 = /dev/fd?u3840 3.5" 3840K Extra Density(1)
36 = /dev/fd?CompaQ Compaq 2880K drive; obsolete?
(1) Autodetectable format
(2) Autodetectable format in a Double Density (720K) drive only
(3) Autodetectable format in a High Density (1440K) drive only
NOTE: The letter in the device name (d, q, h or u)
signifies the type of drive: 5.25" Double Density (d),
5.25" Quad Density (q), 5.25" High Density (h) or 3.5"
(any model, u). The use of the capital letters D, H
and E for the 3.5" models have been deprecated, since
the drive type is insignificant for these devices.
3 char Pseudo-TTY slaves
0 = /dev/ttyp0 First PTY slave
1 = /dev/ttyp1 Second PTY slave
...
255 = /dev/ttyef 256th PTY slave
These are the old-style (BSD) PTY devices; Unix98
devices are on major 136 and above.
3 block First MFM, RLL and IDE hard disk/CD-ROM interface
0 = /dev/hda Master: whole disk (or CD-ROM)
64 = /dev/hdb Slave: whole disk (or CD-ROM)
For partitions, add to the whole disk device number:
0 = /dev/hd? Whole disk
1 = /dev/hd?1 First partition
2 = /dev/hd?2 Second partition
...
63 = /dev/hd?63 63rd partition
For Linux/i386, partitions 1-4 are the primary
partitions, and 5 and above are logical partitions.
Other versions of Linux use partitioning schemes
appropriate to their respective architectures.
4 char TTY devices
0 = /dev/tty0 Current virtual console
1 = /dev/tty1 First virtual console
...
63 = /dev/tty63 63rd virtual console
64 = /dev/ttyS0 First UART serial port
...
255 = /dev/ttyS191 192nd UART serial port
UART serial ports refer to 8250/16450/16550 series devices.
Older versions of the Linux kernel used this major
number for BSD PTY devices. As of Linux 2.1.115, this
is no longer supported. Use major numbers 2 and 3.
4 block Aliases for dynamically allocated major devices to be used
when its not possible to create the real device nodes
because the root filesystem is mounted read-only.
0 = /dev/root
5 char Alternate TTY devices
0 = /dev/tty Current TTY device
1 = /dev/console System console
2 = /dev/ptmx PTY master multiplex
3 = /dev/ttyprintk User messages via printk TTY device
64 = /dev/cua0 Callout device for ttyS0
...
255 = /dev/cua191 Callout device for ttyS191
(5,1) is /dev/console starting with Linux 2.1.71. See
the section on terminal devices for more information
on /dev/console.
6 char Parallel printer devices
0 = /dev/lp0 Parallel printer on parport0
1 = /dev/lp1 Parallel printer on parport1
...
Current Linux kernels no longer have a fixed mapping
between parallel ports and I/O addresses. Instead,
they are redirected through the parport multiplex layer.
7 char Virtual console capture devices
0 = /dev/vcs Current vc text contents
1 = /dev/vcs1 tty1 text contents
...
63 = /dev/vcs63 tty63 text contents
128 = /dev/vcsa Current vc text/attribute contents
129 = /dev/vcsa1 tty1 text/attribute contents
...
191 = /dev/vcsa63 tty63 text/attribute contents
NOTE: These devices permit both read and write access.
7 block Loopback devices
0 = /dev/loop0 First loop device
1 = /dev/loop1 Second loop device
...
The loop devices are used to mount filesystems not
associated with block devices. The binding to the
loop devices is handled by mount(8) or losetup(8).
8 block SCSI disk devices (0-15)
0 = /dev/sda First SCSI disk whole disk
16 = /dev/sdb Second SCSI disk whole disk
32 = /dev/sdc Third SCSI disk whole disk
...
240 = /dev/sdp Sixteenth SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
9 char SCSI tape devices
0 = /dev/st0 First SCSI tape, mode 0
1 = /dev/st1 Second SCSI tape, mode 0
...
32 = /dev/st0l First SCSI tape, mode 1
33 = /dev/st1l Second SCSI tape, mode 1
...
64 = /dev/st0m First SCSI tape, mode 2
65 = /dev/st1m Second SCSI tape, mode 2
...
96 = /dev/st0a First SCSI tape, mode 3
97 = /dev/st1a Second SCSI tape, mode 3
...
128 = /dev/nst0 First SCSI tape, mode 0, no rewind
129 = /dev/nst1 Second SCSI tape, mode 0, no rewind
...
160 = /dev/nst0l First SCSI tape, mode 1, no rewind
161 = /dev/nst1l Second SCSI tape, mode 1, no rewind
...
192 = /dev/nst0m First SCSI tape, mode 2, no rewind
193 = /dev/nst1m Second SCSI tape, mode 2, no rewind
...
224 = /dev/nst0a First SCSI tape, mode 3, no rewind
225 = /dev/nst1a Second SCSI tape, mode 3, no rewind
...
"No rewind" refers to the omission of the default
automatic rewind on device close. The MTREW or MTOFFL
ioctl()'s can be used to rewind the tape regardless of
the device used to access it.
9 block Metadisk (RAID) devices
0 = /dev/md0 First metadisk group
1 = /dev/md1 Second metadisk group
...
The metadisk driver is used to span a
filesystem across multiple physical disks.
10 char Non-serial mice, misc features
0 = /dev/logibm Logitech bus mouse
1 = /dev/psaux PS/2-style mouse port
2 = /dev/inportbm Microsoft Inport bus mouse
3 = /dev/atibm ATI XL bus mouse
4 = /dev/jbm J-mouse
4 = /dev/amigamouse Amiga mouse (68k/Amiga)
5 = /dev/atarimouse Atari mouse
6 = /dev/sunmouse Sun mouse
7 = /dev/amigamouse1 Second Amiga mouse
8 = /dev/smouse Simple serial mouse driver
9 = /dev/pc110pad IBM PC-110 digitizer pad
10 = /dev/adbmouse Apple Desktop Bus mouse
11 = /dev/vrtpanel Vr41xx embedded touch panel
13 = /dev/vpcmouse Connectix Virtual PC Mouse
14 = /dev/touchscreen/ucb1x00 UCB 1x00 touchscreen
15 = /dev/touchscreen/mk712 MK712 touchscreen
128 = /dev/beep Fancy beep device
129 =
130 = /dev/watchdog Watchdog timer port
131 = /dev/temperature Machine internal temperature
132 = /dev/hwtrap Hardware fault trap
133 = /dev/exttrp External device trap
134 = /dev/apm_bios Advanced Power Management BIOS
135 = /dev/rtc Real Time Clock
137 = /dev/vhci Bluetooth virtual HCI driver
139 = /dev/openprom SPARC OpenBoot PROM
140 = /dev/relay8 Berkshire Products Octal relay card
141 = /dev/relay16 Berkshire Products ISO-16 relay card
142 =
143 = /dev/pciconf PCI configuration space
144 = /dev/nvram Non-volatile configuration RAM
145 = /dev/hfmodem Soundcard shortwave modem control
146 = /dev/graphics Linux/SGI graphics device
147 = /dev/opengl Linux/SGI OpenGL pipe
148 = /dev/gfx Linux/SGI graphics effects device
149 = /dev/input/mouse Linux/SGI Irix emulation mouse
150 = /dev/input/keyboard Linux/SGI Irix emulation keyboard
151 = /dev/led Front panel LEDs
152 = /dev/kpoll Kernel Poll Driver
153 = /dev/mergemem Memory merge device
154 = /dev/pmu Macintosh PowerBook power manager
155 = /dev/isictl MultiTech ISICom serial control
156 = /dev/lcd Front panel LCD display
157 = /dev/ac Applicom Intl Profibus card
158 = /dev/nwbutton Netwinder external button
159 = /dev/nwdebug Netwinder debug interface
160 = /dev/nwflash Netwinder flash memory
161 = /dev/userdma User-space DMA access
162 = /dev/smbus System Management Bus
163 = /dev/lik Logitech Internet Keyboard
164 = /dev/ipmo Intel Intelligent Platform Management
165 = /dev/vmmon VMware virtual machine monitor
166 = /dev/i2o/ctl I2O configuration manager
167 = /dev/specialix_sxctl Specialix serial control
168 = /dev/tcldrv Technology Concepts serial control
169 = /dev/specialix_rioctl Specialix RIO serial control
170 = /dev/thinkpad/thinkpad IBM Thinkpad devices
171 = /dev/srripc QNX4 API IPC manager
172 = /dev/usemaclone Semaphore clone device
173 = /dev/ipmikcs Intelligent Platform Management
174 = /dev/uctrl SPARCbook 3 microcontroller
175 = /dev/agpgart AGP Graphics Address Remapping Table
176 = /dev/gtrsc Gorgy Timing radio clock
177 = /dev/cbm Serial CBM bus
178 = /dev/jsflash JavaStation OS flash SIMM
179 = /dev/xsvc High-speed shared-mem/semaphore service
180 = /dev/vrbuttons Vr41xx button input device
181 = /dev/toshiba Toshiba laptop SMM support
182 = /dev/perfctr Performance-monitoring counters
183 = /dev/hwrng Generic random number generator
184 = /dev/cpu/microcode CPU microcode update interface
186 = /dev/atomicps Atomic shapshot of process state data
187 = /dev/irnet IrNET device
188 = /dev/smbusbios SMBus BIOS
189 = /dev/ussp_ctl User space serial port control
190 = /dev/crash Mission Critical Linux crash dump facility
191 = /dev/pcl181 <information missing>
192 = /dev/nas_xbus NAS xbus LCD/buttons access
193 = /dev/d7s SPARC 7-segment display
194 = /dev/zkshim Zero-Knowledge network shim control
195 = /dev/elographics/e2201 Elographics touchscreen E271-2201
196 = /dev/vfio/vfio VFIO userspace driver interface
197 = /dev/pxa3xx-gcu PXA3xx graphics controller unit driver
198 = /dev/sexec Signed executable interface
199 = /dev/scanners/cuecat :CueCat barcode scanner
200 = /dev/net/tun TAP/TUN network device
201 = /dev/button/gulpb Transmeta GULP-B buttons
202 = /dev/emd/ctl Enhanced Metadisk RAID (EMD) control
203 = /dev/cuse Cuse (character device in user-space)
204 = /dev/video/em8300 EM8300 DVD decoder control
205 = /dev/video/em8300_mv EM8300 DVD decoder video
206 = /dev/video/em8300_ma EM8300 DVD decoder audio
207 = /dev/video/em8300_sp EM8300 DVD decoder subpicture
208 = /dev/compaq/cpqphpc Compaq PCI Hot Plug Controller
209 = /dev/compaq/cpqrid Compaq Remote Insight Driver
210 = /dev/impi/bt IMPI coprocessor block transfer
211 = /dev/impi/smic IMPI coprocessor stream interface
212 = /dev/watchdogs/0 First watchdog device
213 = /dev/watchdogs/1 Second watchdog device
214 = /dev/watchdogs/2 Third watchdog device
215 = /dev/watchdogs/3 Fourth watchdog device
216 = /dev/fujitsu/apanel Fujitsu/Siemens application panel
217 = /dev/ni/natmotn National Instruments Motion
218 = /dev/kchuid Inter-process chuid control
219 = /dev/modems/mwave MWave modem firmware upload
220 = /dev/mptctl Message passing technology (MPT) control
221 = /dev/mvista/hssdsi Montavista PICMG hot swap system driver
222 = /dev/mvista/hasi Montavista PICMG high availability
223 = /dev/input/uinput User level driver support for input
224 = /dev/tpm TCPA TPM driver
225 = /dev/pps Pulse Per Second driver
226 = /dev/systrace Systrace device
227 = /dev/mcelog X86_64 Machine Check Exception driver
228 = /dev/hpet HPET driver
229 = /dev/fuse Fuse (virtual filesystem in user-space)
230 = /dev/midishare MidiShare driver
231 = /dev/snapshot System memory snapshot device
232 = /dev/kvm Kernel-based virtual machine (hardware virtualization extensions)
233 = /dev/kmview View-OS A process with a view
234 = /dev/btrfs-control Btrfs control device
235 = /dev/autofs Autofs control device
236 = /dev/mapper/control Device-Mapper control device
237 = /dev/loop-control Loopback control device
238 = /dev/vhost-net Host kernel accelerator for virtio net
239 = /dev/uhid User-space I/O driver support for HID subsystem
240-254 Reserved for local use
255 Reserved for MISC_DYNAMIC_MINOR
11 char Raw keyboard device (Linux/SPARC only)
0 = /dev/kbd Raw keyboard device
11 char Serial Mux device (Linux/PA-RISC only)
0 = /dev/ttyB0 First mux port
1 = /dev/ttyB1 Second mux port
...
11 block SCSI CD-ROM devices
0 = /dev/scd0 First SCSI CD-ROM
1 = /dev/scd1 Second SCSI CD-ROM
...
The prefix /dev/sr (instead of /dev/scd) has been deprecated.
12 char QIC-02 tape
2 = /dev/ntpqic11 QIC-11, no rewind-on-close
3 = /dev/tpqic11 QIC-11, rewind-on-close
4 = /dev/ntpqic24 QIC-24, no rewind-on-close
5 = /dev/tpqic24 QIC-24, rewind-on-close
6 = /dev/ntpqic120 QIC-120, no rewind-on-close
7 = /dev/tpqic120 QIC-120, rewind-on-close
8 = /dev/ntpqic150 QIC-150, no rewind-on-close
9 = /dev/tpqic150 QIC-150, rewind-on-close
The device names specified are proposed -- if there
are "standard" names for these devices, please let me know.
12 block
13 char Input core
0 = /dev/input/js0 First joystick
1 = /dev/input/js1 Second joystick
...
32 = /dev/input/mouse0 First mouse
33 = /dev/input/mouse1 Second mouse
...
63 = /dev/input/mice Unified mouse
64 = /dev/input/event0 First event queue
65 = /dev/input/event1 Second event queue
...
Each device type has 5 bits (32 minors).
13 block Previously used for the XT disk (/dev/xdN)
Deleted in kernel v3.9.
14 char Open Sound System (OSS)
0 = /dev/mixer Mixer control
1 = /dev/sequencer Audio sequencer
2 = /dev/midi00 First MIDI port
3 = /dev/dsp Digital audio
4 = /dev/audio Sun-compatible digital audio
6 =
7 = /dev/audioctl SPARC audio control device
8 = /dev/sequencer2 Sequencer -- alternate device
16 = /dev/mixer1 Second soundcard mixer control
17 = /dev/patmgr0 Sequencer patch manager
18 = /dev/midi01 Second MIDI port
19 = /dev/dsp1 Second soundcard digital audio
20 = /dev/audio1 Second soundcard Sun digital audio
33 = /dev/patmgr1 Sequencer patch manager
34 = /dev/midi02 Third MIDI port
50 = /dev/midi03 Fourth MIDI port
14 block
15 char Joystick
0 = /dev/js0 First analog joystick
1 = /dev/js1 Second analog joystick
...
128 = /dev/djs0 First digital joystick
129 = /dev/djs1 Second digital joystick
...
15 block Sony CDU-31A/CDU-33A CD-ROM
0 = /dev/sonycd Sony CDU-31a CD-ROM
16 char Non-SCSI scanners
0 = /dev/gs4500 Genius 4500 handheld scanner
16 block GoldStar CD-ROM
0 = /dev/gscd GoldStar CD-ROM
17 char OBSOLETE (was Chase serial card)
0 = /dev/ttyH0 First Chase port
1 = /dev/ttyH1 Second Chase port
...
17 block Optics Storage CD-ROM
0 = /dev/optcd Optics Storage CD-ROM
18 char OBSOLETE (was Chase serial card - alternate devices)
0 = /dev/cuh0 Callout device for ttyH0
1 = /dev/cuh1 Callout device for ttyH1
...
18 block Sanyo CD-ROM
0 = /dev/sjcd Sanyo CD-ROM
19 char Cyclades serial card
0 = /dev/ttyC0 First Cyclades port
...
31 = /dev/ttyC31 32nd Cyclades port
19 block "Double" compressed disk
0 = /dev/double0 First compressed disk
...
7 = /dev/double7 Eighth compressed disk
128 = /dev/cdouble0 Mirror of first compressed disk
...
135 = /dev/cdouble7 Mirror of eighth compressed disk
See the Double documentation for the meaning of the
mirror devices.
20 char Cyclades serial card - alternate devices
0 = /dev/cub0 Callout device for ttyC0
...
31 = /dev/cub31 Callout device for ttyC31
20 block Hitachi CD-ROM (under development)
0 = /dev/hitcd Hitachi CD-ROM
21 char Generic SCSI access
0 = /dev/sg0 First generic SCSI device
1 = /dev/sg1 Second generic SCSI device
...
Most distributions name these /dev/sga, /dev/sgb...;
this sets an unnecessary limit of 26 SCSI devices in
the system and is counter to standard Linux
device-naming practice.
21 block Acorn MFM hard drive interface
0 = /dev/mfma First MFM drive whole disk
64 = /dev/mfmb Second MFM drive whole disk
This device is used on the ARM-based Acorn RiscPC.
Partitions are handled the same way as for IDE disks
(see major number 3).
22 char Digiboard serial card
0 = /dev/ttyD0 First Digiboard port
1 = /dev/ttyD1 Second Digiboard port
...
22 block Second IDE hard disk/CD-ROM interface
0 = /dev/hdc Master: whole disk (or CD-ROM)
64 = /dev/hdd Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
23 char Digiboard serial card - alternate devices
0 = /dev/cud0 Callout device for ttyD0
1 = /dev/cud1 Callout device for ttyD1
...
23 block Mitsumi proprietary CD-ROM
0 = /dev/mcd Mitsumi CD-ROM
24 char Stallion serial card
0 = /dev/ttyE0 Stallion port 0 card 0
1 = /dev/ttyE1 Stallion port 1 card 0
...
64 = /dev/ttyE64 Stallion port 0 card 1
65 = /dev/ttyE65 Stallion port 1 card 1
...
128 = /dev/ttyE128 Stallion port 0 card 2
129 = /dev/ttyE129 Stallion port 1 card 2
...
192 = /dev/ttyE192 Stallion port 0 card 3
193 = /dev/ttyE193 Stallion port 1 card 3
...
24 block Sony CDU-535 CD-ROM
0 = /dev/cdu535 Sony CDU-535 CD-ROM
25 char Stallion serial card - alternate devices
0 = /dev/cue0 Callout device for ttyE0
1 = /dev/cue1 Callout device for ttyE1
...
64 = /dev/cue64 Callout device for ttyE64
65 = /dev/cue65 Callout device for ttyE65
...
128 = /dev/cue128 Callout device for ttyE128
129 = /dev/cue129 Callout device for ttyE129
...
192 = /dev/cue192 Callout device for ttyE192
193 = /dev/cue193 Callout device for ttyE193
...
25 block First Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd0 Panasonic CD-ROM controller 0 unit 0
1 = /dev/sbpcd1 Panasonic CD-ROM controller 0 unit 1
2 = /dev/sbpcd2 Panasonic CD-ROM controller 0 unit 2
3 = /dev/sbpcd3 Panasonic CD-ROM controller 0 unit 3
26 char
26 block Second Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd4 Panasonic CD-ROM controller 1 unit 0
1 = /dev/sbpcd5 Panasonic CD-ROM controller 1 unit 1
2 = /dev/sbpcd6 Panasonic CD-ROM controller 1 unit 2
3 = /dev/sbpcd7 Panasonic CD-ROM controller 1 unit 3
27 char QIC-117 tape
0 = /dev/qft0 Unit 0, rewind-on-close
1 = /dev/qft1 Unit 1, rewind-on-close
2 = /dev/qft2 Unit 2, rewind-on-close
3 = /dev/qft3 Unit 3, rewind-on-close
4 = /dev/nqft0 Unit 0, no rewind-on-close
5 = /dev/nqft1 Unit 1, no rewind-on-close
6 = /dev/nqft2 Unit 2, no rewind-on-close
7 = /dev/nqft3 Unit 3, no rewind-on-close
16 = /dev/zqft0 Unit 0, rewind-on-close, compression
17 = /dev/zqft1 Unit 1, rewind-on-close, compression
18 = /dev/zqft2 Unit 2, rewind-on-close, compression
19 = /dev/zqft3 Unit 3, rewind-on-close, compression
20 = /dev/nzqft0 Unit 0, no rewind-on-close, compression
21 = /dev/nzqft1 Unit 1, no rewind-on-close, compression
22 = /dev/nzqft2 Unit 2, no rewind-on-close, compression
23 = /dev/nzqft3 Unit 3, no rewind-on-close, compression
32 = /dev/rawqft0 Unit 0, rewind-on-close, no file marks
33 = /dev/rawqft1 Unit 1, rewind-on-close, no file marks
34 = /dev/rawqft2 Unit 2, rewind-on-close, no file marks
35 = /dev/rawqft3 Unit 3, rewind-on-close, no file marks
36 = /dev/nrawqft0 Unit 0, no rewind-on-close, no file marks
37 = /dev/nrawqft1 Unit 1, no rewind-on-close, no file marks
38 = /dev/nrawqft2 Unit 2, no rewind-on-close, no file marks
39 = /dev/nrawqft3 Unit 3, no rewind-on-close, no file marks
27 block Third Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd8 Panasonic CD-ROM controller 2 unit 0
1 = /dev/sbpcd9 Panasonic CD-ROM controller 2 unit 1
2 = /dev/sbpcd10 Panasonic CD-ROM controller 2 unit 2
3 = /dev/sbpcd11 Panasonic CD-ROM controller 2 unit 3
28 char Stallion serial card - card programming
0 = /dev/staliomem0 First Stallion card I/O memory
1 = /dev/staliomem1 Second Stallion card I/O memory
2 = /dev/staliomem2 Third Stallion card I/O memory
3 = /dev/staliomem3 Fourth Stallion card I/O memory
28 char Atari SLM ACSI laser printer (68k/Atari)
0 = /dev/slm0 First SLM laser printer
1 = /dev/slm1 Second SLM laser printer
...
28 block Fourth Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd12 Panasonic CD-ROM controller 3 unit 0
1 = /dev/sbpcd13 Panasonic CD-ROM controller 3 unit 1
2 = /dev/sbpcd14 Panasonic CD-ROM controller 3 unit 2
3 = /dev/sbpcd15 Panasonic CD-ROM controller 3 unit 3
28 block ACSI disk (68k/Atari)
0 = /dev/ada First ACSI disk whole disk
16 = /dev/adb Second ACSI disk whole disk
32 = /dev/adc Third ACSI disk whole disk
...
240 = /dev/adp 16th ACSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15, like SCSI.
29 char Universal frame buffer
0 = /dev/fb0 First frame buffer
1 = /dev/fb1 Second frame buffer
...
31 = /dev/fb31 32nd frame buffer
29 block Aztech/Orchid/Okano/Wearnes CD-ROM
0 = /dev/aztcd Aztech CD-ROM
30 char iBCS-2 compatibility devices
0 = /dev/socksys Socket access
1 = /dev/spx SVR3 local X interface
32 = /dev/inet/ip Network access
33 = /dev/inet/icmp
34 = /dev/inet/ggp
35 = /dev/inet/ipip
36 = /dev/inet/tcp
37 = /dev/inet/egp
38 = /dev/inet/pup
39 = /dev/inet/udp
40 = /dev/inet/idp
41 = /dev/inet/rawip
Additionally, iBCS-2 requires the following links:
/dev/ip -> /dev/inet/ip
/dev/icmp -> /dev/inet/icmp
/dev/ggp -> /dev/inet/ggp
/dev/ipip -> /dev/inet/ipip
/dev/tcp -> /dev/inet/tcp
/dev/egp -> /dev/inet/egp
/dev/pup -> /dev/inet/pup
/dev/udp -> /dev/inet/udp
/dev/idp -> /dev/inet/idp
/dev/rawip -> /dev/inet/rawip
/dev/inet/arp -> /dev/inet/udp
/dev/inet/rip -> /dev/inet/udp
/dev/nfsd -> /dev/socksys
/dev/X0R -> /dev/null (? apparently not required ?)
30 block Philips LMS CM-205 CD-ROM
0 = /dev/cm205cd Philips LMS CM-205 CD-ROM
/dev/lmscd is an older name for this device. This
driver does not work with the CM-205MS CD-ROM.
31 char MPU-401 MIDI
0 = /dev/mpu401data MPU-401 data port
1 = /dev/mpu401stat MPU-401 status port
31 block ROM/flash memory card
0 = /dev/rom0 First ROM card (rw)
...
7 = /dev/rom7 Eighth ROM card (rw)
8 = /dev/rrom0 First ROM card (ro)
...
15 = /dev/rrom7 Eighth ROM card (ro)
16 = /dev/flash0 First flash memory card (rw)
...
23 = /dev/flash7 Eighth flash memory card (rw)
24 = /dev/rflash0 First flash memory card (ro)
...
31 = /dev/rflash7 Eighth flash memory card (ro)
The read-write (rw) devices support back-caching
written data in RAM, as well as writing to flash RAM
devices. The read-only devices (ro) support reading
only.
32 char Specialix serial card
0 = /dev/ttyX0 First Specialix port
1 = /dev/ttyX1 Second Specialix port
...
32 block Philips LMS CM-206 CD-ROM
0 = /dev/cm206cd Philips LMS CM-206 CD-ROM
33 char Specialix serial card - alternate devices
0 = /dev/cux0 Callout device for ttyX0
1 = /dev/cux1 Callout device for ttyX1
...
33 block Third IDE hard disk/CD-ROM interface
0 = /dev/hde Master: whole disk (or CD-ROM)
64 = /dev/hdf Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
34 char Z8530 HDLC driver
0 = /dev/scc0 First Z8530, first port
1 = /dev/scc1 First Z8530, second port
2 = /dev/scc2 Second Z8530, first port
3 = /dev/scc3 Second Z8530, second port
...
In a previous version these devices were named
/dev/sc1 for /dev/scc0, /dev/sc2 for /dev/scc1, and so
on.
34 block Fourth IDE hard disk/CD-ROM interface
0 = /dev/hdg Master: whole disk (or CD-ROM)
64 = /dev/hdh Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
35 char tclmidi MIDI driver
0 = /dev/midi0 First MIDI port, kernel timed
1 = /dev/midi1 Second MIDI port, kernel timed
2 = /dev/midi2 Third MIDI port, kernel timed
3 = /dev/midi3 Fourth MIDI port, kernel timed
64 = /dev/rmidi0 First MIDI port, untimed
65 = /dev/rmidi1 Second MIDI port, untimed
66 = /dev/rmidi2 Third MIDI port, untimed
67 = /dev/rmidi3 Fourth MIDI port, untimed
128 = /dev/smpte0 First MIDI port, SMPTE timed
129 = /dev/smpte1 Second MIDI port, SMPTE timed
130 = /dev/smpte2 Third MIDI port, SMPTE timed
131 = /dev/smpte3 Fourth MIDI port, SMPTE timed
35 block Slow memory ramdisk
0 = /dev/slram Slow memory ramdisk
36 char Netlink support
0 = /dev/route Routing, device updates, kernel to user
1 = /dev/skip enSKIP security cache control
3 = /dev/fwmonitor Firewall packet copies
16 = /dev/tap0 First Ethertap device
...
31 = /dev/tap15 16th Ethertap device
36 block OBSOLETE (was MCA ESDI hard disk)
37 char IDE tape
0 = /dev/ht0 First IDE tape
1 = /dev/ht1 Second IDE tape
...
128 = /dev/nht0 First IDE tape, no rewind-on-close
129 = /dev/nht1 Second IDE tape, no rewind-on-close
...
Currently, only one IDE tape drive is supported.
37 block Zorro II ramdisk
0 = /dev/z2ram Zorro II ramdisk
38 char Myricom PCI Myrinet board
0 = /dev/mlanai0 First Myrinet board
1 = /dev/mlanai1 Second Myrinet board
...
This device is used for status query, board control
and "user level packet I/O." This board is also
accessible as a standard networking "eth" device.
38 block OBSOLETE (was Linux/AP+)
39 char ML-16P experimental I/O board
0 = /dev/ml16pa-a0 First card, first analog channel
1 = /dev/ml16pa-a1 First card, second analog channel
...
15 = /dev/ml16pa-a15 First card, 16th analog channel
16 = /dev/ml16pa-d First card, digital lines
17 = /dev/ml16pa-c0 First card, first counter/timer
18 = /dev/ml16pa-c1 First card, second counter/timer
19 = /dev/ml16pa-c2 First card, third counter/timer
32 = /dev/ml16pb-a0 Second card, first analog channel
33 = /dev/ml16pb-a1 Second card, second analog channel
...
47 = /dev/ml16pb-a15 Second card, 16th analog channel
48 = /dev/ml16pb-d Second card, digital lines
49 = /dev/ml16pb-c0 Second card, first counter/timer
50 = /dev/ml16pb-c1 Second card, second counter/timer
51 = /dev/ml16pb-c2 Second card, third counter/timer
...
39 block
40 char
40 block
41 char Yet Another Micro Monitor
0 = /dev/yamm Yet Another Micro Monitor
41 block
42 char Demo/sample use
42 block Demo/sample use
This number is intended for use in sample code, as
well as a general "example" device number. It
should never be used for a device driver that is being
distributed; either obtain an official number or use
the local/experimental range. The sudden addition or
removal of a driver with this number should not cause
ill effects to the system (bugs excepted.)
IN PARTICULAR, ANY DISTRIBUTION WHICH CONTAINS A
DEVICE DRIVER USING MAJOR NUMBER 42 IS NONCOMPLIANT.
43 char isdn4linux virtual modem
0 = /dev/ttyI0 First virtual modem
...
63 = /dev/ttyI63 64th virtual modem
43 block Network block devices
0 = /dev/nb0 First network block device
1 = /dev/nb1 Second network block device
...
Network Block Device is somehow similar to loopback
devices: If you read from it, it sends packet across
network asking server for data. If you write to it, it
sends packet telling server to write. It could be used
to mounting filesystems over the net, swapping over
the net, implementing block device in userland etc.
44 char isdn4linux virtual modem - alternate devices
0 = /dev/cui0 Callout device for ttyI0
...
63 = /dev/cui63 Callout device for ttyI63
44 block Flash Translation Layer (FTL) filesystems
0 = /dev/ftla FTL on first Memory Technology Device
16 = /dev/ftlb FTL on second Memory Technology Device
32 = /dev/ftlc FTL on third Memory Technology Device
...
240 = /dev/ftlp FTL on 16th Memory Technology Device
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the partition
limit is 15 rather than 63 per disk (same as SCSI.)
45 char isdn4linux ISDN BRI driver
0 = /dev/isdn0 First virtual B channel raw data
...
63 = /dev/isdn63 64th virtual B channel raw data
64 = /dev/isdnctrl0 First channel control/debug
...
127 = /dev/isdnctrl63 64th channel control/debug
128 = /dev/ippp0 First SyncPPP device
...
191 = /dev/ippp63 64th SyncPPP device
255 = /dev/isdninfo ISDN monitor interface
45 block Parallel port IDE disk devices
0 = /dev/pda First parallel port IDE disk
16 = /dev/pdb Second parallel port IDE disk
32 = /dev/pdc Third parallel port IDE disk
48 = /dev/pdd Fourth parallel port IDE disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the partition
limit is 15 rather than 63 per disk.
46 char Comtrol Rocketport serial card
0 = /dev/ttyR0 First Rocketport port
1 = /dev/ttyR1 Second Rocketport port
...
46 block Parallel port ATAPI CD-ROM devices
0 = /dev/pcd0 First parallel port ATAPI CD-ROM
1 = /dev/pcd1 Second parallel port ATAPI CD-ROM
2 = /dev/pcd2 Third parallel port ATAPI CD-ROM
3 = /dev/pcd3 Fourth parallel port ATAPI CD-ROM
47 char Comtrol Rocketport serial card - alternate devices
0 = /dev/cur0 Callout device for ttyR0
1 = /dev/cur1 Callout device for ttyR1
...
47 block Parallel port ATAPI disk devices
0 = /dev/pf0 First parallel port ATAPI disk
1 = /dev/pf1 Second parallel port ATAPI disk
2 = /dev/pf2 Third parallel port ATAPI disk
3 = /dev/pf3 Fourth parallel port ATAPI disk
This driver is intended for floppy disks and similar
devices and hence does not support partitioning.
48 char SDL RISCom serial card
0 = /dev/ttyL0 First RISCom port
1 = /dev/ttyL1 Second RISCom port
...
48 block Mylex DAC960 PCI RAID controller; first controller
0 = /dev/rd/c0d0 First disk, whole disk
8 = /dev/rd/c0d1 Second disk, whole disk
...
248 = /dev/rd/c0d31 32nd disk, whole disk
For partitions add:
0 = /dev/rd/c?d? Whole disk
1 = /dev/rd/c?d?p1 First partition
...
7 = /dev/rd/c?d?p7 Seventh partition
49 char SDL RISCom serial card - alternate devices
0 = /dev/cul0 Callout device for ttyL0
1 = /dev/cul1 Callout device for ttyL1
...
49 block Mylex DAC960 PCI RAID controller; second controller
0 = /dev/rd/c1d0 First disk, whole disk
8 = /dev/rd/c1d1 Second disk, whole disk
...
248 = /dev/rd/c1d31 32nd disk, whole disk
Partitions are handled as for major 48.
50 char Reserved for GLINT
50 block Mylex DAC960 PCI RAID controller; third controller
0 = /dev/rd/c2d0 First disk, whole disk
8 = /dev/rd/c2d1 Second disk, whole disk
...
248 = /dev/rd/c2d31 32nd disk, whole disk
51 char Baycom radio modem OR Radio Tech BIM-XXX-RS232 radio modem
0 = /dev/bc0 First Baycom radio modem
1 = /dev/bc1 Second Baycom radio modem
...
51 block Mylex DAC960 PCI RAID controller; fourth controller
0 = /dev/rd/c3d0 First disk, whole disk
8 = /dev/rd/c3d1 Second disk, whole disk
...
248 = /dev/rd/c3d31 32nd disk, whole disk
Partitions are handled as for major 48.
52 char Spellcaster DataComm/BRI ISDN card
0 = /dev/dcbri0 First DataComm card
1 = /dev/dcbri1 Second DataComm card
2 = /dev/dcbri2 Third DataComm card
3 = /dev/dcbri3 Fourth DataComm card
52 block Mylex DAC960 PCI RAID controller; fifth controller
0 = /dev/rd/c4d0 First disk, whole disk
8 = /dev/rd/c4d1 Second disk, whole disk
...
248 = /dev/rd/c4d31 32nd disk, whole disk
Partitions are handled as for major 48.
53 char BDM interface for remote debugging MC683xx microcontrollers
0 = /dev/pd_bdm0 PD BDM interface on lp0
1 = /dev/pd_bdm1 PD BDM interface on lp1
2 = /dev/pd_bdm2 PD BDM interface on lp2
4 = /dev/icd_bdm0 ICD BDM interface on lp0
5 = /dev/icd_bdm1 ICD BDM interface on lp1
6 = /dev/icd_bdm2 ICD BDM interface on lp2
This device is used for the interfacing to the MC683xx
microcontrollers via Background Debug Mode by use of a
Parallel Port interface. PD is the Motorola Public
Domain Interface and ICD is the commercial interface
by P&E.
53 block Mylex DAC960 PCI RAID controller; sixth controller
0 = /dev/rd/c5d0 First disk, whole disk
8 = /dev/rd/c5d1 Second disk, whole disk
...
248 = /dev/rd/c5d31 32nd disk, whole disk
Partitions are handled as for major 48.
54 char Electrocardiognosis Holter serial card
0 = /dev/holter0 First Holter port
1 = /dev/holter1 Second Holter port
2 = /dev/holter2 Third Holter port
A custom serial card used by Electrocardiognosis SRL
<mseritan@ottonel.pub.ro> to transfer data from Holter
24-hour heart monitoring equipment.
54 block Mylex DAC960 PCI RAID controller; seventh controller
0 = /dev/rd/c6d0 First disk, whole disk
8 = /dev/rd/c6d1 Second disk, whole disk
...
248 = /dev/rd/c6d31 32nd disk, whole disk
Partitions are handled as for major 48.
55 char DSP56001 digital signal processor
0 = /dev/dsp56k First DSP56001
55 block Mylex DAC960 PCI RAID controller; eighth controller
0 = /dev/rd/c7d0 First disk, whole disk
8 = /dev/rd/c7d1 Second disk, whole disk
...
248 = /dev/rd/c7d31 32nd disk, whole disk
Partitions are handled as for major 48.
56 char Apple Desktop Bus
0 = /dev/adb ADB bus control
Additional devices will be added to this number, all
starting with /dev/adb.
56 block Fifth IDE hard disk/CD-ROM interface
0 = /dev/hdi Master: whole disk (or CD-ROM)
64 = /dev/hdj Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
57 char Hayes ESP serial card
0 = /dev/ttyP0 First ESP port
1 = /dev/ttyP1 Second ESP port
...
57 block Sixth IDE hard disk/CD-ROM interface
0 = /dev/hdk Master: whole disk (or CD-ROM)
64 = /dev/hdl Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
58 char Hayes ESP serial card - alternate devices
0 = /dev/cup0 Callout device for ttyP0
1 = /dev/cup1 Callout device for ttyP1
...
58 block Reserved for logical volume manager
59 char sf firewall package
0 = /dev/firewall Communication with sf kernel module
59 block Generic PDA filesystem device
0 = /dev/pda0 First PDA device
1 = /dev/pda1 Second PDA device
...
The pda devices are used to mount filesystems on
remote pda's (basically slow handheld machines with
proprietary OS's and limited memory and storage
running small fs translation drivers) through serial /
IRDA / parallel links.
NAMING CONFLICT -- PROPOSED REVISED NAME /dev/rpda0 etc
60-63 char LOCAL/EXPERIMENTAL USE
60-63 block LOCAL/EXPERIMENTAL USE
Allocated for local/experimental use. For devices not
assigned official numbers, these ranges should be
used in order to avoid conflicting with future assignments.
64 char ENskip kernel encryption package
0 = /dev/enskip Communication with ENskip kernel module
64 block Scramdisk/DriveCrypt encrypted devices
0 = /dev/scramdisk/master Master node for ioctls
1 = /dev/scramdisk/1 First encrypted device
2 = /dev/scramdisk/2 Second encrypted device
...
255 = /dev/scramdisk/255 255th encrypted device
The filename of the encrypted container and the passwords
are sent via ioctls (using the sdmount tool) to the master
node which then activates them via one of the
/dev/scramdisk/x nodes for loop mounting (all handled
through the sdmount tool).
Requested by: andy@scramdisklinux.org
65 char Sundance "plink" Transputer boards (obsolete, unused)
0 = /dev/plink0 First plink device
1 = /dev/plink1 Second plink device
2 = /dev/plink2 Third plink device
3 = /dev/plink3 Fourth plink device
64 = /dev/rplink0 First plink device, raw
65 = /dev/rplink1 Second plink device, raw
66 = /dev/rplink2 Third plink device, raw
67 = /dev/rplink3 Fourth plink device, raw
128 = /dev/plink0d First plink device, debug
129 = /dev/plink1d Second plink device, debug
130 = /dev/plink2d Third plink device, debug
131 = /dev/plink3d Fourth plink device, debug
192 = /dev/rplink0d First plink device, raw, debug
193 = /dev/rplink1d Second plink device, raw, debug
194 = /dev/rplink2d Third plink device, raw, debug
195 = /dev/rplink3d Fourth plink device, raw, debug
This is a commercial driver; contact James Howes
<jth@prosig.demon.co.uk> for information.
65 block SCSI disk devices (16-31)
0 = /dev/sdq 17th SCSI disk whole disk
16 = /dev/sdr 18th SCSI disk whole disk
32 = /dev/sds 19th SCSI disk whole disk
...
240 = /dev/sdaf 32nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
66 char YARC PowerPC PCI coprocessor card
0 = /dev/yppcpci0 First YARC card
1 = /dev/yppcpci1 Second YARC card
...
66 block SCSI disk devices (32-47)
0 = /dev/sdag 33th SCSI disk whole disk
16 = /dev/sdah 34th SCSI disk whole disk
32 = /dev/sdai 35th SCSI disk whole disk
...
240 = /dev/sdav 48nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
67 char Coda network file system
0 = /dev/cfs0 Coda cache manager
See http://www.coda.cs.cmu.edu for information about Coda.
67 block SCSI disk devices (48-63)
0 = /dev/sdaw 49th SCSI disk whole disk
16 = /dev/sdax 50th SCSI disk whole disk
32 = /dev/sday 51st SCSI disk whole disk
...
240 = /dev/sdbl 64th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
68 char CAPI 2.0 interface
0 = /dev/capi20 Control device
1 = /dev/capi20.00 First CAPI 2.0 application
2 = /dev/capi20.01 Second CAPI 2.0 application
...
20 = /dev/capi20.19 19th CAPI 2.0 application
ISDN CAPI 2.0 driver for use with CAPI 2.0
applications; currently supports the AVM B1 card.
68 block SCSI disk devices (64-79)
0 = /dev/sdbm 65th SCSI disk whole disk
16 = /dev/sdbn 66th SCSI disk whole disk
32 = /dev/sdbo 67th SCSI disk whole disk
...
240 = /dev/sdcb 80th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
69 char MA16 numeric accelerator card
0 = /dev/ma16 Board memory access
69 block SCSI disk devices (80-95)
0 = /dev/sdcc 81st SCSI disk whole disk
16 = /dev/sdcd 82nd SCSI disk whole disk
32 = /dev/sdce 83th SCSI disk whole disk
...
240 = /dev/sdcr 96th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
70 char SpellCaster Protocol Services Interface
0 = /dev/apscfg Configuration interface
1 = /dev/apsauth Authentication interface
2 = /dev/apslog Logging interface
3 = /dev/apsdbg Debugging interface
64 = /dev/apsisdn ISDN command interface
65 = /dev/apsasync Async command interface
128 = /dev/apsmon Monitor interface
70 block SCSI disk devices (96-111)
0 = /dev/sdcs 97th SCSI disk whole disk
16 = /dev/sdct 98th SCSI disk whole disk
32 = /dev/sdcu 99th SCSI disk whole disk
...
240 = /dev/sddh 112nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
71 char Computone IntelliPort II serial card
0 = /dev/ttyF0 IntelliPort II board 0, port 0
1 = /dev/ttyF1 IntelliPort II board 0, port 1
...
63 = /dev/ttyF63 IntelliPort II board 0, port 63
64 = /dev/ttyF64 IntelliPort II board 1, port 0
65 = /dev/ttyF65 IntelliPort II board 1, port 1
...
127 = /dev/ttyF127 IntelliPort II board 1, port 63
128 = /dev/ttyF128 IntelliPort II board 2, port 0
129 = /dev/ttyF129 IntelliPort II board 2, port 1
...
191 = /dev/ttyF191 IntelliPort II board 2, port 63
192 = /dev/ttyF192 IntelliPort II board 3, port 0
193 = /dev/ttyF193 IntelliPort II board 3, port 1
...
255 = /dev/ttyF255 IntelliPort II board 3, port 63
71 block SCSI disk devices (112-127)
0 = /dev/sddi 113th SCSI disk whole disk
16 = /dev/sddj 114th SCSI disk whole disk
32 = /dev/sddk 115th SCSI disk whole disk
...
240 = /dev/sddx 128th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
72 char Computone IntelliPort II serial card - alternate devices
0 = /dev/cuf0 Callout device for ttyF0
1 = /dev/cuf1 Callout device for ttyF1
...
63 = /dev/cuf63 Callout device for ttyF63
64 = /dev/cuf64 Callout device for ttyF64
65 = /dev/cuf65 Callout device for ttyF65
...
127 = /dev/cuf127 Callout device for ttyF127
128 = /dev/cuf128 Callout device for ttyF128
129 = /dev/cuf129 Callout device for ttyF129
...
191 = /dev/cuf191 Callout device for ttyF191
192 = /dev/cuf192 Callout device for ttyF192
193 = /dev/cuf193 Callout device for ttyF193
...
255 = /dev/cuf255 Callout device for ttyF255
72 block Compaq Intelligent Drive Array, first controller
0 = /dev/ida/c0d0 First logical drive whole disk
16 = /dev/ida/c0d1 Second logical drive whole disk
...
240 = /dev/ida/c0d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
73 char Computone IntelliPort II serial card - control devices
0 = /dev/ip2ipl0 Loadware device for board 0
1 = /dev/ip2stat0 Status device for board 0
4 = /dev/ip2ipl1 Loadware device for board 1
5 = /dev/ip2stat1 Status device for board 1
8 = /dev/ip2ipl2 Loadware device for board 2
9 = /dev/ip2stat2 Status device for board 2
12 = /dev/ip2ipl3 Loadware device for board 3
13 = /dev/ip2stat3 Status device for board 3
73 block Compaq Intelligent Drive Array, second controller
0 = /dev/ida/c1d0 First logical drive whole disk
16 = /dev/ida/c1d1 Second logical drive whole disk
...
240 = /dev/ida/c1d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
74 char SCI bridge
0 = /dev/SCI/0 SCI device 0
1 = /dev/SCI/1 SCI device 1
...
Currently for Dolphin Interconnect Solutions' PCI-SCI
bridge.
74 block Compaq Intelligent Drive Array, third controller
0 = /dev/ida/c2d0 First logical drive whole disk
16 = /dev/ida/c2d1 Second logical drive whole disk
...
240 = /dev/ida/c2d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
75 char Specialix IO8+ serial card
0 = /dev/ttyW0 First IO8+ port, first card
1 = /dev/ttyW1 Second IO8+ port, first card
...
8 = /dev/ttyW8 First IO8+ port, second card
...
75 block Compaq Intelligent Drive Array, fourth controller
0 = /dev/ida/c3d0 First logical drive whole disk
16 = /dev/ida/c3d1 Second logical drive whole disk
...
240 = /dev/ida/c3d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
76 char Specialix IO8+ serial card - alternate devices
0 = /dev/cuw0 Callout device for ttyW0
1 = /dev/cuw1 Callout device for ttyW1
...
8 = /dev/cuw8 Callout device for ttyW8
...
76 block Compaq Intelligent Drive Array, fifth controller
0 = /dev/ida/c4d0 First logical drive whole disk
16 = /dev/ida/c4d1 Second logical drive whole disk
...
240 = /dev/ida/c4d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
77 char ComScire Quantum Noise Generator
0 = /dev/qng ComScire Quantum Noise Generator
77 block Compaq Intelligent Drive Array, sixth controller
0 = /dev/ida/c5d0 First logical drive whole disk
16 = /dev/ida/c5d1 Second logical drive whole disk
...
240 = /dev/ida/c5d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
78 char PAM Software's multimodem boards
0 = /dev/ttyM0 First PAM modem
1 = /dev/ttyM1 Second PAM modem
...
78 block Compaq Intelligent Drive Array, seventh controller
0 = /dev/ida/c6d0 First logical drive whole disk
16 = /dev/ida/c6d1 Second logical drive whole disk
...
240 = /dev/ida/c6d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
79 char PAM Software's multimodem boards - alternate devices
0 = /dev/cum0 Callout device for ttyM0
1 = /dev/cum1 Callout device for ttyM1
...
79 block Compaq Intelligent Drive Array, eighth controller
0 = /dev/ida/c7d0 First logical drive whole disk
16 = /dev/ida/c7d1 Second logical drive whole disk
...
240 = /dev/ida/c715 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
80 char Photometrics AT200 CCD camera
0 = /dev/at200 Photometrics AT200 CCD camera
80 block I2O hard disk
0 = /dev/i2o/hda First I2O hard disk, whole disk
16 = /dev/i2o/hdb Second I2O hard disk, whole disk
...
240 = /dev/i2o/hdp 16th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
81 char video4linux
0 = /dev/video0 Video capture/overlay device
...
63 = /dev/video63 Video capture/overlay device
64 = /dev/radio0 Radio device
...
127 = /dev/radio63 Radio device
128 = /dev/swradio0 Software Defined Radio device
...
191 = /dev/swradio63 Software Defined Radio device
224 = /dev/vbi0 Vertical blank interrupt
...
255 = /dev/vbi31 Vertical blank interrupt
Minor numbers are allocated dynamically unless
CONFIG_VIDEO_FIXED_MINOR_RANGES (default n)
configuration option is set.
81 block I2O hard disk
0 = /dev/i2o/hdq 17th I2O hard disk, whole disk
16 = /dev/i2o/hdr 18th I2O hard disk, whole disk
...
240 = /dev/i2o/hdaf 32nd I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
82 char WiNRADiO communications receiver card
0 = /dev/winradio0 First WiNRADiO card
1 = /dev/winradio1 Second WiNRADiO card
...
The driver and documentation may be obtained from
http://www.winradio.com/
82 block I2O hard disk
0 = /dev/i2o/hdag 33rd I2O hard disk, whole disk
16 = /dev/i2o/hdah 34th I2O hard disk, whole disk
...
240 = /dev/i2o/hdav 48th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
83 char Matrox mga_vid video driver
0 = /dev/mga_vid0 1st video card
1 = /dev/mga_vid1 2nd video card
2 = /dev/mga_vid2 3rd video card
...
15 = /dev/mga_vid15 16th video card
83 block I2O hard disk
0 = /dev/i2o/hdaw 49th I2O hard disk, whole disk
16 = /dev/i2o/hdax 50th I2O hard disk, whole disk
...
240 = /dev/i2o/hdbl 64th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
84 char Ikon 1011[57] Versatec Greensheet Interface
0 = /dev/ihcp0 First Greensheet port
1 = /dev/ihcp1 Second Greensheet port
84 block I2O hard disk
0 = /dev/i2o/hdbm 65th I2O hard disk, whole disk
16 = /dev/i2o/hdbn 66th I2O hard disk, whole disk
...
240 = /dev/i2o/hdcb 80th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
85 char Linux/SGI shared memory input queue
0 = /dev/shmiq Master shared input queue
1 = /dev/qcntl0 First device pushed
2 = /dev/qcntl1 Second device pushed
...
85 block I2O hard disk
0 = /dev/i2o/hdcc 81st I2O hard disk, whole disk
16 = /dev/i2o/hdcd 82nd I2O hard disk, whole disk
...
240 = /dev/i2o/hdcr 96th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
86 char SCSI media changer
0 = /dev/sch0 First SCSI media changer
1 = /dev/sch1 Second SCSI media changer
...
86 block I2O hard disk
0 = /dev/i2o/hdcs 97th I2O hard disk, whole disk
16 = /dev/i2o/hdct 98th I2O hard disk, whole disk
...
240 = /dev/i2o/hddh 112th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
87 char Sony Control-A1 stereo control bus
0 = /dev/controla0 First device on chain
1 = /dev/controla1 Second device on chain
...
87 block I2O hard disk
0 = /dev/i2o/hddi 113rd I2O hard disk, whole disk
16 = /dev/i2o/hddj 114th I2O hard disk, whole disk
...
240 = /dev/i2o/hddx 128th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
88 char COMX synchronous serial card
0 = /dev/comx0 COMX channel 0
1 = /dev/comx1 COMX channel 1
...
88 block Seventh IDE hard disk/CD-ROM interface
0 = /dev/hdm Master: whole disk (or CD-ROM)
64 = /dev/hdn Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
89 char I2C bus interface
0 = /dev/i2c-0 First I2C adapter
1 = /dev/i2c-1 Second I2C adapter
...
89 block Eighth IDE hard disk/CD-ROM interface
0 = /dev/hdo Master: whole disk (or CD-ROM)
64 = /dev/hdp Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
90 char Memory Technology Device (RAM, ROM, Flash)
0 = /dev/mtd0 First MTD (rw)
1 = /dev/mtdr0 First MTD (ro)
...
30 = /dev/mtd15 16th MTD (rw)
31 = /dev/mtdr15 16th MTD (ro)
90 block Ninth IDE hard disk/CD-ROM interface
0 = /dev/hdq Master: whole disk (or CD-ROM)
64 = /dev/hdr Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
91 char CAN-Bus devices
0 = /dev/can0 First CAN-Bus controller
1 = /dev/can1 Second CAN-Bus controller
...
91 block Tenth IDE hard disk/CD-ROM interface
0 = /dev/hds Master: whole disk (or CD-ROM)
64 = /dev/hdt Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
92 char Reserved for ith Kommunikationstechnik MIC ISDN card
92 block PPDD encrypted disk driver
0 = /dev/ppdd0 First encrypted disk
1 = /dev/ppdd1 Second encrypted disk
...
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
93 char
93 block NAND Flash Translation Layer filesystem
0 = /dev/nftla First NFTL layer
16 = /dev/nftlb Second NFTL layer
...
240 = /dev/nftlp 16th NTFL layer
94 char
94 block IBM S/390 DASD block storage
0 = /dev/dasda First DASD device, major
1 = /dev/dasda1 First DASD device, block 1
2 = /dev/dasda2 First DASD device, block 2
3 = /dev/dasda3 First DASD device, block 3
4 = /dev/dasdb Second DASD device, major
5 = /dev/dasdb1 Second DASD device, block 1
6 = /dev/dasdb2 Second DASD device, block 2
7 = /dev/dasdb3 Second DASD device, block 3
...
95 char IP filter
0 = /dev/ipl Filter control device/log file
1 = /dev/ipnat NAT control device/log file
2 = /dev/ipstate State information log file
3 = /dev/ipauth Authentication control device/log file
...
96 char Parallel port ATAPI tape devices
0 = /dev/pt0 First parallel port ATAPI tape
1 = /dev/pt1 Second parallel port ATAPI tape
...
128 = /dev/npt0 First p.p. ATAPI tape, no rewind
129 = /dev/npt1 Second p.p. ATAPI tape, no rewind
...
96 block Inverse NAND Flash Translation Layer
0 = /dev/inftla First INFTL layer
16 = /dev/inftlb Second INFTL layer
...
240 = /dev/inftlp 16th INTFL layer
97 char Parallel port generic ATAPI interface
0 = /dev/pg0 First parallel port ATAPI device
1 = /dev/pg1 Second parallel port ATAPI device
2 = /dev/pg2 Third parallel port ATAPI device
3 = /dev/pg3 Fourth parallel port ATAPI device
These devices support the same API as the generic SCSI
devices.
98 char Control and Measurement Device (comedi)
0 = /dev/comedi0 First comedi device
1 = /dev/comedi1 Second comedi device
...
See http://stm.lbl.gov/comedi.
98 block User-mode virtual block device
0 = /dev/ubda First user-mode block device
16 = /dev/udbb Second user-mode block device
...
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
This device is used by the user-mode virtual kernel port.
99 char Raw parallel ports
0 = /dev/parport0 First parallel port
1 = /dev/parport1 Second parallel port
...
99 block JavaStation flash disk
0 = /dev/jsfd JavaStation flash disk
100 char Telephony for Linux
0 = /dev/phone0 First telephony device
1 = /dev/phone1 Second telephony device
...
101 char Motorola DSP 56xxx board
0 = /dev/mdspstat Status information
1 = /dev/mdsp1 First DSP board I/O controls
...
16 = /dev/mdsp16 16th DSP board I/O controls
101 block AMI HyperDisk RAID controller
0 = /dev/amiraid/ar0 First array whole disk
16 = /dev/amiraid/ar1 Second array whole disk
...
240 = /dev/amiraid/ar15 16th array whole disk
For each device, partitions are added as:
0 = /dev/amiraid/ar? Whole disk
1 = /dev/amiraid/ar?p1 First partition
2 = /dev/amiraid/ar?p2 Second partition
...
15 = /dev/amiraid/ar?p15 15th partition
102 char
102 block Compressed block device
0 = /dev/cbd/a First compressed block device, whole device
16 = /dev/cbd/b Second compressed block device, whole device
...
240 = /dev/cbd/p 16th compressed block device, whole device
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
103 char Arla network file system
0 = /dev/nnpfs0 First NNPFS device
1 = /dev/nnpfs1 Second NNPFS device
Arla is a free clone of the Andrew File System, AFS.
The NNPFS device gives user mode filesystem
implementations a kernel presence for caching and easy
mounting. For more information about the project,
write to <arla-drinkers@stacken.kth.se> or see
http://www.stacken.kth.se/project/arla/
103 block Audit device
0 = /dev/audit Audit device
104 char Flash BIOS support
104 block Compaq Next Generation Drive Array, first controller
0 = /dev/cciss/c0d0 First logical drive, whole disk
16 = /dev/cciss/c0d1 Second logical drive, whole disk
...
240 = /dev/cciss/c0d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
105 char Comtrol VS-1000 serial controller
0 = /dev/ttyV0 First VS-1000 port
1 = /dev/ttyV1 Second VS-1000 port
...
105 block Compaq Next Generation Drive Array, second controller
0 = /dev/cciss/c1d0 First logical drive, whole disk
16 = /dev/cciss/c1d1 Second logical drive, whole disk
...
240 = /dev/cciss/c1d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
106 char Comtrol VS-1000 serial controller - alternate devices
0 = /dev/cuv0 First VS-1000 port
1 = /dev/cuv1 Second VS-1000 port
...
106 block Compaq Next Generation Drive Array, third controller
0 = /dev/cciss/c2d0 First logical drive, whole disk
16 = /dev/cciss/c2d1 Second logical drive, whole disk
...
240 = /dev/cciss/c2d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
107 char 3Dfx Voodoo Graphics device
0 = /dev/3dfx Primary 3Dfx graphics device
107 block Compaq Next Generation Drive Array, fourth controller
0 = /dev/cciss/c3d0 First logical drive, whole disk
16 = /dev/cciss/c3d1 Second logical drive, whole disk
...
240 = /dev/cciss/c3d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
108 char Device independent PPP interface
0 = /dev/ppp Device independent PPP interface
108 block Compaq Next Generation Drive Array, fifth controller
0 = /dev/cciss/c4d0 First logical drive, whole disk
16 = /dev/cciss/c4d1 Second logical drive, whole disk
...
240 = /dev/cciss/c4d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
109 char Reserved for logical volume manager
109 block Compaq Next Generation Drive Array, sixth controller
0 = /dev/cciss/c5d0 First logical drive, whole disk
16 = /dev/cciss/c5d1 Second logical drive, whole disk
...
240 = /dev/cciss/c5d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
110 char miroMEDIA Surround board
0 = /dev/srnd0 First miroMEDIA Surround board
1 = /dev/srnd1 Second miroMEDIA Surround board
...
110 block Compaq Next Generation Drive Array, seventh controller
0 = /dev/cciss/c6d0 First logical drive, whole disk
16 = /dev/cciss/c6d1 Second logical drive, whole disk
...
240 = /dev/cciss/c6d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
111 char
111 block Compaq Next Generation Drive Array, eighth controller
0 = /dev/cciss/c7d0 First logical drive, whole disk
16 = /dev/cciss/c7d1 Second logical drive, whole disk
...
240 = /dev/cciss/c7d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
112 char ISI serial card
0 = /dev/ttyM0 First ISI port
1 = /dev/ttyM1 Second ISI port
...
There is currently a device-naming conflict between
these and PAM multimodems (major 78).
112 block IBM iSeries virtual disk
0 = /dev/iseries/vda First virtual disk, whole disk
8 = /dev/iseries/vdb Second virtual disk, whole disk
...
200 = /dev/iseries/vdz 26th virtual disk, whole disk
208 = /dev/iseries/vdaa 27th virtual disk, whole disk
...
248 = /dev/iseries/vdaf 32nd virtual disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 7.
113 char ISI serial card - alternate devices
0 = /dev/cum0 Callout device for ttyM0
1 = /dev/cum1 Callout device for ttyM1
...
113 block IBM iSeries virtual CD-ROM
0 = /dev/iseries/vcda First virtual CD-ROM
1 = /dev/iseries/vcdb Second virtual CD-ROM
...
114 char Picture Elements ISE board
0 = /dev/ise0 First ISE board
1 = /dev/ise1 Second ISE board
...
128 = /dev/isex0 Control node for first ISE board
129 = /dev/isex1 Control node for second ISE board
...
The ISE board is an embedded computer, optimized for
image processing. The /dev/iseN nodes are the general
I/O access to the board, the /dev/isex0 nodes command
nodes used to control the board.
114 block IDE BIOS powered software RAID interfaces such as the
Promise Fastrak
0 = /dev/ataraid/d0
1 = /dev/ataraid/d0p1
2 = /dev/ataraid/d0p2
...
16 = /dev/ataraid/d1
17 = /dev/ataraid/d1p1
18 = /dev/ataraid/d1p2
...
255 = /dev/ataraid/d15p15
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
115 char TI link cable devices (115 was formerly the console driver speaker)
0 = /dev/tipar0 Parallel cable on first parallel port
...
7 = /dev/tipar7 Parallel cable on seventh parallel port
8 = /dev/tiser0 Serial cable on first serial port
...
15 = /dev/tiser7 Serial cable on seventh serial port
16 = /dev/tiusb0 First USB cable
...
47 = /dev/tiusb31 32nd USB cable
115 block NetWare (NWFS) Devices (0-255)
The NWFS (NetWare) devices are used to present a
collection of NetWare Mirror Groups or NetWare
Partitions as a logical storage segment for
use in mounting NetWare volumes. A maximum of
256 NetWare volumes can be supported in a single
machine.
http://cgfa.telepac.pt/ftp2/kernel.org/linux/kernel/people/jmerkey/nwfs/
0 = /dev/nwfs/v0 First NetWare (NWFS) Logical Volume
1 = /dev/nwfs/v1 Second NetWare (NWFS) Logical Volume
2 = /dev/nwfs/v2 Third NetWare (NWFS) Logical Volume
...
255 = /dev/nwfs/v255 Last NetWare (NWFS) Logical Volume
116 char Advanced Linux Sound Driver (ALSA)
116 block MicroMemory battery backed RAM adapter (NVRAM)
Supports 16 boards, 15 partitions each.
Requested by neilb at cse.unsw.edu.au.
0 = /dev/umem/d0 Whole of first board
1 = /dev/umem/d0p1 First partition of first board
2 = /dev/umem/d0p2 Second partition of first board
15 = /dev/umem/d0p15 15th partition of first board
16 = /dev/umem/d1 Whole of second board
17 = /dev/umem/d1p1 First partition of second board
...
255= /dev/umem/d15p15 15th partition of 16th board.
117 char COSA/SRP synchronous serial card
0 = /dev/cosa0c0 1st board, 1st channel
1 = /dev/cosa0c1 1st board, 2nd channel
...
16 = /dev/cosa1c0 2nd board, 1st channel
17 = /dev/cosa1c1 2nd board, 2nd channel
...
117 block Enterprise Volume Management System (EVMS)
The EVMS driver uses a layered, plug-in model to provide
unparalleled flexibility and extensibility in managing
storage. This allows for easy expansion or customization
of various levels of volume management. Requested by
Mark Peloquin (peloquin at us.ibm.com).
Note: EVMS populates and manages all the devnodes in
/dev/evms.
http://sf.net/projects/evms
0 = /dev/evms/block_device EVMS block device
1 = /dev/evms/legacyname1 First EVMS legacy device
2 = /dev/evms/legacyname2 Second EVMS legacy device
...
Both ranges can grow (down or up) until they meet.
...
254 = /dev/evms/EVMSname2 Second EVMS native device
255 = /dev/evms/EVMSname1 First EVMS native device
Note: legacyname(s) are derived from the normal legacy
device names. For example, /dev/hda5 would become
/dev/evms/hda5.
118 char IBM Cryptographic Accelerator
0 = /dev/ica Virtual interface to all IBM Crypto Accelerators
1 = /dev/ica0 IBMCA Device 0
2 = /dev/ica1 IBMCA Device 1
...
119 char VMware virtual network control
0 = /dev/vnet0 1st virtual network
1 = /dev/vnet1 2nd virtual network
...
120-127 char LOCAL/EXPERIMENTAL USE
120-127 block LOCAL/EXPERIMENTAL USE
Allocated for local/experimental use. For devices not
assigned official numbers, these ranges should be
used in order to avoid conflicting with future assignments.
128-135 char Unix98 PTY masters
These devices should not have corresponding device
nodes; instead they should be accessed through the
/dev/ptmx cloning interface.
128 block SCSI disk devices (128-143)
0 = /dev/sddy 129th SCSI disk whole disk
16 = /dev/sddz 130th SCSI disk whole disk
32 = /dev/sdea 131th SCSI disk whole disk
...
240 = /dev/sden 144th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
129 block SCSI disk devices (144-159)
0 = /dev/sdeo 145th SCSI disk whole disk
16 = /dev/sdep 146th SCSI disk whole disk
32 = /dev/sdeq 147th SCSI disk whole disk
...
240 = /dev/sdfd 160th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
130 char (Misc devices)
130 block SCSI disk devices (160-175)
0 = /dev/sdfe 161st SCSI disk whole disk
16 = /dev/sdff 162nd SCSI disk whole disk
32 = /dev/sdfg 163rd SCSI disk whole disk
...
240 = /dev/sdft 176th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
131 block SCSI disk devices (176-191)
0 = /dev/sdfu 177th SCSI disk whole disk
16 = /dev/sdfv 178th SCSI disk whole disk
32 = /dev/sdfw 179th SCSI disk whole disk
...
240 = /dev/sdgj 192nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
132 block SCSI disk devices (192-207)
0 = /dev/sdgk 193rd SCSI disk whole disk
16 = /dev/sdgl 194th SCSI disk whole disk
32 = /dev/sdgm 195th SCSI disk whole disk
...
240 = /dev/sdgz 208th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
133 block SCSI disk devices (208-223)
0 = /dev/sdha 209th SCSI disk whole disk
16 = /dev/sdhb 210th SCSI disk whole disk
32 = /dev/sdhc 211th SCSI disk whole disk
...
240 = /dev/sdhp 224th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
134 block SCSI disk devices (224-239)
0 = /dev/sdhq 225th SCSI disk whole disk
16 = /dev/sdhr 226th SCSI disk whole disk
32 = /dev/sdhs 227th SCSI disk whole disk
...
240 = /dev/sdif 240th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
135 block SCSI disk devices (240-255)
0 = /dev/sdig 241st SCSI disk whole disk
16 = /dev/sdih 242nd SCSI disk whole disk
32 = /dev/sdih 243rd SCSI disk whole disk
...
240 = /dev/sdiv 256th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
136-143 char Unix98 PTY slaves
0 = /dev/pts/0 First Unix98 pseudo-TTY
1 = /dev/pts/1 Second Unix98 pseudo-TTY
...
These device nodes are automatically generated with
the proper permissions and modes by mounting the
devpts filesystem onto /dev/pts with the appropriate
mount options (distribution dependent, however, on
*most* distributions the appropriate options are
"mode=0620,gid=<gid of the "tty" group>".)
136 block Mylex DAC960 PCI RAID controller; ninth controller
0 = /dev/rd/c8d0 First disk, whole disk
8 = /dev/rd/c8d1 Second disk, whole disk
...
248 = /dev/rd/c8d31 32nd disk, whole disk
Partitions are handled as for major 48.
137 block Mylex DAC960 PCI RAID controller; tenth controller
0 = /dev/rd/c9d0 First disk, whole disk
8 = /dev/rd/c9d1 Second disk, whole disk
...
248 = /dev/rd/c9d31 32nd disk, whole disk
Partitions are handled as for major 48.
138 block Mylex DAC960 PCI RAID controller; eleventh controller
0 = /dev/rd/c10d0 First disk, whole disk
8 = /dev/rd/c10d1 Second disk, whole disk
...
248 = /dev/rd/c10d31 32nd disk, whole disk
Partitions are handled as for major 48.
139 block Mylex DAC960 PCI RAID controller; twelfth controller
0 = /dev/rd/c11d0 First disk, whole disk
8 = /dev/rd/c11d1 Second disk, whole disk
...
248 = /dev/rd/c11d31 32nd disk, whole disk
Partitions are handled as for major 48.
140 block Mylex DAC960 PCI RAID controller; thirteenth controller
0 = /dev/rd/c12d0 First disk, whole disk
8 = /dev/rd/c12d1 Second disk, whole disk
...
248 = /dev/rd/c12d31 32nd disk, whole disk
Partitions are handled as for major 48.
141 block Mylex DAC960 PCI RAID controller; fourteenth controller
0 = /dev/rd/c13d0 First disk, whole disk
8 = /dev/rd/c13d1 Second disk, whole disk
...
248 = /dev/rd/c13d31 32nd disk, whole disk
Partitions are handled as for major 48.
142 block Mylex DAC960 PCI RAID controller; fifteenth controller
0 = /dev/rd/c14d0 First disk, whole disk
8 = /dev/rd/c14d1 Second disk, whole disk
...
248 = /dev/rd/c14d31 32nd disk, whole disk
Partitions are handled as for major 48.
143 block Mylex DAC960 PCI RAID controller; sixteenth controller
0 = /dev/rd/c15d0 First disk, whole disk
8 = /dev/rd/c15d1 Second disk, whole disk
...
248 = /dev/rd/c15d31 32nd disk, whole disk
Partitions are handled as for major 48.
144 char Encapsulated PPP
0 = /dev/pppox0 First PPP over Ethernet
...
63 = /dev/pppox63 64th PPP over Ethernet
This is primarily used for ADSL.
The SST 5136-DN DeviceNet interface driver has been
relocated to major 183 due to an unfortunate conflict.
144 block Expansion Area #1 for more non-device (e.g. NFS) mounts
0 = mounted device 256
255 = mounted device 511
145 char SAM9407-based soundcard
0 = /dev/sam0_mixer
1 = /dev/sam0_sequencer
2 = /dev/sam0_midi00
3 = /dev/sam0_dsp
4 = /dev/sam0_audio
6 = /dev/sam0_sndstat
18 = /dev/sam0_midi01
34 = /dev/sam0_midi02
50 = /dev/sam0_midi03
64 = /dev/sam1_mixer
...
128 = /dev/sam2_mixer
...
192 = /dev/sam3_mixer
...
Device functions match OSS, but offer a number of
addons, which are sam9407 specific. OSS can be
operated simultaneously, taking care of the codec.
145 block Expansion Area #2 for more non-device (e.g. NFS) mounts
0 = mounted device 512
255 = mounted device 767
146 char SYSTRAM SCRAMNet mirrored-memory network
0 = /dev/scramnet0 First SCRAMNet device
1 = /dev/scramnet1 Second SCRAMNet device
...
146 block Expansion Area #3 for more non-device (e.g. NFS) mounts
0 = mounted device 768
255 = mounted device 1023
147 char Aureal Semiconductor Vortex Audio device
0 = /dev/aureal0 First Aureal Vortex
1 = /dev/aureal1 Second Aureal Vortex
...
147 block Distributed Replicated Block Device (DRBD)
0 = /dev/drbd0 First DRBD device
1 = /dev/drbd1 Second DRBD device
...
148 char Technology Concepts serial card
0 = /dev/ttyT0 First TCL port
1 = /dev/ttyT1 Second TCL port
...
149 char Technology Concepts serial card - alternate devices
0 = /dev/cut0 Callout device for ttyT0
1 = /dev/cut0 Callout device for ttyT1
...
150 char Real-Time Linux FIFOs
0 = /dev/rtf0 First RTLinux FIFO
1 = /dev/rtf1 Second RTLinux FIFO
...
151 char DPT I2O SmartRaid V controller
0 = /dev/dpti0 First DPT I2O adapter
1 = /dev/dpti1 Second DPT I2O adapter
...
152 char EtherDrive Control Device
0 = /dev/etherd/ctl Connect/Disconnect an EtherDrive
1 = /dev/etherd/err Monitor errors
2 = /dev/etherd/raw Raw AoE packet monitor
152 block EtherDrive Block Devices
0 = /dev/etherd/0 EtherDrive 0
...
255 = /dev/etherd/255 EtherDrive 255
153 char SPI Bus Interface (sometimes referred to as MicroWire)
0 = /dev/spi0 First SPI device on the bus
1 = /dev/spi1 Second SPI device on the bus
...
15 = /dev/spi15 Sixteenth SPI device on the bus
153 block Enhanced Metadisk RAID (EMD) storage units
0 = /dev/emd/0 First unit
1 = /dev/emd/0p1 Partition 1 on First unit
2 = /dev/emd/0p2 Partition 2 on First unit
...
15 = /dev/emd/0p15 Partition 15 on First unit
16 = /dev/emd/1 Second unit
32 = /dev/emd/2 Third unit
...
240 = /dev/emd/15 Sixteenth unit
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
154 char Specialix RIO serial card
0 = /dev/ttySR0 First RIO port
...
255 = /dev/ttySR255 256th RIO port
155 char Specialix RIO serial card - alternate devices
0 = /dev/cusr0 Callout device for ttySR0
...
255 = /dev/cusr255 Callout device for ttySR255
156 char Specialix RIO serial card
0 = /dev/ttySR256 257th RIO port
...
255 = /dev/ttySR511 512th RIO port
157 char Specialix RIO serial card - alternate devices
0 = /dev/cusr256 Callout device for ttySR256
...
255 = /dev/cusr511 Callout device for ttySR511
158 char Dialogic GammaLink fax driver
0 = /dev/gfax0 GammaLink channel 0
1 = /dev/gfax1 GammaLink channel 1
...
159 char RESERVED
159 block RESERVED
160 char General Purpose Instrument Bus (GPIB)
0 = /dev/gpib0 First GPIB bus
1 = /dev/gpib1 Second GPIB bus
...
160 block Carmel 8-port SATA Disks on First Controller
0 = /dev/carmel/0 SATA disk 0 whole disk
1 = /dev/carmel/0p1 SATA disk 0 partition 1
...
31 = /dev/carmel/0p31 SATA disk 0 partition 31
32 = /dev/carmel/1 SATA disk 1 whole disk
64 = /dev/carmel/2 SATA disk 2 whole disk
...
224 = /dev/carmel/7 SATA disk 7 whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 31.
161 char IrCOMM devices (IrDA serial/parallel emulation)
0 = /dev/ircomm0 First IrCOMM device
1 = /dev/ircomm1 Second IrCOMM device
...
16 = /dev/irlpt0 First IrLPT device
17 = /dev/irlpt1 Second IrLPT device
...
161 block Carmel 8-port SATA Disks on Second Controller
0 = /dev/carmel/8 SATA disk 8 whole disk
1 = /dev/carmel/8p1 SATA disk 8 partition 1
...
31 = /dev/carmel/8p31 SATA disk 8 partition 31
32 = /dev/carmel/9 SATA disk 9 whole disk
64 = /dev/carmel/10 SATA disk 10 whole disk
...
224 = /dev/carmel/15 SATA disk 15 whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 31.
162 char Raw block device interface
0 = /dev/rawctl Raw I/O control device
1 = /dev/raw/raw1 First raw I/O device
2 = /dev/raw/raw2 Second raw I/O device
...
max minor number of raw device is set by kernel config
MAX_RAW_DEVS or raw module parameter 'max_raw_devs'
163 char
164 char Chase Research AT/PCI-Fast serial card
0 = /dev/ttyCH0 AT/PCI-Fast board 0, port 0
...
15 = /dev/ttyCH15 AT/PCI-Fast board 0, port 15
16 = /dev/ttyCH16 AT/PCI-Fast board 1, port 0
...
31 = /dev/ttyCH31 AT/PCI-Fast board 1, port 15
32 = /dev/ttyCH32 AT/PCI-Fast board 2, port 0
...
47 = /dev/ttyCH47 AT/PCI-Fast board 2, port 15
48 = /dev/ttyCH48 AT/PCI-Fast board 3, port 0
...
63 = /dev/ttyCH63 AT/PCI-Fast board 3, port 15
165 char Chase Research AT/PCI-Fast serial card - alternate devices
0 = /dev/cuch0 Callout device for ttyCH0
...
63 = /dev/cuch63 Callout device for ttyCH63
166 char ACM USB modems
0 = /dev/ttyACM0 First ACM modem
1 = /dev/ttyACM1 Second ACM modem
...
167 char ACM USB modems - alternate devices
0 = /dev/cuacm0 Callout device for ttyACM0
1 = /dev/cuacm1 Callout device for ttyACM1
...
168 char Eracom CSA7000 PCI encryption adaptor
0 = /dev/ecsa0 First CSA7000
1 = /dev/ecsa1 Second CSA7000
...
169 char Eracom CSA8000 PCI encryption adaptor
0 = /dev/ecsa8-0 First CSA8000
1 = /dev/ecsa8-1 Second CSA8000
...
170 char AMI MegaRAC remote access controller
0 = /dev/megarac0 First MegaRAC card
1 = /dev/megarac1 Second MegaRAC card
...
171 char Reserved for IEEE 1394 (Firewire)
172 char Moxa Intellio serial card
0 = /dev/ttyMX0 First Moxa port
1 = /dev/ttyMX1 Second Moxa port
...
127 = /dev/ttyMX127 128th Moxa port
128 = /dev/moxactl Moxa control port
173 char Moxa Intellio serial card - alternate devices
0 = /dev/cumx0 Callout device for ttyMX0
1 = /dev/cumx1 Callout device for ttyMX1
...
127 = /dev/cumx127 Callout device for ttyMX127
174 char SmartIO serial card
0 = /dev/ttySI0 First SmartIO port
1 = /dev/ttySI1 Second SmartIO port
...
175 char SmartIO serial card - alternate devices
0 = /dev/cusi0 Callout device for ttySI0
1 = /dev/cusi1 Callout device for ttySI1
...
176 char nCipher nFast PCI crypto accelerator
0 = /dev/nfastpci0 First nFast PCI device
1 = /dev/nfastpci1 First nFast PCI device
...
177 char TI PCILynx memory spaces
0 = /dev/pcilynx/aux0 AUX space of first PCILynx card
...
15 = /dev/pcilynx/aux15 AUX space of 16th PCILynx card
16 = /dev/pcilynx/rom0 ROM space of first PCILynx card
...
31 = /dev/pcilynx/rom15 ROM space of 16th PCILynx card
32 = /dev/pcilynx/ram0 RAM space of first PCILynx card
...
47 = /dev/pcilynx/ram15 RAM space of 16th PCILynx card
178 char Giganet cLAN1xxx virtual interface adapter
0 = /dev/clanvi0 First cLAN adapter
1 = /dev/clanvi1 Second cLAN adapter
...
179 block MMC block devices
0 = /dev/mmcblk0 First SD/MMC card
1 = /dev/mmcblk0p1 First partition on first MMC card
8 = /dev/mmcblk1 Second SD/MMC card
...
The start of next SD/MMC card can be configured with
CONFIG_MMC_BLOCK_MINORS, or overridden at boot/modprobe
time using the mmcblk.perdev_minors option. That would
bump the offset between each card to be the configured
value instead of the default 8.
179 char CCube DVXChip-based PCI products
0 = /dev/dvxirq0 First DVX device
1 = /dev/dvxirq1 Second DVX device
...
180 char USB devices
0 = /dev/usb/lp0 First USB printer
...
15 = /dev/usb/lp15 16th USB printer
48 = /dev/usb/scanner0 First USB scanner
...
63 = /dev/usb/scanner15 16th USB scanner
64 = /dev/usb/rio500 Diamond Rio 500
65 = /dev/usb/usblcd USBLCD Interface (info@usblcd.de)
66 = /dev/usb/cpad0 Synaptics cPad (mouse/LCD)
96 = /dev/usb/hiddev0 1st USB HID device
...
111 = /dev/usb/hiddev15 16th USB HID device
112 = /dev/usb/auer0 1st auerswald ISDN device
...
127 = /dev/usb/auer15 16th auerswald ISDN device
128 = /dev/usb/brlvgr0 First Braille Voyager device
...
131 = /dev/usb/brlvgr3 Fourth Braille Voyager device
132 = /dev/usb/idmouse ID Mouse (fingerprint scanner) device
133 = /dev/usb/sisusbvga1 First SiSUSB VGA device
...
140 = /dev/usb/sisusbvga8 Eighth SISUSB VGA device
144 = /dev/usb/lcd USB LCD device
160 = /dev/usb/legousbtower0 1st USB Legotower device
...
175 = /dev/usb/legousbtower15 16th USB Legotower device
176 = /dev/usb/usbtmc1 First USB TMC device
...
191 = /dev/usb/usbtmc16 16th USB TMC device
192 = /dev/usb/yurex1 First USB Yurex device
...
209 = /dev/usb/yurex16 16th USB Yurex device
180 block USB block devices
0 = /dev/uba First USB block device
8 = /dev/ubb Second USB block device
16 = /dev/ubc Third USB block device
...
181 char Conrad Electronic parallel port radio clocks
0 = /dev/pcfclock0 First Conrad radio clock
1 = /dev/pcfclock1 Second Conrad radio clock
...
182 char Picture Elements THR2 binarizer
0 = /dev/pethr0 First THR2 board
1 = /dev/pethr1 Second THR2 board
...
183 char SST 5136-DN DeviceNet interface
0 = /dev/ss5136dn0 First DeviceNet interface
1 = /dev/ss5136dn1 Second DeviceNet interface
...
This device used to be assigned to major number 144.
It had to be moved due to an unfortunate conflict.
184 char Picture Elements' video simulator/sender
0 = /dev/pevss0 First sender board
1 = /dev/pevss1 Second sender board
...
185 char InterMezzo high availability file system
0 = /dev/intermezzo0 First cache manager
1 = /dev/intermezzo1 Second cache manager
...
See http://web.archive.org/web/20080115195241/
http://inter-mezzo.org/index.html
186 char Object-based storage control device
0 = /dev/obd0 First obd control device
1 = /dev/obd1 Second obd control device
...
See ftp://ftp.lustre.org/pub/obd for code and information.
187 char DESkey hardware encryption device
0 = /dev/deskey0 First DES key
1 = /dev/deskey1 Second DES key
...
188 char USB serial converters
0 = /dev/ttyUSB0 First USB serial converter
1 = /dev/ttyUSB1 Second USB serial converter
...
189 char USB serial converters - alternate devices
0 = /dev/cuusb0 Callout device for ttyUSB0
1 = /dev/cuusb1 Callout device for ttyUSB1
...
190 char Kansas City tracker/tuner card
0 = /dev/kctt0 First KCT/T card
1 = /dev/kctt1 Second KCT/T card
...
191 char Reserved for PCMCIA
192 char Kernel profiling interface
0 = /dev/profile Profiling control device
1 = /dev/profile0 Profiling device for CPU 0
2 = /dev/profile1 Profiling device for CPU 1
...
193 char Kernel event-tracing interface
0 = /dev/trace Tracing control device
1 = /dev/trace0 Tracing device for CPU 0
2 = /dev/trace1 Tracing device for CPU 1
...
194 char linVideoStreams (LINVS)
0 = /dev/mvideo/status0 Video compression status
1 = /dev/mvideo/stream0 Video stream
2 = /dev/mvideo/frame0 Single compressed frame
3 = /dev/mvideo/rawframe0 Raw uncompressed frame
4 = /dev/mvideo/codec0 Direct codec access
5 = /dev/mvideo/video4linux0 Video4Linux compatibility
16 = /dev/mvideo/status1 Second device
...
32 = /dev/mvideo/status2 Third device
...
...
240 = /dev/mvideo/status15 16th device
...
195 char Nvidia graphics devices
0 = /dev/nvidia0 First Nvidia card
1 = /dev/nvidia1 Second Nvidia card
...
255 = /dev/nvidiactl Nvidia card control device
196 char Tormenta T1 card
0 = /dev/tor/0 Master control channel for all cards
1 = /dev/tor/1 First DS0
2 = /dev/tor/2 Second DS0
...
48 = /dev/tor/48 48th DS0
49 = /dev/tor/49 First pseudo-channel
50 = /dev/tor/50 Second pseudo-channel
...
197 char OpenTNF tracing facility
0 = /dev/tnf/t0 Trace 0 data extraction
1 = /dev/tnf/t1 Trace 1 data extraction
...
128 = /dev/tnf/status Tracing facility status
130 = /dev/tnf/trace Tracing device
198 char Total Impact TPMP2 quad coprocessor PCI card
0 = /dev/tpmp2/0 First card
1 = /dev/tpmp2/1 Second card
...
199 char Veritas volume manager (VxVM) volumes
0 = /dev/vx/rdsk/*/* First volume
1 = /dev/vx/rdsk/*/* Second volume
...
199 block Veritas volume manager (VxVM) volumes
0 = /dev/vx/dsk/*/* First volume
1 = /dev/vx/dsk/*/* Second volume
...
The namespace in these directories is maintained by
the user space VxVM software.
200 char Veritas VxVM configuration interface
0 = /dev/vx/config Configuration access node
1 = /dev/vx/trace Volume i/o trace access node
2 = /dev/vx/iod Volume i/o daemon access node
3 = /dev/vx/info Volume information access node
4 = /dev/vx/task Volume tasks access node
5 = /dev/vx/taskmon Volume tasks monitor daemon
201 char Veritas VxVM dynamic multipathing driver
0 = /dev/vx/rdmp/* First multipath device
1 = /dev/vx/rdmp/* Second multipath device
...
201 block Veritas VxVM dynamic multipathing driver
0 = /dev/vx/dmp/* First multipath device
1 = /dev/vx/dmp/* Second multipath device
...
The namespace in these directories is maintained by
the user space VxVM software.
202 char CPU model-specific registers
0 = /dev/cpu/0/msr MSRs on CPU 0
1 = /dev/cpu/1/msr MSRs on CPU 1
...
202 block Xen Virtual Block Device
0 = /dev/xvda First Xen VBD whole disk
16 = /dev/xvdb Second Xen VBD whole disk
32 = /dev/xvdc Third Xen VBD whole disk
...
240 = /dev/xvdp Sixteenth Xen VBD whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
203 char CPU CPUID information
0 = /dev/cpu/0/cpuid CPUID on CPU 0
1 = /dev/cpu/1/cpuid CPUID on CPU 1
...
204 char Low-density serial ports
0 = /dev/ttyLU0 LinkUp Systems L72xx UART - port 0
1 = /dev/ttyLU1 LinkUp Systems L72xx UART - port 1
2 = /dev/ttyLU2 LinkUp Systems L72xx UART - port 2
3 = /dev/ttyLU3 LinkUp Systems L72xx UART - port 3
4 = /dev/ttyFB0 Intel Footbridge (ARM)
5 = /dev/ttySA0 StrongARM builtin serial port 0
6 = /dev/ttySA1 StrongARM builtin serial port 1
7 = /dev/ttySA2 StrongARM builtin serial port 2
8 = /dev/ttySC0 SCI serial port (SuperH) - port 0
9 = /dev/ttySC1 SCI serial port (SuperH) - port 1
10 = /dev/ttySC2 SCI serial port (SuperH) - port 2
11 = /dev/ttySC3 SCI serial port (SuperH) - port 3
12 = /dev/ttyFW0 Firmware console - port 0
13 = /dev/ttyFW1 Firmware console - port 1
14 = /dev/ttyFW2 Firmware console - port 2
15 = /dev/ttyFW3 Firmware console - port 3
16 = /dev/ttyAM0 ARM "AMBA" serial port 0
...
31 = /dev/ttyAM15 ARM "AMBA" serial port 15
32 = /dev/ttyDB0 DataBooster serial port 0
...
39 = /dev/ttyDB7 DataBooster serial port 7
40 = /dev/ttySG0 SGI Altix console port
41 = /dev/ttySMX0 Motorola i.MX - port 0
42 = /dev/ttySMX1 Motorola i.MX - port 1
43 = /dev/ttySMX2 Motorola i.MX - port 2
44 = /dev/ttyMM0 Marvell MPSC - port 0
45 = /dev/ttyMM1 Marvell MPSC - port 1
46 = /dev/ttyCPM0 PPC CPM (SCC or SMC) - port 0
...
47 = /dev/ttyCPM5 PPC CPM (SCC or SMC) - port 5
50 = /dev/ttyIOC0 Altix serial card
...
81 = /dev/ttyIOC31 Altix serial card
82 = /dev/ttyVR0 NEC VR4100 series SIU
83 = /dev/ttyVR1 NEC VR4100 series DSIU
84 = /dev/ttyIOC84 Altix ioc4 serial card
...
115 = /dev/ttyIOC115 Altix ioc4 serial card
116 = /dev/ttySIOC0 Altix ioc3 serial card
...
147 = /dev/ttySIOC31 Altix ioc3 serial card
148 = /dev/ttyPSC0 PPC PSC - port 0
...
153 = /dev/ttyPSC5 PPC PSC - port 5
154 = /dev/ttyAT0 ATMEL serial port 0
...
169 = /dev/ttyAT15 ATMEL serial port 15
170 = /dev/ttyNX0 Hilscher netX serial port 0
...
185 = /dev/ttyNX15 Hilscher netX serial port 15
186 = /dev/ttyJ0 JTAG1 DCC protocol based serial port emulation
187 = /dev/ttyUL0 Xilinx uartlite - port 0
...
190 = /dev/ttyUL3 Xilinx uartlite - port 3
191 = /dev/xvc0 Xen virtual console - port 0
192 = /dev/ttyPZ0 pmac_zilog - port 0
...
195 = /dev/ttyPZ3 pmac_zilog - port 3
196 = /dev/ttyTX0 TX39/49 serial port 0
...
204 = /dev/ttyTX7 TX39/49 serial port 7
205 = /dev/ttySC0 SC26xx serial port 0
206 = /dev/ttySC1 SC26xx serial port 1
207 = /dev/ttySC2 SC26xx serial port 2
208 = /dev/ttySC3 SC26xx serial port 3
209 = /dev/ttyMAX0 MAX3100 serial port 0
210 = /dev/ttyMAX1 MAX3100 serial port 1
211 = /dev/ttyMAX2 MAX3100 serial port 2
212 = /dev/ttyMAX3 MAX3100 serial port 3
205 char Low-density serial ports (alternate device)
0 = /dev/culu0 Callout device for ttyLU0
1 = /dev/culu1 Callout device for ttyLU1
2 = /dev/culu2 Callout device for ttyLU2
3 = /dev/culu3 Callout device for ttyLU3
4 = /dev/cufb0 Callout device for ttyFB0
5 = /dev/cusa0 Callout device for ttySA0
6 = /dev/cusa1 Callout device for ttySA1
7 = /dev/cusa2 Callout device for ttySA2
8 = /dev/cusc0 Callout device for ttySC0
9 = /dev/cusc1 Callout device for ttySC1
10 = /dev/cusc2 Callout device for ttySC2
11 = /dev/cusc3 Callout device for ttySC3
12 = /dev/cufw0 Callout device for ttyFW0
13 = /dev/cufw1 Callout device for ttyFW1
14 = /dev/cufw2 Callout device for ttyFW2
15 = /dev/cufw3 Callout device for ttyFW3
16 = /dev/cuam0 Callout device for ttyAM0
...
31 = /dev/cuam15 Callout device for ttyAM15
32 = /dev/cudb0 Callout device for ttyDB0
...
39 = /dev/cudb7 Callout device for ttyDB7
40 = /dev/cusg0 Callout device for ttySG0
41 = /dev/ttycusmx0 Callout device for ttySMX0
42 = /dev/ttycusmx1 Callout device for ttySMX1
43 = /dev/ttycusmx2 Callout device for ttySMX2
46 = /dev/cucpm0 Callout device for ttyCPM0
...
49 = /dev/cucpm5 Callout device for ttyCPM5
50 = /dev/cuioc40 Callout device for ttyIOC40
...
81 = /dev/cuioc431 Callout device for ttyIOC431
82 = /dev/cuvr0 Callout device for ttyVR0
83 = /dev/cuvr1 Callout device for ttyVR1
206 char OnStream SC-x0 tape devices
0 = /dev/osst0 First OnStream SCSI tape, mode 0
1 = /dev/osst1 Second OnStream SCSI tape, mode 0
...
32 = /dev/osst0l First OnStream SCSI tape, mode 1
33 = /dev/osst1l Second OnStream SCSI tape, mode 1
...
64 = /dev/osst0m First OnStream SCSI tape, mode 2
65 = /dev/osst1m Second OnStream SCSI tape, mode 2
...
96 = /dev/osst0a First OnStream SCSI tape, mode 3
97 = /dev/osst1a Second OnStream SCSI tape, mode 3
...
128 = /dev/nosst0 No rewind version of /dev/osst0
129 = /dev/nosst1 No rewind version of /dev/osst1
...
160 = /dev/nosst0l No rewind version of /dev/osst0l
161 = /dev/nosst1l No rewind version of /dev/osst1l
...
192 = /dev/nosst0m No rewind version of /dev/osst0m
193 = /dev/nosst1m No rewind version of /dev/osst1m
...
224 = /dev/nosst0a No rewind version of /dev/osst0a
225 = /dev/nosst1a No rewind version of /dev/osst1a
...
The OnStream SC-x0 SCSI tapes do not support the
standard SCSI SASD command set and therefore need
their own driver "osst". Note that the IDE, USB (and
maybe ParPort) versions may be driven via ide-scsi or
usb-storage SCSI emulation and this osst device and
driver as well. The ADR-x0 drives are QIC-157
compliant and don't need osst.
207 char Compaq ProLiant health feature indicate
0 = /dev/cpqhealth/cpqw Redirector interface
1 = /dev/cpqhealth/crom EISA CROM
2 = /dev/cpqhealth/cdt Data Table
3 = /dev/cpqhealth/cevt Event Log
4 = /dev/cpqhealth/casr Automatic Server Recovery
5 = /dev/cpqhealth/cecc ECC Memory
6 = /dev/cpqhealth/cmca Machine Check Architecture
7 = /dev/cpqhealth/ccsm Deprecated CDT
8 = /dev/cpqhealth/cnmi NMI Handling
9 = /dev/cpqhealth/css Sideshow Management
10 = /dev/cpqhealth/cram CMOS interface
11 = /dev/cpqhealth/cpci PCI IRQ interface
208 char User space serial ports
0 = /dev/ttyU0 First user space serial port
1 = /dev/ttyU1 Second user space serial port
...
209 char User space serial ports (alternate devices)
0 = /dev/cuu0 Callout device for ttyU0
1 = /dev/cuu1 Callout device for ttyU1
...
210 char SBE, Inc. sync/async serial card
0 = /dev/sbei/wxcfg0 Configuration device for board 0
1 = /dev/sbei/dld0 Download device for board 0
2 = /dev/sbei/wan00 WAN device, port 0, board 0
3 = /dev/sbei/wan01 WAN device, port 1, board 0
4 = /dev/sbei/wan02 WAN device, port 2, board 0
5 = /dev/sbei/wan03 WAN device, port 3, board 0
6 = /dev/sbei/wanc00 WAN clone device, port 0, board 0
7 = /dev/sbei/wanc01 WAN clone device, port 1, board 0
8 = /dev/sbei/wanc02 WAN clone device, port 2, board 0
9 = /dev/sbei/wanc03 WAN clone device, port 3, board 0
10 = /dev/sbei/wxcfg1 Configuration device for board 1
11 = /dev/sbei/dld1 Download device for board 1
12 = /dev/sbei/wan10 WAN device, port 0, board 1
13 = /dev/sbei/wan11 WAN device, port 1, board 1
14 = /dev/sbei/wan12 WAN device, port 2, board 1
15 = /dev/sbei/wan13 WAN device, port 3, board 1
16 = /dev/sbei/wanc10 WAN clone device, port 0, board 1
17 = /dev/sbei/wanc11 WAN clone device, port 1, board 1
18 = /dev/sbei/wanc12 WAN clone device, port 2, board 1
19 = /dev/sbei/wanc13 WAN clone device, port 3, board 1
...
Yes, each board is really spaced 10 (decimal) apart.
211 char Addinum CPCI1500 digital I/O card
0 = /dev/addinum/cpci1500/0 First CPCI1500 card
1 = /dev/addinum/cpci1500/1 Second CPCI1500 card
...
212 char LinuxTV.org DVB driver subsystem
0 = /dev/dvb/adapter0/video0 first video decoder of first card
1 = /dev/dvb/adapter0/audio0 first audio decoder of first card
2 = /dev/dvb/adapter0/sec0 (obsolete/unused)
3 = /dev/dvb/adapter0/frontend0 first frontend device of first card
4 = /dev/dvb/adapter0/demux0 first demux device of first card
5 = /dev/dvb/adapter0/dvr0 first digital video recoder device of first card
6 = /dev/dvb/adapter0/ca0 first common access port of first card
7 = /dev/dvb/adapter0/net0 first network device of first card
8 = /dev/dvb/adapter0/osd0 first on-screen-display device of first card
9 = /dev/dvb/adapter0/video1 second video decoder of first card
...
64 = /dev/dvb/adapter1/video0 first video decoder of second card
...
128 = /dev/dvb/adapter2/video0 first video decoder of third card
...
196 = /dev/dvb/adapter3/video0 first video decoder of fourth card
216 char Bluetooth RFCOMM TTY devices
0 = /dev/rfcomm0 First Bluetooth RFCOMM TTY device
1 = /dev/rfcomm1 Second Bluetooth RFCOMM TTY device
...
217 char Bluetooth RFCOMM TTY devices (alternate devices)
0 = /dev/curf0 Callout device for rfcomm0
1 = /dev/curf1 Callout device for rfcomm1
...
218 char The Logical Company bus Unibus/Qbus adapters
0 = /dev/logicalco/bci/0 First bus adapter
1 = /dev/logicalco/bci/1 First bus adapter
...
219 char The Logical Company DCI-1300 digital I/O card
0 = /dev/logicalco/dci1300/0 First DCI-1300 card
1 = /dev/logicalco/dci1300/1 Second DCI-1300 card
...
220 char Myricom Myrinet "GM" board
0 = /dev/myricom/gm0 First Myrinet GM board
1 = /dev/myricom/gmp0 First board "root access"
2 = /dev/myricom/gm1 Second Myrinet GM board
3 = /dev/myricom/gmp1 Second board "root access"
...
221 char VME bus
0 = /dev/bus/vme/m0 First master image
1 = /dev/bus/vme/m1 Second master image
2 = /dev/bus/vme/m2 Third master image
3 = /dev/bus/vme/m3 Fourth master image
4 = /dev/bus/vme/s0 First slave image
5 = /dev/bus/vme/s1 Second slave image
6 = /dev/bus/vme/s2 Third slave image
7 = /dev/bus/vme/s3 Fourth slave image
8 = /dev/bus/vme/ctl Control
It is expected that all VME bus drivers will use the
same interface. For interface documentation see
http://www.vmelinux.org/.
224 char A2232 serial card
0 = /dev/ttyY0 First A2232 port
1 = /dev/ttyY1 Second A2232 port
...
225 char A2232 serial card (alternate devices)
0 = /dev/cuy0 Callout device for ttyY0
1 = /dev/cuy1 Callout device for ttyY1
...
226 char Direct Rendering Infrastructure (DRI)
0 = /dev/dri/card0 First graphics card
1 = /dev/dri/card1 Second graphics card
...
227 char IBM 3270 terminal Unix tty access
1 = /dev/3270/tty1 First 3270 terminal
2 = /dev/3270/tty2 Seconds 3270 terminal
...
228 char IBM 3270 terminal block-mode access
0 = /dev/3270/tub Controlling interface
1 = /dev/3270/tub1 First 3270 terminal
2 = /dev/3270/tub2 Second 3270 terminal
...
229 char IBM iSeries/pSeries virtual console
0 = /dev/hvc0 First console port
1 = /dev/hvc1 Second console port
...
230 char IBM iSeries virtual tape
0 = /dev/iseries/vt0 First virtual tape, mode 0
1 = /dev/iseries/vt1 Second virtual tape, mode 0
...
32 = /dev/iseries/vt0l First virtual tape, mode 1
33 = /dev/iseries/vt1l Second virtual tape, mode 1
...
64 = /dev/iseries/vt0m First virtual tape, mode 2
65 = /dev/iseries/vt1m Second virtual tape, mode 2
...
96 = /dev/iseries/vt0a First virtual tape, mode 3
97 = /dev/iseries/vt1a Second virtual tape, mode 3
...
128 = /dev/iseries/nvt0 First virtual tape, mode 0, no rewind
129 = /dev/iseries/nvt1 Second virtual tape, mode 0, no rewind
...
160 = /dev/iseries/nvt0l First virtual tape, mode 1, no rewind
161 = /dev/iseries/nvt1l Second virtual tape, mode 1, no rewind
...
192 = /dev/iseries/nvt0m First virtual tape, mode 2, no rewind
193 = /dev/iseries/nvt1m Second virtual tape, mode 2, no rewind
...
224 = /dev/iseries/nvt0a First virtual tape, mode 3, no rewind
225 = /dev/iseries/nvt1a Second virtual tape, mode 3, no rewind
...
"No rewind" refers to the omission of the default
automatic rewind on device close. The MTREW or MTOFFL
ioctl()'s can be used to rewind the tape regardless of
the device used to access it.
231 char InfiniBand
0 = /dev/infiniband/umad0
1 = /dev/infiniband/umad1
...
63 = /dev/infiniband/umad63 63rd InfiniBandMad device
64 = /dev/infiniband/issm0 First InfiniBand IsSM device
65 = /dev/infiniband/issm1 Second InfiniBand IsSM device
...
127 = /dev/infiniband/issm63 63rd InfiniBand IsSM device
128 = /dev/infiniband/uverbs0 First InfiniBand verbs device
129 = /dev/infiniband/uverbs1 Second InfiniBand verbs device
...
159 = /dev/infiniband/uverbs31 31st InfiniBand verbs device
232 char Biometric Devices
0 = /dev/biometric/sensor0/fingerprint first fingerprint sensor on first device
1 = /dev/biometric/sensor0/iris first iris sensor on first device
2 = /dev/biometric/sensor0/retina first retina sensor on first device
3 = /dev/biometric/sensor0/voiceprint first voiceprint sensor on first device
4 = /dev/biometric/sensor0/facial first facial sensor on first device
5 = /dev/biometric/sensor0/hand first hand sensor on first device
...
10 = /dev/biometric/sensor1/fingerprint first fingerprint sensor on second device
...
20 = /dev/biometric/sensor2/fingerprint first fingerprint sensor on third device
...
233 char PathScale InfiniPath interconnect
0 = /dev/ipath Primary device for programs (any unit)
1 = /dev/ipath0 Access specifically to unit 0
2 = /dev/ipath1 Access specifically to unit 1
...
4 = /dev/ipath3 Access specifically to unit 3
129 = /dev/ipath_sma Device used by Subnet Management Agent
130 = /dev/ipath_diag Device used by diagnostics programs
234-254 char RESERVED FOR DYNAMIC ASSIGNMENT
Character devices that request a dynamic allocation of major number will
take numbers starting from 254 and downward.
240-254 block LOCAL/EXPERIMENTAL USE
Allocated for local/experimental use. For devices not
assigned official numbers, these ranges should be
used in order to avoid conflicting with future assignments.
255 char RESERVED
255 block RESERVED
This major is reserved to assist the expansion to a
larger number space. No device nodes with this major
should ever be created on the filesystem.
(This is probably not true anymore, but I'll leave it
for now /Torben)
---LARGE MAJORS!!!!!---
256 char Equinox SST multi-port serial boards
0 = /dev/ttyEQ0 First serial port on first Equinox SST board
127 = /dev/ttyEQ127 Last serial port on first Equinox SST board
128 = /dev/ttyEQ128 First serial port on second Equinox SST board
...
1027 = /dev/ttyEQ1027 Last serial port on eighth Equinox SST board
256 block Resident Flash Disk Flash Translation Layer
0 = /dev/rfda First RFD FTL layer
16 = /dev/rfdb Second RFD FTL layer
...
240 = /dev/rfdp 16th RFD FTL layer
257 char Phoenix Technologies Cryptographic Services Driver
0 = /dev/ptlsec Crypto Services Driver
257 block SSFDC Flash Translation Layer filesystem
0 = /dev/ssfdca First SSFDC layer
8 = /dev/ssfdcb Second SSFDC layer
16 = /dev/ssfdcc Third SSFDC layer
24 = /dev/ssfdcd 4th SSFDC layer
32 = /dev/ssfdce 5th SSFDC layer
40 = /dev/ssfdcf 6th SSFDC layer
48 = /dev/ssfdcg 7th SSFDC layer
56 = /dev/ssfdch 8th SSFDC layer
258 block ROM/Flash read-only translation layer
0 = /dev/blockrom0 First ROM card's translation layer interface
1 = /dev/blockrom1 Second ROM card's translation layer interface
...
259 block Block Extended Major
Used dynamically to hold additional partition minor
numbers and allow large numbers of partitions per device
259 char FPGA configuration interfaces
0 = /dev/icap0 First Xilinx internal configuration
1 = /dev/icap1 Second Xilinx internal configuration
260 char OSD (Object-based-device) SCSI Device
0 = /dev/osd0 First OSD Device
1 = /dev/osd1 Second OSD Device
...
255 = /dev/osd255 256th OSD Device
Additional ``/dev/`` directory entries Additional ``/dev/`` directory entries
-------------------------------------- --------------------------------------
......
Documentation/admin-guide/devices.txt 0 → 100644
浏览文件 @ 63ac0cf9
0 Unnamed devices (e.g. non-device mounts)
0 = reserved as null device number
See block major 144, 145, 146 for expansion areas.
1 char Memory devices
1 = /dev/mem Physical memory access
2 = /dev/kmem Kernel virtual memory access
3 = /dev/null Null device
4 = /dev/port I/O port access
5 = /dev/zero Null byte source
6 = /dev/core OBSOLETE - replaced by /proc/kcore
7 = /dev/full Returns ENOSPC on write
8 = /dev/random Nondeterministic random number gen.
9 = /dev/urandom Faster, less secure random number gen.
10 = /dev/aio Asynchronous I/O notification interface
11 = /dev/kmsg Writes to this come out as printk's, reads
export the buffered printk records.
12 = /dev/oldmem OBSOLETE - replaced by /proc/vmcore
1 block RAM disk
0 = /dev/ram0 First RAM disk
1 = /dev/ram1 Second RAM disk
...
250 = /dev/initrd Initial RAM disk
Older kernels had /dev/ramdisk (1, 1) here.
/dev/initrd refers to a RAM disk which was preloaded
by the boot loader; newer kernels use /dev/ram0 for
the initrd.
2 char Pseudo-TTY masters
0 = /dev/ptyp0 First PTY master
1 = /dev/ptyp1 Second PTY master
...
255 = /dev/ptyef 256th PTY master
Pseudo-tty's are named as follows:
* Masters are "pty", slaves are "tty";
* the fourth letter is one of pqrstuvwxyzabcde indicating
the 1st through 16th series of 16 pseudo-ttys each, and
* the fifth letter is one of 0123456789abcdef indicating
the position within the series.
These are the old-style (BSD) PTY devices; Unix98
devices are on major 128 and above and use the PTY
master multiplex (/dev/ptmx) to acquire a PTY on
demand.
2 block Floppy disks
0 = /dev/fd0 Controller 0, drive 0, autodetect
1 = /dev/fd1 Controller 0, drive 1, autodetect
2 = /dev/fd2 Controller 0, drive 2, autodetect
3 = /dev/fd3 Controller 0, drive 3, autodetect
128 = /dev/fd4 Controller 1, drive 0, autodetect
129 = /dev/fd5 Controller 1, drive 1, autodetect
130 = /dev/fd6 Controller 1, drive 2, autodetect
131 = /dev/fd7 Controller 1, drive 3, autodetect
To specify format, add to the autodetect device number:
0 = /dev/fd? Autodetect format
4 = /dev/fd?d360 5.25" 360K in a 360K drive(1)
20 = /dev/fd?h360 5.25" 360K in a 1200K drive(1)
48 = /dev/fd?h410 5.25" 410K in a 1200K drive
64 = /dev/fd?h420 5.25" 420K in a 1200K drive
24 = /dev/fd?h720 5.25" 720K in a 1200K drive
80 = /dev/fd?h880 5.25" 880K in a 1200K drive(1)
8 = /dev/fd?h1200 5.25" 1200K in a 1200K drive(1)
40 = /dev/fd?h1440 5.25" 1440K in a 1200K drive(1)
56 = /dev/fd?h1476 5.25" 1476K in a 1200K drive
72 = /dev/fd?h1494 5.25" 1494K in a 1200K drive
92 = /dev/fd?h1600 5.25" 1600K in a 1200K drive(1)
12 = /dev/fd?u360 3.5" 360K Double Density(2)
16 = /dev/fd?u720 3.5" 720K Double Density(1)
120 = /dev/fd?u800 3.5" 800K Double Density(2)
52 = /dev/fd?u820 3.5" 820K Double Density
68 = /dev/fd?u830 3.5" 830K Double Density
84 = /dev/fd?u1040 3.5" 1040K Double Density(1)
88 = /dev/fd?u1120 3.5" 1120K Double Density(1)
28 = /dev/fd?u1440 3.5" 1440K High Density(1)
124 = /dev/fd?u1600 3.5" 1600K High Density(1)
44 = /dev/fd?u1680 3.5" 1680K High Density(3)
60 = /dev/fd?u1722 3.5" 1722K High Density
76 = /dev/fd?u1743 3.5" 1743K High Density
96 = /dev/fd?u1760 3.5" 1760K High Density
116 = /dev/fd?u1840 3.5" 1840K High Density(3)
100 = /dev/fd?u1920 3.5" 1920K High Density(1)
32 = /dev/fd?u2880 3.5" 2880K Extra Density(1)
104 = /dev/fd?u3200 3.5" 3200K Extra Density
108 = /dev/fd?u3520 3.5" 3520K Extra Density
112 = /dev/fd?u3840 3.5" 3840K Extra Density(1)
36 = /dev/fd?CompaQ Compaq 2880K drive; obsolete?
(1) Autodetectable format
(2) Autodetectable format in a Double Density (720K) drive only
(3) Autodetectable format in a High Density (1440K) drive only
NOTE: The letter in the device name (d, q, h or u)
signifies the type of drive: 5.25" Double Density (d),
5.25" Quad Density (q), 5.25" High Density (h) or 3.5"
(any model, u). The use of the capital letters D, H
and E for the 3.5" models have been deprecated, since
the drive type is insignificant for these devices.
3 char Pseudo-TTY slaves
0 = /dev/ttyp0 First PTY slave
1 = /dev/ttyp1 Second PTY slave
...
255 = /dev/ttyef 256th PTY slave
These are the old-style (BSD) PTY devices; Unix98
devices are on major 136 and above.
3 block First MFM, RLL and IDE hard disk/CD-ROM interface
0 = /dev/hda Master: whole disk (or CD-ROM)
64 = /dev/hdb Slave: whole disk (or CD-ROM)
For partitions, add to the whole disk device number:
0 = /dev/hd? Whole disk
1 = /dev/hd?1 First partition
2 = /dev/hd?2 Second partition
...
63 = /dev/hd?63 63rd partition
For Linux/i386, partitions 1-4 are the primary
partitions, and 5 and above are logical partitions.
Other versions of Linux use partitioning schemes
appropriate to their respective architectures.
4 char TTY devices
0 = /dev/tty0 Current virtual console
1 = /dev/tty1 First virtual console
...
63 = /dev/tty63 63rd virtual console
64 = /dev/ttyS0 First UART serial port
...
255 = /dev/ttyS191 192nd UART serial port
UART serial ports refer to 8250/16450/16550 series devices.
Older versions of the Linux kernel used this major
number for BSD PTY devices. As of Linux 2.1.115, this
is no longer supported. Use major numbers 2 and 3.
4 block Aliases for dynamically allocated major devices to be used
when its not possible to create the real device nodes
because the root filesystem is mounted read-only.
0 = /dev/root
5 char Alternate TTY devices
0 = /dev/tty Current TTY device
1 = /dev/console System console
2 = /dev/ptmx PTY master multiplex
3 = /dev/ttyprintk User messages via printk TTY device
64 = /dev/cua0 Callout device for ttyS0
...
255 = /dev/cua191 Callout device for ttyS191
(5,1) is /dev/console starting with Linux 2.1.71. See
the section on terminal devices for more information
on /dev/console.
6 char Parallel printer devices
0 = /dev/lp0 Parallel printer on parport0
1 = /dev/lp1 Parallel printer on parport1
...
Current Linux kernels no longer have a fixed mapping
between parallel ports and I/O addresses. Instead,
they are redirected through the parport multiplex layer.
7 char Virtual console capture devices
0 = /dev/vcs Current vc text contents
1 = /dev/vcs1 tty1 text contents
...
63 = /dev/vcs63 tty63 text contents
128 = /dev/vcsa Current vc text/attribute contents
129 = /dev/vcsa1 tty1 text/attribute contents
...
191 = /dev/vcsa63 tty63 text/attribute contents
NOTE: These devices permit both read and write access.
7 block Loopback devices
0 = /dev/loop0 First loop device
1 = /dev/loop1 Second loop device
...
The loop devices are used to mount filesystems not
associated with block devices. The binding to the
loop devices is handled by mount(8) or losetup(8).
8 block SCSI disk devices (0-15)
0 = /dev/sda First SCSI disk whole disk
16 = /dev/sdb Second SCSI disk whole disk
32 = /dev/sdc Third SCSI disk whole disk
...
240 = /dev/sdp Sixteenth SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
9 char SCSI tape devices
0 = /dev/st0 First SCSI tape, mode 0
1 = /dev/st1 Second SCSI tape, mode 0
...
32 = /dev/st0l First SCSI tape, mode 1
33 = /dev/st1l Second SCSI tape, mode 1
...
64 = /dev/st0m First SCSI tape, mode 2
65 = /dev/st1m Second SCSI tape, mode 2
...
96 = /dev/st0a First SCSI tape, mode 3
97 = /dev/st1a Second SCSI tape, mode 3
...
128 = /dev/nst0 First SCSI tape, mode 0, no rewind
129 = /dev/nst1 Second SCSI tape, mode 0, no rewind
...
160 = /dev/nst0l First SCSI tape, mode 1, no rewind
161 = /dev/nst1l Second SCSI tape, mode 1, no rewind
...
192 = /dev/nst0m First SCSI tape, mode 2, no rewind
193 = /dev/nst1m Second SCSI tape, mode 2, no rewind
...
224 = /dev/nst0a First SCSI tape, mode 3, no rewind
225 = /dev/nst1a Second SCSI tape, mode 3, no rewind
...
"No rewind" refers to the omission of the default
automatic rewind on device close. The MTREW or MTOFFL
ioctl()'s can be used to rewind the tape regardless of
the device used to access it.
9 block Metadisk (RAID) devices
0 = /dev/md0 First metadisk group
1 = /dev/md1 Second metadisk group
...
The metadisk driver is used to span a
filesystem across multiple physical disks.
10 char Non-serial mice, misc features
0 = /dev/logibm Logitech bus mouse
1 = /dev/psaux PS/2-style mouse port
2 = /dev/inportbm Microsoft Inport bus mouse
3 = /dev/atibm ATI XL bus mouse
4 = /dev/jbm J-mouse
4 = /dev/amigamouse Amiga mouse (68k/Amiga)
5 = /dev/atarimouse Atari mouse
6 = /dev/sunmouse Sun mouse
7 = /dev/amigamouse1 Second Amiga mouse
8 = /dev/smouse Simple serial mouse driver
9 = /dev/pc110pad IBM PC-110 digitizer pad
10 = /dev/adbmouse Apple Desktop Bus mouse
11 = /dev/vrtpanel Vr41xx embedded touch panel
13 = /dev/vpcmouse Connectix Virtual PC Mouse
14 = /dev/touchscreen/ucb1x00 UCB 1x00 touchscreen
15 = /dev/touchscreen/mk712 MK712 touchscreen
128 = /dev/beep Fancy beep device
129 =
130 = /dev/watchdog Watchdog timer port
131 = /dev/temperature Machine internal temperature
132 = /dev/hwtrap Hardware fault trap
133 = /dev/exttrp External device trap
134 = /dev/apm_bios Advanced Power Management BIOS
135 = /dev/rtc Real Time Clock
137 = /dev/vhci Bluetooth virtual HCI driver
139 = /dev/openprom SPARC OpenBoot PROM
140 = /dev/relay8 Berkshire Products Octal relay card
141 = /dev/relay16 Berkshire Products ISO-16 relay card
142 =
143 = /dev/pciconf PCI configuration space
144 = /dev/nvram Non-volatile configuration RAM
145 = /dev/hfmodem Soundcard shortwave modem control
146 = /dev/graphics Linux/SGI graphics device
147 = /dev/opengl Linux/SGI OpenGL pipe
148 = /dev/gfx Linux/SGI graphics effects device
149 = /dev/input/mouse Linux/SGI Irix emulation mouse
150 = /dev/input/keyboard Linux/SGI Irix emulation keyboard
151 = /dev/led Front panel LEDs
152 = /dev/kpoll Kernel Poll Driver
153 = /dev/mergemem Memory merge device
154 = /dev/pmu Macintosh PowerBook power manager
155 = /dev/isictl MultiTech ISICom serial control
156 = /dev/lcd Front panel LCD display
157 = /dev/ac Applicom Intl Profibus card
158 = /dev/nwbutton Netwinder external button
159 = /dev/nwdebug Netwinder debug interface
160 = /dev/nwflash Netwinder flash memory
161 = /dev/userdma User-space DMA access
162 = /dev/smbus System Management Bus
163 = /dev/lik Logitech Internet Keyboard
164 = /dev/ipmo Intel Intelligent Platform Management
165 = /dev/vmmon VMware virtual machine monitor
166 = /dev/i2o/ctl I2O configuration manager
167 = /dev/specialix_sxctl Specialix serial control
168 = /dev/tcldrv Technology Concepts serial control
169 = /dev/specialix_rioctl Specialix RIO serial control
170 = /dev/thinkpad/thinkpad IBM Thinkpad devices
171 = /dev/srripc QNX4 API IPC manager
172 = /dev/usemaclone Semaphore clone device
173 = /dev/ipmikcs Intelligent Platform Management
174 = /dev/uctrl SPARCbook 3 microcontroller
175 = /dev/agpgart AGP Graphics Address Remapping Table
176 = /dev/gtrsc Gorgy Timing radio clock
177 = /dev/cbm Serial CBM bus
178 = /dev/jsflash JavaStation OS flash SIMM
179 = /dev/xsvc High-speed shared-mem/semaphore service
180 = /dev/vrbuttons Vr41xx button input device
181 = /dev/toshiba Toshiba laptop SMM support
182 = /dev/perfctr Performance-monitoring counters
183 = /dev/hwrng Generic random number generator
184 = /dev/cpu/microcode CPU microcode update interface
186 = /dev/atomicps Atomic shapshot of process state data
187 = /dev/irnet IrNET device
188 = /dev/smbusbios SMBus BIOS
189 = /dev/ussp_ctl User space serial port control
190 = /dev/crash Mission Critical Linux crash dump facility
191 = /dev/pcl181 <information missing>
192 = /dev/nas_xbus NAS xbus LCD/buttons access
193 = /dev/d7s SPARC 7-segment display
194 = /dev/zkshim Zero-Knowledge network shim control
195 = /dev/elographics/e2201 Elographics touchscreen E271-2201
196 = /dev/vfio/vfio VFIO userspace driver interface
197 = /dev/pxa3xx-gcu PXA3xx graphics controller unit driver
198 = /dev/sexec Signed executable interface
199 = /dev/scanners/cuecat :CueCat barcode scanner
200 = /dev/net/tun TAP/TUN network device
201 = /dev/button/gulpb Transmeta GULP-B buttons
202 = /dev/emd/ctl Enhanced Metadisk RAID (EMD) control
203 = /dev/cuse Cuse (character device in user-space)
204 = /dev/video/em8300 EM8300 DVD decoder control
205 = /dev/video/em8300_mv EM8300 DVD decoder video
206 = /dev/video/em8300_ma EM8300 DVD decoder audio
207 = /dev/video/em8300_sp EM8300 DVD decoder subpicture
208 = /dev/compaq/cpqphpc Compaq PCI Hot Plug Controller
209 = /dev/compaq/cpqrid Compaq Remote Insight Driver
210 = /dev/impi/bt IMPI coprocessor block transfer
211 = /dev/impi/smic IMPI coprocessor stream interface
212 = /dev/watchdogs/0 First watchdog device
213 = /dev/watchdogs/1 Second watchdog device
214 = /dev/watchdogs/2 Third watchdog device
215 = /dev/watchdogs/3 Fourth watchdog device
216 = /dev/fujitsu/apanel Fujitsu/Siemens application panel
217 = /dev/ni/natmotn National Instruments Motion
218 = /dev/kchuid Inter-process chuid control
219 = /dev/modems/mwave MWave modem firmware upload
220 = /dev/mptctl Message passing technology (MPT) control
221 = /dev/mvista/hssdsi Montavista PICMG hot swap system driver
222 = /dev/mvista/hasi Montavista PICMG high availability
223 = /dev/input/uinput User level driver support for input
224 = /dev/tpm TCPA TPM driver
225 = /dev/pps Pulse Per Second driver
226 = /dev/systrace Systrace device
227 = /dev/mcelog X86_64 Machine Check Exception driver
228 = /dev/hpet HPET driver
229 = /dev/fuse Fuse (virtual filesystem in user-space)
230 = /dev/midishare MidiShare driver
231 = /dev/snapshot System memory snapshot device
232 = /dev/kvm Kernel-based virtual machine (hardware virtualization extensions)
233 = /dev/kmview View-OS A process with a view
234 = /dev/btrfs-control Btrfs control device
235 = /dev/autofs Autofs control device
236 = /dev/mapper/control Device-Mapper control device
237 = /dev/loop-control Loopback control device
238 = /dev/vhost-net Host kernel accelerator for virtio net
239 = /dev/uhid User-space I/O driver support for HID subsystem
240-254 Reserved for local use
255 Reserved for MISC_DYNAMIC_MINOR
11 char Raw keyboard device (Linux/SPARC only)
0 = /dev/kbd Raw keyboard device
11 char Serial Mux device (Linux/PA-RISC only)
0 = /dev/ttyB0 First mux port
1 = /dev/ttyB1 Second mux port
...
11 block SCSI CD-ROM devices
0 = /dev/scd0 First SCSI CD-ROM
1 = /dev/scd1 Second SCSI CD-ROM
...
The prefix /dev/sr (instead of /dev/scd) has been deprecated.
12 char QIC-02 tape
2 = /dev/ntpqic11 QIC-11, no rewind-on-close
3 = /dev/tpqic11 QIC-11, rewind-on-close
4 = /dev/ntpqic24 QIC-24, no rewind-on-close
5 = /dev/tpqic24 QIC-24, rewind-on-close
6 = /dev/ntpqic120 QIC-120, no rewind-on-close
7 = /dev/tpqic120 QIC-120, rewind-on-close
8 = /dev/ntpqic150 QIC-150, no rewind-on-close
9 = /dev/tpqic150 QIC-150, rewind-on-close
The device names specified are proposed -- if there
are "standard" names for these devices, please let me know.
12 block
13 char Input core
0 = /dev/input/js0 First joystick
1 = /dev/input/js1 Second joystick
...
32 = /dev/input/mouse0 First mouse
33 = /dev/input/mouse1 Second mouse
...
63 = /dev/input/mice Unified mouse
64 = /dev/input/event0 First event queue
65 = /dev/input/event1 Second event queue
...
Each device type has 5 bits (32 minors).
13 block Previously used for the XT disk (/dev/xdN)
Deleted in kernel v3.9.
14 char Open Sound System (OSS)
0 = /dev/mixer Mixer control
1 = /dev/sequencer Audio sequencer
2 = /dev/midi00 First MIDI port
3 = /dev/dsp Digital audio
4 = /dev/audio Sun-compatible digital audio
6 =
7 = /dev/audioctl SPARC audio control device
8 = /dev/sequencer2 Sequencer -- alternate device
16 = /dev/mixer1 Second soundcard mixer control
17 = /dev/patmgr0 Sequencer patch manager
18 = /dev/midi01 Second MIDI port
19 = /dev/dsp1 Second soundcard digital audio
20 = /dev/audio1 Second soundcard Sun digital audio
33 = /dev/patmgr1 Sequencer patch manager
34 = /dev/midi02 Third MIDI port
50 = /dev/midi03 Fourth MIDI port
14 block
15 char Joystick
0 = /dev/js0 First analog joystick
1 = /dev/js1 Second analog joystick
...
128 = /dev/djs0 First digital joystick
129 = /dev/djs1 Second digital joystick
...
15 block Sony CDU-31A/CDU-33A CD-ROM
0 = /dev/sonycd Sony CDU-31a CD-ROM
16 char Non-SCSI scanners
0 = /dev/gs4500 Genius 4500 handheld scanner
16 block GoldStar CD-ROM
0 = /dev/gscd GoldStar CD-ROM
17 char OBSOLETE (was Chase serial card)
0 = /dev/ttyH0 First Chase port
1 = /dev/ttyH1 Second Chase port
...
17 block Optics Storage CD-ROM
0 = /dev/optcd Optics Storage CD-ROM
18 char OBSOLETE (was Chase serial card - alternate devices)
0 = /dev/cuh0 Callout device for ttyH0
1 = /dev/cuh1 Callout device for ttyH1
...
18 block Sanyo CD-ROM
0 = /dev/sjcd Sanyo CD-ROM
19 char Cyclades serial card
0 = /dev/ttyC0 First Cyclades port
...
31 = /dev/ttyC31 32nd Cyclades port
19 block "Double" compressed disk
0 = /dev/double0 First compressed disk
...
7 = /dev/double7 Eighth compressed disk
128 = /dev/cdouble0 Mirror of first compressed disk
...
135 = /dev/cdouble7 Mirror of eighth compressed disk
See the Double documentation for the meaning of the
mirror devices.
20 char Cyclades serial card - alternate devices
0 = /dev/cub0 Callout device for ttyC0
...
31 = /dev/cub31 Callout device for ttyC31
20 block Hitachi CD-ROM (under development)
0 = /dev/hitcd Hitachi CD-ROM
21 char Generic SCSI access
0 = /dev/sg0 First generic SCSI device
1 = /dev/sg1 Second generic SCSI device
...
Most distributions name these /dev/sga, /dev/sgb...;
this sets an unnecessary limit of 26 SCSI devices in
the system and is counter to standard Linux
device-naming practice.
21 block Acorn MFM hard drive interface
0 = /dev/mfma First MFM drive whole disk
64 = /dev/mfmb Second MFM drive whole disk
This device is used on the ARM-based Acorn RiscPC.
Partitions are handled the same way as for IDE disks
(see major number 3).
22 char Digiboard serial card
0 = /dev/ttyD0 First Digiboard port
1 = /dev/ttyD1 Second Digiboard port
...
22 block Second IDE hard disk/CD-ROM interface
0 = /dev/hdc Master: whole disk (or CD-ROM)
64 = /dev/hdd Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
23 char Digiboard serial card - alternate devices
0 = /dev/cud0 Callout device for ttyD0
1 = /dev/cud1 Callout device for ttyD1
...
23 block Mitsumi proprietary CD-ROM
0 = /dev/mcd Mitsumi CD-ROM
24 char Stallion serial card
0 = /dev/ttyE0 Stallion port 0 card 0
1 = /dev/ttyE1 Stallion port 1 card 0
...
64 = /dev/ttyE64 Stallion port 0 card 1
65 = /dev/ttyE65 Stallion port 1 card 1
...
128 = /dev/ttyE128 Stallion port 0 card 2
129 = /dev/ttyE129 Stallion port 1 card 2
...
192 = /dev/ttyE192 Stallion port 0 card 3
193 = /dev/ttyE193 Stallion port 1 card 3
...
24 block Sony CDU-535 CD-ROM
0 = /dev/cdu535 Sony CDU-535 CD-ROM
25 char Stallion serial card - alternate devices
0 = /dev/cue0 Callout device for ttyE0
1 = /dev/cue1 Callout device for ttyE1
...
64 = /dev/cue64 Callout device for ttyE64
65 = /dev/cue65 Callout device for ttyE65
...
128 = /dev/cue128 Callout device for ttyE128
129 = /dev/cue129 Callout device for ttyE129
...
192 = /dev/cue192 Callout device for ttyE192
193 = /dev/cue193 Callout device for ttyE193
...
25 block First Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd0 Panasonic CD-ROM controller 0 unit 0
1 = /dev/sbpcd1 Panasonic CD-ROM controller 0 unit 1
2 = /dev/sbpcd2 Panasonic CD-ROM controller 0 unit 2
3 = /dev/sbpcd3 Panasonic CD-ROM controller 0 unit 3
26 char
26 block Second Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd4 Panasonic CD-ROM controller 1 unit 0
1 = /dev/sbpcd5 Panasonic CD-ROM controller 1 unit 1
2 = /dev/sbpcd6 Panasonic CD-ROM controller 1 unit 2
3 = /dev/sbpcd7 Panasonic CD-ROM controller 1 unit 3
27 char QIC-117 tape
0 = /dev/qft0 Unit 0, rewind-on-close
1 = /dev/qft1 Unit 1, rewind-on-close
2 = /dev/qft2 Unit 2, rewind-on-close
3 = /dev/qft3 Unit 3, rewind-on-close
4 = /dev/nqft0 Unit 0, no rewind-on-close
5 = /dev/nqft1 Unit 1, no rewind-on-close
6 = /dev/nqft2 Unit 2, no rewind-on-close
7 = /dev/nqft3 Unit 3, no rewind-on-close
16 = /dev/zqft0 Unit 0, rewind-on-close, compression
17 = /dev/zqft1 Unit 1, rewind-on-close, compression
18 = /dev/zqft2 Unit 2, rewind-on-close, compression
19 = /dev/zqft3 Unit 3, rewind-on-close, compression
20 = /dev/nzqft0 Unit 0, no rewind-on-close, compression
21 = /dev/nzqft1 Unit 1, no rewind-on-close, compression
22 = /dev/nzqft2 Unit 2, no rewind-on-close, compression
23 = /dev/nzqft3 Unit 3, no rewind-on-close, compression
32 = /dev/rawqft0 Unit 0, rewind-on-close, no file marks
33 = /dev/rawqft1 Unit 1, rewind-on-close, no file marks
34 = /dev/rawqft2 Unit 2, rewind-on-close, no file marks
35 = /dev/rawqft3 Unit 3, rewind-on-close, no file marks
36 = /dev/nrawqft0 Unit 0, no rewind-on-close, no file marks
37 = /dev/nrawqft1 Unit 1, no rewind-on-close, no file marks
38 = /dev/nrawqft2 Unit 2, no rewind-on-close, no file marks
39 = /dev/nrawqft3 Unit 3, no rewind-on-close, no file marks
27 block Third Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd8 Panasonic CD-ROM controller 2 unit 0
1 = /dev/sbpcd9 Panasonic CD-ROM controller 2 unit 1
2 = /dev/sbpcd10 Panasonic CD-ROM controller 2 unit 2
3 = /dev/sbpcd11 Panasonic CD-ROM controller 2 unit 3
28 char Stallion serial card - card programming
0 = /dev/staliomem0 First Stallion card I/O memory
1 = /dev/staliomem1 Second Stallion card I/O memory
2 = /dev/staliomem2 Third Stallion card I/O memory
3 = /dev/staliomem3 Fourth Stallion card I/O memory
28 char Atari SLM ACSI laser printer (68k/Atari)
0 = /dev/slm0 First SLM laser printer
1 = /dev/slm1 Second SLM laser printer
...
28 block Fourth Matsushita (Panasonic/SoundBlaster) CD-ROM
0 = /dev/sbpcd12 Panasonic CD-ROM controller 3 unit 0
1 = /dev/sbpcd13 Panasonic CD-ROM controller 3 unit 1
2 = /dev/sbpcd14 Panasonic CD-ROM controller 3 unit 2
3 = /dev/sbpcd15 Panasonic CD-ROM controller 3 unit 3
28 block ACSI disk (68k/Atari)
0 = /dev/ada First ACSI disk whole disk
16 = /dev/adb Second ACSI disk whole disk
32 = /dev/adc Third ACSI disk whole disk
...
240 = /dev/adp 16th ACSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15, like SCSI.
29 char Universal frame buffer
0 = /dev/fb0 First frame buffer
1 = /dev/fb1 Second frame buffer
...
31 = /dev/fb31 32nd frame buffer
29 block Aztech/Orchid/Okano/Wearnes CD-ROM
0 = /dev/aztcd Aztech CD-ROM
30 char iBCS-2 compatibility devices
0 = /dev/socksys Socket access
1 = /dev/spx SVR3 local X interface
32 = /dev/inet/ip Network access
33 = /dev/inet/icmp
34 = /dev/inet/ggp
35 = /dev/inet/ipip
36 = /dev/inet/tcp
37 = /dev/inet/egp
38 = /dev/inet/pup
39 = /dev/inet/udp
40 = /dev/inet/idp
41 = /dev/inet/rawip
Additionally, iBCS-2 requires the following links:
/dev/ip -> /dev/inet/ip
/dev/icmp -> /dev/inet/icmp
/dev/ggp -> /dev/inet/ggp
/dev/ipip -> /dev/inet/ipip
/dev/tcp -> /dev/inet/tcp
/dev/egp -> /dev/inet/egp
/dev/pup -> /dev/inet/pup
/dev/udp -> /dev/inet/udp
/dev/idp -> /dev/inet/idp
/dev/rawip -> /dev/inet/rawip
/dev/inet/arp -> /dev/inet/udp
/dev/inet/rip -> /dev/inet/udp
/dev/nfsd -> /dev/socksys
/dev/X0R -> /dev/null (? apparently not required ?)
30 block Philips LMS CM-205 CD-ROM
0 = /dev/cm205cd Philips LMS CM-205 CD-ROM
/dev/lmscd is an older name for this device. This
driver does not work with the CM-205MS CD-ROM.
31 char MPU-401 MIDI
0 = /dev/mpu401data MPU-401 data port
1 = /dev/mpu401stat MPU-401 status port
31 block ROM/flash memory card
0 = /dev/rom0 First ROM card (rw)
...
7 = /dev/rom7 Eighth ROM card (rw)
8 = /dev/rrom0 First ROM card (ro)
...
15 = /dev/rrom7 Eighth ROM card (ro)
16 = /dev/flash0 First flash memory card (rw)
...
23 = /dev/flash7 Eighth flash memory card (rw)
24 = /dev/rflash0 First flash memory card (ro)
...
31 = /dev/rflash7 Eighth flash memory card (ro)
The read-write (rw) devices support back-caching
written data in RAM, as well as writing to flash RAM
devices. The read-only devices (ro) support reading
only.
32 char Specialix serial card
0 = /dev/ttyX0 First Specialix port
1 = /dev/ttyX1 Second Specialix port
...
32 block Philips LMS CM-206 CD-ROM
0 = /dev/cm206cd Philips LMS CM-206 CD-ROM
33 char Specialix serial card - alternate devices
0 = /dev/cux0 Callout device for ttyX0
1 = /dev/cux1 Callout device for ttyX1
...
33 block Third IDE hard disk/CD-ROM interface
0 = /dev/hde Master: whole disk (or CD-ROM)
64 = /dev/hdf Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
34 char Z8530 HDLC driver
0 = /dev/scc0 First Z8530, first port
1 = /dev/scc1 First Z8530, second port
2 = /dev/scc2 Second Z8530, first port
3 = /dev/scc3 Second Z8530, second port
...
In a previous version these devices were named
/dev/sc1 for /dev/scc0, /dev/sc2 for /dev/scc1, and so
on.
34 block Fourth IDE hard disk/CD-ROM interface
0 = /dev/hdg Master: whole disk (or CD-ROM)
64 = /dev/hdh Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
35 char tclmidi MIDI driver
0 = /dev/midi0 First MIDI port, kernel timed
1 = /dev/midi1 Second MIDI port, kernel timed
2 = /dev/midi2 Third MIDI port, kernel timed
3 = /dev/midi3 Fourth MIDI port, kernel timed
64 = /dev/rmidi0 First MIDI port, untimed
65 = /dev/rmidi1 Second MIDI port, untimed
66 = /dev/rmidi2 Third MIDI port, untimed
67 = /dev/rmidi3 Fourth MIDI port, untimed
128 = /dev/smpte0 First MIDI port, SMPTE timed
129 = /dev/smpte1 Second MIDI port, SMPTE timed
130 = /dev/smpte2 Third MIDI port, SMPTE timed
131 = /dev/smpte3 Fourth MIDI port, SMPTE timed
35 block Slow memory ramdisk
0 = /dev/slram Slow memory ramdisk
36 char Netlink support
0 = /dev/route Routing, device updates, kernel to user
1 = /dev/skip enSKIP security cache control
3 = /dev/fwmonitor Firewall packet copies
16 = /dev/tap0 First Ethertap device
...
31 = /dev/tap15 16th Ethertap device
36 block OBSOLETE (was MCA ESDI hard disk)
37 char IDE tape
0 = /dev/ht0 First IDE tape
1 = /dev/ht1 Second IDE tape
...
128 = /dev/nht0 First IDE tape, no rewind-on-close
129 = /dev/nht1 Second IDE tape, no rewind-on-close
...
Currently, only one IDE tape drive is supported.
37 block Zorro II ramdisk
0 = /dev/z2ram Zorro II ramdisk
38 char Myricom PCI Myrinet board
0 = /dev/mlanai0 First Myrinet board
1 = /dev/mlanai1 Second Myrinet board
...
This device is used for status query, board control
and "user level packet I/O." This board is also
accessible as a standard networking "eth" device.
38 block OBSOLETE (was Linux/AP+)
39 char ML-16P experimental I/O board
0 = /dev/ml16pa-a0 First card, first analog channel
1 = /dev/ml16pa-a1 First card, second analog channel
...
15 = /dev/ml16pa-a15 First card, 16th analog channel
16 = /dev/ml16pa-d First card, digital lines
17 = /dev/ml16pa-c0 First card, first counter/timer
18 = /dev/ml16pa-c1 First card, second counter/timer
19 = /dev/ml16pa-c2 First card, third counter/timer
32 = /dev/ml16pb-a0 Second card, first analog channel
33 = /dev/ml16pb-a1 Second card, second analog channel
...
47 = /dev/ml16pb-a15 Second card, 16th analog channel
48 = /dev/ml16pb-d Second card, digital lines
49 = /dev/ml16pb-c0 Second card, first counter/timer
50 = /dev/ml16pb-c1 Second card, second counter/timer
51 = /dev/ml16pb-c2 Second card, third counter/timer
...
39 block
40 char
40 block
41 char Yet Another Micro Monitor
0 = /dev/yamm Yet Another Micro Monitor
41 block
42 char Demo/sample use
42 block Demo/sample use
This number is intended for use in sample code, as
well as a general "example" device number. It
should never be used for a device driver that is being
distributed; either obtain an official number or use
the local/experimental range. The sudden addition or
removal of a driver with this number should not cause
ill effects to the system (bugs excepted.)
IN PARTICULAR, ANY DISTRIBUTION WHICH CONTAINS A
DEVICE DRIVER USING MAJOR NUMBER 42 IS NONCOMPLIANT.
43 char isdn4linux virtual modem
0 = /dev/ttyI0 First virtual modem
...
63 = /dev/ttyI63 64th virtual modem
43 block Network block devices
0 = /dev/nb0 First network block device
1 = /dev/nb1 Second network block device
...
Network Block Device is somehow similar to loopback
devices: If you read from it, it sends packet across
network asking server for data. If you write to it, it
sends packet telling server to write. It could be used
to mounting filesystems over the net, swapping over
the net, implementing block device in userland etc.
44 char isdn4linux virtual modem - alternate devices
0 = /dev/cui0 Callout device for ttyI0
...
63 = /dev/cui63 Callout device for ttyI63
44 block Flash Translation Layer (FTL) filesystems
0 = /dev/ftla FTL on first Memory Technology Device
16 = /dev/ftlb FTL on second Memory Technology Device
32 = /dev/ftlc FTL on third Memory Technology Device
...
240 = /dev/ftlp FTL on 16th Memory Technology Device
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the partition
limit is 15 rather than 63 per disk (same as SCSI.)
45 char isdn4linux ISDN BRI driver
0 = /dev/isdn0 First virtual B channel raw data
...
63 = /dev/isdn63 64th virtual B channel raw data
64 = /dev/isdnctrl0 First channel control/debug
...
127 = /dev/isdnctrl63 64th channel control/debug
128 = /dev/ippp0 First SyncPPP device
...
191 = /dev/ippp63 64th SyncPPP device
255 = /dev/isdninfo ISDN monitor interface
45 block Parallel port IDE disk devices
0 = /dev/pda First parallel port IDE disk
16 = /dev/pdb Second parallel port IDE disk
32 = /dev/pdc Third parallel port IDE disk
48 = /dev/pdd Fourth parallel port IDE disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the partition
limit is 15 rather than 63 per disk.
46 char Comtrol Rocketport serial card
0 = /dev/ttyR0 First Rocketport port
1 = /dev/ttyR1 Second Rocketport port
...
46 block Parallel port ATAPI CD-ROM devices
0 = /dev/pcd0 First parallel port ATAPI CD-ROM
1 = /dev/pcd1 Second parallel port ATAPI CD-ROM
2 = /dev/pcd2 Third parallel port ATAPI CD-ROM
3 = /dev/pcd3 Fourth parallel port ATAPI CD-ROM
47 char Comtrol Rocketport serial card - alternate devices
0 = /dev/cur0 Callout device for ttyR0
1 = /dev/cur1 Callout device for ttyR1
...
47 block Parallel port ATAPI disk devices
0 = /dev/pf0 First parallel port ATAPI disk
1 = /dev/pf1 Second parallel port ATAPI disk
2 = /dev/pf2 Third parallel port ATAPI disk
3 = /dev/pf3 Fourth parallel port ATAPI disk
This driver is intended for floppy disks and similar
devices and hence does not support partitioning.
48 char SDL RISCom serial card
0 = /dev/ttyL0 First RISCom port
1 = /dev/ttyL1 Second RISCom port
...
48 block Mylex DAC960 PCI RAID controller; first controller
0 = /dev/rd/c0d0 First disk, whole disk
8 = /dev/rd/c0d1 Second disk, whole disk
...
248 = /dev/rd/c0d31 32nd disk, whole disk
For partitions add:
0 = /dev/rd/c?d? Whole disk
1 = /dev/rd/c?d?p1 First partition
...
7 = /dev/rd/c?d?p7 Seventh partition
49 char SDL RISCom serial card - alternate devices
0 = /dev/cul0 Callout device for ttyL0
1 = /dev/cul1 Callout device for ttyL1
...
49 block Mylex DAC960 PCI RAID controller; second controller
0 = /dev/rd/c1d0 First disk, whole disk
8 = /dev/rd/c1d1 Second disk, whole disk
...
248 = /dev/rd/c1d31 32nd disk, whole disk
Partitions are handled as for major 48.
50 char Reserved for GLINT
50 block Mylex DAC960 PCI RAID controller; third controller
0 = /dev/rd/c2d0 First disk, whole disk
8 = /dev/rd/c2d1 Second disk, whole disk
...
248 = /dev/rd/c2d31 32nd disk, whole disk
51 char Baycom radio modem OR Radio Tech BIM-XXX-RS232 radio modem
0 = /dev/bc0 First Baycom radio modem
1 = /dev/bc1 Second Baycom radio modem
...
51 block Mylex DAC960 PCI RAID controller; fourth controller
0 = /dev/rd/c3d0 First disk, whole disk
8 = /dev/rd/c3d1 Second disk, whole disk
...
248 = /dev/rd/c3d31 32nd disk, whole disk
Partitions are handled as for major 48.
52 char Spellcaster DataComm/BRI ISDN card
0 = /dev/dcbri0 First DataComm card
1 = /dev/dcbri1 Second DataComm card
2 = /dev/dcbri2 Third DataComm card
3 = /dev/dcbri3 Fourth DataComm card
52 block Mylex DAC960 PCI RAID controller; fifth controller
0 = /dev/rd/c4d0 First disk, whole disk
8 = /dev/rd/c4d1 Second disk, whole disk
...
248 = /dev/rd/c4d31 32nd disk, whole disk
Partitions are handled as for major 48.
53 char BDM interface for remote debugging MC683xx microcontrollers
0 = /dev/pd_bdm0 PD BDM interface on lp0
1 = /dev/pd_bdm1 PD BDM interface on lp1
2 = /dev/pd_bdm2 PD BDM interface on lp2
4 = /dev/icd_bdm0 ICD BDM interface on lp0
5 = /dev/icd_bdm1 ICD BDM interface on lp1
6 = /dev/icd_bdm2 ICD BDM interface on lp2
This device is used for the interfacing to the MC683xx
microcontrollers via Background Debug Mode by use of a
Parallel Port interface. PD is the Motorola Public
Domain Interface and ICD is the commercial interface
by P&E.
53 block Mylex DAC960 PCI RAID controller; sixth controller
0 = /dev/rd/c5d0 First disk, whole disk
8 = /dev/rd/c5d1 Second disk, whole disk
...
248 = /dev/rd/c5d31 32nd disk, whole disk
Partitions are handled as for major 48.
54 char Electrocardiognosis Holter serial card
0 = /dev/holter0 First Holter port
1 = /dev/holter1 Second Holter port
2 = /dev/holter2 Third Holter port
A custom serial card used by Electrocardiognosis SRL
<mseritan@ottonel.pub.ro> to transfer data from Holter
24-hour heart monitoring equipment.
54 block Mylex DAC960 PCI RAID controller; seventh controller
0 = /dev/rd/c6d0 First disk, whole disk
8 = /dev/rd/c6d1 Second disk, whole disk
...
248 = /dev/rd/c6d31 32nd disk, whole disk
Partitions are handled as for major 48.
55 char DSP56001 digital signal processor
0 = /dev/dsp56k First DSP56001
55 block Mylex DAC960 PCI RAID controller; eighth controller
0 = /dev/rd/c7d0 First disk, whole disk
8 = /dev/rd/c7d1 Second disk, whole disk
...
248 = /dev/rd/c7d31 32nd disk, whole disk
Partitions are handled as for major 48.
56 char Apple Desktop Bus
0 = /dev/adb ADB bus control
Additional devices will be added to this number, all
starting with /dev/adb.
56 block Fifth IDE hard disk/CD-ROM interface
0 = /dev/hdi Master: whole disk (or CD-ROM)
64 = /dev/hdj Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
57 char Hayes ESP serial card
0 = /dev/ttyP0 First ESP port
1 = /dev/ttyP1 Second ESP port
...
57 block Sixth IDE hard disk/CD-ROM interface
0 = /dev/hdk Master: whole disk (or CD-ROM)
64 = /dev/hdl Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
58 char Hayes ESP serial card - alternate devices
0 = /dev/cup0 Callout device for ttyP0
1 = /dev/cup1 Callout device for ttyP1
...
58 block Reserved for logical volume manager
59 char sf firewall package
0 = /dev/firewall Communication with sf kernel module
59 block Generic PDA filesystem device
0 = /dev/pda0 First PDA device
1 = /dev/pda1 Second PDA device
...
The pda devices are used to mount filesystems on
remote pda's (basically slow handheld machines with
proprietary OS's and limited memory and storage
running small fs translation drivers) through serial /
IRDA / parallel links.
NAMING CONFLICT -- PROPOSED REVISED NAME /dev/rpda0 etc
60-63 char LOCAL/EXPERIMENTAL USE
60-63 block LOCAL/EXPERIMENTAL USE
Allocated for local/experimental use. For devices not
assigned official numbers, these ranges should be
used in order to avoid conflicting with future assignments.
64 char ENskip kernel encryption package
0 = /dev/enskip Communication with ENskip kernel module
64 block Scramdisk/DriveCrypt encrypted devices
0 = /dev/scramdisk/master Master node for ioctls
1 = /dev/scramdisk/1 First encrypted device
2 = /dev/scramdisk/2 Second encrypted device
...
255 = /dev/scramdisk/255 255th encrypted device
The filename of the encrypted container and the passwords
are sent via ioctls (using the sdmount tool) to the master
node which then activates them via one of the
/dev/scramdisk/x nodes for loop mounting (all handled
through the sdmount tool).
Requested by: andy@scramdisklinux.org
65 char Sundance "plink" Transputer boards (obsolete, unused)
0 = /dev/plink0 First plink device
1 = /dev/plink1 Second plink device
2 = /dev/plink2 Third plink device
3 = /dev/plink3 Fourth plink device
64 = /dev/rplink0 First plink device, raw
65 = /dev/rplink1 Second plink device, raw
66 = /dev/rplink2 Third plink device, raw
67 = /dev/rplink3 Fourth plink device, raw
128 = /dev/plink0d First plink device, debug
129 = /dev/plink1d Second plink device, debug
130 = /dev/plink2d Third plink device, debug
131 = /dev/plink3d Fourth plink device, debug
192 = /dev/rplink0d First plink device, raw, debug
193 = /dev/rplink1d Second plink device, raw, debug
194 = /dev/rplink2d Third plink device, raw, debug
195 = /dev/rplink3d Fourth plink device, raw, debug
This is a commercial driver; contact James Howes
<jth@prosig.demon.co.uk> for information.
65 block SCSI disk devices (16-31)
0 = /dev/sdq 17th SCSI disk whole disk
16 = /dev/sdr 18th SCSI disk whole disk
32 = /dev/sds 19th SCSI disk whole disk
...
240 = /dev/sdaf 32nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
66 char YARC PowerPC PCI coprocessor card
0 = /dev/yppcpci0 First YARC card
1 = /dev/yppcpci1 Second YARC card
...
66 block SCSI disk devices (32-47)
0 = /dev/sdag 33th SCSI disk whole disk
16 = /dev/sdah 34th SCSI disk whole disk
32 = /dev/sdai 35th SCSI disk whole disk
...
240 = /dev/sdav 48nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
67 char Coda network file system
0 = /dev/cfs0 Coda cache manager
See http://www.coda.cs.cmu.edu for information about Coda.
67 block SCSI disk devices (48-63)
0 = /dev/sdaw 49th SCSI disk whole disk
16 = /dev/sdax 50th SCSI disk whole disk
32 = /dev/sday 51st SCSI disk whole disk
...
240 = /dev/sdbl 64th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
68 char CAPI 2.0 interface
0 = /dev/capi20 Control device
1 = /dev/capi20.00 First CAPI 2.0 application
2 = /dev/capi20.01 Second CAPI 2.0 application
...
20 = /dev/capi20.19 19th CAPI 2.0 application
ISDN CAPI 2.0 driver for use with CAPI 2.0
applications; currently supports the AVM B1 card.
68 block SCSI disk devices (64-79)
0 = /dev/sdbm 65th SCSI disk whole disk
16 = /dev/sdbn 66th SCSI disk whole disk
32 = /dev/sdbo 67th SCSI disk whole disk
...
240 = /dev/sdcb 80th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
69 char MA16 numeric accelerator card
0 = /dev/ma16 Board memory access
69 block SCSI disk devices (80-95)
0 = /dev/sdcc 81st SCSI disk whole disk
16 = /dev/sdcd 82nd SCSI disk whole disk
32 = /dev/sdce 83th SCSI disk whole disk
...
240 = /dev/sdcr 96th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
70 char SpellCaster Protocol Services Interface
0 = /dev/apscfg Configuration interface
1 = /dev/apsauth Authentication interface
2 = /dev/apslog Logging interface
3 = /dev/apsdbg Debugging interface
64 = /dev/apsisdn ISDN command interface
65 = /dev/apsasync Async command interface
128 = /dev/apsmon Monitor interface
70 block SCSI disk devices (96-111)
0 = /dev/sdcs 97th SCSI disk whole disk
16 = /dev/sdct 98th SCSI disk whole disk
32 = /dev/sdcu 99th SCSI disk whole disk
...
240 = /dev/sddh 112nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
71 char Computone IntelliPort II serial card
0 = /dev/ttyF0 IntelliPort II board 0, port 0
1 = /dev/ttyF1 IntelliPort II board 0, port 1
...
63 = /dev/ttyF63 IntelliPort II board 0, port 63
64 = /dev/ttyF64 IntelliPort II board 1, port 0
65 = /dev/ttyF65 IntelliPort II board 1, port 1
...
127 = /dev/ttyF127 IntelliPort II board 1, port 63
128 = /dev/ttyF128 IntelliPort II board 2, port 0
129 = /dev/ttyF129 IntelliPort II board 2, port 1
...
191 = /dev/ttyF191 IntelliPort II board 2, port 63
192 = /dev/ttyF192 IntelliPort II board 3, port 0
193 = /dev/ttyF193 IntelliPort II board 3, port 1
...
255 = /dev/ttyF255 IntelliPort II board 3, port 63
71 block SCSI disk devices (112-127)
0 = /dev/sddi 113th SCSI disk whole disk
16 = /dev/sddj 114th SCSI disk whole disk
32 = /dev/sddk 115th SCSI disk whole disk
...
240 = /dev/sddx 128th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
72 char Computone IntelliPort II serial card - alternate devices
0 = /dev/cuf0 Callout device for ttyF0
1 = /dev/cuf1 Callout device for ttyF1
...
63 = /dev/cuf63 Callout device for ttyF63
64 = /dev/cuf64 Callout device for ttyF64
65 = /dev/cuf65 Callout device for ttyF65
...
127 = /dev/cuf127 Callout device for ttyF127
128 = /dev/cuf128 Callout device for ttyF128
129 = /dev/cuf129 Callout device for ttyF129
...
191 = /dev/cuf191 Callout device for ttyF191
192 = /dev/cuf192 Callout device for ttyF192
193 = /dev/cuf193 Callout device for ttyF193
...
255 = /dev/cuf255 Callout device for ttyF255
72 block Compaq Intelligent Drive Array, first controller
0 = /dev/ida/c0d0 First logical drive whole disk
16 = /dev/ida/c0d1 Second logical drive whole disk
...
240 = /dev/ida/c0d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
73 char Computone IntelliPort II serial card - control devices
0 = /dev/ip2ipl0 Loadware device for board 0
1 = /dev/ip2stat0 Status device for board 0
4 = /dev/ip2ipl1 Loadware device for board 1
5 = /dev/ip2stat1 Status device for board 1
8 = /dev/ip2ipl2 Loadware device for board 2
9 = /dev/ip2stat2 Status device for board 2
12 = /dev/ip2ipl3 Loadware device for board 3
13 = /dev/ip2stat3 Status device for board 3
73 block Compaq Intelligent Drive Array, second controller
0 = /dev/ida/c1d0 First logical drive whole disk
16 = /dev/ida/c1d1 Second logical drive whole disk
...
240 = /dev/ida/c1d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
74 char SCI bridge
0 = /dev/SCI/0 SCI device 0
1 = /dev/SCI/1 SCI device 1
...
Currently for Dolphin Interconnect Solutions' PCI-SCI
bridge.
74 block Compaq Intelligent Drive Array, third controller
0 = /dev/ida/c2d0 First logical drive whole disk
16 = /dev/ida/c2d1 Second logical drive whole disk
...
240 = /dev/ida/c2d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
75 char Specialix IO8+ serial card
0 = /dev/ttyW0 First IO8+ port, first card
1 = /dev/ttyW1 Second IO8+ port, first card
...
8 = /dev/ttyW8 First IO8+ port, second card
...
75 block Compaq Intelligent Drive Array, fourth controller
0 = /dev/ida/c3d0 First logical drive whole disk
16 = /dev/ida/c3d1 Second logical drive whole disk
...
240 = /dev/ida/c3d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
76 char Specialix IO8+ serial card - alternate devices
0 = /dev/cuw0 Callout device for ttyW0
1 = /dev/cuw1 Callout device for ttyW1
...
8 = /dev/cuw8 Callout device for ttyW8
...
76 block Compaq Intelligent Drive Array, fifth controller
0 = /dev/ida/c4d0 First logical drive whole disk
16 = /dev/ida/c4d1 Second logical drive whole disk
...
240 = /dev/ida/c4d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
77 char ComScire Quantum Noise Generator
0 = /dev/qng ComScire Quantum Noise Generator
77 block Compaq Intelligent Drive Array, sixth controller
0 = /dev/ida/c5d0 First logical drive whole disk
16 = /dev/ida/c5d1 Second logical drive whole disk
...
240 = /dev/ida/c5d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
78 char PAM Software's multimodem boards
0 = /dev/ttyM0 First PAM modem
1 = /dev/ttyM1 Second PAM modem
...
78 block Compaq Intelligent Drive Array, seventh controller
0 = /dev/ida/c6d0 First logical drive whole disk
16 = /dev/ida/c6d1 Second logical drive whole disk
...
240 = /dev/ida/c6d15 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
79 char PAM Software's multimodem boards - alternate devices
0 = /dev/cum0 Callout device for ttyM0
1 = /dev/cum1 Callout device for ttyM1
...
79 block Compaq Intelligent Drive Array, eighth controller
0 = /dev/ida/c7d0 First logical drive whole disk
16 = /dev/ida/c7d1 Second logical drive whole disk
...
240 = /dev/ida/c715 16th logical drive whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
80 char Photometrics AT200 CCD camera
0 = /dev/at200 Photometrics AT200 CCD camera
80 block I2O hard disk
0 = /dev/i2o/hda First I2O hard disk, whole disk
16 = /dev/i2o/hdb Second I2O hard disk, whole disk
...
240 = /dev/i2o/hdp 16th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
81 char video4linux
0 = /dev/video0 Video capture/overlay device
...
63 = /dev/video63 Video capture/overlay device
64 = /dev/radio0 Radio device
...
127 = /dev/radio63 Radio device
128 = /dev/swradio0 Software Defined Radio device
...
191 = /dev/swradio63 Software Defined Radio device
224 = /dev/vbi0 Vertical blank interrupt
...
255 = /dev/vbi31 Vertical blank interrupt
Minor numbers are allocated dynamically unless
CONFIG_VIDEO_FIXED_MINOR_RANGES (default n)
configuration option is set.
81 block I2O hard disk
0 = /dev/i2o/hdq 17th I2O hard disk, whole disk
16 = /dev/i2o/hdr 18th I2O hard disk, whole disk
...
240 = /dev/i2o/hdaf 32nd I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
82 char WiNRADiO communications receiver card
0 = /dev/winradio0 First WiNRADiO card
1 = /dev/winradio1 Second WiNRADiO card
...
The driver and documentation may be obtained from
http://www.winradio.com/
82 block I2O hard disk
0 = /dev/i2o/hdag 33rd I2O hard disk, whole disk
16 = /dev/i2o/hdah 34th I2O hard disk, whole disk
...
240 = /dev/i2o/hdav 48th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
83 char Matrox mga_vid video driver
0 = /dev/mga_vid0 1st video card
1 = /dev/mga_vid1 2nd video card
2 = /dev/mga_vid2 3rd video card
...
15 = /dev/mga_vid15 16th video card
83 block I2O hard disk
0 = /dev/i2o/hdaw 49th I2O hard disk, whole disk
16 = /dev/i2o/hdax 50th I2O hard disk, whole disk
...
240 = /dev/i2o/hdbl 64th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
84 char Ikon 1011[57] Versatec Greensheet Interface
0 = /dev/ihcp0 First Greensheet port
1 = /dev/ihcp1 Second Greensheet port
84 block I2O hard disk
0 = /dev/i2o/hdbm 65th I2O hard disk, whole disk
16 = /dev/i2o/hdbn 66th I2O hard disk, whole disk
...
240 = /dev/i2o/hdcb 80th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
85 char Linux/SGI shared memory input queue
0 = /dev/shmiq Master shared input queue
1 = /dev/qcntl0 First device pushed
2 = /dev/qcntl1 Second device pushed
...
85 block I2O hard disk
0 = /dev/i2o/hdcc 81st I2O hard disk, whole disk
16 = /dev/i2o/hdcd 82nd I2O hard disk, whole disk
...
240 = /dev/i2o/hdcr 96th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
86 char SCSI media changer
0 = /dev/sch0 First SCSI media changer
1 = /dev/sch1 Second SCSI media changer
...
86 block I2O hard disk
0 = /dev/i2o/hdcs 97th I2O hard disk, whole disk
16 = /dev/i2o/hdct 98th I2O hard disk, whole disk
...
240 = /dev/i2o/hddh 112th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
87 char Sony Control-A1 stereo control bus
0 = /dev/controla0 First device on chain
1 = /dev/controla1 Second device on chain
...
87 block I2O hard disk
0 = /dev/i2o/hddi 113rd I2O hard disk, whole disk
16 = /dev/i2o/hddj 114th I2O hard disk, whole disk
...
240 = /dev/i2o/hddx 128th I2O hard disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
88 char COMX synchronous serial card
0 = /dev/comx0 COMX channel 0
1 = /dev/comx1 COMX channel 1
...
88 block Seventh IDE hard disk/CD-ROM interface
0 = /dev/hdm Master: whole disk (or CD-ROM)
64 = /dev/hdn Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
89 char I2C bus interface
0 = /dev/i2c-0 First I2C adapter
1 = /dev/i2c-1 Second I2C adapter
...
89 block Eighth IDE hard disk/CD-ROM interface
0 = /dev/hdo Master: whole disk (or CD-ROM)
64 = /dev/hdp Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
90 char Memory Technology Device (RAM, ROM, Flash)
0 = /dev/mtd0 First MTD (rw)
1 = /dev/mtdr0 First MTD (ro)
...
30 = /dev/mtd15 16th MTD (rw)
31 = /dev/mtdr15 16th MTD (ro)
90 block Ninth IDE hard disk/CD-ROM interface
0 = /dev/hdq Master: whole disk (or CD-ROM)
64 = /dev/hdr Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
91 char CAN-Bus devices
0 = /dev/can0 First CAN-Bus controller
1 = /dev/can1 Second CAN-Bus controller
...
91 block Tenth IDE hard disk/CD-ROM interface
0 = /dev/hds Master: whole disk (or CD-ROM)
64 = /dev/hdt Slave: whole disk (or CD-ROM)
Partitions are handled the same way as for the first
interface (see major number 3).
92 char Reserved for ith Kommunikationstechnik MIC ISDN card
92 block PPDD encrypted disk driver
0 = /dev/ppdd0 First encrypted disk
1 = /dev/ppdd1 Second encrypted disk
...
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
93 char
93 block NAND Flash Translation Layer filesystem
0 = /dev/nftla First NFTL layer
16 = /dev/nftlb Second NFTL layer
...
240 = /dev/nftlp 16th NTFL layer
94 char
94 block IBM S/390 DASD block storage
0 = /dev/dasda First DASD device, major
1 = /dev/dasda1 First DASD device, block 1
2 = /dev/dasda2 First DASD device, block 2
3 = /dev/dasda3 First DASD device, block 3
4 = /dev/dasdb Second DASD device, major
5 = /dev/dasdb1 Second DASD device, block 1
6 = /dev/dasdb2 Second DASD device, block 2
7 = /dev/dasdb3 Second DASD device, block 3
...
95 char IP filter
0 = /dev/ipl Filter control device/log file
1 = /dev/ipnat NAT control device/log file
2 = /dev/ipstate State information log file
3 = /dev/ipauth Authentication control device/log file
...
96 char Parallel port ATAPI tape devices
0 = /dev/pt0 First parallel port ATAPI tape
1 = /dev/pt1 Second parallel port ATAPI tape
...
128 = /dev/npt0 First p.p. ATAPI tape, no rewind
129 = /dev/npt1 Second p.p. ATAPI tape, no rewind
...
96 block Inverse NAND Flash Translation Layer
0 = /dev/inftla First INFTL layer
16 = /dev/inftlb Second INFTL layer
...
240 = /dev/inftlp 16th INTFL layer
97 char Parallel port generic ATAPI interface
0 = /dev/pg0 First parallel port ATAPI device
1 = /dev/pg1 Second parallel port ATAPI device
2 = /dev/pg2 Third parallel port ATAPI device
3 = /dev/pg3 Fourth parallel port ATAPI device
These devices support the same API as the generic SCSI
devices.
98 char Control and Measurement Device (comedi)
0 = /dev/comedi0 First comedi device
1 = /dev/comedi1 Second comedi device
...
See http://stm.lbl.gov/comedi.
98 block User-mode virtual block device
0 = /dev/ubda First user-mode block device
16 = /dev/udbb Second user-mode block device
...
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
This device is used by the user-mode virtual kernel port.
99 char Raw parallel ports
0 = /dev/parport0 First parallel port
1 = /dev/parport1 Second parallel port
...
99 block JavaStation flash disk
0 = /dev/jsfd JavaStation flash disk
100 char Telephony for Linux
0 = /dev/phone0 First telephony device
1 = /dev/phone1 Second telephony device
...
101 char Motorola DSP 56xxx board
0 = /dev/mdspstat Status information
1 = /dev/mdsp1 First DSP board I/O controls
...
16 = /dev/mdsp16 16th DSP board I/O controls
101 block AMI HyperDisk RAID controller
0 = /dev/amiraid/ar0 First array whole disk
16 = /dev/amiraid/ar1 Second array whole disk
...
240 = /dev/amiraid/ar15 16th array whole disk
For each device, partitions are added as:
0 = /dev/amiraid/ar? Whole disk
1 = /dev/amiraid/ar?p1 First partition
2 = /dev/amiraid/ar?p2 Second partition
...
15 = /dev/amiraid/ar?p15 15th partition
102 char
102 block Compressed block device
0 = /dev/cbd/a First compressed block device, whole device
16 = /dev/cbd/b Second compressed block device, whole device
...
240 = /dev/cbd/p 16th compressed block device, whole device
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
103 char Arla network file system
0 = /dev/nnpfs0 First NNPFS device
1 = /dev/nnpfs1 Second NNPFS device
Arla is a free clone of the Andrew File System, AFS.
The NNPFS device gives user mode filesystem
implementations a kernel presence for caching and easy
mounting. For more information about the project,
write to <arla-drinkers@stacken.kth.se> or see
http://www.stacken.kth.se/project/arla/
103 block Audit device
0 = /dev/audit Audit device
104 char Flash BIOS support
104 block Compaq Next Generation Drive Array, first controller
0 = /dev/cciss/c0d0 First logical drive, whole disk
16 = /dev/cciss/c0d1 Second logical drive, whole disk
...
240 = /dev/cciss/c0d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
105 char Comtrol VS-1000 serial controller
0 = /dev/ttyV0 First VS-1000 port
1 = /dev/ttyV1 Second VS-1000 port
...
105 block Compaq Next Generation Drive Array, second controller
0 = /dev/cciss/c1d0 First logical drive, whole disk
16 = /dev/cciss/c1d1 Second logical drive, whole disk
...
240 = /dev/cciss/c1d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
106 char Comtrol VS-1000 serial controller - alternate devices
0 = /dev/cuv0 First VS-1000 port
1 = /dev/cuv1 Second VS-1000 port
...
106 block Compaq Next Generation Drive Array, third controller
0 = /dev/cciss/c2d0 First logical drive, whole disk
16 = /dev/cciss/c2d1 Second logical drive, whole disk
...
240 = /dev/cciss/c2d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
107 char 3Dfx Voodoo Graphics device
0 = /dev/3dfx Primary 3Dfx graphics device
107 block Compaq Next Generation Drive Array, fourth controller
0 = /dev/cciss/c3d0 First logical drive, whole disk
16 = /dev/cciss/c3d1 Second logical drive, whole disk
...
240 = /dev/cciss/c3d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
108 char Device independent PPP interface
0 = /dev/ppp Device independent PPP interface
108 block Compaq Next Generation Drive Array, fifth controller
0 = /dev/cciss/c4d0 First logical drive, whole disk
16 = /dev/cciss/c4d1 Second logical drive, whole disk
...
240 = /dev/cciss/c4d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
109 char Reserved for logical volume manager
109 block Compaq Next Generation Drive Array, sixth controller
0 = /dev/cciss/c5d0 First logical drive, whole disk
16 = /dev/cciss/c5d1 Second logical drive, whole disk
...
240 = /dev/cciss/c5d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
110 char miroMEDIA Surround board
0 = /dev/srnd0 First miroMEDIA Surround board
1 = /dev/srnd1 Second miroMEDIA Surround board
...
110 block Compaq Next Generation Drive Array, seventh controller
0 = /dev/cciss/c6d0 First logical drive, whole disk
16 = /dev/cciss/c6d1 Second logical drive, whole disk
...
240 = /dev/cciss/c6d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
111 char
111 block Compaq Next Generation Drive Array, eighth controller
0 = /dev/cciss/c7d0 First logical drive, whole disk
16 = /dev/cciss/c7d1 Second logical drive, whole disk
...
240 = /dev/cciss/c7d15 16th logical drive, whole disk
Partitions are handled the same way as for Mylex
DAC960 (see major number 48) except that the limit on
partitions is 15.
112 char ISI serial card
0 = /dev/ttyM0 First ISI port
1 = /dev/ttyM1 Second ISI port
...
There is currently a device-naming conflict between
these and PAM multimodems (major 78).
112 block IBM iSeries virtual disk
0 = /dev/iseries/vda First virtual disk, whole disk
8 = /dev/iseries/vdb Second virtual disk, whole disk
...
200 = /dev/iseries/vdz 26th virtual disk, whole disk
208 = /dev/iseries/vdaa 27th virtual disk, whole disk
...
248 = /dev/iseries/vdaf 32nd virtual disk, whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 7.
113 char ISI serial card - alternate devices
0 = /dev/cum0 Callout device for ttyM0
1 = /dev/cum1 Callout device for ttyM1
...
113 block IBM iSeries virtual CD-ROM
0 = /dev/iseries/vcda First virtual CD-ROM
1 = /dev/iseries/vcdb Second virtual CD-ROM
...
114 char Picture Elements ISE board
0 = /dev/ise0 First ISE board
1 = /dev/ise1 Second ISE board
...
128 = /dev/isex0 Control node for first ISE board
129 = /dev/isex1 Control node for second ISE board
...
The ISE board is an embedded computer, optimized for
image processing. The /dev/iseN nodes are the general
I/O access to the board, the /dev/isex0 nodes command
nodes used to control the board.
114 block IDE BIOS powered software RAID interfaces such as the
Promise Fastrak
0 = /dev/ataraid/d0
1 = /dev/ataraid/d0p1
2 = /dev/ataraid/d0p2
...
16 = /dev/ataraid/d1
17 = /dev/ataraid/d1p1
18 = /dev/ataraid/d1p2
...
255 = /dev/ataraid/d15p15
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
115 char TI link cable devices (115 was formerly the console driver speaker)
0 = /dev/tipar0 Parallel cable on first parallel port
...
7 = /dev/tipar7 Parallel cable on seventh parallel port
8 = /dev/tiser0 Serial cable on first serial port
...
15 = /dev/tiser7 Serial cable on seventh serial port
16 = /dev/tiusb0 First USB cable
...
47 = /dev/tiusb31 32nd USB cable
115 block NetWare (NWFS) Devices (0-255)
The NWFS (NetWare) devices are used to present a
collection of NetWare Mirror Groups or NetWare
Partitions as a logical storage segment for
use in mounting NetWare volumes. A maximum of
256 NetWare volumes can be supported in a single
machine.
http://cgfa.telepac.pt/ftp2/kernel.org/linux/kernel/people/jmerkey/nwfs/
0 = /dev/nwfs/v0 First NetWare (NWFS) Logical Volume
1 = /dev/nwfs/v1 Second NetWare (NWFS) Logical Volume
2 = /dev/nwfs/v2 Third NetWare (NWFS) Logical Volume
...
255 = /dev/nwfs/v255 Last NetWare (NWFS) Logical Volume
116 char Advanced Linux Sound Driver (ALSA)
116 block MicroMemory battery backed RAM adapter (NVRAM)
Supports 16 boards, 15 partitions each.
Requested by neilb at cse.unsw.edu.au.
0 = /dev/umem/d0 Whole of first board
1 = /dev/umem/d0p1 First partition of first board
2 = /dev/umem/d0p2 Second partition of first board
15 = /dev/umem/d0p15 15th partition of first board
16 = /dev/umem/d1 Whole of second board
17 = /dev/umem/d1p1 First partition of second board
...
255= /dev/umem/d15p15 15th partition of 16th board.
117 char COSA/SRP synchronous serial card
0 = /dev/cosa0c0 1st board, 1st channel
1 = /dev/cosa0c1 1st board, 2nd channel
...
16 = /dev/cosa1c0 2nd board, 1st channel
17 = /dev/cosa1c1 2nd board, 2nd channel
...
117 block Enterprise Volume Management System (EVMS)
The EVMS driver uses a layered, plug-in model to provide
unparalleled flexibility and extensibility in managing
storage. This allows for easy expansion or customization
of various levels of volume management. Requested by
Mark Peloquin (peloquin at us.ibm.com).
Note: EVMS populates and manages all the devnodes in
/dev/evms.
http://sf.net/projects/evms
0 = /dev/evms/block_device EVMS block device
1 = /dev/evms/legacyname1 First EVMS legacy device
2 = /dev/evms/legacyname2 Second EVMS legacy device
...
Both ranges can grow (down or up) until they meet.
...
254 = /dev/evms/EVMSname2 Second EVMS native device
255 = /dev/evms/EVMSname1 First EVMS native device
Note: legacyname(s) are derived from the normal legacy
device names. For example, /dev/hda5 would become
/dev/evms/hda5.
118 char IBM Cryptographic Accelerator
0 = /dev/ica Virtual interface to all IBM Crypto Accelerators
1 = /dev/ica0 IBMCA Device 0
2 = /dev/ica1 IBMCA Device 1
...
119 char VMware virtual network control
0 = /dev/vnet0 1st virtual network
1 = /dev/vnet1 2nd virtual network
...
120-127 char LOCAL/EXPERIMENTAL USE
120-127 block LOCAL/EXPERIMENTAL USE
Allocated for local/experimental use. For devices not
assigned official numbers, these ranges should be
used in order to avoid conflicting with future assignments.
128-135 char Unix98 PTY masters
These devices should not have corresponding device
nodes; instead they should be accessed through the
/dev/ptmx cloning interface.
128 block SCSI disk devices (128-143)
0 = /dev/sddy 129th SCSI disk whole disk
16 = /dev/sddz 130th SCSI disk whole disk
32 = /dev/sdea 131th SCSI disk whole disk
...
240 = /dev/sden 144th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
129 block SCSI disk devices (144-159)
0 = /dev/sdeo 145th SCSI disk whole disk
16 = /dev/sdep 146th SCSI disk whole disk
32 = /dev/sdeq 147th SCSI disk whole disk
...
240 = /dev/sdfd 160th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
130 char (Misc devices)
130 block SCSI disk devices (160-175)
0 = /dev/sdfe 161st SCSI disk whole disk
16 = /dev/sdff 162nd SCSI disk whole disk
32 = /dev/sdfg 163rd SCSI disk whole disk
...
240 = /dev/sdft 176th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
131 block SCSI disk devices (176-191)
0 = /dev/sdfu 177th SCSI disk whole disk
16 = /dev/sdfv 178th SCSI disk whole disk
32 = /dev/sdfw 179th SCSI disk whole disk
...
240 = /dev/sdgj 192nd SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
132 block SCSI disk devices (192-207)
0 = /dev/sdgk 193rd SCSI disk whole disk
16 = /dev/sdgl 194th SCSI disk whole disk
32 = /dev/sdgm 195th SCSI disk whole disk
...
240 = /dev/sdgz 208th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
133 block SCSI disk devices (208-223)
0 = /dev/sdha 209th SCSI disk whole disk
16 = /dev/sdhb 210th SCSI disk whole disk
32 = /dev/sdhc 211th SCSI disk whole disk
...
240 = /dev/sdhp 224th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
134 block SCSI disk devices (224-239)
0 = /dev/sdhq 225th SCSI disk whole disk
16 = /dev/sdhr 226th SCSI disk whole disk
32 = /dev/sdhs 227th SCSI disk whole disk
...
240 = /dev/sdif 240th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
135 block SCSI disk devices (240-255)
0 = /dev/sdig 241st SCSI disk whole disk
16 = /dev/sdih 242nd SCSI disk whole disk
32 = /dev/sdih 243rd SCSI disk whole disk
...
240 = /dev/sdiv 256th SCSI disk whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
136-143 char Unix98 PTY slaves
0 = /dev/pts/0 First Unix98 pseudo-TTY
1 = /dev/pts/1 Second Unix98 pseudo-TTY
...
These device nodes are automatically generated with
the proper permissions and modes by mounting the
devpts filesystem onto /dev/pts with the appropriate
mount options (distribution dependent, however, on
*most* distributions the appropriate options are
"mode=0620,gid=<gid of the "tty" group>".)
136 block Mylex DAC960 PCI RAID controller; ninth controller
0 = /dev/rd/c8d0 First disk, whole disk
8 = /dev/rd/c8d1 Second disk, whole disk
...
248 = /dev/rd/c8d31 32nd disk, whole disk
Partitions are handled as for major 48.
137 block Mylex DAC960 PCI RAID controller; tenth controller
0 = /dev/rd/c9d0 First disk, whole disk
8 = /dev/rd/c9d1 Second disk, whole disk
...
248 = /dev/rd/c9d31 32nd disk, whole disk
Partitions are handled as for major 48.
138 block Mylex DAC960 PCI RAID controller; eleventh controller
0 = /dev/rd/c10d0 First disk, whole disk
8 = /dev/rd/c10d1 Second disk, whole disk
...
248 = /dev/rd/c10d31 32nd disk, whole disk
Partitions are handled as for major 48.
139 block Mylex DAC960 PCI RAID controller; twelfth controller
0 = /dev/rd/c11d0 First disk, whole disk
8 = /dev/rd/c11d1 Second disk, whole disk
...
248 = /dev/rd/c11d31 32nd disk, whole disk
Partitions are handled as for major 48.
140 block Mylex DAC960 PCI RAID controller; thirteenth controller
0 = /dev/rd/c12d0 First disk, whole disk
8 = /dev/rd/c12d1 Second disk, whole disk
...
248 = /dev/rd/c12d31 32nd disk, whole disk
Partitions are handled as for major 48.
141 block Mylex DAC960 PCI RAID controller; fourteenth controller
0 = /dev/rd/c13d0 First disk, whole disk
8 = /dev/rd/c13d1 Second disk, whole disk
...
248 = /dev/rd/c13d31 32nd disk, whole disk
Partitions are handled as for major 48.
142 block Mylex DAC960 PCI RAID controller; fifteenth controller
0 = /dev/rd/c14d0 First disk, whole disk
8 = /dev/rd/c14d1 Second disk, whole disk
...
248 = /dev/rd/c14d31 32nd disk, whole disk
Partitions are handled as for major 48.
143 block Mylex DAC960 PCI RAID controller; sixteenth controller
0 = /dev/rd/c15d0 First disk, whole disk
8 = /dev/rd/c15d1 Second disk, whole disk
...
248 = /dev/rd/c15d31 32nd disk, whole disk
Partitions are handled as for major 48.
144 char Encapsulated PPP
0 = /dev/pppox0 First PPP over Ethernet
...
63 = /dev/pppox63 64th PPP over Ethernet
This is primarily used for ADSL.
The SST 5136-DN DeviceNet interface driver has been
relocated to major 183 due to an unfortunate conflict.
144 block Expansion Area #1 for more non-device (e.g. NFS) mounts
0 = mounted device 256
255 = mounted device 511
145 char SAM9407-based soundcard
0 = /dev/sam0_mixer
1 = /dev/sam0_sequencer
2 = /dev/sam0_midi00
3 = /dev/sam0_dsp
4 = /dev/sam0_audio
6 = /dev/sam0_sndstat
18 = /dev/sam0_midi01
34 = /dev/sam0_midi02
50 = /dev/sam0_midi03
64 = /dev/sam1_mixer
...
128 = /dev/sam2_mixer
...
192 = /dev/sam3_mixer
...
Device functions match OSS, but offer a number of
addons, which are sam9407 specific. OSS can be
operated simultaneously, taking care of the codec.
145 block Expansion Area #2 for more non-device (e.g. NFS) mounts
0 = mounted device 512
255 = mounted device 767
146 char SYSTRAM SCRAMNet mirrored-memory network
0 = /dev/scramnet0 First SCRAMNet device
1 = /dev/scramnet1 Second SCRAMNet device
...
146 block Expansion Area #3 for more non-device (e.g. NFS) mounts
0 = mounted device 768
255 = mounted device 1023
147 char Aureal Semiconductor Vortex Audio device
0 = /dev/aureal0 First Aureal Vortex
1 = /dev/aureal1 Second Aureal Vortex
...
147 block Distributed Replicated Block Device (DRBD)
0 = /dev/drbd0 First DRBD device
1 = /dev/drbd1 Second DRBD device
...
148 char Technology Concepts serial card
0 = /dev/ttyT0 First TCL port
1 = /dev/ttyT1 Second TCL port
...
149 char Technology Concepts serial card - alternate devices
0 = /dev/cut0 Callout device for ttyT0
1 = /dev/cut0 Callout device for ttyT1
...
150 char Real-Time Linux FIFOs
0 = /dev/rtf0 First RTLinux FIFO
1 = /dev/rtf1 Second RTLinux FIFO
...
151 char DPT I2O SmartRaid V controller
0 = /dev/dpti0 First DPT I2O adapter
1 = /dev/dpti1 Second DPT I2O adapter
...
152 char EtherDrive Control Device
0 = /dev/etherd/ctl Connect/Disconnect an EtherDrive
1 = /dev/etherd/err Monitor errors
2 = /dev/etherd/raw Raw AoE packet monitor
152 block EtherDrive Block Devices
0 = /dev/etherd/0 EtherDrive 0
...
255 = /dev/etherd/255 EtherDrive 255
153 char SPI Bus Interface (sometimes referred to as MicroWire)
0 = /dev/spi0 First SPI device on the bus
1 = /dev/spi1 Second SPI device on the bus
...
15 = /dev/spi15 Sixteenth SPI device on the bus
153 block Enhanced Metadisk RAID (EMD) storage units
0 = /dev/emd/0 First unit
1 = /dev/emd/0p1 Partition 1 on First unit
2 = /dev/emd/0p2 Partition 2 on First unit
...
15 = /dev/emd/0p15 Partition 15 on First unit
16 = /dev/emd/1 Second unit
32 = /dev/emd/2 Third unit
...
240 = /dev/emd/15 Sixteenth unit
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
154 char Specialix RIO serial card
0 = /dev/ttySR0 First RIO port
...
255 = /dev/ttySR255 256th RIO port
155 char Specialix RIO serial card - alternate devices
0 = /dev/cusr0 Callout device for ttySR0
...
255 = /dev/cusr255 Callout device for ttySR255
156 char Specialix RIO serial card
0 = /dev/ttySR256 257th RIO port
...
255 = /dev/ttySR511 512th RIO port
157 char Specialix RIO serial card - alternate devices
0 = /dev/cusr256 Callout device for ttySR256
...
255 = /dev/cusr511 Callout device for ttySR511
158 char Dialogic GammaLink fax driver
0 = /dev/gfax0 GammaLink channel 0
1 = /dev/gfax1 GammaLink channel 1
...
159 char RESERVED
159 block RESERVED
160 char General Purpose Instrument Bus (GPIB)
0 = /dev/gpib0 First GPIB bus
1 = /dev/gpib1 Second GPIB bus
...
160 block Carmel 8-port SATA Disks on First Controller
0 = /dev/carmel/0 SATA disk 0 whole disk
1 = /dev/carmel/0p1 SATA disk 0 partition 1
...
31 = /dev/carmel/0p31 SATA disk 0 partition 31
32 = /dev/carmel/1 SATA disk 1 whole disk
64 = /dev/carmel/2 SATA disk 2 whole disk
...
224 = /dev/carmel/7 SATA disk 7 whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 31.
161 char IrCOMM devices (IrDA serial/parallel emulation)
0 = /dev/ircomm0 First IrCOMM device
1 = /dev/ircomm1 Second IrCOMM device
...
16 = /dev/irlpt0 First IrLPT device
17 = /dev/irlpt1 Second IrLPT device
...
161 block Carmel 8-port SATA Disks on Second Controller
0 = /dev/carmel/8 SATA disk 8 whole disk
1 = /dev/carmel/8p1 SATA disk 8 partition 1
...
31 = /dev/carmel/8p31 SATA disk 8 partition 31
32 = /dev/carmel/9 SATA disk 9 whole disk
64 = /dev/carmel/10 SATA disk 10 whole disk
...
224 = /dev/carmel/15 SATA disk 15 whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 31.
162 char Raw block device interface
0 = /dev/rawctl Raw I/O control device
1 = /dev/raw/raw1 First raw I/O device
2 = /dev/raw/raw2 Second raw I/O device
...
max minor number of raw device is set by kernel config
MAX_RAW_DEVS or raw module parameter 'max_raw_devs'
163 char
164 char Chase Research AT/PCI-Fast serial card
0 = /dev/ttyCH0 AT/PCI-Fast board 0, port 0
...
15 = /dev/ttyCH15 AT/PCI-Fast board 0, port 15
16 = /dev/ttyCH16 AT/PCI-Fast board 1, port 0
...
31 = /dev/ttyCH31 AT/PCI-Fast board 1, port 15
32 = /dev/ttyCH32 AT/PCI-Fast board 2, port 0
...
47 = /dev/ttyCH47 AT/PCI-Fast board 2, port 15
48 = /dev/ttyCH48 AT/PCI-Fast board 3, port 0
...
63 = /dev/ttyCH63 AT/PCI-Fast board 3, port 15
165 char Chase Research AT/PCI-Fast serial card - alternate devices
0 = /dev/cuch0 Callout device for ttyCH0
...
63 = /dev/cuch63 Callout device for ttyCH63
166 char ACM USB modems
0 = /dev/ttyACM0 First ACM modem
1 = /dev/ttyACM1 Second ACM modem
...
167 char ACM USB modems - alternate devices
0 = /dev/cuacm0 Callout device for ttyACM0
1 = /dev/cuacm1 Callout device for ttyACM1
...
168 char Eracom CSA7000 PCI encryption adaptor
0 = /dev/ecsa0 First CSA7000
1 = /dev/ecsa1 Second CSA7000
...
169 char Eracom CSA8000 PCI encryption adaptor
0 = /dev/ecsa8-0 First CSA8000
1 = /dev/ecsa8-1 Second CSA8000
...
170 char AMI MegaRAC remote access controller
0 = /dev/megarac0 First MegaRAC card
1 = /dev/megarac1 Second MegaRAC card
...
171 char Reserved for IEEE 1394 (Firewire)
172 char Moxa Intellio serial card
0 = /dev/ttyMX0 First Moxa port
1 = /dev/ttyMX1 Second Moxa port
...
127 = /dev/ttyMX127 128th Moxa port
128 = /dev/moxactl Moxa control port
173 char Moxa Intellio serial card - alternate devices
0 = /dev/cumx0 Callout device for ttyMX0
1 = /dev/cumx1 Callout device for ttyMX1
...
127 = /dev/cumx127 Callout device for ttyMX127
174 char SmartIO serial card
0 = /dev/ttySI0 First SmartIO port
1 = /dev/ttySI1 Second SmartIO port
...
175 char SmartIO serial card - alternate devices
0 = /dev/cusi0 Callout device for ttySI0
1 = /dev/cusi1 Callout device for ttySI1
...
176 char nCipher nFast PCI crypto accelerator
0 = /dev/nfastpci0 First nFast PCI device
1 = /dev/nfastpci1 First nFast PCI device
...
177 char TI PCILynx memory spaces
0 = /dev/pcilynx/aux0 AUX space of first PCILynx card
...
15 = /dev/pcilynx/aux15 AUX space of 16th PCILynx card
16 = /dev/pcilynx/rom0 ROM space of first PCILynx card
...
31 = /dev/pcilynx/rom15 ROM space of 16th PCILynx card
32 = /dev/pcilynx/ram0 RAM space of first PCILynx card
...
47 = /dev/pcilynx/ram15 RAM space of 16th PCILynx card
178 char Giganet cLAN1xxx virtual interface adapter
0 = /dev/clanvi0 First cLAN adapter
1 = /dev/clanvi1 Second cLAN adapter
...
179 block MMC block devices
0 = /dev/mmcblk0 First SD/MMC card
1 = /dev/mmcblk0p1 First partition on first MMC card
8 = /dev/mmcblk1 Second SD/MMC card
...
The start of next SD/MMC card can be configured with
CONFIG_MMC_BLOCK_MINORS, or overridden at boot/modprobe
time using the mmcblk.perdev_minors option. That would
bump the offset between each card to be the configured
value instead of the default 8.
179 char CCube DVXChip-based PCI products
0 = /dev/dvxirq0 First DVX device
1 = /dev/dvxirq1 Second DVX device
...
180 char USB devices
0 = /dev/usb/lp0 First USB printer
...
15 = /dev/usb/lp15 16th USB printer
48 = /dev/usb/scanner0 First USB scanner
...
63 = /dev/usb/scanner15 16th USB scanner
64 = /dev/usb/rio500 Diamond Rio 500
65 = /dev/usb/usblcd USBLCD Interface (info@usblcd.de)
66 = /dev/usb/cpad0 Synaptics cPad (mouse/LCD)
96 = /dev/usb/hiddev0 1st USB HID device
...
111 = /dev/usb/hiddev15 16th USB HID device
112 = /dev/usb/auer0 1st auerswald ISDN device
...
127 = /dev/usb/auer15 16th auerswald ISDN device
128 = /dev/usb/brlvgr0 First Braille Voyager device
...
131 = /dev/usb/brlvgr3 Fourth Braille Voyager device
132 = /dev/usb/idmouse ID Mouse (fingerprint scanner) device
133 = /dev/usb/sisusbvga1 First SiSUSB VGA device
...
140 = /dev/usb/sisusbvga8 Eighth SISUSB VGA device
144 = /dev/usb/lcd USB LCD device
160 = /dev/usb/legousbtower0 1st USB Legotower device
...
175 = /dev/usb/legousbtower15 16th USB Legotower device
176 = /dev/usb/usbtmc1 First USB TMC device
...
191 = /dev/usb/usbtmc16 16th USB TMC device
192 = /dev/usb/yurex1 First USB Yurex device
...
209 = /dev/usb/yurex16 16th USB Yurex device
180 block USB block devices
0 = /dev/uba First USB block device
8 = /dev/ubb Second USB block device
16 = /dev/ubc Third USB block device
...
181 char Conrad Electronic parallel port radio clocks
0 = /dev/pcfclock0 First Conrad radio clock
1 = /dev/pcfclock1 Second Conrad radio clock
...
182 char Picture Elements THR2 binarizer
0 = /dev/pethr0 First THR2 board
1 = /dev/pethr1 Second THR2 board
...
183 char SST 5136-DN DeviceNet interface
0 = /dev/ss5136dn0 First DeviceNet interface
1 = /dev/ss5136dn1 Second DeviceNet interface
...
This device used to be assigned to major number 144.
It had to be moved due to an unfortunate conflict.
184 char Picture Elements' video simulator/sender
0 = /dev/pevss0 First sender board
1 = /dev/pevss1 Second sender board
...
185 char InterMezzo high availability file system
0 = /dev/intermezzo0 First cache manager
1 = /dev/intermezzo1 Second cache manager
...
See http://web.archive.org/web/20080115195241/
http://inter-mezzo.org/index.html
186 char Object-based storage control device
0 = /dev/obd0 First obd control device
1 = /dev/obd1 Second obd control device
...
See ftp://ftp.lustre.org/pub/obd for code and information.
187 char DESkey hardware encryption device
0 = /dev/deskey0 First DES key
1 = /dev/deskey1 Second DES key
...
188 char USB serial converters
0 = /dev/ttyUSB0 First USB serial converter
1 = /dev/ttyUSB1 Second USB serial converter
...
189 char USB serial converters - alternate devices
0 = /dev/cuusb0 Callout device for ttyUSB0
1 = /dev/cuusb1 Callout device for ttyUSB1
...
190 char Kansas City tracker/tuner card
0 = /dev/kctt0 First KCT/T card
1 = /dev/kctt1 Second KCT/T card
...
191 char Reserved for PCMCIA
192 char Kernel profiling interface
0 = /dev/profile Profiling control device
1 = /dev/profile0 Profiling device for CPU 0
2 = /dev/profile1 Profiling device for CPU 1
...
193 char Kernel event-tracing interface
0 = /dev/trace Tracing control device
1 = /dev/trace0 Tracing device for CPU 0
2 = /dev/trace1 Tracing device for CPU 1
...
194 char linVideoStreams (LINVS)
0 = /dev/mvideo/status0 Video compression status
1 = /dev/mvideo/stream0 Video stream
2 = /dev/mvideo/frame0 Single compressed frame
3 = /dev/mvideo/rawframe0 Raw uncompressed frame
4 = /dev/mvideo/codec0 Direct codec access
5 = /dev/mvideo/video4linux0 Video4Linux compatibility
16 = /dev/mvideo/status1 Second device
...
32 = /dev/mvideo/status2 Third device
...
...
240 = /dev/mvideo/status15 16th device
...
195 char Nvidia graphics devices
0 = /dev/nvidia0 First Nvidia card
1 = /dev/nvidia1 Second Nvidia card
...
255 = /dev/nvidiactl Nvidia card control device
196 char Tormenta T1 card
0 = /dev/tor/0 Master control channel for all cards
1 = /dev/tor/1 First DS0
2 = /dev/tor/2 Second DS0
...
48 = /dev/tor/48 48th DS0
49 = /dev/tor/49 First pseudo-channel
50 = /dev/tor/50 Second pseudo-channel
...
197 char OpenTNF tracing facility
0 = /dev/tnf/t0 Trace 0 data extraction
1 = /dev/tnf/t1 Trace 1 data extraction
...
128 = /dev/tnf/status Tracing facility status
130 = /dev/tnf/trace Tracing device
198 char Total Impact TPMP2 quad coprocessor PCI card
0 = /dev/tpmp2/0 First card
1 = /dev/tpmp2/1 Second card
...
199 char Veritas volume manager (VxVM) volumes
0 = /dev/vx/rdsk/*/* First volume
1 = /dev/vx/rdsk/*/* Second volume
...
199 block Veritas volume manager (VxVM) volumes
0 = /dev/vx/dsk/*/* First volume
1 = /dev/vx/dsk/*/* Second volume
...
The namespace in these directories is maintained by
the user space VxVM software.
200 char Veritas VxVM configuration interface
0 = /dev/vx/config Configuration access node
1 = /dev/vx/trace Volume i/o trace access node
2 = /dev/vx/iod Volume i/o daemon access node
3 = /dev/vx/info Volume information access node
4 = /dev/vx/task Volume tasks access node
5 = /dev/vx/taskmon Volume tasks monitor daemon
201 char Veritas VxVM dynamic multipathing driver
0 = /dev/vx/rdmp/* First multipath device
1 = /dev/vx/rdmp/* Second multipath device
...
201 block Veritas VxVM dynamic multipathing driver
0 = /dev/vx/dmp/* First multipath device
1 = /dev/vx/dmp/* Second multipath device
...
The namespace in these directories is maintained by
the user space VxVM software.
202 char CPU model-specific registers
0 = /dev/cpu/0/msr MSRs on CPU 0
1 = /dev/cpu/1/msr MSRs on CPU 1
...
202 block Xen Virtual Block Device
0 = /dev/xvda First Xen VBD whole disk
16 = /dev/xvdb Second Xen VBD whole disk
32 = /dev/xvdc Third Xen VBD whole disk
...
240 = /dev/xvdp Sixteenth Xen VBD whole disk
Partitions are handled in the same way as for IDE
disks (see major number 3) except that the limit on
partitions is 15.
203 char CPU CPUID information
0 = /dev/cpu/0/cpuid CPUID on CPU 0
1 = /dev/cpu/1/cpuid CPUID on CPU 1
...
204 char Low-density serial ports
0 = /dev/ttyLU0 LinkUp Systems L72xx UART - port 0
1 = /dev/ttyLU1 LinkUp Systems L72xx UART - port 1
2 = /dev/ttyLU2 LinkUp Systems L72xx UART - port 2
3 = /dev/ttyLU3 LinkUp Systems L72xx UART - port 3
4 = /dev/ttyFB0 Intel Footbridge (ARM)
5 = /dev/ttySA0 StrongARM builtin serial port 0
6 = /dev/ttySA1 StrongARM builtin serial port 1
7 = /dev/ttySA2 StrongARM builtin serial port 2
8 = /dev/ttySC0 SCI serial port (SuperH) - port 0
9 = /dev/ttySC1 SCI serial port (SuperH) - port 1
10 = /dev/ttySC2 SCI serial port (SuperH) - port 2
11 = /dev/ttySC3 SCI serial port (SuperH) - port 3
12 = /dev/ttyFW0 Firmware console - port 0
13 = /dev/ttyFW1 Firmware console - port 1
14 = /dev/ttyFW2 Firmware console - port 2
15 = /dev/ttyFW3 Firmware console - port 3
16 = /dev/ttyAM0 ARM "AMBA" serial port 0
...
31 = /dev/ttyAM15 ARM "AMBA" serial port 15
32 = /dev/ttyDB0 DataBooster serial port 0
...
39 = /dev/ttyDB7 DataBooster serial port 7
40 = /dev/ttySG0 SGI Altix console port
41 = /dev/ttySMX0 Motorola i.MX - port 0
42 = /dev/ttySMX1 Motorola i.MX - port 1
43 = /dev/ttySMX2 Motorola i.MX - port 2
44 = /dev/ttyMM0 Marvell MPSC - port 0
45 = /dev/ttyMM1 Marvell MPSC - port 1
46 = /dev/ttyCPM0 PPC CPM (SCC or SMC) - port 0
...
47 = /dev/ttyCPM5 PPC CPM (SCC or SMC) - port 5
50 = /dev/ttyIOC0 Altix serial card
...
81 = /dev/ttyIOC31 Altix serial card
82 = /dev/ttyVR0 NEC VR4100 series SIU
83 = /dev/ttyVR1 NEC VR4100 series DSIU
84 = /dev/ttyIOC84 Altix ioc4 serial card
...
115 = /dev/ttyIOC115 Altix ioc4 serial card
116 = /dev/ttySIOC0 Altix ioc3 serial card
...
147 = /dev/ttySIOC31 Altix ioc3 serial card
148 = /dev/ttyPSC0 PPC PSC - port 0
...
153 = /dev/ttyPSC5 PPC PSC - port 5
154 = /dev/ttyAT0 ATMEL serial port 0
...
169 = /dev/ttyAT15 ATMEL serial port 15
170 = /dev/ttyNX0 Hilscher netX serial port 0
...
185 = /dev/ttyNX15 Hilscher netX serial port 15
186 = /dev/ttyJ0 JTAG1 DCC protocol based serial port emulation
187 = /dev/ttyUL0 Xilinx uartlite - port 0
...
190 = /dev/ttyUL3 Xilinx uartlite - port 3
191 = /dev/xvc0 Xen virtual console - port 0
192 = /dev/ttyPZ0 pmac_zilog - port 0
...
195 = /dev/ttyPZ3 pmac_zilog - port 3
196 = /dev/ttyTX0 TX39/49 serial port 0
...
204 = /dev/ttyTX7 TX39/49 serial port 7
205 = /dev/ttySC0 SC26xx serial port 0
206 = /dev/ttySC1 SC26xx serial port 1
207 = /dev/ttySC2 SC26xx serial port 2
208 = /dev/ttySC3 SC26xx serial port 3
209 = /dev/ttyMAX0 MAX3100 serial port 0
210 = /dev/ttyMAX1 MAX3100 serial port 1
211 = /dev/ttyMAX2 MAX3100 serial port 2
212 = /dev/ttyMAX3 MAX3100 serial port 3
205 char Low-density serial ports (alternate device)
0 = /dev/culu0 Callout device for ttyLU0
1 = /dev/culu1 Callout device for ttyLU1
2 = /dev/culu2 Callout device for ttyLU2
3 = /dev/culu3 Callout device for ttyLU3
4 = /dev/cufb0 Callout device for ttyFB0
5 = /dev/cusa0 Callout device for ttySA0
6 = /dev/cusa1 Callout device for ttySA1
7 = /dev/cusa2 Callout device for ttySA2
8 = /dev/cusc0 Callout device for ttySC0
9 = /dev/cusc1 Callout device for ttySC1
10 = /dev/cusc2 Callout device for ttySC2
11 = /dev/cusc3 Callout device for ttySC3
12 = /dev/cufw0 Callout device for ttyFW0
13 = /dev/cufw1 Callout device for ttyFW1
14 = /dev/cufw2 Callout device for ttyFW2
15 = /dev/cufw3 Callout device for ttyFW3
16 = /dev/cuam0 Callout device for ttyAM0
...
31 = /dev/cuam15 Callout device for ttyAM15
32 = /dev/cudb0 Callout device for ttyDB0
...
39 = /dev/cudb7 Callout device for ttyDB7
40 = /dev/cusg0 Callout device for ttySG0
41 = /dev/ttycusmx0 Callout device for ttySMX0
42 = /dev/ttycusmx1 Callout device for ttySMX1
43 = /dev/ttycusmx2 Callout device for ttySMX2
46 = /dev/cucpm0 Callout device for ttyCPM0
...
49 = /dev/cucpm5 Callout device for ttyCPM5
50 = /dev/cuioc40 Callout device for ttyIOC40
...
81 = /dev/cuioc431 Callout device for ttyIOC431
82 = /dev/cuvr0 Callout device for ttyVR0
83 = /dev/cuvr1 Callout device for ttyVR1
206 char OnStream SC-x0 tape devices
0 = /dev/osst0 First OnStream SCSI tape, mode 0
1 = /dev/osst1 Second OnStream SCSI tape, mode 0
...
32 = /dev/osst0l First OnStream SCSI tape, mode 1
33 = /dev/osst1l Second OnStream SCSI tape, mode 1
...
64 = /dev/osst0m First OnStream SCSI tape, mode 2
65 = /dev/osst1m Second OnStream SCSI tape, mode 2
...
96 = /dev/osst0a First OnStream SCSI tape, mode 3
97 = /dev/osst1a Second OnStream SCSI tape, mode 3
...
128 = /dev/nosst0 No rewind version of /dev/osst0
129 = /dev/nosst1 No rewind version of /dev/osst1
...
160 = /dev/nosst0l No rewind version of /dev/osst0l
161 = /dev/nosst1l No rewind version of /dev/osst1l
...
192 = /dev/nosst0m No rewind version of /dev/osst0m
193 = /dev/nosst1m No rewind version of /dev/osst1m
...
224 = /dev/nosst0a No rewind version of /dev/osst0a
225 = /dev/nosst1a No rewind version of /dev/osst1a
...
The OnStream SC-x0 SCSI tapes do not support the
standard SCSI SASD command set and therefore need
their own driver "osst". Note that the IDE, USB (and
maybe ParPort) versions may be driven via ide-scsi or
usb-storage SCSI emulation and this osst device and
driver as well. The ADR-x0 drives are QIC-157
compliant and don't need osst.
207 char Compaq ProLiant health feature indicate
0 = /dev/cpqhealth/cpqw Redirector interface
1 = /dev/cpqhealth/crom EISA CROM
2 = /dev/cpqhealth/cdt Data Table
3 = /dev/cpqhealth/cevt Event Log
4 = /dev/cpqhealth/casr Automatic Server Recovery
5 = /dev/cpqhealth/cecc ECC Memory
6 = /dev/cpqhealth/cmca Machine Check Architecture
7 = /dev/cpqhealth/ccsm Deprecated CDT
8 = /dev/cpqhealth/cnmi NMI Handling
9 = /dev/cpqhealth/css Sideshow Management
10 = /dev/cpqhealth/cram CMOS interface
11 = /dev/cpqhealth/cpci PCI IRQ interface
208 char User space serial ports
0 = /dev/ttyU0 First user space serial port
1 = /dev/ttyU1 Second user space serial port
...
209 char User space serial ports (alternate devices)
0 = /dev/cuu0 Callout device for ttyU0
1 = /dev/cuu1 Callout device for ttyU1
...
210 char SBE, Inc. sync/async serial card
0 = /dev/sbei/wxcfg0 Configuration device for board 0
1 = /dev/sbei/dld0 Download device for board 0
2 = /dev/sbei/wan00 WAN device, port 0, board 0
3 = /dev/sbei/wan01 WAN device, port 1, board 0
4 = /dev/sbei/wan02 WAN device, port 2, board 0
5 = /dev/sbei/wan03 WAN device, port 3, board 0
6 = /dev/sbei/wanc00 WAN clone device, port 0, board 0
7 = /dev/sbei/wanc01 WAN clone device, port 1, board 0
8 = /dev/sbei/wanc02 WAN clone device, port 2, board 0
9 = /dev/sbei/wanc03 WAN clone device, port 3, board 0
10 = /dev/sbei/wxcfg1 Configuration device for board 1
11 = /dev/sbei/dld1 Download device for board 1
12 = /dev/sbei/wan10 WAN device, port 0, board 1
13 = /dev/sbei/wan11 WAN device, port 1, board 1
14 = /dev/sbei/wan12 WAN device, port 2, board 1
15 = /dev/sbei/wan13 WAN device, port 3, board 1
16 = /dev/sbei/wanc10 WAN clone device, port 0, board 1
17 = /dev/sbei/wanc11 WAN clone device, port 1, board 1
18 = /dev/sbei/wanc12 WAN clone device, port 2, board 1
19 = /dev/sbei/wanc13 WAN clone device, port 3, board 1
...
Yes, each board is really spaced 10 (decimal) apart.
211 char Addinum CPCI1500 digital I/O card
0 = /dev/addinum/cpci1500/0 First CPCI1500 card
1 = /dev/addinum/cpci1500/1 Second CPCI1500 card
...
212 char LinuxTV.org DVB driver subsystem
0 = /dev/dvb/adapter0/video0 first video decoder of first card
1 = /dev/dvb/adapter0/audio0 first audio decoder of first card
2 = /dev/dvb/adapter0/sec0 (obsolete/unused)
3 = /dev/dvb/adapter0/frontend0 first frontend device of first card
4 = /dev/dvb/adapter0/demux0 first demux device of first card
5 = /dev/dvb/adapter0/dvr0 first digital video recoder device of first card
6 = /dev/dvb/adapter0/ca0 first common access port of first card
7 = /dev/dvb/adapter0/net0 first network device of first card
8 = /dev/dvb/adapter0/osd0 first on-screen-display device of first card
9 = /dev/dvb/adapter0/video1 second video decoder of first card
...
64 = /dev/dvb/adapter1/video0 first video decoder of second card
...
128 = /dev/dvb/adapter2/video0 first video decoder of third card
...
196 = /dev/dvb/adapter3/video0 first video decoder of fourth card
216 char Bluetooth RFCOMM TTY devices
0 = /dev/rfcomm0 First Bluetooth RFCOMM TTY device
1 = /dev/rfcomm1 Second Bluetooth RFCOMM TTY device
...
217 char Bluetooth RFCOMM TTY devices (alternate devices)
0 = /dev/curf0 Callout device for rfcomm0
1 = /dev/curf1 Callout device for rfcomm1
...
218 char The Logical Company bus Unibus/Qbus adapters
0 = /dev/logicalco/bci/0 First bus adapter
1 = /dev/logicalco/bci/1 First bus adapter
...
219 char The Logical Company DCI-1300 digital I/O card
0 = /dev/logicalco/dci1300/0 First DCI-1300 card
1 = /dev/logicalco/dci1300/1 Second DCI-1300 card
...
220 char Myricom Myrinet "GM" board
0 = /dev/myricom/gm0 First Myrinet GM board
1 = /dev/myricom/gmp0 First board "root access"
2 = /dev/myricom/gm1 Second Myrinet GM board
3 = /dev/myricom/gmp1 Second board "root access"
...
221 char VME bus
0 = /dev/bus/vme/m0 First master image
1 = /dev/bus/vme/m1 Second master image
2 = /dev/bus/vme/m2 Third master image
3 = /dev/bus/vme/m3 Fourth master image
4 = /dev/bus/vme/s0 First slave image
5 = /dev/bus/vme/s1 Second slave image
6 = /dev/bus/vme/s2 Third slave image
7 = /dev/bus/vme/s3 Fourth slave image
8 = /dev/bus/vme/ctl Control
It is expected that all VME bus drivers will use the
same interface. For interface documentation see
http://www.vmelinux.org/.
224 char A2232 serial card
0 = /dev/ttyY0 First A2232 port
1 = /dev/ttyY1 Second A2232 port
...
225 char A2232 serial card (alternate devices)
0 = /dev/cuy0 Callout device for ttyY0
1 = /dev/cuy1 Callout device for ttyY1
...
226 char Direct Rendering Infrastructure (DRI)
0 = /dev/dri/card0 First graphics card
1 = /dev/dri/card1 Second graphics card
...
227 char IBM 3270 terminal Unix tty access
1 = /dev/3270/tty1 First 3270 terminal
2 = /dev/3270/tty2 Seconds 3270 terminal
...
228 char IBM 3270 terminal block-mode access
0 = /dev/3270/tub Controlling interface
1 = /dev/3270/tub1 First 3270 terminal
2 = /dev/3270/tub2 Second 3270 terminal
...
229 char IBM iSeries/pSeries virtual console
0 = /dev/hvc0 First console port
1 = /dev/hvc1 Second console port
...
230 char IBM iSeries virtual tape
0 = /dev/iseries/vt0 First virtual tape, mode 0
1 = /dev/iseries/vt1 Second virtual tape, mode 0
...
32 = /dev/iseries/vt0l First virtual tape, mode 1
33 = /dev/iseries/vt1l Second virtual tape, mode 1
...
64 = /dev/iseries/vt0m First virtual tape, mode 2
65 = /dev/iseries/vt1m Second virtual tape, mode 2
...
96 = /dev/iseries/vt0a First virtual tape, mode 3
97 = /dev/iseries/vt1a Second virtual tape, mode 3
...
128 = /dev/iseries/nvt0 First virtual tape, mode 0, no rewind
129 = /dev/iseries/nvt1 Second virtual tape, mode 0, no rewind
...
160 = /dev/iseries/nvt0l First virtual tape, mode 1, no rewind
161 = /dev/iseries/nvt1l Second virtual tape, mode 1, no rewind
...
192 = /dev/iseries/nvt0m First virtual tape, mode 2, no rewind
193 = /dev/iseries/nvt1m Second virtual tape, mode 2, no rewind
...
224 = /dev/iseries/nvt0a First virtual tape, mode 3, no rewind
225 = /dev/iseries/nvt1a Second virtual tape, mode 3, no rewind
...
"No rewind" refers to the omission of the default
automatic rewind on device close. The MTREW or MTOFFL
ioctl()'s can be used to rewind the tape regardless of
the device used to access it.
231 char InfiniBand
0 = /dev/infiniband/umad0
1 = /dev/infiniband/umad1
...
63 = /dev/infiniband/umad63 63rd InfiniBandMad device
64 = /dev/infiniband/issm0 First InfiniBand IsSM device
65 = /dev/infiniband/issm1 Second InfiniBand IsSM device
...
127 = /dev/infiniband/issm63 63rd InfiniBand IsSM device
128 = /dev/infiniband/uverbs0 First InfiniBand verbs device
129 = /dev/infiniband/uverbs1 Second InfiniBand verbs device
...
159 = /dev/infiniband/uverbs31 31st InfiniBand verbs device
232 char Biometric Devices
0 = /dev/biometric/sensor0/fingerprint first fingerprint sensor on first device
1 = /dev/biometric/sensor0/iris first iris sensor on first device
2 = /dev/biometric/sensor0/retina first retina sensor on first device
3 = /dev/biometric/sensor0/voiceprint first voiceprint sensor on first device
4 = /dev/biometric/sensor0/facial first facial sensor on first device
5 = /dev/biometric/sensor0/hand first hand sensor on first device
...
10 = /dev/biometric/sensor1/fingerprint first fingerprint sensor on second device
...
20 = /dev/biometric/sensor2/fingerprint first fingerprint sensor on third device
...
233 char PathScale InfiniPath interconnect
0 = /dev/ipath Primary device for programs (any unit)
1 = /dev/ipath0 Access specifically to unit 0
2 = /dev/ipath1 Access specifically to unit 1
...
4 = /dev/ipath3 Access specifically to unit 3
129 = /dev/ipath_sma Device used by Subnet Management Agent
130 = /dev/ipath_diag Device used by diagnostics programs
234-254 char RESERVED FOR DYNAMIC ASSIGNMENT
Character devices that request a dynamic allocation of major number will
take numbers starting from 254 and downward.
240-254 block LOCAL/EXPERIMENTAL USE
Allocated for local/experimental use. For devices not
assigned official numbers, these ranges should be
used in order to avoid conflicting with future assignments.
255 char RESERVED
255 block RESERVED
This major is reserved to assist the expansion to a
larger number space. No device nodes with this major
should ever be created on the filesystem.
(This is probably not true anymore, but I'll leave it
for now /Torben)
---LARGE MAJORS!!!!!---
256 char Equinox SST multi-port serial boards
0 = /dev/ttyEQ0 First serial port on first Equinox SST board
127 = /dev/ttyEQ127 Last serial port on first Equinox SST board
128 = /dev/ttyEQ128 First serial port on second Equinox SST board
...
1027 = /dev/ttyEQ1027 Last serial port on eighth Equinox SST board
256 block Resident Flash Disk Flash Translation Layer
0 = /dev/rfda First RFD FTL layer
16 = /dev/rfdb Second RFD FTL layer
...
240 = /dev/rfdp 16th RFD FTL layer
257 char Phoenix Technologies Cryptographic Services Driver
0 = /dev/ptlsec Crypto Services Driver
257 block SSFDC Flash Translation Layer filesystem
0 = /dev/ssfdca First SSFDC layer
8 = /dev/ssfdcb Second SSFDC layer
16 = /dev/ssfdcc Third SSFDC layer
24 = /dev/ssfdcd 4th SSFDC layer
32 = /dev/ssfdce 5th SSFDC layer
40 = /dev/ssfdcf 6th SSFDC layer
48 = /dev/ssfdcg 7th SSFDC layer
56 = /dev/ssfdch 8th SSFDC layer
258 block ROM/Flash read-only translation layer
0 = /dev/blockrom0 First ROM card's translation layer interface
1 = /dev/blockrom1 Second ROM card's translation layer interface
...
259 block Block Extended Major
Used dynamically to hold additional partition minor
numbers and allow large numbers of partitions per device
259 char FPGA configuration interfaces
0 = /dev/icap0 First Xilinx internal configuration
1 = /dev/icap1 Second Xilinx internal configuration
260 char OSD (Object-based-device) SCSI Device
0 = /dev/osd0 First OSD Device
1 = /dev/osd1 Second OSD Device
...
255 = /dev/osd255 256th OSD Device
Documentation/admin-guide/java.rst
浏览文件 @ 63ac0cf9
...@@ -66,7 +66,9 @@ other program after you have done the following: ...@@ -66,7 +66,9 @@ other program after you have done the following:
Both the javawrapper shellscript and the javaclassname program Both the javawrapper shellscript and the javaclassname program
were supplied by Colin J. Watson <cjw44@cam.ac.uk>. were supplied by Colin J. Watson <cjw44@cam.ac.uk>.
Javawrapper shell script:: Javawrapper shell script:
.. code-block:: sh
#!/bin/bash #!/bin/bash
# /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java # /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java
...@@ -155,29 +157,31 @@ Javawrapper shell script:: ...@@ -155,29 +157,31 @@ Javawrapper shell script::
shift shift
/usr/bin/java $FQCLASS "$@" /usr/bin/java $FQCLASS "$@"
javaclassname.c:: javaclassname.c:
.. code-block:: c
/* javaclassname.c /* javaclassname.c
* *
* Extracts the class name from a Java class file; intended for use in a Java * Extracts the class name from a Java class file; intended for use in a Java
* wrapper of the type supported by the binfmt_misc option in the Linux kernel. * wrapper of the type supported by the binfmt_misc option in the Linux kernel.
* *
* Copyright (C) 1999 Colin J. Watson <cjw44@cam.ac.uk>. * Copyright (C) 1999 Colin J. Watson <cjw44@cam.ac.uk>.
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by * it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or * the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version. * (at your option) any later version.
* *
* This program is distributed in the hope that it will be useful, * This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of * but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details. * GNU General Public License for more details.
* *
* You should have received a copy of the GNU General Public License * You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software * along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/ */
#include <stdlib.h> #include <stdlib.h>
#include <stdio.h> #include <stdio.h>
...@@ -378,7 +382,9 @@ added to your CLASSPATH during execution. ...@@ -378,7 +382,9 @@ added to your CLASSPATH during execution.
To test your new setup, enter in the following simple Java app, and name To test your new setup, enter in the following simple Java app, and name
it "HelloWorld.java":: it "HelloWorld.java":
.. code-block:: java
class HelloWorld { class HelloWorld {
public static void main(String args[]) { public static void main(String args[]) {
......
Documentation/admin-guide/kernel-parameters.rst
浏览文件 @ 63ac0cf9
...@@ -198,4378 +198,10 @@ and is between 256 and 4096 characters. It is defined in the file ...@@ -198,4378 +198,10 @@ and is between 256 and 4096 characters. It is defined in the file
Finally, the [KMG] suffix is commonly described after a number of kernel Finally, the [KMG] suffix is commonly described after a number of kernel
parameter values. These 'K', 'M', and 'G' letters represent the _binary_ parameter values. These 'K', 'M', and 'G' letters represent the _binary_
multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30 multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30
bytes respectively. Such letter suffixes can also be entirely omitted:: bytes respectively. Such letter suffixes can also be entirely omitted:
.. include:: kernel-parameters.txt
acpi= [HW,ACPI,X86,ARM64] :literal:
Advanced Configuration and Power Interface
Format: { force | on | off | strict | noirq | rsdt |
copy_dsdt }
force -- enable ACPI if default was off
on -- enable ACPI but allow fallback to DT [arm64]
off -- disable ACPI if default was on
noirq -- do not use ACPI for IRQ routing
strict -- Be less tolerant of platforms that are not
strictly ACPI specification compliant.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
For ARM64, ONLY "acpi=off", "acpi=on" or "acpi=force"
are available
See also Documentation/power/runtime_pm.txt, pci=noacpi
acpi_apic_instance= [ACPI, IOAPIC]
Format: <int>
2: use 2nd APIC table, if available
1,0: use 1st APIC table
default: 0
acpi_backlight= [HW,ACPI]
acpi_backlight=vendor
acpi_backlight=video
If set to vendor, prefer vendor specific driver
(e.g. thinkpad_acpi, sony_acpi, etc.) instead
of the ACPI video.ko driver.
acpi_force_32bit_fadt_addr
force FADT to use 32 bit addresses rather than the
64 bit X_* addresses. Some firmware have broken 64
bit addresses for force ACPI ignore these and use
the older legacy 32 bit addresses.
acpica_no_return_repair [HW, ACPI]
Disable AML predefined validation mechanism
This mechanism can repair the evaluation result to make
the return objects more ACPI specification compliant.
This option is useful for developers to identify the
root cause of an AML interpreter issue when the issue
has something to do with the repair mechanism.
acpi.debug_layer= [HW,ACPI,ACPI_DEBUG]
acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
Format: <int>
CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
debug output. Bits in debug_layer correspond to a
_COMPONENT in an ACPI source file, e.g.,
#define _COMPONENT ACPI_PCI_COMPONENT
Bits in debug_level correspond to a level in
ACPI_DEBUG_PRINT statements, e.g.,
ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
The debug_level mask defaults to "info". See
Documentation/acpi/debug.txt for more information about
debug layers and levels.
Enable processor driver info messages:
acpi.debug_layer=0x20000000
Enable PCI/PCI interrupt routing info messages:
acpi.debug_layer=0x400000
Enable AML "Debug" output, i.e., stores to the Debug
object while interpreting AML:
acpi.debug_layer=0xffffffff acpi.debug_level=0x2
Enable all messages related to ACPI hardware:
acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
Some values produce so much output that the system is
unusable. The "log_buf_len" parameter may be useful
if you need to capture more output.
acpi_enforce_resources= [ACPI]
{ strict | lax | no }
Check for resource conflicts between native drivers
and ACPI OperationRegions (SystemIO and SystemMemory
only). IO ports and memory declared in ACPI might be
used by the ACPI subsystem in arbitrary AML code and
can interfere with legacy drivers.
strict (default): access to resources claimed by ACPI
is denied; legacy drivers trying to access reserved
resources will fail to bind to device using them.
lax: access to resources claimed by ACPI is allowed;
legacy drivers trying to access reserved resources
will bind successfully but a warning message is logged.
no: ACPI OperationRegions are not marked as reserved,
no further checks are performed.
acpi_force_table_verification [HW,ACPI]
Enable table checksum verification during early stage.
By default, this is disabled due to x86 early mapping
size limitation.
acpi_irq_balance [HW,ACPI]
ACPI will balance active IRQs
default in APIC mode
acpi_irq_nobalance [HW,ACPI]
ACPI will not move active IRQs (default)
default in PIC mode
acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Format: <irq>,<irq>...
acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
use by PCI
Format: <irq>,<irq>...
acpi_no_auto_serialize [HW,ACPI]
Disable auto-serialization of AML methods
AML control methods that contain the opcodes to create
named objects will be marked as "Serialized" by the
auto-serialization feature.
This feature is enabled by default.
This option allows to turn off the feature.
acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kdump
kernels.
acpi_no_static_ssdt [HW,ACPI]
Disable installation of static SSDTs at early boot time
By default, SSDTs contained in the RSDT/XSDT will be
installed automatically and they will appear under
/sys/firmware/acpi/tables.
This option turns off this feature.
Note that specifying this option does not affect
dynamic table installation which will install SSDT
tables to /sys/firmware/acpi/tables/dynamic.
acpi_rsdp= [ACPI,EFI,KEXEC]
Pass the RSDP address to the kernel, mostly used
on machines running EFI runtime service to boot the
second kernel for kdump.
acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
Format: To spoof as Windows 98: ="Microsoft Windows"
acpi_rev_override [ACPI] Override the _REV object to return 5 (instead
of 2 which is mandated by ACPI 6) as the supported ACPI
specification revision (when using this switch, it may
be necessary to carry out a cold reboot _twice_ in a
row to make it take effect on the platform firmware).
acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
acpi_osi="string1" # add string1
acpi_osi="!string2" # remove string2
acpi_osi=!* # remove all strings
acpi_osi=! # disable all built-in OS vendor
strings
acpi_osi=!! # enable all built-in OS vendor
strings
acpi_osi= # disable all strings
'acpi_osi=!' can be used in combination with single or
multiple 'acpi_osi="string1"' to support specific OS
vendor string(s). Note that such command can only
affect the default state of the OS vendor strings, thus
it cannot affect the default state of the feature group
strings and the current state of the OS vendor strings,
specifying it multiple times through kernel command line
is meaningless. This command is useful when one do not
care about the state of the feature group strings which
should be controlled by the OSPM.
Examples:
1. 'acpi_osi=! acpi_osi="Windows 2000"' is equivalent
to 'acpi_osi="Windows 2000" acpi_osi=!', they all
can make '_OSI("Windows 2000")' TRUE.
'acpi_osi=' cannot be used in combination with other
'acpi_osi=' command lines, the _OSI method will not
exist in the ACPI namespace. NOTE that such command can
only affect the _OSI support state, thus specifying it
multiple times through kernel command line is also
meaningless.
Examples:
1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)'
FALSE.
'acpi_osi=!*' can be used in combination with single or
multiple 'acpi_osi="string1"' to support specific
string(s). Note that such command can affect the
current state of both the OS vendor strings and the
feature group strings, thus specifying it multiple times
through kernel command line is meaningful. But it may
still not able to affect the final state of a string if
there are quirks related to this string. This command
is useful when one want to control the state of the
feature group strings to debug BIOS issues related to
the OSPM features.
Examples:
1. 'acpi_osi="Module Device" acpi_osi=!*' can make
'_OSI("Module Device")' FALSE.
2. 'acpi_osi=!* acpi_osi="Module Device"' can make
'_OSI("Module Device")' TRUE.
3. 'acpi_osi=! acpi_osi=!* acpi_osi="Windows 2000"' is
equivalent to
'acpi_osi=!* acpi_osi=! acpi_osi="Windows 2000"'
and
'acpi_osi=!* acpi_osi="Windows 2000" acpi_osi=!',
they all will make '_OSI("Windows 2000")' TRUE.
acpi_pm_good [X86]
Override the pmtimer bug detection: force the kernel
to assume that this machine's pmtimer latches its value
and always returns good values.
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
acpi_skip_timer_override [HW,ACPI]
Recognize and ignore IRQ0/pin2 Interrupt Override.
For broken nForce2 BIOS resulting in XT-PIC timer.
acpi_sleep= [HW,ACPI] Sleep options
Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
old_ordering, nonvs, sci_force_enable }
See Documentation/power/video.txt for information on
s3_bios and s3_mode.
s3_beep is for debugging; it makes the PC's speaker beep
as soon as the kernel's real-mode entry point is called.
s4_nohwsig prevents ACPI hardware signature from being
used during resume from hibernation.
old_ordering causes the ACPI 1.0 ordering of the _PTS
control method, with respect to putting devices into
low power states, to be enforced (the ACPI 2.0 ordering
of _PTS is used by default).
nonvs prevents the kernel from saving/restoring the
ACPI NVS memory during suspend/hibernation and resume.
sci_force_enable causes the kernel to set SCI_EN directly
on resume from S1/S3 (which is against the ACPI spec,
but some broken systems don't work without it).
acpi_use_timer_override [HW,ACPI]
Use timer override. For some broken Nvidia NF5 boards
that require a timer override, but don't have HPET
add_efi_memmap [EFI; X86] Include EFI memory map in
kernel's map of available physical RAM.
agp= [AGP]
{ off | try_unsupported }
off: disable AGP support
try_unsupported: try to drive unsupported chipsets
(may crash computer or cause data corruption)
ALSA [HW,ALSA]
See Documentation/sound/alsa/alsa-parameters.txt
alignment= [KNL,ARM]
Allow the default userspace alignment fault handler
behaviour to be specified. Bit 0 enables warnings,
bit 1 enables fixups, and bit 2 sends a segfault.
align_va_addr= [X86-64]
Align virtual addresses by clearing slice [14:12] when
allocating a VMA at process creation time. This option
gives you up to 3% performance improvement on AMD F15h
machines (where it is enabled by default) for a
CPU-intensive style benchmark, and it can vary highly in
a microbenchmark depending on workload and compiler.
32: only for 32-bit processes
64: only for 64-bit processes
on: enable for both 32- and 64-bit processes
off: disable for both 32- and 64-bit processes
alloc_snapshot [FTRACE]
Allocate the ftrace snapshot buffer on boot up when the
main buffer is allocated. This is handy if debugging
and you need to use tracing_snapshot() on boot up, and
do not want to use tracing_snapshot_alloc() as it needs
to be done where GFP_KERNEL allocations are allowed.
amd_iommu= [HW,X86-64]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are:
fullflush - enable flushing of IO/TLB entries when
they are unmapped. Otherwise they are
flushed before they will be reused, which
is a lot of faster
off - do not initialize any AMD IOMMU found in
the system
force_isolation - Force device isolation for all
devices. The IOMMU driver is not
allowed anymore to lift isolation
requirements as needed. This option
does not override iommu=pt
amd_iommu_dump= [HW,X86-64]
Enable AMD IOMMU driver option to dump the ACPI table
for AMD IOMMU. With this option enabled, AMD IOMMU
driver will print ACPI tables for AMD IOMMU during
IOMMU initialization.
amd_iommu_intr= [HW,X86-64]
Specifies one of the following AMD IOMMU interrupt
remapping modes:
legacy - Use legacy interrupt remapping mode.
vapic - Use virtual APIC mode, which allows IOMMU
to inject interrupts directly into guest.
This mode requires kvm-amd.avic=1.
(Default when IOMMU HW support is present.)
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Format: <a>,<b>
See also Documentation/input/joystick.txt
analog.map= [HW,JOY] Analog joystick and gamepad support
Specifies type or capabilities of an analog joystick
connected to one of 16 gameports
Format: <type1>,<type2>,..<type16>
apc= [HW,SPARC]
Power management functions (SPARCstation-4/5 + deriv.)
Format: noidle
Disable APC CPU standby support. SPARCstation-Fox does
not play well with APC CPU idle - disable it if you have
APC and your system crashes randomly.
apic= [APIC,X86-32] Advanced Programmable Interrupt Controller
Change the output verbosity whilst booting
Format: { quiet (default) | verbose | debug }
Change the amount of debugging information output
when initialising the APIC and IO-APIC components.
apic_extnmi= [APIC,X86] External NMI delivery setting
Format: { bsp (default) | all | none }
bsp: External NMI is delivered only to CPU 0
all: External NMIs are broadcast to all CPUs as a
backup of CPU 0
none: External NMI is masked for all CPUs. This is
useful so that a dump capture kernel won't be
shot down by NMI
autoconf= [IPV6]
See Documentation/networking/ipv6.txt.
show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
Limit apic dumping. The parameter defines the maximal
number of local apics being dumped. Also it is possible
to set it to "all" by meaning -- no limit here.
Format: { 1 (default) | 2 | ... | all }.
The parameter valid if only apic=debug or
apic=verbose is specified.
Example: apic=debug show_lapic=all
apm= [APM] Advanced Power Management
See header of arch/x86/kernel/apm_32.c.
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
Format: <io>,<irq>,<nodeID>
ataflop= [HW,M68k]
atarimouse= [HW,MOUSE] Atari Mouse
atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
EzKey and similar keyboards
atkbd.reset= [HW] Reset keyboard during initialization
atkbd.set= [HW] Select keyboard code set
Format: <int> (2 = AT (default), 3 = PS/2)
atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
keyboards
atkbd.softraw= [HW] Choose between synthetic and real raw mode
Format: <bool> (0 = real, 1 = synthetic (default))
atkbd.softrepeat= [HW]
Use software keyboard repeat
audit= [KNL] Enable the audit sub-system
Format: { "0" | "1" } (0 = disabled, 1 = enabled)
0 - kernel audit is disabled and can not be enabled
until the next reboot
unset - kernel audit is initialized but disabled and
will be fully enabled by the userspace auditd.
1 - kernel audit is initialized and partially enabled,
storing at most audit_backlog_limit messages in
RAM until it is fully enabled by the userspace
auditd.
Default: unset
audit_backlog_limit= [KNL] Set the audit queue size limit.
Format: <int> (must be >=0)
Default: 64
bau= [X86_UV] Enable the BAU on SGI UV. The default
behavior is to disable the BAU (i.e. bau=0).
Format: { "0" | "1" }
0 - Disable the BAU.
1 - Enable the BAU.
unset - Disable the BAU.
baycom_epp= [HW,AX25]
Format: <io>,<mode>
baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
Format: <io>,<mode>
See header of drivers/net/hamradio/baycom_par.c.
baycom_ser_fdx= [HW,AX25]
BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Format: <io>,<irq>,<mode>[,<baud>]
See header of drivers/net/hamradio/baycom_ser_fdx.c.
baycom_ser_hdx= [HW,AX25]
BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Format: <io>,<irq>,<mode>
See header of drivers/net/hamradio/baycom_ser_hdx.c.
blkdevparts= Manual partition parsing of block device(s) for
embedded devices based on command line input.
See Documentation/block/cmdline-partition.txt
boot_delay= Milliseconds to delay each printk during boot.
Values larger than 10 seconds (10000) are changed to
no delay (0).
Format: integer
bootmem_debug [KNL] Enable bootmem allocator debug messages.
bert_disable [ACPI]
Disable BERT OS support on buggy BIOSes.
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
kernel args too.
bttv.pll= See Documentation/video4linux/bttv/Insmod-options
bttv.tuner=
bulk_remove=off [PPC] This parameter disables the use of the pSeries
firmware feature for flushing multiple hpte entries
at a time.
c101= [NET] Moxa C101 synchronous serial card
cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Sometimes CPU hardware bugs make them report the cache
size incorrectly. The kernel will attempt work arounds
to fix known problems, but for some CPUs it is not
possible to determine what the correct size should be.
This option provides an override for these situations.
ca_keys= [KEYS] This parameter identifies a specific key(s) on
the system trusted keyring to be used for certificate
trust validation.
format: { id:<keyid> | builtin }
cca= [MIPS] Override the kernel pages' cache coherency
algorithm. Accepted values range from 0 to 7
inclusive. See arch/mips/include/asm/pgtable-bits.h
for platform specific values (SB1, Loongson3 and
others).
ccw_timeout_log [S390]
See Documentation/s390/CommonIO for details.
cgroup_disable= [KNL] Disable a particular controller
Format: {name of the controller(s) to disable}
The effects of cgroup_disable=foo are:
- foo isn't auto-mounted if you mount all cgroups in
a single hierarchy
- foo isn't visible as an individually mountable
subsystem
{Currently only "memory" controller deal with this and
cut the overhead, others just disable the usage. So
only cgroup_disable=memory is actually worthy}
cgroup_no_v1= [KNL] Disable one, multiple, all cgroup controllers in v1
Format: { controller[,controller...] | "all" }
Like cgroup_disable, but only applies to cgroup v1;
the blacklisted controllers remain available in cgroup2.
cgroup.memory= [KNL] Pass options to the cgroup memory controller.
Format: <string>
nosocket -- Disable socket memory accounting.
nokmem -- Disable kernel memory accounting.
checkreqprot [SELINUX] Set initial checkreqprot flag value.
Format: { "0" | "1" }
See security/selinux/Kconfig help text.
0 -- check protection applied by kernel (includes
any implied execute protection).
1 -- check protection requested by application.
Default value is set via a kernel config option.
Value can be changed at runtime via
/selinux/checkreqprot.
cio_ignore= [S390]
See Documentation/s390/CommonIO for details.
clk_ignore_unused
[CLK]
Prevents the clock framework from automatically gating
clocks that have not been explicitly enabled by a Linux
device driver but are enabled in hardware at reset or
by the bootloader/firmware. Note that this does not
force such clocks to be always-on nor does it reserve
those clocks in any way. This parameter is useful for
debug and development, but should not be needed on a
platform with proper driver support. For more
information, see Documentation/clk.txt.
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
Forces specified clocksource (if available) to be used
when calculating gettimeofday(). If specified
clocksource is not available, it defaults to PIT.
Format: { pit | tsc | cyclone | pmtmr }
clocksource= Override the default clocksource
Format: <string>
Override the default clocksource and use the clocksource
with the name specified.
Some clocksource names to choose from, depending on
the platform:
[all] jiffies (this is the base, fallback clocksource)
[ACPI] acpi_pm
[ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
pxa_timer,timer3,32k_counter,timer0_1
[AVR32] avr32
[X86-32] pit,hpet,tsc;
scx200_hrt on Geode; cyclone on IBM x440
[MIPS] MIPS
[PARISC] cr16
[S390] tod
[SH] SuperH
[SPARC64] tick
[X86-64] hpet,tsc
clocksource.arm_arch_timer.evtstrm=
[ARM,ARM64]
Format: <bool>
Enable/disable the eventstream feature of the ARM
architected timer so that code using WFE-based polling
loops can be debugged more effectively on production
systems.
clocksource.arm_arch_timer.fsl-a008585=
[ARM64]
Format: <bool>
Enable/disable the workaround of Freescale/NXP
erratum A-008585. This can be useful for KVM
guests, if the guest device tree doesn't show the
erratum. If unspecified, the workaround is
enabled based on the device tree.
clearcpuid=BITNUM [X86]
Disable CPUID feature X for the kernel. See
arch/x86/include/asm/cpufeatures.h for the valid bit
numbers. Note the Linux specific bits are not necessarily
stable over kernel options, but the vendor specific
ones should be.
Also note that user programs calling CPUID directly
or using the feature without checking anything
will still see it. This just prevents it from
being used by the kernel or shown in /proc/cpuinfo.
Also note the kernel might malfunction if you disable
some critical bits.
cma=nn[MG]@[start[MG][-end[MG]]]
[ARM,X86,KNL]
Sets the size of kernel global memory area for
contiguous memory allocations and optionally the
placement constraint by the physical address range of
memory allocations. A value of 0 disables CMA
altogether. For more information, see
include/linux/dma-contiguous.h
cmo_free_hint= [PPC] Format: { yes | no }
Specify whether pages are marked as being inactive
when they are freed. This is used in CMO environments
to determine OS memory pressure for page stealing by
a hypervisor.
Default: yes
coherent_pool=nn[KMG] [ARM,KNL]
Sets the size of memory pool for coherent, atomic dma
allocations, by default set to 256K.
code_bytes [X86] How many bytes of object code to print
in an oops report.
Range: 0 - 8192
Default: 64
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
Format: <io>[,<irq>]
com90xx= [HW,NET]
ARCnet - COM90xx chipset (memory-mapped buffers)
Format: <io>[,<irq>[,<memstart>]]
condev= [HW,S390] console device
conmode=
console= [KNL] Output console device and options.
tty<n> Use the virtual console device <n>.
ttyS<n>[,options]
ttyUSB0[,options]
Use the specified serial port. The options are of
the form "bbbbpnf", where "bbbb" is the baud rate,
"p" is parity ("n", "o", or "e"), "n" is number of
bits, and "f" is flow control ("r" for RTS or
omit it). Default is "9600n8".
See Documentation/admin-guide/serial-console.rst for more
information. See
Documentation/networking/netconsole.txt for an
alternative.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio16,<addr>[,options]
uart[8250],mmio32,<addr>[,options]
uart[8250],0x<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address,
switching to the matching ttyS device later.
MMIO inter-register address stride is either 8-bit
(mmio), 16-bit (mmio16), or 32-bit (mmio32).
If none of [io|mmio|mmio16|mmio32], <addr> is assumed
to be equivalent to 'mmio'. 'options' are specified in
the same format described for ttyS above; if unspecified,
the h/w is not re-initialized.
hvc<n> Use the hypervisor console device <n>. This is for
both Xen and PowerPC hypervisors.
If the device connected to the port is not a TTY but a braille
device, prepend "brl," before the device type, for instance
console=brl,ttyS0
For now, only VisioBraille is supported.
consoleblank= [KNL] The console blank (screen saver) timeout in
seconds. Defaults to 10*60 = 10mins. A value of 0
disables the blank timer.
coredump_filter=
[KNL] Change the default value for
/proc/<pid>/coredump_filter.
See also Documentation/filesystems/proc.txt.
cpuidle.off=1 [CPU_IDLE]
disable the cpuidle sub-system
cpu_init_udelay=N
[X86] Delay for N microsec between assert and de-assert
of APIC INIT to start processors. This delay occurs
on every CPU online, such as boot, and resume from suspend.
Default: 10000
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
crashkernel=size[KMG][@offset[KMG]]
[KNL] Using kexec, Linux can switch to a 'crash kernel'
upon panic. This parameter reserves the physical
memory region [offset, offset + size] for that kernel
image. If '@offset' is omitted, then a suitable offset
is selected automatically. Check
Documentation/kdump/kdump.txt for further details.
crashkernel=range1:size1[,range2:size2,...][@offset]
[KNL] Same as above, but depends on the memory
in the running system. The syntax of range is
start-[end] where start and end are both
a memory unit (amount[KMG]). See also
Documentation/kdump/kdump.txt for an example.
crashkernel=size[KMG],high
[KNL, x86_64] range could be above 4G. Allow kernel
to allocate physical memory region from top, so could
be above 4G if system have more than 4G ram installed.
Otherwise memory region will be allocated below 4G, if
available.
It will be ignored if crashkernel=X is specified.
crashkernel=size[KMG],low
[KNL, x86_64] range under 4G. When crashkernel=X,high
is passed, kernel could allocate physical memory region
above 4G, that cause second kernel crash on system
that require some amount of low memory, e.g. swiotlb
requires at least 64M+32K low memory, also enough extra
low memory is needed to make sure DMA buffers for 32-bit
devices won't run out. Kernel would try to allocate at
at least 256M below 4G automatically.
This one let user to specify own low range under 4G
for second kernel instead.
0: to disable low allocation.
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
cryptomgr.notests
[KNL] Disable crypto self-tests
cs89x0_dma= [HW,NET]
Format: <dma>
cs89x0_media= [HW,NET]
Format: { rj45 | aui | bnc }
dasd= [HW,NET]
See header of drivers/s390/block/dasd_devmap.c.
db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
(one device per port)
Format: <port#>,<type>
See also Documentation/input/joystick-parport.txt
ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
time. See Documentation/dynamic-debug-howto.txt for
details. Deprecated, see dyndbg.
debug [KNL] Enable kernel debugging (events log level).
debug_locks_verbose=
[KNL] verbose self-tests
Format=<0|1>
Print debugging info while doing the locking API
self-tests.
We default to 0 (no extra messages), setting it to
1 will print _a lot_ more information - normally
only useful to kernel developers.
debug_objects [KNL] Enable object debugging
no_debug_objects
[KNL] Disable object debugging
debug_guardpage_minorder=
[KNL] When CONFIG_DEBUG_PAGEALLOC is set, this
parameter allows control of the order of pages that will
be intentionally kept free (and hence protected) by the
buddy allocator. Bigger value increase the probability
of catching random memory corruption, but reduce the
amount of memory for normal system use. The maximum
possible value is MAX_ORDER/2. Setting this parameter
to 1 or 2 should be enough to identify most random
memory corruption problems caused by bugs in kernel or
driver code when a CPU writes to (or reads from) a
random memory location. Note that there exists a class
of memory corruptions problems caused by buggy H/W or
F/W or by drivers badly programing DMA (basically when
memory is written at bus level and the CPU MMU is
bypassed) which are not detectable by
CONFIG_DEBUG_PAGEALLOC, hence this option will not help
tracking down these problems.
debug_pagealloc=
[KNL] When CONFIG_DEBUG_PAGEALLOC is set, this
parameter enables the feature at boot time. In
default, it is disabled. We can avoid allocating huge
chunk of memory for debug pagealloc if we don't enable
it at boot time and the system will work mostly same
with the kernel built without CONFIG_DEBUG_PAGEALLOC.
on: enable the feature
debugpat [X86] Enable PAT debugging
decnet.addr= [HW,NET]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
default_hugepagesz=
[same as hugepagesz=] The size of the default
HugeTLB page size. This is the size represented by
the legacy /proc/ hugepages APIs, used for SHM, and
default size when mounting hugetlbfs filesystems.
Defaults to the default architecture's huge page size
if not specified.
dhash_entries= [KNL]
Set number of hash buckets for dentry cache.
disable_1tb_segments [PPC]
Disables the use of 1TB hash page table segments. This
causes the kernel to fall back to 256MB segments which
can be useful when debugging issues that require an SLB
miss to occur.
disable= [IPV6]
See Documentation/networking/ipv6.txt.
disable_radix [PPC]
Disable RADIX MMU mode on POWER9
disable_cpu_apicid= [X86,APIC,SMP]
Format: <int>
The number of initial APIC ID for the
corresponding CPU to be disabled at boot,
mostly used for the kdump 2nd kernel to
disable BSP to wake up multiple CPUs without
causing system reset or hang due to sending
INIT from AP to BSP.
disable_ddw [PPC/PSERIES]
Disable Dynamic DMA Window support. Use this if
to workaround buggy firmware.
disable_ipv6= [IPV6]
See Documentation/networking/ipv6.txt.
disable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
entry later. This parameter disables that.
disable_mtrr_trim [X86, Intel and AMD only]
By default the kernel will trim any uncacheable
memory out of your available memory pool based on
MTRR settings. This parameter disables that behavior,
possibly causing your machine to run very slowly.
disable_timer_pin_1 [X86]
Disable PIN 1 of APIC timer
Can be useful to work around chipset bugs.
dis_ucode_ldr [X86] Disable the microcode loader.
dma_debug=off If the kernel is compiled with DMA_API_DEBUG support,
this option disables the debugging code at boot.
dma_debug_entries=<number>
This option allows to tune the number of preallocated
entries for DMA-API debugging code. One entry is
required per DMA-API allocation. Use this if the
DMA-API debugging code disables itself because the
architectural default is too low.
dma_debug_driver=<driver_name>
With this option the DMA-API debugging driver
filter feature can be enabled at boot time. Just
pass the driver to filter for as the parameter.
The filter can be disabled or changed to another
driver later using sysfs.
drm_kms_helper.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
Broken monitors, graphic adapters, KVMs and EDIDless
panels may send no or incorrect EDID data sets.
This parameter allows to specify an EDID data sets
in the /lib/firmware directory that are used instead.
Generic built-in EDID data sets are used, if one of
edid/1024x768.bin, edid/1280x1024.bin,
edid/1680x1050.bin, or edid/1920x1080.bin is given
and no file with the same name exists. Details and
instructions how to build your own EDID data are
available in Documentation/EDID/HOWTO.txt. An EDID
data set will only be used for a particular connector,
if its name and a colon are prepended to the EDID
name. Each connector may use a unique EDID data
set by separating the files with a comma. An EDID
data set with no connector name will be used for
any connectors not explicitly specified.
dscc4.setup= [NET]
dyndbg[="val"] [KNL,DYNAMIC_DEBUG]
module.dyndbg[="val"]
Enable debug messages at boot time. See
Documentation/dynamic-debug-howto.txt for details.
nompx [X86] Disables Intel Memory Protection Extensions.
See Documentation/x86/intel_mpx.txt for more
information about the feature.
nopku [X86] Disable Memory Protection Keys CPU feature found
in some Intel CPUs.
eagerfpu= [X86]
on enable eager fpu restore
off disable eager fpu restore
auto selects the default scheme, which automatically
enables eagerfpu restore for xsaveopt.
module.async_probe [KNL]
Enable asynchronous probe on this module.
early_ioremap_debug [KNL]
Enable debug messages in early_ioremap support. This
is useful for tracking down temporary early mappings
which are not unmapped.
earlycon= [KNL] Output early console device and options.
When used with no options, the early console is
determined by the stdout-path property in device
tree's chosen node.
cdns,<addr>[,options]
Start an early, polled-mode console on a Cadence
(xuartps) serial port at the specified address. Only
supported option is baud rate. If baud rate is not
specified, the serial port must already be setup and
configured.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio32,<addr>[,options]
uart[8250],mmio32be,<addr>[,options]
uart[8250],0x<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
MMIO inter-register address stride is either 8-bit
(mmio) or 32-bit (mmio32 or mmio32be).
If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
to be equivalent to 'mmio'. 'options' are specified
in the same format described for "console=ttyS<n>"; if
unspecified, the h/w is not initialized.
pl011,<addr>
pl011,mmio32,<addr>
Start an early, polled-mode console on a pl011 serial
port at the specified address. The pl011 serial port
must already be setup and configured. Options are not
yet supported. If 'mmio32' is specified, then only
the driver will use only 32-bit accessors to read/write
the device registers.
meson,<addr>
Start an early, polled-mode console on a meson serial
port at the specified address. The serial port must
already be setup and configured. Options are not yet
supported.
msm_serial,<addr>
Start an early, polled-mode console on an msm serial
port at the specified address. The serial port
must already be setup and configured. Options are not
yet supported.
msm_serial_dm,<addr>
Start an early, polled-mode console on an msm serial
dm port at the specified address. The serial port
must already be setup and configured. Options are not
yet supported.
smh Use ARM semihosting calls for early console.
s3c2410,<addr>
s3c2412,<addr>
s3c2440,<addr>
s3c6400,<addr>
s5pv210,<addr>
exynos4210,<addr>
Use early console provided by serial driver available
on Samsung SoCs, requires selecting proper type and
a correct base address of the selected UART port. The
serial port must already be setup and configured.
Options are not yet supported.
lpuart,<addr>
lpuart32,<addr>
Use early console provided by Freescale LP UART driver
found on Freescale Vybrid and QorIQ LS1021A processors.
A valid base address must be provided, and the serial
port must already be setup and configured.
armada3700_uart,<addr>
Start an early, polled-mode console on the
Armada 3700 serial port at the specified
address. The serial port must already be setup
and configured. Options are not yet supported.
earlyprintk= [X86,SH,BLACKFIN,ARM,M68k]
earlyprintk=vga
earlyprintk=efi
earlyprintk=xen
earlyprintk=serial[,ttySn[,baudrate]]
earlyprintk=serial[,0x...[,baudrate]]
earlyprintk=ttySn[,baudrate]
earlyprintk=dbgp[debugController#]
earlyprintk=pciserial,bus:device.function[,baudrate]
earlyprintk is useful when the kernel crashes before
the normal console is initialized. It is not enabled by
default because it has some cosmetic problems.
Append ",keep" to not disable it when the real console
takes over.
Only one of vga, efi, serial, or usb debug port can
be used at a time.
Currently only ttyS0 and ttyS1 may be specified by
name. Other I/O ports may be explicitly specified
on some architectures (x86 and arm at least) by
replacing ttySn with an I/O port address, like this:
earlyprintk=serial,0x1008,115200
You can find the port for a given device in
/proc/tty/driver/serial:
2: uart:ST16650V2 port:00001008 irq:18 ...
Interaction with the standard serial driver is not
very good.
The VGA and EFI output is eventually overwritten by
the real console.
The xen output can only be used by Xen PV guests.
edac_report= [HW,EDAC] Control how to report EDAC event
Format: {"on" | "off" | "force"}
on: enable EDAC to report H/W event. May be overridden
by other higher priority error reporting module.
off: disable H/W event reporting through EDAC.
force: enforce the use of EDAC to report H/W event.
default: on.
ekgdboc= [X86,KGDB] Allow early kernel console debugging
ekgdboc=kbd
This is designed to be used in conjunction with
the boot argument: earlyprintk=vga
edd= [EDD]
Format: {"off" | "on" | "skip[mbr]"}
efi= [EFI]
Format: { "old_map", "nochunk", "noruntime", "debug" }
old_map [X86-64]: switch to the old ioremap-based EFI
runtime services mapping. 32-bit still uses this one by
default.
nochunk: disable reading files in "chunks" in the EFI
boot stub, as chunking can cause problems with some
firmware implementations.
noruntime : disable EFI runtime services support
debug: enable misc debug output
efi_no_storage_paranoia [EFI; X86]
Using this parameter you can use more than 50% of
your efi variable storage. Use this parameter only if
you are really sure that your UEFI does sane gc and
fulfills the spec otherwise your board may brick.
efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86]
Add arbitrary attribute to specific memory range by
updating original EFI memory map.
Region of memory which aa attribute is added to is
from ss to ss+nn.
If efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000
is specified, EFI_MEMORY_MORE_RELIABLE(0x10000)
attribute is added to range 0x100000000-0x180000000 and
0x10a0000000-0x1120000000.
Using this parameter you can do debugging of EFI memmap
related feature. For example, you can do debugging of
Address Range Mirroring feature even if your box
doesn't support it.
efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT
that is to be dynamically loaded by Linux. If there are
multiple variables with the same name but with different
vendor GUIDs, all of them will be loaded. See
Documentation/acpi/ssdt-overlays.txt for details.
eisa_irq_edge= [PARISC,HW]
See header of drivers/parisc/eisa.c.
elanfreq= [X86-32]
See comment before function elanfreq_setup() in
arch/x86/kernel/cpu/cpufreq/elanfreq.c.
elevator= [IOSCHED]
Format: {"cfq" | "deadline" | "noop"}
See Documentation/block/cfq-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390]
Specifies physical address of start of kernel core
image elf header and optionally the size. Generally
kexec loader will pass this option to capture kernel.
See Documentation/kdump/kdump.txt for details.
enable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
entry later. This parameter enables that.
enable_timer_pin_1 [X86]
Enable PIN 1 of APIC timer
Can be useful to work around chipset bugs
(in particular on some ATI chipsets).
The kernel tries to set a reasonable default.
enforcing [SELINUX] Set initial enforcing status.
Format: {"0" | "1"}
See security/selinux/Kconfig help text.
0 -- permissive (log only, no denials).
1 -- enforcing (deny and log).
Default value is 0.
Value can be changed at runtime via /selinux/enforce.
erst_disable [ACPI]
Disable Error Record Serialization Table (ERST)
support.
ether= [HW,NET] Ethernet cards parameters
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
evm= [EVM]
Format: { "fix" }
Permit 'security.evm' to be updated regardless of
current integrity status.
failslab=
fail_page_alloc=
fail_make_request=[KNL]
General fault injection mechanism.
Format: <interval>,<probability>,<space>,<times>
See also Documentation/fault-injection/.
floppy= [HW]
See Documentation/blockdev/floppy.txt.
force_pal_cache_flush
[IA-64] Avoid check_sal_cache_flush which may hang on
buggy SAL_CACHE_FLUSH implementations. Using this
parameter will force ia64_sal_cache_flush to call
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
forcepae [X86-32]
Forcefully enable Physical Address Extension (PAE).
Many Pentium M systems disable PAE but may have a
functionally usable PAE implementation.
Warning: use of this parameter will taint the kernel
and may cause unknown problems.
ftrace=[tracer]
[FTRACE] will set and start the specified tracer
as early as possible in order to facilitate early
boot debugging.
ftrace_dump_on_oops[=orig_cpu]
[FTRACE] will dump the trace buffers on oops.
If no parameter is passed, ftrace will dump
buffers of all CPUs, but if you pass orig_cpu, it will
dump only the buffer of the CPU that triggered the
oops.
ftrace_filter=[function-list]
[FTRACE] Limit the functions traced by the function
tracer at boot up. function-list is a comma separated
list of functions. This list can be changed at run
time by the set_ftrace_filter file in the debugfs
tracing directory.
ftrace_notrace=[function-list]
[FTRACE] Do not trace the functions specified in
function-list. This list can be changed at run time
by the set_ftrace_notrace file in the debugfs
tracing directory.
ftrace_graph_filter=[function-list]
[FTRACE] Limit the top level callers functions traced
by the function graph tracer at boot up.
function-list is a comma separated list of functions
that can be changed at run time by the
set_graph_function file in the debugfs tracing directory.
ftrace_graph_notrace=[function-list]
[FTRACE] Do not trace from the functions specified in
function-list. This list is a comma separated list of
functions that can be changed at run time by the
set_graph_notrace file in the debugfs tracing directory.
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
See also Documentation/input/joystick-parport.txt
gamma= [HW,DRM]
gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
Format: off | on
default: on
gcov_persist= [GCOV] When non-zero (default), profiling data for
kernel modules is saved and remains accessible via
debugfs, even when the module is unloaded/reloaded.
When zero, profiling data is discarded and associated
debugfs files are removed at module unload time.
gpt [EFI] Forces disk with valid GPT signature but
invalid Protective MBR to be treated as GPT. If the
primary GPT is corrupted, it enables the backup/alternate
GPT to be used instead.
grcan.enable0= [HW] Configuration of physical interface 0. Determines
the "Enable 0" bit of the configuration register.
Format: 0 | 1
Default: 0
grcan.enable1= [HW] Configuration of physical interface 1. Determines
the "Enable 0" bit of the configuration register.
Format: 0 | 1
Default: 0
grcan.select= [HW] Select which physical interface to use.
Format: 0 | 1
Default: 0
grcan.txsize= [HW] Sets the size of the tx buffer.
Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0.
Default: 1024
grcan.rxsize= [HW] Sets the size of the rx buffer.
Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0.
Default: 1024
gpio-mockup.gpio_mockup_ranges
[HW] Sets the ranges of gpiochip of for this device.
Format: <start1>,<end1>,<start2>,<end2>...
hardlockup_all_cpu_backtrace=
[KNL] Should the hard-lockup detector generate
backtraces on all cpus.
Format: <integer>
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
for 64-bit NUMA, off otherwise.
Format: 0 | 1 (for off | on)
hcl= [IA-64] SGI's Hardware Graph compatibility layer
hd= [EIDE] (E)IDE hard drive subsystem geometry
Format: <cyl>,<head>,<sect>
hest_disable [ACPI]
Disable Hardware Error Source Table (HEST) support;
corresponding firmware-first mode error processing
logic will be disabled.
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
size of <nn>. This works even on boxes that have no
highmem otherwise. This also works to reduce highmem
size on bigger boxes.
highres= [KNL] Enable/disable high resolution timer mode.
Valid parameters: "on", "off"
Default: "on"
hisax= [HW,ISDN]
See Documentation/isdn/README.HiSax.
hlt [BUGS=ARM,SH]
hpet= [X86-32,HPET] option to control HPET usage
Format: { enable (default) | disable | force |
verbose }
disable: disable HPET and use PIT instead
force: allow force enabled of undocumented chips (ICH4,
VIA, nVidia)
verbose: show contents of HPET registers during setup
hpet_mmap= [X86, HPET_MMAP] Allow userspace to mmap HPET
registers. Default set by CONFIG_HPET_MMAP_DEFAULT.
hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
On x86-64 and powerpc, this option can be specified
multiple times interleaved with hugepages= to reserve
huge pages of different sizes. Valid pages sizes on
x86-64 are 2M (when the CPU supports "pse") and 1G
(when the CPU supports the "pdpe1gb" cpuinfo flag).
hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
terminal devices. Valid values: 0..8
hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
If specified, z/VM IUCV HVC accepts connections
from listed z/VM user IDs only.
hwthread_map= [METAG] Comma-separated list of Linux cpu id to
hardware thread id mappings.
Format: <cpu>:<hwthread>
keep_bootcon [KNL]
Do not unregister boot console at start. This is only
useful for debugging when something happens in the window
between unregistering the boot console and initializing
the real console.
i2c_bus= [HW] Override the default board specific I2C bus speed
or register an additional I2C bus that is not
registered from board initialization code.
Format:
<bus_id>,<clkrate>
i8042.debug [HW] Toggle i8042 debug mode
i8042.unmask_kbd_data
[HW] Enable printing of interrupt data from the KBD port
(disabled by default, and as a pre-condition
requires that i8042.debug=1 be enabled)
i8042.direct [HW] Put keyboard port into non-translated mode
i8042.dumbkbd [HW] Pretend that controller can only read data from
keyboard and cannot control its state
(Don't attempt to blink the leds)
i8042.noaux [HW] Don't check for auxiliary (== mouse) port
i8042.nokbd [HW] Don't check/create keyboard port
i8042.noloop [HW] Disable the AUX Loopback command while probing
for the AUX port
i8042.nomux [HW] Don't check presence of an active multiplexing
controller
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
controllers
i8042.notimeout [HW] Ignore timeout condition signalled by controller
i8042.reset [HW] Reset the controller during init, cleanup and
suspend-to-ram transitions, only during s2r
transitions, or never reset
Format: { 1 | Y | y | 0 | N | n }
1, Y, y: always reset controller
0, N, n: don't ever reset controller
Default: only on s2r transitions on x86; most other
architectures force reset to be always executed
i8042.unlock [HW] Unlock (ignore) the keylock
i8042.kbdreset [HW] Reset device connected to KBD port
i810= [HW,DRM]
i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
indicates that the driver is running on unsupported
hardware.
i8k.force [HW] Activate i8k driver even if SMM BIOS signature
does not match list of supported models.
i8k.power_status
[HW] Report power status in /proc/i8k
(disabled by default)
i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
capability is set.
i915.invert_brightness=
[DRM] Invert the sense of the variable that is used to
set the brightness of the panel backlight. Normally a
brightness value of 0 indicates backlight switched off,
and the maximum of the brightness value sets the backlight
to maximum brightness. If this parameter is set to 0
(default) and the machine requires it, or this parameter
is set to 1, a brightness value of 0 sets the backlight
to maximum brightness, and the maximum of the brightness
value switches the backlight off.
-1 -- never invert brightness
0 -- machine default
1 -- force brightness inversion
icn= [HW,ISDN]
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
ide-core.nodma= [HW] (E)IDE subsystem
Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
.vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr
.cdrom .chs .ignore_cable are additional options
See Documentation/ide/ide.txt.
ide-generic.probe-mask= [HW] (E)IDE subsystem
Format: <int>
Probe mask for legacy ISA IDE ports. Depending on
platform up to 6 ports are supported, enabled by
setting corresponding bits in the mask to 1. The
default value is 0x0, which has a special meaning.
On systems that have PCI, it triggers scanning the
PCI bus for the first and the second port, which
are then probed. On systems without PCI the value
of 0x0 enables probing the two first ports as if it
was 0x3.
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
Claim all unknown PCI IDE storage controllers.
idle= [X86]
Format: idle=poll, idle=halt, idle=nomwait
Poll forces a polling idle loop that can slightly
improve the performance of waking up a idle CPU, but
will use a lot of power and make the system run hot.
Not recommended.
idle=halt: Halt is forced to be used for CPU idle.
In such case C2/C3 won't be used again.
idle=nomwait: Disable mwait for CPU C-states
ieee754= [MIPS] Select IEEE Std 754 conformance mode
Format: { strict | legacy | 2008 | relaxed }
Default: strict
Choose which programs will be accepted for execution
based on the IEEE 754 NaN encoding(s) supported by
the FPU and the NaN encoding requested with the value
of an ELF file header flag individually set by each
binary. Hardware implementations are permitted to
support either or both of the legacy and the 2008 NaN
encoding mode.
Available settings are as follows:
strict accept binaries that request a NaN encoding
supported by the FPU
legacy only accept legacy-NaN binaries, if supported
by the FPU
2008 only accept 2008-NaN binaries, if supported
by the FPU
relaxed accept any binaries regardless of whether
supported by the FPU
The FPU emulator is always able to support both NaN
encodings, so if no FPU hardware is present or it has
been disabled with 'nofpu', then the settings of
'legacy' and '2008' strap the emulator accordingly,
'relaxed' straps the emulator for both legacy-NaN and
2008-NaN, whereas 'strict' enables legacy-NaN only on
legacy processors and both NaN encodings on MIPS32 or
MIPS64 CPUs.
The setting for ABS.fmt/NEG.fmt instruction execution
mode generally follows that for the NaN encoding,
except where unsupported by hardware.
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
kernel messages to the console. Useful for debugging.
We also add it as printk module parameter, so users
could change it dynamically, usually by
/sys/module/printk/parameters/ignore_loglevel.
ignore_rlimit_data
Ignore RLIMIT_DATA setting for data mappings,
print warning at first misuse. Can be changed via
/sys/module/kernel/parameters/ignore_rlimit_data.
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
ima_appraise= [IMA] appraise integrity measurements
Format: { "off" | "enforce" | "fix" | "log" }
default: "enforce"
ima_appraise_tcb [IMA]
The builtin appraise policy appraises all files
owned by uid=0.
ima_hash= [IMA]
Format: { md5 | sha1 | rmd160 | sha256 | sha384
| sha512 | ... }
default: "sha1"
The list of supported hash algorithms is defined
in crypto/hash_info.h.
ima_policy= [IMA]
The builtin measurement policy to load during IMA
setup. Specyfing "tcb" as the value, measures all
programs exec'd, files mmap'd for exec, and all files
opened with the read mode bit set by either the
effective uid (euid=0) or uid=0.
Format: "tcb"
ima_tcb [IMA] Deprecated. Use ima_policy= instead.
Load a policy which meets the needs of the Trusted
Computing Base. This means IMA will measure all
programs exec'd, files mmap'd for exec, and all files
opened for read by uid=0.
ima_template= [IMA]
Select one of defined IMA measurements template formats.
Formats: { "ima" | "ima-ng" | "ima-sig" }
Default: "ima-ng"
ima_template_fmt=
[IMA] Define a custom template format.
Format: { "field1|...|fieldN" }
ima.ahash_minsize= [IMA] Minimum file size for asynchronous hash usage
Format: <min_file_size>
Set the minimal file size for using asynchronous hash.
If left unspecified, ahash usage is disabled.
ahash performance varies for different data sizes on
different crypto accelerators. This option can be used
to achieve the best performance for a particular HW.
ima.ahash_bufsize= [IMA] Asynchronous hash buffer size
Format: <bufsize>
Set hashing buffer size. Default: 4k.
ahash performance varies for different chunk sizes on
different crypto accelerators. This option can be used
to achieve best performance for particular HW.
init= [KNL]
Format: <full_path>
Run specified binary instead of /sbin/init as init
process.
initcall_debug [KNL] Trace initcalls as they are executed. Useful
for working out where the kernel is dying during
startup.
initcall_blacklist= [KNL] Do not execute a comma-separated list of
initcall functions. Useful for debugging built-in
modules and initcalls.
initrd= [BOOT] Specify the location of the initial ramdisk
init_pkru= [x86] Specify the default memory protection keys rights
register contents for all processes. 0x55555554 by
default (disallow access to all but pkey 0). Can
override in debugfs after boot.
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
int_pln_enable [x86] Enable power limit notification interrupt
integrity_audit=[IMA]
Format: { "0" | "1" }
0 -- basic integrity auditing messages. (Default)
1 -- additional integrity auditing messages.
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
on
Enable intel iommu driver.
off
Disable intel iommu driver.
igfx_off [Default Off]
By default, gfx is mapped as normal device. If a gfx
device has a dedicated DMAR unit, the DMAR unit is
bypassed by not enabling DMAR with this option. In
this case, gfx device will use physical address for
DMA.
forcedac [x86_64]
With this option iommu will not optimize to look
for io virtual address below 32-bit forcing dual
address cycle on pci bus for cards supporting greater
than 32-bit addressing. The default is to look
for translation below 32-bit and if not available
then look in the higher range.
strict [Default Off]
With this option on every unmap_single operation will
result in a hardware IOTLB flush operation as opposed
to batching them for performance.
sp_off [Default Off]
By default, super page will be supported if Intel IOMMU
has the capability. With this option, super page will
not be supported.
ecs_off [Default Off]
By default, extended context tables will be supported if
the hardware advertises that it has support both for the
extended tables themselves, and also PASID support. With
this option set, extended tables will not be used even
on hardware which claims to support them.
intel_idle.max_cstate= [KNL,HW,ACPI,X86]
0 disables intel_idle and fall back on acpi_idle.
1 to 9 specify maximum depth of C-state.
intel_pstate= [X86]
disable
Do not enable intel_pstate as the default
scaling driver for the supported processors
force
Enable intel_pstate on systems that prohibit it by default
in favor of acpi-cpufreq. Forcing the intel_pstate driver
instead of acpi-cpufreq may disable platform features, such
as thermal controls and power capping, that rely on ACPI
P-States information being indicated to OSPM and therefore
should be used with caution. This option does not work with
processors that aren't supported by the intel_pstate driver
or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
no_hwp
Do not enable hardware P state control (HWP)
if available.
hwp_only
Only load intel_pstate on systems which support
hardware P state control (HWP) if available.
support_acpi_ppc
Enforce ACPI _PPC performance limits. If the Fixed ACPI
Description Table, specifies preferred power management
profile as "Enterprise Server" or "Performance Server",
then this feature is turned on by default.
intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
off disable Interrupt Remapping
nosid disable Source ID checking
no_x2apic_optout
BIOS x2APIC opt-out request will be ignored
nopost disable Interrupt Posting
iomem= Disable strict checking of access to MMIO memory
strict regions from userspace.
relaxed
iommu= [x86]
off
force
noforce
biomerge
panic
nopanic
merge
nomerge
forcesac
soft
pt [x86, IA-64]
nobypass [PPC/POWERNV]
Disable IOMMU bypass, using IOMMU for PCI devices.
io7= [HW] IO7 for Marvel based alpha systems
See comment before marvel_specify_io7 in
arch/alpha/kernel/core_marvel.c.
io_delay= [X86] I/O delay method
0x80
Standard port 0x80 based delay
0xed
Alternate port 0xed based delay (needed on some systems)
udelay
Simple two microseconds delay
none
No delay
ip= [IP_PNP]
See Documentation/filesystems/nfs/nfsroot.txt.
irqaffinity= [SMP] Set the default irq affinity mask
The argument is a cpu list, as described above.
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
firmware running.
irqpoll [HW]
When an interrupt is not handled search all handlers
for it. Also check all handlers each timer
interrupt. Intended to get systems with badly broken
firmware running.
isapnp= [ISAPNP]
Format: <RDP>,<reset>,<pci_scan>,<verbosity>
isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
The argument is a cpu list, as described above.
This option can be used to specify one or more CPUs
to isolate from the general SMP balancing and scheduling
algorithms. You can move a process onto or off an
"isolated" CPU via the CPU affinity syscalls or cpuset.
<cpu number> begins at 0 and the maximum value is
"number of CPUs in system - 1".
This option is the preferred way to isolate CPUs. The
alternative -- manually setting the CPU mask of all
tasks in the system -- can cause problems and
suboptimal load balancer performance.
iucv= [HW,NET]
ivrs_ioapic [HW,X86_64]
Provide an override to the IOAPIC-ID<->DEVICE-ID
mapping provided in the IVRS ACPI table. For
example, to map IOAPIC-ID decimal 10 to
PCI device 00:14.0 write the parameter as:
ivrs_ioapic[10]=00:14.0
ivrs_hpet [HW,X86_64]
Provide an override to the HPET-ID<->DEVICE-ID
mapping provided in the IVRS ACPI table. For
example, to map HPET-ID decimal 0 to
PCI device 00:14.0 write the parameter as:
ivrs_hpet[0]=00:14.0
ivrs_acpihid [HW,X86_64]
Provide an override to the ACPI-HID:UID<->DEVICE-ID
mapping provided in the IVRS ACPI table. For
example, to map UART-HID:UID AMD0020:0 to
PCI device 00:14.5 write the parameter as:
ivrs_acpihid[00:14.5]=AMD0020:0
js= [HW,JOY] Analog joystick
See Documentation/input/joystick.txt.
nokaslr [KNL]
When CONFIG_RANDOMIZE_BASE is set, this disables
kernel and module base offset ASLR (Address Space
Layout Randomization).
keepinitrd [HW,ARM]
kernelcore= [KNL,X86,IA-64,PPC]
Format: nn[KMGTPE] | "mirror"
This parameter
specifies the amount of memory usable by the kernel
for non-movable allocations. The requested amount is
spread evenly throughout all nodes in the system. The
remaining memory in each node is used for Movable
pages. In the event, a node is too small to have both
kernelcore and Movable pages, kernelcore pages will
take priority and other nodes will have a larger number
of Movable pages. The Movable zone is used for the
allocation of pages that may be reclaimed or moved
by the page migration subsystem. This means that
HugeTLB pages may not be allocated from this zone.
Note that allocations like PTEs-from-HighMem still
use the HighMem zone if it exists, and the Normal
zone if it does not.
Instead of specifying the amount of memory (nn[KMGTPE]),
you can specify "mirror" option. In case "mirror"
option is specified, mirrored (reliable) memory is used
for non-movable allocations and remaining memory is used
for Movable pages. nn[KMGTPE] and "mirror" are exclusive,
so you can NOT specify nn[KMGTPE] and "mirror" at the same
time.
kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
Format: <Controller#>[,poll interval]
The controller # is the number of the ehci usb debug
port as it is probed via PCI. The poll interval is
optional and is the number seconds in between
each poll cycle to the debug port in case you need
the functionality for interrupting the kernel with
gdb or control-c on the dbgp connection. When
not using this parameter you use sysrq-g to break into
the kernel debugger.
kgdboc= [KGDB,HW] kgdb over consoles.
Requires a tty driver that supports console polling,
or a supported polling keyboard driver (non-usb).
Serial only format: <serial_device>[,baud]
keyboard only format: kbd
keyboard and serial format: kbd,<serial_device>[,baud]
Optional Kernel mode setting:
kms, kbd format: kms,kbd
kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]
kgdbwait [KGDB] Stop kernel execution and enter the
kernel debugger at the earliest opportunity.
kmac= [MIPS] korina ethernet MAC address.
Configure the RouterBoard 532 series on-chip
Ethernet adapter MAC address.
kmemleak= [KNL] Boot-time kmemleak enable/disable
Valid arguments: on, off
Default: on
Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
the default is off.
kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode
Valid arguments: 0, 1, 2
kmemcheck=0 (disabled)
kmemcheck=1 (enabled)
kmemcheck=2 (one-shot mode)
Default: 2 (one-shot mode)
kstack=N [X86] Print N words from the kernel stack
in oops dumps.
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
Default is 0 (don't ignore, but inject #GP)
kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit
KVM MMU at runtime.
Default is 0 (off)
kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
Default is 1 (enabled)
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
for all guests.
Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
kvm-intel.ept= [KVM,Intel] Disable extended page tables
(virtualized MMU) support on capable Intel chips.
Default is 1 (enabled)
kvm-intel.emulate_invalid_guest_state=
[KVM,Intel] Enable emulation of invalid guest states
Default is 0 (disabled)
kvm-intel.flexpriority=
[KVM,Intel] Disable FlexPriority feature (TPR shadow).
Default is 1 (enabled)
kvm-intel.nested=
[KVM,Intel] Enable VMX nesting (nVMX).
Default is 0 (disabled)
kvm-intel.unrestricted_guest=
[KVM,Intel] Disable unrestricted guest feature
(virtualized real and unpaged mode) on capable
Intel chips. Default is 1 (enabled)
kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
feature (tagged TLBs) on capable Intel chips.
Default is 1 (enabled)
l2cr= [PPC]
l3cr= [PPC]
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline
value for LAPIC timer one-shot implementation. Default
back to the programmable timer unit in the LAPIC.
lapic_timer_c2_ok [X86,APIC] trust the local apic timer
in C2 power state.
libata.dma= [LIBATA] DMA control
libata.dma=0 Disable all PATA and SATA DMA
libata.dma=1 PATA and SATA Disk DMA only
libata.dma=2 ATAPI (CDROM) DMA only
libata.dma=4 Compact Flash DMA only
Combinations also work, so libata.dma=3 enables DMA
for disks and CDROMs, but not CFs.
libata.ignore_hpa= [LIBATA] Ignore HPA limit
libata.ignore_hpa=0 keep BIOS limits (default)
libata.ignore_hpa=1 ignore limits, using full disk
libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
when set.
Format: <int>
libata.force= [LIBATA] Force configurations. The format is comma
separated list of "[ID:]VAL" where ID is
PORT[.DEVICE]. PORT and DEVICE are decimal numbers
matching port, link or device. Basically, it matches
the ATA ID string printed on console by libata. If
the whole ID part is omitted, the last PORT and DEVICE
values are used. If ID hasn't been specified yet, the
configuration applies to all ports, links and devices.
If only DEVICE is omitted, the parameter applies to
the port and all links and devices behind it. DEVICE
number of 0 either selects the first device or the
first fan-out link behind PMP device. It does not
select the host link. DEVICE number of 15 selects the
host link and device attached to it.
The VAL specifies the configuration to force. As long
as there's no ambiguity shortcut notation is allowed.
For example, both 1.5 and 1.5G would work for 1.5Gbps.
The following configurations can be forced.
* Cable type: 40c, 80c, short40c, unk, ign or sata.
Any ID with matching PORT is used.
* SATA link speed limit: 1.5Gbps or 3.0Gbps.
* Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
udma[/][16,25,33,44,66,100,133] notation is also
allowed.
* [no]ncq: Turn on or off NCQ.
* [no]ncqtrim: Turn off queued DSM TRIM.
* nohrst, nosrst, norst: suppress hard, soft
and both resets.
* rstonce: only attempt one reset during
hot-unplug link recovery
* dump_id: dump IDENTIFY data.
* atapi_dmadir: Enable ATAPI DMADIR bridge support
* disable: Disable this device.
If there are multiple matching configurations changing
the same attribute, the last one is used.
memblock=debug [KNL] Enable memblock debug messages.
load_ramdisk= [RAM] List of ramdisks to load from floppy
See Documentation/blockdev/ramdisk.txt.
lockd.nlm_grace_period=P [NFS] Assign grace period.
Format: <integer>
lockd.nlm_tcpport=N [NFS] Assign TCP port.
Format: <integer>
lockd.nlm_timeout=T [NFS] Assign timeout value.
Format: <integer>
lockd.nlm_udpport=M [NFS] Assign UDP port.
Format: <integer>
locktorture.nreaders_stress= [KNL]
Set the number of locking read-acquisition kthreads.
Defaults to being automatically set based on the
number of online CPUs.
locktorture.nwriters_stress= [KNL]
Set the number of locking write-acquisition kthreads.
locktorture.onoff_holdoff= [KNL]
Set time (s) after boot for CPU-hotplug testing.
locktorture.onoff_interval= [KNL]
Set time (s) between CPU-hotplug operations, or
zero to disable CPU-hotplug testing.
locktorture.shuffle_interval= [KNL]
Set task-shuffle interval (jiffies). Shuffling
tasks allows some CPUs to go into dyntick-idle
mode during the locktorture test.
locktorture.shutdown_secs= [KNL]
Set time (s) after boot system shutdown. This
is useful for hands-off automated testing.
locktorture.stat_interval= [KNL]
Time (s) between statistics printk()s.
locktorture.stutter= [KNL]
Time (s) to stutter testing, for example,
specifying five seconds causes the test to run for
five seconds, wait for five seconds, and so on.
This tests the locking primitive's ability to
transition abruptly to and from idle.
locktorture.torture_runnable= [BOOT]
Start locktorture running at boot time.
locktorture.torture_type= [KNL]
Specify the locking implementation to test.
locktorture.verbose= [KNL]
Enable additional printk() statements.
logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
Format: <irq>
loglevel= All Kernel Messages with a loglevel smaller than the
console loglevel will be printed to the console. It can
also be changed with klogd or other programs. The
loglevels are defined as follows:
0 (KERN_EMERG) system is unusable
1 (KERN_ALERT) action must be taken immediately
2 (KERN_CRIT) critical conditions
3 (KERN_ERR) error conditions
4 (KERN_WARNING) warning conditions
5 (KERN_NOTICE) normal but significant condition
6 (KERN_INFO) informational
7 (KERN_DEBUG) debug-level messages
log_buf_len=n[KMG] Sets the size of the printk ring buffer,
in bytes. n must be a power of two and greater
than the minimal size. The minimal size is defined
by LOG_BUF_SHIFT kernel config parameter. There is
also CONFIG_LOG_CPU_MAX_BUF_SHIFT config parameter
that allows to increase the default size depending on
the number of CPUs. See init/Kconfig for more details.
logo.nologo [FB] Disables display of the built-in Linux logo.
This may be used to provide more screen space for
kernel log messages and is useful when debugging
kernel boot problems.
lp=0 [LP] Specify parallel ports to use, e.g,
lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
lp=reset first parallel port). 'lp=0' disables the
lp=auto printer driver. 'lp=reset' (which can be
specified in addition to the ports) causes
attached printers to be reset. Using
lp=port1,port2,... specifies the parallel ports
to associate lp devices with, starting with
lp0. A port specification may be 'none' to skip
that lp device, or a parport name such as
'parport0'. Specifying 'lp=auto' instead of a
port specification list means that device IDs
from each port should be examined, to see if
an IEEE 1284-compliant printer is attached; if
so, the driver will manage that printer.
See also header of drivers/char/lp.c.
lpj=n [KNL]
Sets loops_per_jiffy to given constant, thus avoiding
time-consuming boot-time autodetection (up to 250 ms per
CPU). 0 enables autodetection (default). To determine
the correct value for your kernel, boot with normal
autodetection and see what value is printed. Note that
on SMP systems the preset will be applied to all CPUs,
which is likely to cause problems if your CPUs need
significantly divergent settings. An incorrect value
will cause delays in the kernel to be wrong, leading to
unpredictable I/O errors and other breakage. Although
unlikely, in the extreme case this might damage your
hardware.
ltpc= [NET]
Format: <io>,<irq>,<dma>
machvec= [IA-64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
machtype= [Loongson] Share the same kernel image file between different
yeeloong laptop.
Example: machtype=lemote-yeeloong-2f-7inch
max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater
than or equal to this physical address is ignored.
maxcpus= [SMP] Maximum number of processors that an SMP kernel
will bring up during bootup. maxcpus=n : n >= 0 limits
the kernel to bring up 'n' processors. Surely after
bootup you can bring up the other plugged cpu by executing
"echo 1 > /sys/devices/system/cpu/cpuX/online". So maxcpus
only takes effect during system bootup.
While n=0 is a special case, it is equivalent to "nosmp",
which also disables the IO APIC.
max_loop= [LOOP] The number of loop block devices that get
(loop.max_loop) unconditionally pre-created at init time. The default
number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead
of statically allocating a predefined number, loop
devices can be requested on-demand with the
/dev/loop-control interface.
mce [X86-32] Machine Check Exception
mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt
md= [HW] RAID subsystems devices and level
See Documentation/admin-guide/md.rst.
mdacon= [MDA]
Format: <first>,<last>
Specifies range of consoles to be captured by the MDA.
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
Amount of memory to be used when the kernel is not able
to see the whole system memory or for test.
[X86] Work as limiting max address. Use together
with memmap= to avoid physical address space collisions.
Without memmap= PCI devices could be placed at addresses
belonging to unused RAM.
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.
memchunk=nn[KMG]
[KNL,SH] Allow user to override the default size for
per-device physically contiguous DMA buffers.
memhp_default_state=online/offline
[KNL] Set the initial state for the memory hotplug
onlining policy. If not specified, the default value is
set according to the
CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config
option.
See Documentation/memory-hotplug.txt.
memmap=exactmap [KNL,X86] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
BIOS output or other requirements. See the memmap=nn@ss
option description.
memmap=nn[KMG]@ss[KMG]
[KNL] Force usage of a specific region of memory.
Region of memory to be used is from ss to ss+nn.
memmap=nn[KMG]#ss[KMG]
[KNL,ACPI] Mark specific memory as ACPI data.
Region of memory to be marked is from ss to ss+nn.
memmap=nn[KMG]$ss[KMG]
[KNL,ACPI] Mark specific memory as reserved.
Region of memory to be reserved is from ss to ss+nn.
Example: Exclude memory from 0x18690000-0x1869ffff
memmap=64K$0x18690000
or
memmap=0x10000$0x18690000
memmap=nn[KMG]!ss[KMG]
[KNL,X86] Mark specific memory as protected.
Region of memory to be used, from ss to ss+nn.
The memory region may be marked as e820 type 12 (0xc)
and is NVDIMM or ADR memory.
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
Setting this option will scan the memory
looking for corruption. Enabling this will
both detect corruption and prevent the kernel
from using the memory being corrupted.
However, its intended as a diagnostic tool; if
repeatable BIOS-originated corruption always
affects the same memory, you can use memmap=
to prevent the kernel from using that memory.
memory_corruption_check_size=size [X86]
By default it checks for corruption in the low
64k, making this memory unavailable for normal
use. Use this parameter to scan for
corruption in more or less memory.
memory_corruption_check_period=seconds [X86]
By default it checks for corruption every 60
seconds. Use this parameter to check at some
other rate. 0 disables periodic checking.
memtest= [KNL,X86,ARM] Enable memtest
Format: <integer>
default : 0 <disable>
Specifies the number of memtest passes to be
performed. Each pass selects another test
pattern from a given set of patterns. Memtest
fills the memory with this pattern, validates
memory contents and reserves bad memory
regions that are detected.
meye.*= [HW] Set MotionEye Camera parameters
See Documentation/video4linux/meye.txt.
mfgpt_irq= [IA-32] Specify the IRQ to use for the
Multi-Function General Purpose Timers on AMD Geode
platforms.
mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
the BIOS has incorrectly applied a workaround. TinyBIOS
version 0.98 is known to be affected, 0.99 fixes the
problem by letting the user disable the workaround.
mga= [HW,DRM]
min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
physical address is ignored.
mini2440= [ARM,HW,KNL]
Format:[0..2][b][c][t]
Default: "0tb"
MINI2440 configuration specification:
0 - The attached screen is the 3.5" TFT
1 - The attached screen is the 7" TFT
2 - The VGA Shield is attached (1024x768)
Leaving out the screen size parameter will not load
the TFT driver, and the framebuffer will be left
unconfigured.
b - Enable backlight. The TFT backlight pin will be
linked to the kernel VESA blanking code and a GPIO
LED. This parameter is not necessary when using the
VGA shield.
c - Enable the s3c camera interface.
t - Reserved for enabling touchscreen support. The
touchscreen support is not enabled in the mainstream
kernel as of 2.6.30, a preliminary port can be found
in the "bleeding edge" mini2440 support kernel at
http://repo.or.cz/w/linux-2.6/mini2440.git
mminit_loglevel=
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
parameter allows control of the logging verbosity for
the additional memory initialisation checks. A value
of 0 disables mminit logging and a level of 4 will
log everything. Information is printed at KERN_DEBUG
so loglevel=8 may also need to be specified.
module.sig_enforce
[KNL] When CONFIG_MODULE_SIG is set, this means that
modules without (valid) signatures will fail to load.
Note that if CONFIG_MODULE_SIG_FORCE is set, that
is always true, so this option does nothing.
module_blacklist= [KNL] Do not load a comma-separated list of
modules. Useful for debugging problem modules.
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
a tap and be reported as a left button click (for
touchpads working in absolute mode only).
Format: <msecs>
mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
reporting absolute coordinates, such as tablets
mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
reporting absolute coordinates, such as tablets
movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
is similar to kernelcore except it specifies the
amount of memory used for migratable allocations.
If both kernelcore and movablecore is specified,
then kernelcore will be at *least* the specified
value but may be more. If movablecore on its own
is specified, the administrator must be careful
that the amount of memory usable for all allocations
is not too small.
movable_node [KNL,X86] Boot-time switch to enable the effects
of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>
MTD_Region= [MTD] Format:
<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
mtdparts= [MTD]
See drivers/mtd/cmdlinepart.c.
multitce=off [PPC] This parameter disables the use of the pSeries
firmware feature for updating multiple TCE entries
at a time.
onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
boundary - index of last SLC block on Flex-OneNAND.
The remaining blocks are configured as MLC blocks.
lock - Configure if Flex-OneNAND boundary should be locked.
Once locked, the boundary cannot be changed.
1 indicates lock status, 0 indicates unlock status.
mtdset= [ARM]
ARM/S3C2412 JIVE boot control
See arch/arm/mach-s3c2412/mach-jive.c
mtouchusb.raw_coordinates=
[HW] Make the MicroTouch USB driver use raw coordinates
('y', default) or cooked coordinates ('n')
mtrr_chunk_size=nn[KMG] [X86]
used for mtrr cleanup. It is largest continuous chunk
that could hold holes aka. UC entries.
mtrr_gran_size=nn[KMG] [X86]
Used for mtrr cleanup. It is granularity of mtrr block.
Default is 1.
Large value could prevent small alignment from
using up MTRRs.
mtrr_spare_reg_nr=n [X86]
Format: <integer>
Range: 0,7 : spare reg number
Default : 1
Used for mtrr cleanup. It is spare mtrr entries number.
Set to 2 or more if your graphical card needs more.
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
netdev= [NET] Network devices parameters
Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
Note that mem_start is often overloaded to mean
something different and driver-specific.
This usage is only documented in each driver source
file if at all.
nf_conntrack.acct=
[NETFILTER] Enable connection tracking flow accounting
0 to disable accounting
1 to enable accounting
Default value is 0.
nfsaddrs= [NFS] Deprecated. Use ip= instead.
See Documentation/filesystems/nfs/nfsroot.txt.
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
See Documentation/filesystems/nfs/nfsroot.txt.
nfsrootdebug [NFS] enable nfsroot debugging messages.
See Documentation/filesystems/nfs/nfsroot.txt.
nfs.callback_nr_threads=
[NFSv4] set the total number of threads that the
NFS client will assign to service NFSv4 callback
requests.
nfs.callback_tcpport=
[NFS] set the TCP port on which the NFSv4 callback
channel should listen.
nfs.cache_getent=
[NFS] sets the pathname to the program which is used
to update the NFS client cache entries.
nfs.cache_getent_timeout=
[NFS] sets the timeout after which an attempt to
update a cache entry is deemed to have failed.
nfs.idmap_cache_timeout=
[NFS] set the maximum lifetime for idmapper cache
entries.
nfs.enable_ino64=
[NFS] enable 64-bit inode numbers.
If zero, the NFS client will fake up a 32-bit inode
number for the readdir() and stat() syscalls instead
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.
nfs.max_session_cb_slots=
[NFSv4.1] Sets the maximum number of session
slots the client will assign to the callback
channel. This determines the maximum number of
callbacks the client will process in parallel for
a particular server.
nfs.max_session_slots=
[NFSv4.1] Sets the maximum number of session slots
the client will attempt to negotiate with the server.
This limits the number of simultaneous RPC requests
that the client can send to the NFSv4.1 server.
Note that there is little point in setting this
value higher than the max_tcp_slot_table_limit.
nfs.nfs4_disable_idmapping=
[NFSv4] When set to the default of '1', this option
ensures that both the RPC level authentication
scheme and the NFS level operations agree to use
numeric uids/gids if the mount is using the
'sec=sys' security flavour. In effect it is
disabling idmapping, which can make migration from
legacy NFSv2/v3 systems to NFSv4 easier.
Servers that do not support this mode of operation
will be autodetected by the client, and it will fall
back to using the idmapper.
To turn off this behaviour, set the value to '0'.
nfs.nfs4_unique_id=
[NFS4] Specify an additional fixed unique ident-
ification string that NFSv4 clients can insert into
their nfs_client_id4 string. This is typically a
UUID that is generated at system install time.
nfs.send_implementation_id =
[NFSv4.1] Send client implementation identification
information in exchange_id requests.
If zero, no implementation identification information
will be sent.
The default is to send the implementation identification
information.
nfs.recover_lost_locks =
[NFSv4] Attempt to recover locks that were lost due
to a lease timeout on the server. Please note that
doing this risks data corruption, since there are
no guarantees that the file will remain unchanged
after the locks are lost.
If you want to enable the kernel legacy behaviour of
attempting to recover these locks, then set this
parameter to '1'.
The default parameter value of '0' causes the kernel
not to attempt recovery of lost locks.
nfs4.layoutstats_timer =
[NFSv4.2] Change the rate at which the kernel sends
layoutstats to the pNFS metadata server.
Setting this to value to 0 causes the kernel to use
whatever value is the default set by the layout
driver. A non-zero value sets the minimum interval
in seconds between layoutstats transmissions.
nfsd.nfs4_disable_idmapping=
[NFSv4] When set to the default of '1', the NFSv4
server will return only numeric uids and gids to
clients using auth_sys, and will accept numeric uids
and gids from such clients. This is intended to ease
migration from NFSv2/v3.
objlayoutdriver.osd_login_prog=
[NFS] [OBJLAYOUT] sets the pathname to the program which
is used to automatically discover and login into new
osd-targets. Please see:
Documentation/filesystems/pnfs.txt for more explanations
nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
when a NMI is triggered.
Format: [state][,regs][,debounce][,die]
nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
Format: [panic,][nopanic,][num]
Valid num: 0 or 1
0 - turn hardlockup detector in nmi_watchdog off
1 - turn hardlockup detector in nmi_watchdog on
When panic is specified, panic when an NMI watchdog
timeout occurs (or 'nopanic' to override the opposite
default). To disable both hard and soft lockup detectors,
please see 'nowatchdog'.
This is useful when you use a panic=... timeout and
need the box quickly up again.
netpoll.carrier_timeout=
[NET] Specifies amount of time (in seconds) that
netpoll should wait for a carrier. By default netpoll
waits 4 seconds.
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
emulation library even if a 387 maths coprocessor
is present.
no_console_suspend
[HW] Never suspend the console
Disable suspending of consoles during suspend and
hibernate operations. Once disabled, debugging
messages can reach various consoles while the rest
of the system is being put to sleep (ie, while
debugging driver suspend/resume hooks). This may
not work reliably with all consoles, but is known
to work with serial and VGA consoles.
To facilitate more flexible debugging, we also add
console_suspend, a printk module parameter to control
it. Users could use console_suspend (usually
/sys/module/printk/parameters/console_suspend) to
turn on/off it dynamically.
noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
caches in the slab allocator. Saves per-node memory,
but will impact performance.
noalign [KNL,ARM]
noapic [SMP,APIC] Tells the kernel to not make use of any
IOAPICs that may be present in the system.
noautogroup Disable scheduler automatic task group creation.
nobats [PPC] Do not use BATs for mapping kernel lowmem
on "Classic" PPC cores.
nocache [ARM]
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
nodelayacct [KNL] Disable per-task delay accounting
nodsp [SH] Disable hardware DSP at boot time.
noefi Disable EFI runtime services support.
noexec [IA-64]
noexec [X86]
On X86-32 available only on PAE configured kernels.
noexec=on: enable non-executable mappings (default)
noexec=off: disable non-executable mappings
nosmap [X86]
Disable SMAP (Supervisor Mode Access Prevention)
even if it is supported by processor.
nosmep [X86]
Disable SMEP (Supervisor Mode Execution Prevention)
even if it is supported by processor.
noexec32 [X86-64]
This affects only 32-bit executables.
noexec32=on: enable non-executable mappings (default)
read doesn't imply executable mappings
noexec32=off: disable non-executable mappings
read implies executable mappings
nofpu [MIPS,SH] Disable hardware FPU at boot time.
nofxsr [BUGS=X86-32] Disables x86 floating point extended
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
nohugeiomap [KNL,x86] Disable kernel huge I/O mappings.
nosmt [KNL,S390] Disable symmetric multithreading (SMT).
Equivalent to smt=1.
noxsave [BUGS=X86] Disables x86 extended register state save
and restore using xsave. The kernel will fallback to
enabling legacy floating-point and sse state.
noxsaveopt [X86] Disables xsaveopt used in saving x86 extended
register states. The kernel will fall back to use
xsave to save the states. By using this parameter,
performance of saving the states is degraded because
xsave doesn't support modified optimization while
xsaveopt supports it on xsaveopt enabled systems.
noxsaves [X86] Disables xsaves and xrstors used in saving and
restoring x86 extended register state in compacted
form of xsave area. The kernel will fall back to use
xsaveopt and xrstor to save and restore the states
in standard form of xsave area. By using this
parameter, xsave area per process might occupy more
memory on xsaves enabled systems.
nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
wfi(ARM) instruction doesn't work correctly and not to
use it. This is also useful when using JTAG debugger.
no_file_caps Tells the kernel not to honor file capabilities. The
only way then for a file to be executed with privilege
is to be setuid root or executed by root.
nohalt [IA-64] Tells the kernel not to use the power saving
function PAL_HALT_LIGHT when idle. This increases
power-consumption. On the positive side, it reduces
interrupt wake-up latency, which may improve performance
in certain environments such as networked servers or
real-time systems.
nohibernate [HIBERNATION] Disable hibernation and resume.
nohz= [KNL] Boottime enable/disable dynamic ticks
Valid arguments: on, off
Default: on
nohz_full= [KNL,BOOT]
The argument is a cpu list, as described above.
In kernels built with CONFIG_NO_HZ_FULL=y, set
the specified list of CPUs whose tick will be stopped
whenever possible. The boot CPU will be forced outside
the range to maintain the timekeeping.
The CPUs in this range must also be included in the
rcu_nocbs= set.
noiotrap [SH] Disables trapped I/O port accesses.
noirqdebug [X86-32] Disables the code which attempts to detect and
disable unhandled interrupt sources.
no_timer_check [X86,APIC] Disables the code which tests for
broken timer IRQ sources.
noisapnp [ISAPNP] Disables ISA PnP code.
noinitrd [RAM] Tells the kernel not to load any configured
initial RAM disk.
nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
remapping.
[Deprecated - use intremap=off]
nointroute [IA-64]
noinvpcid [X86] Disable the INVPCID cpu feature.
nojitter [IA-64] Disables jitter checking for ITC timers.
no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
fault handling.
no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
steal time is computed, but won't influence scheduler
behaviour
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
noltlbs [PPC] Do not use large page/tlb entries for kernel
lowmem mapping on PPC40x and PPC8xx
nomca [IA-64] Disable machine check abort handling
nomce [X86-32] Disable Machine Check Exception
nomfgpt [X86-32] Disable Multi-Function General Purpose
Timer usage (for AMD Geode machines).
nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to
shutdown the other cpus. Instead use the REBOOT_VECTOR
irq.
nomodule Disable module load
nopat [X86] Disable PAT (page attribute table extension of
pagetables) support.
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
with UP alternatives
nordrand [X86] Disable kernel use of the RDRAND and
RDSEED instructions even if they are supported
by the processor. RDRAND and RDSEED are still
available to user space applications.
noresume [SWSUSP] Disables resume and restores original swap
space.
no-scroll [VGA] Disables scrollback.
This is required for the Braillex ib80-piezo Braille
reader made by F.H. Papenmeier (Germany).
nosbagart [IA-64]
nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
and disable the IO APIC. legacy for "maxcpus=0".
nosoftlockup [KNL] Disable the soft-lockup detector.
nosync [HW,M68K] Disables sync negotiation for all devices.
notsc [BUGS=X86-32] Disable Time Stamp Counter
nowatchdog [KNL] Disable both lockup detectors, i.e.
soft-lockup and NMI watchdog (hard-lockup).
nowb [ARM]
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off.
Some features depend on CPU0. Known dependencies are:
1. Resume from suspend/hibernate depends on CPU0.
Suspend/hibernate will fail if CPU0 is offline and you
need to online CPU0 before suspend/hibernate.
2. PIC interrupts also depend on CPU0. CPU0 can't be
removed if a PIC interrupt is detected.
It's said poweroff/reboot may depend on CPU0 on some
machines although I haven't seen such issues so far
after CPU0 is offline on a few tested machines.
If the dependencies are under your control, you can
turn on cpu0_hotplug.
nptcg= [IA-64] Override max number of concurrent global TLB
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
nr_cpus= [SMP] Maximum number of processors that an SMP kernel
could support. nr_cpus=n : n >= 1 limits the kernel to
support 'n' processors. It could be larger than the
number of already plugged CPU during bootup, later in
runtime you can physically add extra cpu until it reaches
n. So during boot up some boot time memory for per-cpu
variables need be pre-allocated for later physical cpu
hot plugging.
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing.
Allowed values are enable and disable
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
one of ['zone', 'node', 'default'] can be specified
This can be set from sysctl after boot.
See Documentation/sysctl/vm.txt for details.
ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
See Documentation/debugging-via-ohci1394.txt for more
info.
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
Rather than timing out after 20 ms if an EC
command is not properly ACKed, override the length
of the timeout. We have interrupts disabled while
waiting for the ACK, so if this is set too high
interrupts *may* be lost!
omap_mux= [OMAP] Override bootloader pin multiplexing.
Format: <mux_mode0.mode_name=value>...
For example, to override I2C bus2:
omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
oprofile.timer= [HW]
Use timer interrupt instead of performance counters
oprofile.cpu_type= Force an oprofile cpu type
This might be useful if you have an older oprofile
userland or if you want common events.
Format: { arch_perfmon }
arch_perfmon: [X86] Force use of architectural
perfmon on Intel CPUs instead of the
CPU specific event set.
timer: [X86] Force use of architectural NMI
timer mode (see also oprofile.timer
for generic hr timer mode)
oops=panic Always panic on oopses. Default is to just kill the
process, but there is a small probability of
deadlocking the machine.
This will also cause panics on machine check exceptions.
Useful together with panic=30 to trigger a reboot.
OSS [HW,OSS]
See Documentation/sound/oss/oss-parameters.txt
page_owner= [KNL] Boot-time page_owner enabling option.
Storage of the information about who allocated
each page is disabled in default. With this switch,
we can turn it on.
on: enable the feature
page_poison= [KNL] Boot-time parameter changing the state of
poisoning on the buddy allocator.
off: turn off poisoning
on: turn on poisoning
panic= [KNL] Kernel behaviour on panic: delay <timeout>
timeout > 0: seconds before rebooting
timeout = 0: wait forever
timeout < 0: reboot immediately
Format: <timeout>
panic_on_warn panic() instead of WARN(). Useful to cause kdump
on a WARN().
crash_kexec_post_notifiers
Run kdump after running panic-notifiers and dumping
kmsg. This only for the users who doubt kdump always
succeeds in any situation.
Note that this also increases risks of kdump failure,
because some panic notifiers can make the crashed
kernel more unstable.
parkbd.port= [HW] Parallel port number the keyboard adapter is
connected to, default is 0.
Format: <parport#>
parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
0 for XT, 1 for AT (default is AT).
Format: <mode>
parport= [HW,PPT] Specify parallel ports. 0 disables.
Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
Use 'auto' to force the driver to use any
IRQ/DMA settings detected (the default is to
ignore detected IRQ/DMA settings because of
possible conflicts). You can specify the base
address, IRQ, and DMA settings; IRQ and DMA
should be numbers, or 'auto' (for using detected
settings on that particular port), or 'nofifo'
(to avoid using a FIFO even if it is detected).
Parallel ports are assigned in the order they
are specified on the command line, starting
with parport0.
parport_init_mode= [HW,PPT]
Configure VIA parallel port to operate in
a specific mode. This is necessary on Pegasos
computer where firmware has no options for setting
up parallel port mode and sets it to spp.
Currently this function knows 686a and 8231 chips.
Format: [spp|ps2|epp|ecp|ecpepp]
pause_on_oops=
Halt all CPUs after the first oops has been printed for
the specified number of seconds. This is to be used if
your oopses keep scrolling off the screen.
pcbit= [HW,ISDN]
pcd. [PARIDE]
See header of drivers/block/paride/pcd.c.
See also Documentation/blockdev/paride.txt.
pci=option[,option...] [PCI] various PCI subsystem options:
earlydump [X86] dump PCI config space before the kernel
changes anything
off [X86] don't probe for the PCI bus
bios [X86-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
has a non-standard PCI host bridge.
nobios [X86-32] disallow use of PCI BIOS, only direct
hardware access methods are allowed. Use this
if you experience crashes upon bootup and you
suspect they are caused by the BIOS.
conf1 [X86] Force use of PCI Configuration Access
Mechanism 1 (config address in IO port 0xCF8,
data in IO port 0xCFC, both 32-bit).
conf2 [X86] Force use of PCI Configuration Access
Mechanism 2 (IO port 0xCF8 is an 8-bit port for
the function, IO port 0xCFA, also 8-bit, sets
bus number. The config space is then accessed
through ports 0xC000-0xCFFF).
See http://wiki.osdev.org/PCI for more info
on the configuration access mechanisms.
noaer [PCIE] If the PCIEAER kernel config parameter is
enabled, this kernel boot option can be used to
disable the use of PCIE advanced error reporting.
nodomains [PCI] Disable support for multiple PCI
root domains (aka PCI segments, in ACPI-speak).
nommconf [X86] Disable use of MMCONFIG for PCI
Configuration
check_enable_amd_mmconf [X86] check for and enable
properly configured MMIO access to PCI
config space on AMD family 10h CPU
nomsi [MSI] If the PCI_MSI kernel config parameter is
enabled, this kernel boot option can be used to
disable the use of MSI interrupts system-wide.
noioapicquirk [APIC] Disable all boot interrupt quirks.
Safety option to keep boot IRQs enabled. This
should never be necessary.
ioapicreroute [APIC] Enable rerouting of boot IRQs to the
primary IO-APIC for bridges that cannot disable
boot IRQs. This fixes a source of spurious IRQs
when the system masks IRQs.
noioapicreroute [APIC] Disable workaround that uses the
boot IRQ equivalent of an IRQ that connects to
a chipset where boot IRQs cannot be disabled.
The opposite of ioapicreroute.
biosirq [X86-32] Use PCI BIOS calls to get the interrupt
routing table. These calls are known to be buggy
on several machines and they hang the machine
when used, but on other computers it's the only
way to get the interrupt routing table. Try
this option if the kernel is unable to allocate
IRQs or discover secondary PCI buses on your
motherboard.
rom [X86] Assign address space to expansion ROMs.
Use with caution as certain devices share
address decoders between ROMs and other
resources.
norom [X86] Do not assign address space to
expansion ROMs that do not already have
BIOS assigned address ranges.
nobar [X86] Do not assign address space to the
BARs that weren't assigned by the BIOS.
irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
assigned automatically to PCI devices. You can
make the kernel exclude IRQs of your ISA cards
this way.
pirqaddr=0xAAAAA [X86] Specify the physical address
of the PIRQ table (normally generated
by the BIOS) if it is outside the
F0000h-100000h range.
lastbus=N [X86] Scan all buses thru bus #N. Can be
useful if the kernel is unable to find your
secondary buses and you want to tell it
explicitly which ones they are.
assign-busses [X86] Always assign all PCI bus
numbers ourselves, overriding
whatever the firmware may have done.
usepirqmask [X86] Honor the possible IRQ mask stored
in the BIOS $PIR table. This is needed on
some systems with broken BIOSes, notably
some HP Pavilion N5400 and Omnibook XE3
notebooks. This will have no effect if ACPI
IRQ routing is enabled.
noacpi [X86] Do not use ACPI for IRQ routing
or for PCI scanning.
use_crs [X86] Use PCI host bridge window information
from ACPI. On BIOSes from 2008 or later, this
is enabled by default. If you need to use this,
please report a bug.
nocrs [X86] Ignore PCI host bridge windows from ACPI.
If you need to use this, please report a bug.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
for broken drivers that don't call it.
skip_isa_align [X86] do not align io start addr, so can
handle more pci cards
noearly [X86] Don't do any early type 1 scanning.
This might help on some broken boards which
machine check when some devices' config space
is read. But various workarounds are disabled
and some IOMMU drivers will not work.
bfsort Sort PCI devices into breadth-first order.
This sorting is done to get a device
order compatible with older (<= 2.4) kernels.
nobfsort Don't sort PCI devices into breadth-first order.
pcie_bus_tune_off Disable PCIe MPS (Max Payload Size)
tuning and use the BIOS-configured MPS defaults.
pcie_bus_safe Set every device's MPS to the largest value
supported by all devices below the root complex.
pcie_bus_perf Set device MPS to the largest allowable MPS
based on its parent bus. Also set MRRS (Max
Read Request Size) to the largest supported
value (no larger than the MPS that the device
or bus can support) for best performance.
pcie_bus_peer2peer Set every device's MPS to 128B, which
every device is guaranteed to support. This
configuration allows peer-to-peer DMA between
any pair of devices, possibly at the cost of
reduced performance. This also guarantees
that hot-added devices will work.
cbiosize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's IO window.
The default value is 256 bytes.
cbmemsize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
resource_alignment=
Format:
[<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
[<order of align>@]pci:<vendor>:<device>\
[:<subvendor>:<subdevice>][; ...]
Specifies alignment and device to reassign
aligned memory resources.
If <order of align> is not specified,
PAGE_SIZE is used as alignment.
PCI-PCI bridge can be specified, if resource
windows need to be expanded.
To specify the alignment for several
instances of a device, the PCI vendor,
device, subvendor, and subdevice may be
specified, e.g., 4096@pci:8086:9c22:103c:198f
ecrc= Enable/disable PCIe ECRC (transaction layer
end-to-end CRC checking).
bios: Use BIOS/firmware settings. This is the
the default.
off: Turn ECRC off
on: Turn ECRC on.
hpiosize=nn[KMG] The fixed amount of bus space which is
reserved for hotplug bridge's IO window.
Default size is 256 bytes.
hpmemsize=nn[KMG] The fixed amount of bus space which is
reserved for hotplug bridge's memory window.
Default size is 2 megabytes.
hpbussize=nn The minimum amount of additional bus numbers
reserved for buses below a hotplug bridge.
Default is 1.
realloc= Enable/disable reallocating PCI bridge resources
if allocations done by BIOS are too small to
accommodate resources required by all child
devices.
off: Turn realloc off
on: Turn realloc on
realloc same as realloc=on
noari do not use PCIe ARI.
pcie_scan_all Scan all possible PCIe devices. Otherwise we
only look for one device below a PCIe downstream
port.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
off Disable ASPM.
force Enable ASPM even on devices that claim not to support it.
WARNING: Forcing ASPM on may cause system lockups.
pcie_hp= [PCIE] PCI Express Hotplug driver options:
nomsi Do not use MSI for PCI Express Native Hotplug (this
makes all PCIe ports use INTx for hotplug services).
pcie_ports= [PCIE] PCIe ports handling:
auto Ask the BIOS whether or not to use native PCIe services
associated with PCIe ports (PME, hot-plug, AER). Use
them only if that is allowed by the BIOS.
native Use native PCIe services associated with PCIe ports
unconditionally.
compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe
ports driver.
pcie_port_pm= [PCIE] PCIe port power management handling:
off Disable power management of all PCIe ports
force Forcibly enable power management of all PCIe ports
pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
nomsi Do not use MSI for native PCIe PME signaling (this makes
all PCIe root ports use INTx for all services).
pcmv= [HW,PCMCIA] BadgePAD 4
pd_ignore_unused
[PM]
Keep all power-domains already enabled by bootloader on,
even if no driver has claimed them. This is useful
for debug and development, but should not be
needed on a platform with proper driver support.
pd. [PARIDE]
See Documentation/blockdev/paride.txt.
pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
boot time.
Format: { 0 | 1 }
See arch/parisc/kernel/pdc_chassis.c
percpu_alloc= Select which percpu first chunk allocator to use.
Currently supported values are "embed" and "page".
Archs may support subset or none of the selections.
See comments in mm/percpu.c for details on each
allocator. This parameter is primarily for debugging
and performance comparison.
pf. [PARIDE]
See Documentation/blockdev/paride.txt.
pg. [PARIDE]
See Documentation/blockdev/paride.txt.
pirq= [SMP,APIC] Manual mp-table setup
See Documentation/x86/i386/IO-APIC.txt.
plip= [PPT,NET] Parallel port network link
Format: { parport<nr> | timid | 0 }
See also Documentation/parport.txt.
pmtmr= [X86] Manual setup of pmtmr I/O Port.
Override pmtimer IOPort with a hex value.
e.g. pmtmr=0x508
pnp.debug=1 [PNP]
Enable PNP debug messages (depends on the
CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
via /sys/module/pnp/parameters/debug. We always show
current resource usage; turning this on also shows
possible settings and some assignment information.
pnpacpi= [ACPI]
{ off }
pnpbios= [ISAPNP]
{ on | off | curr | res | no-curr | no-res }
pnp_reserve_irq=
[ISAPNP] Exclude IRQs for the autoconfiguration
pnp_reserve_dma=
[ISAPNP] Exclude DMAs for the autoconfiguration
pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Ranges are in pairs (I/O port base and size).
pnp_reserve_mem=
[ISAPNP] Exclude memory regions for the
autoconfiguration.
Ranges are in pairs (memory base and size).
ports= [IP_VS_FTP] IPVS ftp helper module
Default is 21.
Up to 8 (IP_VS_APP_MAX_PORTS) ports
may be specified.
Format: <port>,<port>....
ppc_strict_facility_enable
[PPC] This option catches any kernel floating point,
Altivec, VSX and SPE outside of regions specifically
allowed (eg kernel_enable_fpu()/kernel_disable_fpu()).
There is some performance impact when enabling this.
print-fatal-signals=
[KNL] debug: print fatal signals
If enabled, warn about various signal handling
related application anomalies: too many signals,
too many POSIX.1 timers, fatal signals causing a
coredump - etc.
If you hit the warning due to signal overflow,
you might want to try "ulimit -i unlimited".
default: off.
printk.always_kmsg_dump=
Trigger kmsg_dump for cases other than kernel oops or
panics
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
default: disabled
printk.devkmsg={on,off,ratelimit}
Control writing to /dev/kmsg.
on - unlimited logging to /dev/kmsg from userspace
off - logging to /dev/kmsg disabled
ratelimit - ratelimit the logging
Default: ratelimit
printk.time= Show timing data prefixed to each printk message line
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
processor.max_cstate= [HW,ACPI]
Limit processor to maximum C-state
max_cstate=9 overrides any DMI blacklist limit.
processor.nocst [HW,ACPI]
Ignore the _CST method to determine C-states,
instead using the legacy FADT method
profile= [KNL] Enable kernel profiling via /proc/profile
Format: [schedule,]<number>
Param: "schedule" - profile schedule points.
Param: <number> - step/bucket size as a power of 2 for
statistical time based profiling.
Param: "sleep" - profile D-state sleeping (millisecs).
Requires CONFIG_SCHEDSTATS
Param: "kvm" - profile VM exits.
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
before loading.
See Documentation/blockdev/ramdisk.txt.
psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
probe for; one of (bare|imps|exps|lifebook|any).
psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
per second.
psmouse.resetafter= [HW,MOUSE]
Try to reset the device after so many bad packets
(0 = never).
psmouse.resolution=
[HW,MOUSE] Set desired mouse resolution, in dpi.
psmouse.smartscroll=
[HW,MOUSE] Controls Logitech smartscroll autorepeat.
0 = disabled, 1 = enabled (default).
pstore.backend= Specify the name of the pstore backend to use
pt. [PARIDE]
See Documentation/blockdev/paride.txt.
pty.legacy_count=
[KNL] Number of legacy pty's. Overwrites compiled-in
default number.
quiet [KNL] Disable most log messages
r128= [HW,DRM]
raid= [HW,RAID]
See Documentation/admin-guide/md.rst.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
See Documentation/blockdev/ramdisk.txt.
rcu_nocbs= [KNL]
The argument is a cpu list, as described above.
In kernels built with CONFIG_RCU_NOCB_CPU=y, set
the specified list of CPUs to be no-callback CPUs.
Invocation of these CPUs' RCU callbacks will
be offloaded to "rcuox/N" kthreads created for
that purpose, where "x" is "b" for RCU-bh, "p"
for RCU-preempt, and "s" for RCU-sched, and "N"
is the CPU number. This reduces OS jitter on the
offloaded CPUs, which can be useful for HPC and
real-time workloads. It can also improve energy
efficiency for asymmetric multiprocessors.
rcu_nocb_poll [KNL]
Rather than requiring that offloaded CPUs
(specified by rcu_nocbs= above) explicitly
awaken the corresponding "rcuoN" kthreads,
make these kthreads poll for callbacks.
This improves the real-time response for the
offloaded CPUs by relieving them of the need to
wake up the corresponding kthread, but degrades
energy efficiency by requiring that the kthreads
periodically wake up to do the polling.
rcutree.blimit= [KNL]
Set maximum number of finished RCU callbacks to
process in one batch.
rcutree.dump_tree= [KNL]
Dump the structure of the rcu_node combining tree
out at early boot. This is used for diagnostic
purposes, to verify correct tree setup.
rcutree.gp_cleanup_delay= [KNL]
Set the number of jiffies to delay each step of
RCU grace-period cleanup. This only has effect
when CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP is set.
rcutree.gp_init_delay= [KNL]
Set the number of jiffies to delay each step of
RCU grace-period initialization. This only has
effect when CONFIG_RCU_TORTURE_TEST_SLOW_INIT
is set.
rcutree.gp_preinit_delay= [KNL]
Set the number of jiffies to delay each step of
RCU grace-period pre-initialization, that is,
the propagation of recent CPU-hotplug changes up
the rcu_node combining tree. This only has effect
when CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT is set.
rcutree.rcu_fanout_exact= [KNL]
Disable autobalancing of the rcu_node combining
tree. This is used by rcutorture, and might
possibly be useful for architectures having high
cache-to-cache transfer latencies.
rcutree.rcu_fanout_leaf= [KNL]
Change the number of CPUs assigned to each
leaf rcu_node structure. Useful for very
large systems, which will choose the value 64,
and for NUMA systems with large remote-access
latencies, which will choose a value aligned
with the appropriate hardware boundaries.
rcutree.jiffies_till_sched_qs= [KNL]
Set required age in jiffies for a
given grace period before RCU starts
soliciting quiescent-state help from
rcu_note_context_switch().
rcutree.jiffies_till_first_fqs= [KNL]
Set delay from grace-period initialization to
first attempt to force quiescent states.
Units are jiffies, minimum value is zero,
and maximum value is HZ.
rcutree.jiffies_till_next_fqs= [KNL]
Set delay between subsequent attempts to force
quiescent states. Units are jiffies, minimum
value is one, and maximum value is HZ.
rcutree.kthread_prio= [KNL,BOOT]
Set the SCHED_FIFO priority of the RCU per-CPU
kthreads (rcuc/N). This value is also used for
the priority of the RCU boost threads (rcub/N)
and for the RCU grace-period kthreads (rcu_bh,
rcu_preempt, and rcu_sched). If RCU_BOOST is
set, valid values are 1-99 and the default is 1
(the least-favored priority). Otherwise, when
RCU_BOOST is not set, valid values are 0-99 and
the default is zero (non-realtime operation).
rcutree.rcu_nocb_leader_stride= [KNL]
Set the number of NOCB kthread groups, which
defaults to the square root of the number of
CPUs. Larger numbers reduces the wakeup overhead
on the per-CPU grace-period kthreads, but increases
that same overhead on each group's leader.
rcutree.qhimark= [KNL]
Set threshold of queued RCU callbacks beyond which
batch limiting is disabled.
rcutree.qlowmark= [KNL]
Set threshold of queued RCU callbacks below which
batch limiting is re-enabled.
rcutree.rcu_idle_gp_delay= [KNL]
Set wakeup interval for idle CPUs that have
RCU callbacks (RCU_FAST_NO_HZ=y).
rcutree.rcu_idle_lazy_gp_delay= [KNL]
Set wakeup interval for idle CPUs that have
only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y).
Lazy RCU callbacks are those which RCU can
prove do nothing more than free memory.
rcuperf.gp_exp= [KNL]
Measure performance of expedited synchronous
grace-period primitives.
rcuperf.holdoff= [KNL]
Set test-start holdoff period. The purpose of
this parameter is to delay the start of the
test until boot completes in order to avoid
interference.
rcuperf.nreaders= [KNL]
Set number of RCU readers. The value -1 selects
N, where N is the number of CPUs. A value
"n" less than -1 selects N-n+1, where N is again
the number of CPUs. For example, -2 selects N
(the number of CPUs), -3 selects N+1, and so on.
A value of "n" less than or equal to -N selects
a single reader.
rcuperf.nwriters= [KNL]
Set number of RCU writers. The values operate
the same as for rcuperf.nreaders.
N, where N is the number of CPUs
rcuperf.perf_runnable= [BOOT]
Start rcuperf running at boot time.
rcuperf.shutdown= [KNL]
Shut the system down after performance tests
complete. This is useful for hands-off automated
testing.
rcuperf.perf_type= [KNL]
Specify the RCU implementation to test.
rcuperf.verbose= [KNL]
Enable additional printk() statements.
rcutorture.cbflood_inter_holdoff= [KNL]
Set holdoff time (jiffies) between successive
callback-flood tests.
rcutorture.cbflood_intra_holdoff= [KNL]
Set holdoff time (jiffies) between successive
bursts of callbacks within a given callback-flood
test.
rcutorture.cbflood_n_burst= [KNL]
Set the number of bursts making up a given
callback-flood test. Set this to zero to
disable callback-flood testing.
rcutorture.cbflood_n_per_burst= [KNL]
Set the number of callbacks to be registered
in a given burst of a callback-flood test.
rcutorture.fqs_duration= [KNL]
Set duration of force_quiescent_state bursts
in microseconds.
rcutorture.fqs_holdoff= [KNL]
Set holdoff time within force_quiescent_state bursts
in microseconds.
rcutorture.fqs_stutter= [KNL]
Set wait time between force_quiescent_state bursts
in seconds.
rcutorture.gp_cond= [KNL]
Use conditional/asynchronous update-side
primitives, if available.
rcutorture.gp_exp= [KNL]
Use expedited update-side primitives, if available.
rcutorture.gp_normal= [KNL]
Use normal (non-expedited) asynchronous
update-side primitives, if available.
rcutorture.gp_sync= [KNL]
Use normal (non-expedited) synchronous
update-side primitives, if available. If all
of rcutorture.gp_cond=, rcutorture.gp_exp=,
rcutorture.gp_normal=, and rcutorture.gp_sync=
are zero, rcutorture acts as if is interpreted
they are all non-zero.
rcutorture.n_barrier_cbs= [KNL]
Set callbacks/threads for rcu_barrier() testing.
rcutorture.nfakewriters= [KNL]
Set number of concurrent RCU writers. These just
stress RCU, they don't participate in the actual
test, hence the "fake".
rcutorture.nreaders= [KNL]
Set number of RCU readers. The value -1 selects
N-1, where N is the number of CPUs. A value
"n" less than -1 selects N-n-2, where N is again
the number of CPUs. For example, -2 selects N
(the number of CPUs), -3 selects N+1, and so on.
rcutorture.object_debug= [KNL]
Enable debug-object double-call_rcu() testing.
rcutorture.onoff_holdoff= [KNL]
Set time (s) after boot for CPU-hotplug testing.
rcutorture.onoff_interval= [KNL]
Set time (s) between CPU-hotplug operations, or
zero to disable CPU-hotplug testing.
rcutorture.shuffle_interval= [KNL]
Set task-shuffle interval (s). Shuffling tasks
allows some CPUs to go into dyntick-idle mode
during the rcutorture test.
rcutorture.shutdown_secs= [KNL]
Set time (s) after boot system shutdown. This
is useful for hands-off automated testing.
rcutorture.stall_cpu= [KNL]
Duration of CPU stall (s) to test RCU CPU stall
warnings, zero to disable.
rcutorture.stall_cpu_holdoff= [KNL]
Time to wait (s) after boot before inducing stall.
rcutorture.stat_interval= [KNL]
Time (s) between statistics printk()s.
rcutorture.stutter= [KNL]
Time (s) to stutter testing, for example, specifying
five seconds causes the test to run for five seconds,
wait for five seconds, and so on. This tests RCU's
ability to transition abruptly to and from idle.
rcutorture.test_boost= [KNL]
Test RCU priority boosting? 0=no, 1=maybe, 2=yes.
"Maybe" means test if the RCU implementation
under test support RCU priority boosting.
rcutorture.test_boost_duration= [KNL]
Duration (s) of each individual boost test.
rcutorture.test_boost_interval= [KNL]
Interval (s) between each boost test.
rcutorture.test_no_idle_hz= [KNL]
Test RCU's dyntick-idle handling. See also the
rcutorture.shuffle_interval parameter.
rcutorture.torture_runnable= [BOOT]
Start rcutorture running at boot time.
rcutorture.torture_type= [KNL]
Specify the RCU implementation to test.
rcutorture.verbose= [KNL]
Enable additional printk() statements.
rcupdate.rcu_cpu_stall_suppress= [KNL]
Suppress RCU CPU stall warning messages.
rcupdate.rcu_cpu_stall_timeout= [KNL]
Set timeout for RCU CPU stall warning messages.
rcupdate.rcu_expedited= [KNL]
Use expedited grace-period primitives, for
example, synchronize_rcu_expedited() instead
of synchronize_rcu(). This reduces latency,
but can increase CPU utilization, degrade
real-time latency, and degrade energy efficiency.
No effect on CONFIG_TINY_RCU kernels.
rcupdate.rcu_normal= [KNL]
Use only normal grace-period primitives,
for example, synchronize_rcu() instead of
synchronize_rcu_expedited(). This improves
real-time latency, CPU utilization, and
energy efficiency, but can expose users to
increased grace-period latency. This parameter
overrides rcupdate.rcu_expedited. No effect on
CONFIG_TINY_RCU kernels.
rcupdate.rcu_normal_after_boot= [KNL]
Once boot has completed (that is, after
rcu_end_inkernel_boot() has been invoked), use
only normal grace-period primitives. No effect
on CONFIG_TINY_RCU kernels.
rcupdate.rcu_task_stall_timeout= [KNL]
Set timeout in jiffies for RCU task stall warning
messages. Disable with a value less than or equal
to zero.
rcupdate.rcu_self_test= [KNL]
Run the RCU early boot self tests
rcupdate.rcu_self_test_bh= [KNL]
Run the RCU bh early boot self tests
rcupdate.rcu_self_test_sched= [KNL]
Run the RCU sched early boot self tests
rdinit= [KNL]
Format: <full_path>
Run specified binary instead of /init from the ramdisk,
used for early userspace startup. See initrd.
reboot= [KNL]
Format (x86 or x86_64):
[w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \
[[,]s[mp]#### \
[[,]b[ios] | a[cpi] | k[bd] | t[riple] | e[fi] | p[ci]] \
[[,]f[orce]
Where reboot_mode is one of warm (soft) or cold (hard) or gpio,
reboot_type is one of bios, acpi, kbd, triple, efi, or pci,
reboot_force is either force or not specified,
reboot_cpu is s[mp]#### with #### being the processor
to be used for rebooting.
relax_domain_level=
[KNL, SMP] Set scheduler's default relax_domain_level.
See Documentation/cgroup-v1/cpusets.txt.
relative_sleep_states=
[SUSPEND] Use sleep state labeling where the deepest
state available other than hibernation is always "mem".
Format: { "0" | "1" }
0 -- Traditional sleep state labels.
1 -- Relative sleep state labels.
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
reservetop= [X86-32]
Format: nn[KMG]
Reserves a hole at the top of the kernel virtual
address space.
reservelow= [X86]
Format: nn[K]
Set the amount of memory to reserve for BIOS at
the bottom of the address space.
reset_devices [KNL] Force drivers to reset the underlying device
during initialization.
resume= [SWSUSP]
Specify the partition device for software suspend
Format:
{/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>}
resume_offset= [SWSUSP]
Specify the offset from the beginning of the partition
given by "resume=" at which the swap header is located,
in <PAGE_SIZE> units (needed only for swap files).
See Documentation/power/swsusp-and-swap-files.txt
resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to
read the resume files
resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up.
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
hibernate= [HIBERNATION]
noresume Don't check if there's a hibernation image
present during boot.
nocompress Don't compress/decompress hibernation images.
no Disable hibernation and resume.
protect_image Turn on image protection during restoration
(that will set all pages holding image data
during restoration read-only).
retain_initrd [RAM] Keep initrd memory after extraction
rfkill.default_state=
0 "airplane mode". All wifi, bluetooth, wimax, gps, fm,
etc. communication is blocked by default.
1 Unblocked.
rfkill.master_switch_mode=
0 The "airplane mode" button does nothing.
1 The "airplane mode" button toggles between everything
blocked and the previous configuration.
2 The "airplane mode" button toggles between everything
blocked and everything unblocked.
rhash_entries= [KNL,NET]
Set number of hash buckets for route cache
ro [KNL] Mount root device read-only on boot
rodata= [KNL]
on Mark read-only kernel memory as read-only (default).
off Leave read-only kernel memory writable for debugging.
rockchip.usb_uart
Enable the uart passthrough on the designated usb port
on Rockchip SoCs. When active, the signals of the
debug-uart get routed to the D+ and D- pins of the usb
port and the regular usb controller gets disabled.
root= [KNL] Root filesystem
See name_to_dev_t comment in init/do_mounts.c.
rootdelay= [KNL] Delay (in seconds) to pause before attempting to
mount the root filesystem
rootflags= [KNL] Set root filesystem mount option string
rootfstype= [KNL] Set root filesystem type
rootwait [KNL] Wait (indefinitely) for root device to show up.
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
rproc_mem=nn[KMG][@address]
[KNL,ARM,CMA] Remoteproc physical memory block.
Memory area to be used by remote processor image,
managed by CMA.
rw [KNL] Mount root device read-write on boot
S [KNL] Run init in single mode
s390_iommu= [HW,S390]
Set s390 IOTLB flushing mode
strict
With strict flushing every unmap operation will result in
an IOTLB flush. Default is lazy flushing before reuse,
which is faster.
sa1100ir [NET]
See drivers/net/irda/sa1100_ir.c.
sbni= [NET] Granch SBNI12 leased line adapter
sched_debug [KNL] Enables verbose scheduler debug messages.
schedstats= [KNL,X86] Enable or disable scheduled statistics.
Allowed values are enable and disable. This feature
incurs a small amount of overhead in the scheduler
but is useful for debugging and performance tuning.
skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
xtime_lock contention on larger systems, and/or RCU lock
contention on all systems with CONFIG_MAXSMP set.
Format: { "0" | "1" }
0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
1 -- enable.
Note: increases power consumption, thus should only be
enabled if running jitter sensitive (HPC/RT) workloads.
security= [SECURITY] Choose a security module to enable at boot.
If this boot parameter is not specified, only the first
security module asking for security registration will be
loaded. An invalid security module name will be treated
as if no module has been chosen.
selinux= [SELINUX] Disable or enable SELinux at boot time.
Format: { "0" | "1" }
See security/selinux/Kconfig help text.
0 -- disable.
1 -- enable.
Default value is set via kernel config option.
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
apparmor= [APPARMOR] Disable or enable AppArmor at boot time
Format: { "0" | "1" }
See security/apparmor/Kconfig help text
0 -- disable.
1 -- enable.
Default value is set via kernel config option.
serialnumber [BUGS=X86-32]
shapers= [NET]
Maximal number of shapers.
show_msr= [x86] show boot-time MSR settings
Format: { <integer> }
Show boot-time (BIOS-initialized) MSR settings.
The parameter means the number of CPUs to show,
for example 1 means boot CPU only.
simeth= [IA-64]
simscsi=
slram= [HW,MTD]
slab_nomerge [MM]
Disable merging of slabs with similar size. May be
necessary if there is some reason to distinguish
allocs to different slabs. Debug options disable
merging on their own.
For more information see Documentation/vm/slub.txt.
slab_max_order= [MM, SLAB]
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
fragmentation. Defaults to 1 for systems with
more than 32MB of RAM, 0 otherwise.
slub_debug[=options[,slabs]] [MM, SLUB]
Enabling slub_debug allows one to determine the
culprit if slab objects become corrupted. Enabling
slub_debug can create guard zones around objects and
may poison objects when not in use. Also tracks the
last alloc / free. For more information see
Documentation/vm/slub.txt.
slub_max_order= [MM, SLUB]
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
fragmentation. For more information see
Documentation/vm/slub.txt.
slub_min_objects= [MM, SLUB]
The minimum number of objects per slab. SLUB will
increase the slab order up to slub_max_order to
generate a sufficiently large slab able to contain
the number of objects indicated. The higher the number
of objects the smaller the overhead of tracking slabs
and the less frequently locks need to be acquired.
For more information see Documentation/vm/slub.txt.
slub_min_order= [MM, SLUB]
Determines the minimum page order for slabs. Must be
lower than slub_max_order.
For more information see Documentation/vm/slub.txt.
slub_nomerge [MM, SLUB]
Same with slab_nomerge. This is supported for legacy.
See slab_nomerge for more information.
smart2= [HW]
Format: <io1>[,<io2>[,...,<io8>]]
smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
smsc-ircc2.ircc_sir= [HW] SIR base I/O port
smsc-ircc2.ircc_fir= [HW] FIR base I/O port
smsc-ircc2.ircc_irq= [HW] IRQ line
smsc-ircc2.ircc_dma= [HW] DMA channel
smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
0: Toshiba Satellite 1800 (GP data pin select)
1: Fast pin select (default)
2: ATC IRMode
smt [KNL,S390] Set the maximum number of threads (logical
CPUs) to use per physical CPU on systems capable of
symmetric multithreading (SMT). Will be capped to the
actual hardware limit.
Format: <integer>
Default: -1 (no limit)
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
Format: <integer>
softlockup_all_cpu_backtrace=
[KNL] Should the soft-lockup detector generate
backtraces on all cpus.
Format: <integer>
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/laptops/sonypi.txt
spia_io_base= [HW,MTD]
spia_fio_base=
spia_pedr=
spia_peddr=
stacktrace [FTRACE]
Enabled the stack tracer on boot up.
stacktrace_filter=[function-list]
[FTRACE] Limit the functions that the stack tracer
will trace at boot up. function-list is a comma separated
list of functions. This list can be changed at run
time by the stack_trace_filter file in the debugfs
tracing directory. Note, this enables stack tracing
and the stacktrace above is not needed.
sti= [PARISC,HW]
Format: <num>
Set the STI (builtin display/keyboard on the HP-PARISC
machines) console (graphic card) which should be used
as the initial boot-console.
See also comment in drivers/video/console/sticore.c.
sti_font= [HW]
See comment in drivers/video/console/sticore.c.
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
sunrpc.min_resvport=
sunrpc.max_resvport=
[NFS,SUNRPC]
SunRPC servers often require that client requests
originate from a privileged port (i.e. a port in the
range 0 < portnr < 1024).
An administrator who wishes to reserve some of these
ports for other uses may adjust the range that the
kernel's sunrpc client considers to be privileged
using these two parameters to set the minimum and
maximum port values.
sunrpc.svc_rpc_per_connection_limit=
[NFS,SUNRPC]
Limit the number of requests that the server will
process in parallel from a single connection.
The default value is 0 (no limit).
sunrpc.pool_mode=
[NFS]
Control how the NFS server code allocates CPUs to
service thread pools. Depending on how many NICs
you have and where their interrupts are bound, this
option will affect which CPUs will do NFS serving.
Note: this parameter cannot be changed while the
NFS server is running.
auto the server chooses an appropriate mode
automatically using heuristics
global a single global pool contains all CPUs
percpu one pool for each CPU
pernode one pool for each NUMA node (equivalent
to global on non-NUMA machines)
sunrpc.tcp_slot_table_entries=
sunrpc.udp_slot_table_entries=
[NFS,SUNRPC]
Sets the upper limit on the number of simultaneous
RPC calls that can be sent from the client to a
server. Increasing these values may allow you to
improve throughput, but will also increase the
amount of memory reserved for use by the client.
suspend.pm_test_delay=
[SUSPEND]
Sets the number of seconds to remain in a suspend test
mode before resuming the system (see
/sys/power/pm_test). Only available when CONFIG_PM_DEBUG
is set. Default value is 5.
swapaccount=[0|1]
[KNL] Enable accounting of swap in memory resource
controller if no parameter or 1 is given or disable
it if 0 is given (See Documentation/cgroup-v1/memory.txt)
swiotlb= [ARM,IA-64,PPC,MIPS,X86]
Format: { <int> | force }
<int> -- Number of I/O TLB slabs
force -- force using of bounce buffers even if they
wouldn't be automatically used by the kernel
switches= [HW,M68k]
sysfs.deprecated=0|1 [KNL]
Enable/disable old style sysfs layout for old udev
on older distributions. When this option is enabled
very new udev will not work anymore. When this option
is disabled (or CONFIG_SYSFS_DEPRECATED not compiled)
in older udev will not work anymore.
Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in
the kernel configuration.
sysrq_always_enabled
[KNL]
Ignore sysrq setting - this boot parameter will
neutralize any effect of /proc/sys/kernel/sysrq.
Useful for debugging.
tcpmhash_entries= [KNL,NET]
Set the number of tcp_metrics_hash slots.
Default value is 8192 or 16384 depending on total
ram pages. This is used to specify the TCP metrics
cache size. See Documentation/networking/ip-sysctl.txt
"tcp_no_metrics_save" section for more details.
tdfx= [HW,DRM]
test_suspend= [SUSPEND][,N]
Specify "mem" (for Suspend-to-RAM) or "standby" (for
standby suspend) or "freeze" (for suspend type freeze)
as the system sleep state during system startup with
the optional capability to repeat N number of times.
The system is woken from this state using a
wakeup-capable RTC alarm.
thash_entries= [KNL,NET]
Set number of hash buckets for TCP connection
thermal.act= [HW,ACPI]
-1: disable all active trip points in all thermal zones
<degrees C>: override all lowest active trip points
thermal.crt= [HW,ACPI]
-1: disable all critical trip points in all thermal zones
<degrees C>: override all critical trip points
thermal.nocrt= [HW,ACPI]
Set to disable actions on ACPI thermal zone
critical and hot trip points.
thermal.off= [HW,ACPI]
1: disable ACPI thermal control
thermal.psv= [HW,ACPI]
-1: disable all passive trip points
<degrees C>: override all passive trip points to this
value
thermal.tzp= [HW,ACPI]
Specify global default ACPI thermal zone polling rate
<deci-seconds>: poll all this frequency
0: no polling (default)
threadirqs [KNL]
Force threading of all interrupt handlers except those
marked explicitly IRQF_NO_THREAD.
tmem [KNL,XEN]
Enable the Transcendent memory driver if built-in.
tmem.cleancache=0|1 [KNL, XEN]
Default is on (1). Disable the usage of the cleancache
API to send anonymous pages to the hypervisor.
tmem.frontswap=0|1 [KNL, XEN]
Default is on (1). Disable the usage of the frontswap
API to send swap pages to the hypervisor. If disabled
the selfballooning and selfshrinking are force disabled.
tmem.selfballooning=0|1 [KNL, XEN]
Default is on (1). Disable the driving of swap pages
to the hypervisor.
tmem.selfshrinking=0|1 [KNL, XEN]
Default is on (1). Partial swapoff that immediately
transfers pages from Xen hypervisor back to the
kernel based on different criteria.
topology= [S390]
Format: {off | on}
Specify if the kernel should make use of the cpu
topology information if the hardware supports this.
The scheduler will make use of this information and
e.g. base its process migration decisions on it.
Default is on.
topology_updates= [KNL, PPC, NUMA]
Format: {off}
Specify if the kernel should ignore (off)
topology updates sent by the hypervisor to this
LPAR.
tp720= [HW,PS2]
tpm_suspend_pcr=[HW,TPM]
Format: integer pcr id
Specify that at suspend time, the tpm driver
should extend the specified pcr with zeros,
as a workaround for some chips which fail to
flush the last written pcr on TPM_SaveState.
This will guarantee that all the other pcrs
are saved.
trace_buf_size=nn[KMG]
[FTRACE] will set tracing buffer size on each cpu.
trace_event=[event-list]
[FTRACE] Set and start specified trace events in order
to facilitate early boot debugging. The event-list is a
comma separated list of trace events to enable. See
also Documentation/trace/events.txt
trace_options=[option-list]
[FTRACE] Enable or disable tracer options at boot.
The option-list is a comma delimited list of options
that can be enabled or disabled just as if you were
to echo the option name into
/sys/kernel/debug/tracing/trace_options
For example, to enable stacktrace option (to dump the
stack trace of each event), add to the command line:
trace_options=stacktrace
See also Documentation/trace/ftrace.txt "trace options"
section.
tp_printk[FTRACE]
Have the tracepoints sent to printk as well as the
tracing ring buffer. This is useful for early boot up
where the system hangs or reboots and does not give the
option for reading the tracing buffer or performing a
ftrace_dump_on_oops.
To turn off having tracepoints sent to printk,
echo 0 > /proc/sys/kernel/tracepoint_printk
Note, echoing 1 into this file without the
tracepoint_printk kernel cmdline option has no effect.
** CAUTION **
Having tracepoints sent to printk() and activating high
frequency tracepoints such as irq or sched, can cause
the system to live lock.
traceoff_on_warning
[FTRACE] enable this option to disable tracing when a
warning is hit. This turns off "tracing_on". Tracing can
be enabled again by echoing '1' into the "tracing_on"
file located in /sys/kernel/debug/tracing/
This option is useful, as it disables the trace before
the WARNING dump is called, which prevents the trace to
be filled with content caused by the warning output.
This option can also be set at run time via the sysctl
option: kernel/traceoff_on_warning
transparent_hugepage=
[KNL]
Format: [always|madvise|never]
Can be used to control the default behavior of the system
with respect to transparent hugepages.
See Documentation/vm/transhuge.txt for more details.
tsc= Disable clocksource stability checks for TSC.
Format: <string>
[x86] reliable: mark tsc clocksource as reliable, this
disables clocksource verification at runtime, as well
as the stability checks done at bootup. Used to enable
high-resolution timer mode on older hardware, and in
virtualized environment.
[x86] noirqtime: Do not use TSC to do irq accounting.
Used to run time disable IRQ_TIME_ACCOUNTING on any
platforms where RDTSC is slow and this accounting
can add overhead.
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
Format:
<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
See also Documentation/input/joystick-parport.txt
udbg-immortal [PPC] When debugging early kernel crashes that
happen after console_init() and before a proper
console driver takes over, this boot options might
help "seeing" what's going on.
uhash_entries= [KNL,NET]
Set number of hash buckets for UDP/UDP-Lite connections
uhci-hcd.ignore_oc=
[USB] Ignore overcurrent events (default N).
Some badly-designed motherboards generate lots of
bogus events, for ports that aren't wired to
anything. Set this parameter to avoid log spamming.
Note that genuine overcurrent events won't be
reported either.
unknown_nmi_panic
[X86] Cause panic on unknown NMI.
usbcore.authorized_default=
[USB] Default USB device authorization:
(default -1 = authorized except for wireless USB,
0 = not authorized, 1 = authorized)
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
for newly-detected USB devices (default 2). This
is the time required before an idle device will be
autosuspended. Devices for which the delay is set
to a negative value won't be autosuspended at all.
usbcore.usbfs_snoop=
[USB] Set to log all usbfs traffic (default 0 = off).
usbcore.usbfs_snoop_max=
[USB] Maximum number of bytes to snoop in each URB
(default = 65536).
usbcore.blinkenlights=
[USB] Set to cycle leds on hubs (default 0 = off).
usbcore.old_scheme_first=
[USB] Start with the old device initialization
scheme (default 0 = off).
usbcore.usbfs_memory_mb=
[USB] Memory limit (in MB) for buffers allocated by
usbfs (default = 16, 0 = max = 2047).
usbcore.use_both_schemes=
[USB] Try the other device initialization scheme
if the first one fails (default 1 = enabled).
usbcore.initial_descriptor_timeout=
[USB] Specifies timeout for the initial 64-byte
USB_REQ_GET_DESCRIPTOR request in milliseconds
(default 5000 = 5.0 seconds).
usbcore.nousb [USB] Disable the USB subsystem
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.
usb-storage.delay_use=
[UMS] The delay in seconds before a new device is
scanned for Logical Units (default 1).
usb-storage.quirks=
[UMS] A list of quirks entries to supplement or
override the built-in unusual_devs list. List
entries are separated by commas. Each entry has
the form VID:PID:Flags where VID and PID are Vendor
and Product ID values (4-digit hex numbers) and
Flags is a set of characters, each corresponding
to a common usb-storage quirk flag as follows:
a = SANE_SENSE (collect more than 18 bytes
of sense data);
b = BAD_SENSE (don't collect more than 18
bytes of sense data);
c = FIX_CAPACITY (decrease the reported
device capacity by one sector);
d = NO_READ_DISC_INFO (don't use
READ_DISC_INFO command);
e = NO_READ_CAPACITY_16 (don't use
READ_CAPACITY_16 command);
f = NO_REPORT_OPCODES (don't use report opcodes
command, uas only);
g = MAX_SECTORS_240 (don't transfer more than
240 sectors at a time, uas only);
h = CAPACITY_HEURISTICS (decrease the
reported device capacity by one
sector if the number is odd);
i = IGNORE_DEVICE (don't bind to this
device);
j = NO_REPORT_LUNS (don't use report luns
command, uas only);
l = NOT_LOCKABLE (don't try to lock and
unlock ejectable media);
m = MAX_SECTORS_64 (don't transfer more
than 64 sectors = 32 KB at a time);
n = INITIAL_READ10 (force a retry of the
initial READ(10) command);
o = CAPACITY_OK (accept the capacity
reported by the device);
p = WRITE_CACHE (the device cache is ON
by default);
r = IGNORE_RESIDUE (the device reports
bogus residue values);
s = SINGLE_LUN (the device has only one
Logical Unit);
t = NO_ATA_1X (don't allow ATA(12) and ATA(16)
commands, uas only);
u = IGNORE_UAS (don't bind to the uas driver);
w = NO_WP_DETECT (don't test whether the
medium is write-protected).
y = ALWAYS_SYNC (issue a SYNCHRONIZE_CACHE
even if the device claims no cache)
Example: quirks=0419:aaf5:rl,0421:0433:rc
user_debug= [KNL,ARM]
Format: <int>
See arch/arm/Kconfig.debug help text.
1 - undefined instruction events
2 - system calls
4 - invalid data aborts
8 - SIGSEGV faults
16 - SIGBUS faults
Example: user_debug=31
userpte=
[X86] Flags controlling user PTE allocations.
nohigh = do not allocate PTE pages in
HIGHMEM regardless of setting
of CONFIG_HIGHPTE.
vdso= [X86,SH]
On X86_32, this is an alias for vdso32=. Otherwise:
vdso=1: enable VDSO (the default)
vdso=0: disable VDSO mapping
vdso32= [X86] Control the 32-bit vDSO
vdso32=1: enable 32-bit VDSO
vdso32=0 or vdso32=2: disable 32-bit VDSO
See the help text for CONFIG_COMPAT_VDSO for more
details. If CONFIG_COMPAT_VDSO is set, the default is
vdso32=0; otherwise, the default is vdso32=1.
For compatibility with older kernels, vdso32=2 is an
alias for vdso32=0.
Try vdso32=0 if you encounter an error that says:
dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
vector= [IA-64,SMP]
vector=percpu: enable percpu vector domain
video= [FB] Frame buffer configuration
See Documentation/fb/modedb.txt.
video.brightness_switch_enabled= [0,1]
If set to 1, on receiving an ACPI notify event
generated by hotkey, video driver will adjust brightness
level and then send out the event to user space through
the allocated input device; If set to 0, video driver
will only send out the event without touching backlight
brightness level.
default: 1
virtio_mmio.device=
[VMMIO] Memory mapped virtio (platform) device.
<size>@<baseaddr>:<irq>[:<id>]
where:
<size> := size (can use standard suffixes
like K, M and G)
<baseaddr> := physical base address
<irq> := interrupt number (as passed to
request_irq())
<id> := (optional) platform device id
example:
virtio_mmio.device=1K@0x100b0000:48:7
Can be used multiple times for multiple devices.
vga= [BOOT,X86-32] Select a particular video mode
See Documentation/x86/boot.txt and
Documentation/svga.txt.
Use vga=ask for menu.
This is actually a boot loader parameter; the value is
passed to the kernel using a special protocol.
vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
size of <nn>. This can be used to increase the
minimum size (128MB on x86). It can also be used to
decrease the size and leave more room for directly
mapped kernel RAM.
vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
Format: <command>
vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
Format: <command>
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
vsyscall= [X86-64]
Controls the behavior of vsyscalls (i.e. calls to
fixed addresses of 0xffffffffff600x00 from legacy
code). Most statically-linked binaries and older
versions of glibc use these calls. Because these
functions are at fixed addresses, they make nice
targets for exploits that can control RIP.
emulate [default] Vsyscalls turn into traps and are
emulated reasonably safely.
native Vsyscalls are native syscall instructions.
This is a little bit faster than trapping
and makes a few dynamic recompilers work
better than they would in emulation mode.
It also makes exploits much easier to write.
none Vsyscalls don't work at all. This makes
them quite hard to use for exploits but
might break your system.
vt.color= [VT] Default text color.
Format: 0xYX, X = foreground, Y = background.
Default: 0x07 = light gray on black.
vt.cur_default= [VT] Default cursor shape.
Format: 0xCCBBAA, where AA, BB, and CC are the same as
the parameters of the <Esc>[?A;B;Cc escape sequence;
see VGA-softcursor.txt. Default: 2 = underline.
vt.default_blu= [VT]
Format: <blue0>,<blue1>,<blue2>,...,<blue15>
Change the default blue palette of the console.
This is a 16-member array composed of values
ranging from 0-255.
vt.default_grn= [VT]
Format: <green0>,<green1>,<green2>,...,<green15>
Change the default green palette of the console.
This is a 16-member array composed of values
ranging from 0-255.
vt.default_red= [VT]
Format: <red0>,<red1>,<red2>,...,<red15>
Change the default red palette of the console.
This is a 16-member array composed of values
ranging from 0-255.
vt.default_utf8=
[VT]
Format=<0|1>
Set system-wide default UTF-8 mode for all tty's.
Default is 1, i.e. UTF-8 mode is enabled for all
newly opened terminals.
vt.global_cursor_default=
[VT]
Format=<-1|0|1>
Set system-wide default for whether a cursor
is shown on new VTs. Default is -1,
i.e. cursors will be created by default unless
overridden by individual drivers. 0 will hide
cursors, 1 will display them.
vt.italic= [VT] Default color for italic text; 0-15.
Default: 2 = green.
vt.underline= [VT] Default color for underlined text; 0-15.
Default: 3 = cyan.
watchdog timers [HW,WDT] For information on watchdog timers,
see Documentation/watchdog/watchdog-parameters.txt
or other driver-specific files in the
Documentation/watchdog/ directory.
workqueue.watchdog_thresh=
If CONFIG_WQ_WATCHDOG is configured, workqueue can
warn stall conditions and dump internal state to
help debugging. 0 disables workqueue stall
detection; otherwise, it's the stall threshold
duration in seconds. The default value is 30 and
it can be updated at runtime by writing to the
corresponding sysfs file.
workqueue.disable_numa
By default, all work items queued to unbound
workqueues are affine to the NUMA nodes they're
issued on, which results in better behavior in
general. If NUMA affinity needs to be disabled for
whatever reason, this option can be used. Note
that this also can be controlled per-workqueue for
workqueues visible under /sys/bus/workqueue/.
workqueue.power_efficient
Per-cpu workqueues are generally preferred because
they show better performance thanks to cache
locality; unfortunately, per-cpu workqueues tend to
be more power hungry than unbound workqueues.
Enabling this makes the per-cpu workqueues which
were observed to contribute significantly to power
consumption unbound, leading to measurably lower
power usage at the cost of small performance
overhead.
The default value of this parameter is determined by
the config option CONFIG_WQ_POWER_EFFICIENT_DEFAULT.
workqueue.debug_force_rr_cpu
Workqueue used to implicitly guarantee that work
items queued without explicit CPU specified are put
on the local CPU. This guarantee is no longer true
and while local CPU is still preferred work items
may be put on foreign CPUs. This debug option
forces round-robin CPU selection to flush out
usages which depend on the now broken guarantee.
When enabled, memory and cache locality will be
impacted.
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
default x2apic cluster mode on platforms
supporting x2apic.
x86_intel_mid_timer= [X86-32,APBT]
Choose timer option for x86 Intel MID platform.
Two valid options are apbt timer only and lapic timer
plus one apbt timer for broadcast timer.
x86_intel_mid_timer=apbt_only | lapic_and_apbt
xen_512gb_limit [KNL,X86-64,XEN]
Restricts the kernel running paravirtualized under Xen
to use only up to 512 GB of RAM. The reason to do so is
crash analysis tools and Xen tools for doing domain
save/restore/migration must be enabled to handle larger
domains.
xen_emul_unplug= [HW,X86,XEN]
Unplug Xen emulated devices
Format: [unplug0,][unplug1]
ide-disks -- unplug primary master IDE devices
aux-ide-disks -- unplug non-primary-master IDE devices
nics -- unplug network devices
all -- unplug all emulated devices (NICs and IDE disks)
unnecessary -- unplugging emulated devices is
unnecessary even if the host did not respond to
the unplug protocol
never -- do not unplug even if version check succeeds
xen_nopvspin [X86,XEN]
Disables the ticketlock slowpath using Xen PV
optimizations.
xen_nopv [X86]
Disables the PV optimizations forcing the HVM guest to
run as generic HVM guest with no PV drivers.
xirc2ps_cs= [NET,PCMCIA]
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
------------------------
Todo Todo
---- ----
......
Documentation/admin-guide/kernel-parameters.txt 0 → 100644
浏览文件 @ 63ac0cf9
acpi= [HW,ACPI,X86,ARM64]
Advanced Configuration and Power Interface
Format: { force | on | off | strict | noirq | rsdt |
copy_dsdt }
force -- enable ACPI if default was off
on -- enable ACPI but allow fallback to DT [arm64]
off -- disable ACPI if default was on
noirq -- do not use ACPI for IRQ routing
strict -- Be less tolerant of platforms that are not
strictly ACPI specification compliant.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
For ARM64, ONLY "acpi=off", "acpi=on" or "acpi=force"
are available
See also Documentation/power/runtime_pm.txt, pci=noacpi
acpi_apic_instance= [ACPI, IOAPIC]
Format: <int>
2: use 2nd APIC table, if available
1,0: use 1st APIC table
default: 0
acpi_backlight= [HW,ACPI]
acpi_backlight=vendor
acpi_backlight=video
If set to vendor, prefer vendor specific driver
(e.g. thinkpad_acpi, sony_acpi, etc.) instead
of the ACPI video.ko driver.
acpi_force_32bit_fadt_addr
force FADT to use 32 bit addresses rather than the
64 bit X_* addresses. Some firmware have broken 64
bit addresses for force ACPI ignore these and use
the older legacy 32 bit addresses.
acpica_no_return_repair [HW, ACPI]
Disable AML predefined validation mechanism
This mechanism can repair the evaluation result to make
the return objects more ACPI specification compliant.
This option is useful for developers to identify the
root cause of an AML interpreter issue when the issue
has something to do with the repair mechanism.
acpi.debug_layer= [HW,ACPI,ACPI_DEBUG]
acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
Format: <int>
CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
debug output. Bits in debug_layer correspond to a
_COMPONENT in an ACPI source file, e.g.,
#define _COMPONENT ACPI_PCI_COMPONENT
Bits in debug_level correspond to a level in
ACPI_DEBUG_PRINT statements, e.g.,
ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
The debug_level mask defaults to "info". See
Documentation/acpi/debug.txt for more information about
debug layers and levels.
Enable processor driver info messages:
acpi.debug_layer=0x20000000
Enable PCI/PCI interrupt routing info messages:
acpi.debug_layer=0x400000
Enable AML "Debug" output, i.e., stores to the Debug
object while interpreting AML:
acpi.debug_layer=0xffffffff acpi.debug_level=0x2
Enable all messages related to ACPI hardware:
acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
Some values produce so much output that the system is
unusable. The "log_buf_len" parameter may be useful
if you need to capture more output.
acpi_enforce_resources= [ACPI]
{ strict | lax | no }
Check for resource conflicts between native drivers
and ACPI OperationRegions (SystemIO and SystemMemory
only). IO ports and memory declared in ACPI might be
used by the ACPI subsystem in arbitrary AML code and
can interfere with legacy drivers.
strict (default): access to resources claimed by ACPI
is denied; legacy drivers trying to access reserved
resources will fail to bind to device using them.
lax: access to resources claimed by ACPI is allowed;
legacy drivers trying to access reserved resources
will bind successfully but a warning message is logged.
no: ACPI OperationRegions are not marked as reserved,
no further checks are performed.
acpi_force_table_verification [HW,ACPI]
Enable table checksum verification during early stage.
By default, this is disabled due to x86 early mapping
size limitation.
acpi_irq_balance [HW,ACPI]
ACPI will balance active IRQs
default in APIC mode
acpi_irq_nobalance [HW,ACPI]
ACPI will not move active IRQs (default)
default in PIC mode
acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Format: <irq>,<irq>...
acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
use by PCI
Format: <irq>,<irq>...
acpi_no_auto_serialize [HW,ACPI]
Disable auto-serialization of AML methods
AML control methods that contain the opcodes to create
named objects will be marked as "Serialized" by the
auto-serialization feature.
This feature is enabled by default.
This option allows to turn off the feature.
acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kdump
kernels.
acpi_no_static_ssdt [HW,ACPI]
Disable installation of static SSDTs at early boot time
By default, SSDTs contained in the RSDT/XSDT will be
installed automatically and they will appear under
/sys/firmware/acpi/tables.
This option turns off this feature.
Note that specifying this option does not affect
dynamic table installation which will install SSDT
tables to /sys/firmware/acpi/tables/dynamic.
acpi_rsdp= [ACPI,EFI,KEXEC]
Pass the RSDP address to the kernel, mostly used
on machines running EFI runtime service to boot the
second kernel for kdump.
acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
Format: To spoof as Windows 98: ="Microsoft Windows"
acpi_rev_override [ACPI] Override the _REV object to return 5 (instead
of 2 which is mandated by ACPI 6) as the supported ACPI
specification revision (when using this switch, it may
be necessary to carry out a cold reboot _twice_ in a
row to make it take effect on the platform firmware).
acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
acpi_osi="string1" # add string1
acpi_osi="!string2" # remove string2
acpi_osi=!* # remove all strings
acpi_osi=! # disable all built-in OS vendor
strings
acpi_osi=!! # enable all built-in OS vendor
strings
acpi_osi= # disable all strings
'acpi_osi=!' can be used in combination with single or
multiple 'acpi_osi="string1"' to support specific OS
vendor string(s). Note that such command can only
affect the default state of the OS vendor strings, thus
it cannot affect the default state of the feature group
strings and the current state of the OS vendor strings,
specifying it multiple times through kernel command line
is meaningless. This command is useful when one do not
care about the state of the feature group strings which
should be controlled by the OSPM.
Examples:
1. 'acpi_osi=! acpi_osi="Windows 2000"' is equivalent
to 'acpi_osi="Windows 2000" acpi_osi=!', they all
can make '_OSI("Windows 2000")' TRUE.
'acpi_osi=' cannot be used in combination with other
'acpi_osi=' command lines, the _OSI method will not
exist in the ACPI namespace. NOTE that such command can
only affect the _OSI support state, thus specifying it
multiple times through kernel command line is also
meaningless.
Examples:
1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)'
FALSE.
'acpi_osi=!*' can be used in combination with single or
multiple 'acpi_osi="string1"' to support specific
string(s). Note that such command can affect the
current state of both the OS vendor strings and the
feature group strings, thus specifying it multiple times
through kernel command line is meaningful. But it may
still not able to affect the final state of a string if
there are quirks related to this string. This command
is useful when one want to control the state of the
feature group strings to debug BIOS issues related to
the OSPM features.
Examples:
1. 'acpi_osi="Module Device" acpi_osi=!*' can make
'_OSI("Module Device")' FALSE.
2. 'acpi_osi=!* acpi_osi="Module Device"' can make
'_OSI("Module Device")' TRUE.
3. 'acpi_osi=! acpi_osi=!* acpi_osi="Windows 2000"' is
equivalent to
'acpi_osi=!* acpi_osi=! acpi_osi="Windows 2000"'
and
'acpi_osi=!* acpi_osi="Windows 2000" acpi_osi=!',
they all will make '_OSI("Windows 2000")' TRUE.
acpi_pm_good [X86]
Override the pmtimer bug detection: force the kernel
to assume that this machine's pmtimer latches its value
and always returns good values.
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
acpi_skip_timer_override [HW,ACPI]
Recognize and ignore IRQ0/pin2 Interrupt Override.
For broken nForce2 BIOS resulting in XT-PIC timer.
acpi_sleep= [HW,ACPI] Sleep options
Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
old_ordering, nonvs, sci_force_enable }
See Documentation/power/video.txt for information on
s3_bios and s3_mode.
s3_beep is for debugging; it makes the PC's speaker beep
as soon as the kernel's real-mode entry point is called.
s4_nohwsig prevents ACPI hardware signature from being
used during resume from hibernation.
old_ordering causes the ACPI 1.0 ordering of the _PTS
control method, with respect to putting devices into
low power states, to be enforced (the ACPI 2.0 ordering
of _PTS is used by default).
nonvs prevents the kernel from saving/restoring the
ACPI NVS memory during suspend/hibernation and resume.
sci_force_enable causes the kernel to set SCI_EN directly
on resume from S1/S3 (which is against the ACPI spec,
but some broken systems don't work without it).
acpi_use_timer_override [HW,ACPI]
Use timer override. For some broken Nvidia NF5 boards
that require a timer override, but don't have HPET
add_efi_memmap [EFI; X86] Include EFI memory map in
kernel's map of available physical RAM.
agp= [AGP]
{ off | try_unsupported }
off: disable AGP support
try_unsupported: try to drive unsupported chipsets
(may crash computer or cause data corruption)
ALSA [HW,ALSA]
See Documentation/sound/alsa/alsa-parameters.txt
alignment= [KNL,ARM]
Allow the default userspace alignment fault handler
behaviour to be specified. Bit 0 enables warnings,
bit 1 enables fixups, and bit 2 sends a segfault.
align_va_addr= [X86-64]
Align virtual addresses by clearing slice [14:12] when
allocating a VMA at process creation time. This option
gives you up to 3% performance improvement on AMD F15h
machines (where it is enabled by default) for a
CPU-intensive style benchmark, and it can vary highly in
a microbenchmark depending on workload and compiler.
32: only for 32-bit processes
64: only for 64-bit processes
on: enable for both 32- and 64-bit processes
off: disable for both 32- and 64-bit processes
alloc_snapshot [FTRACE]
Allocate the ftrace snapshot buffer on boot up when the
main buffer is allocated. This is handy if debugging
and you need to use tracing_snapshot() on boot up, and
do not want to use tracing_snapshot_alloc() as it needs
to be done where GFP_KERNEL allocations are allowed.
amd_iommu= [HW,X86-64]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are:
fullflush - enable flushing of IO/TLB entries when
they are unmapped. Otherwise they are
flushed before they will be reused, which
is a lot of faster
off - do not initialize any AMD IOMMU found in
the system
force_isolation - Force device isolation for all
devices. The IOMMU driver is not
allowed anymore to lift isolation
requirements as needed. This option
does not override iommu=pt
amd_iommu_dump= [HW,X86-64]
Enable AMD IOMMU driver option to dump the ACPI table
for AMD IOMMU. With this option enabled, AMD IOMMU
driver will print ACPI tables for AMD IOMMU during
IOMMU initialization.
amd_iommu_intr= [HW,X86-64]
Specifies one of the following AMD IOMMU interrupt
remapping modes:
legacy - Use legacy interrupt remapping mode.
vapic - Use virtual APIC mode, which allows IOMMU
to inject interrupts directly into guest.
This mode requires kvm-amd.avic=1.
(Default when IOMMU HW support is present.)
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Format: <a>,<b>
See also Documentation/input/joystick.txt
analog.map= [HW,JOY] Analog joystick and gamepad support
Specifies type or capabilities of an analog joystick
connected to one of 16 gameports
Format: <type1>,<type2>,..<type16>
apc= [HW,SPARC]
Power management functions (SPARCstation-4/5 + deriv.)
Format: noidle
Disable APC CPU standby support. SPARCstation-Fox does
not play well with APC CPU idle - disable it if you have
APC and your system crashes randomly.
apic= [APIC,X86-32] Advanced Programmable Interrupt Controller
Change the output verbosity whilst booting
Format: { quiet (default) | verbose | debug }
Change the amount of debugging information output
when initialising the APIC and IO-APIC components.
apic_extnmi= [APIC,X86] External NMI delivery setting
Format: { bsp (default) | all | none }
bsp: External NMI is delivered only to CPU 0
all: External NMIs are broadcast to all CPUs as a
backup of CPU 0
none: External NMI is masked for all CPUs. This is
useful so that a dump capture kernel won't be
shot down by NMI
autoconf= [IPV6]
See Documentation/networking/ipv6.txt.
show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
Limit apic dumping. The parameter defines the maximal
number of local apics being dumped. Also it is possible
to set it to "all" by meaning -- no limit here.
Format: { 1 (default) | 2 | ... | all }.
The parameter valid if only apic=debug or
apic=verbose is specified.
Example: apic=debug show_lapic=all
apm= [APM] Advanced Power Management
See header of arch/x86/kernel/apm_32.c.
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
Format: <io>,<irq>,<nodeID>
ataflop= [HW,M68k]
atarimouse= [HW,MOUSE] Atari Mouse
atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
EzKey and similar keyboards
atkbd.reset= [HW] Reset keyboard during initialization
atkbd.set= [HW] Select keyboard code set
Format: <int> (2 = AT (default), 3 = PS/2)
atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
keyboards
atkbd.softraw= [HW] Choose between synthetic and real raw mode
Format: <bool> (0 = real, 1 = synthetic (default))
atkbd.softrepeat= [HW]
Use software keyboard repeat
audit= [KNL] Enable the audit sub-system
Format: { "0" | "1" } (0 = disabled, 1 = enabled)
0 - kernel audit is disabled and can not be enabled
until the next reboot
unset - kernel audit is initialized but disabled and
will be fully enabled by the userspace auditd.
1 - kernel audit is initialized and partially enabled,
storing at most audit_backlog_limit messages in
RAM until it is fully enabled by the userspace
auditd.
Default: unset
audit_backlog_limit= [KNL] Set the audit queue size limit.
Format: <int> (must be >=0)
Default: 64
bau= [X86_UV] Enable the BAU on SGI UV. The default
behavior is to disable the BAU (i.e. bau=0).
Format: { "0" | "1" }
0 - Disable the BAU.
1 - Enable the BAU.
unset - Disable the BAU.
baycom_epp= [HW,AX25]
Format: <io>,<mode>
baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
Format: <io>,<mode>
See header of drivers/net/hamradio/baycom_par.c.
baycom_ser_fdx= [HW,AX25]
BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Format: <io>,<irq>,<mode>[,<baud>]
See header of drivers/net/hamradio/baycom_ser_fdx.c.
baycom_ser_hdx= [HW,AX25]
BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Format: <io>,<irq>,<mode>
See header of drivers/net/hamradio/baycom_ser_hdx.c.
blkdevparts= Manual partition parsing of block device(s) for
embedded devices based on command line input.
See Documentation/block/cmdline-partition.txt
boot_delay= Milliseconds to delay each printk during boot.
Values larger than 10 seconds (10000) are changed to
no delay (0).
Format: integer
bootmem_debug [KNL] Enable bootmem allocator debug messages.
bert_disable [ACPI]
Disable BERT OS support on buggy BIOSes.
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
bttv.radio= Most important insmod options are available as
kernel args too.
bttv.pll= See Documentation/video4linux/bttv/Insmod-options
bttv.tuner=
bulk_remove=off [PPC] This parameter disables the use of the pSeries
firmware feature for flushing multiple hpte entries
at a time.
c101= [NET] Moxa C101 synchronous serial card
cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Sometimes CPU hardware bugs make them report the cache
size incorrectly. The kernel will attempt work arounds
to fix known problems, but for some CPUs it is not
possible to determine what the correct size should be.
This option provides an override for these situations.
ca_keys= [KEYS] This parameter identifies a specific key(s) on
the system trusted keyring to be used for certificate
trust validation.
format: { id:<keyid> | builtin }
cca= [MIPS] Override the kernel pages' cache coherency
algorithm. Accepted values range from 0 to 7
inclusive. See arch/mips/include/asm/pgtable-bits.h
for platform specific values (SB1, Loongson3 and
others).
ccw_timeout_log [S390]
See Documentation/s390/CommonIO for details.
cgroup_disable= [KNL] Disable a particular controller
Format: {name of the controller(s) to disable}
The effects of cgroup_disable=foo are:
- foo isn't auto-mounted if you mount all cgroups in
a single hierarchy
- foo isn't visible as an individually mountable
subsystem
{Currently only "memory" controller deal with this and
cut the overhead, others just disable the usage. So
only cgroup_disable=memory is actually worthy}
cgroup_no_v1= [KNL] Disable one, multiple, all cgroup controllers in v1
Format: { controller[,controller...] | "all" }
Like cgroup_disable, but only applies to cgroup v1;
the blacklisted controllers remain available in cgroup2.
cgroup.memory= [KNL] Pass options to the cgroup memory controller.
Format: <string>
nosocket -- Disable socket memory accounting.
nokmem -- Disable kernel memory accounting.
checkreqprot [SELINUX] Set initial checkreqprot flag value.
Format: { "0" | "1" }
See security/selinux/Kconfig help text.
0 -- check protection applied by kernel (includes
any implied execute protection).
1 -- check protection requested by application.
Default value is set via a kernel config option.
Value can be changed at runtime via
/selinux/checkreqprot.
cio_ignore= [S390]
See Documentation/s390/CommonIO for details.
clk_ignore_unused
[CLK]
Prevents the clock framework from automatically gating
clocks that have not been explicitly enabled by a Linux
device driver but are enabled in hardware at reset or
by the bootloader/firmware. Note that this does not
force such clocks to be always-on nor does it reserve
those clocks in any way. This parameter is useful for
debug and development, but should not be needed on a
platform with proper driver support. For more
information, see Documentation/clk.txt.
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
Forces specified clocksource (if available) to be used
when calculating gettimeofday(). If specified
clocksource is not available, it defaults to PIT.
Format: { pit | tsc | cyclone | pmtmr }
clocksource= Override the default clocksource
Format: <string>
Override the default clocksource and use the clocksource
with the name specified.
Some clocksource names to choose from, depending on
the platform:
[all] jiffies (this is the base, fallback clocksource)
[ACPI] acpi_pm
[ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
pxa_timer,timer3,32k_counter,timer0_1
[AVR32] avr32
[X86-32] pit,hpet,tsc;
scx200_hrt on Geode; cyclone on IBM x440
[MIPS] MIPS
[PARISC] cr16
[S390] tod
[SH] SuperH
[SPARC64] tick
[X86-64] hpet,tsc
clocksource.arm_arch_timer.evtstrm=
[ARM,ARM64]
Format: <bool>
Enable/disable the eventstream feature of the ARM
architected timer so that code using WFE-based polling
loops can be debugged more effectively on production
systems.
clocksource.arm_arch_timer.fsl-a008585=
[ARM64]
Format: <bool>
Enable/disable the workaround of Freescale/NXP
erratum A-008585. This can be useful for KVM
guests, if the guest device tree doesn't show the
erratum. If unspecified, the workaround is
enabled based on the device tree.
clearcpuid=BITNUM [X86]
Disable CPUID feature X for the kernel. See
arch/x86/include/asm/cpufeatures.h for the valid bit
numbers. Note the Linux specific bits are not necessarily
stable over kernel options, but the vendor specific
ones should be.
Also note that user programs calling CPUID directly
or using the feature without checking anything
will still see it. This just prevents it from
being used by the kernel or shown in /proc/cpuinfo.
Also note the kernel might malfunction if you disable
some critical bits.
cma=nn[MG]@[start[MG][-end[MG]]]
[ARM,X86,KNL]
Sets the size of kernel global memory area for
contiguous memory allocations and optionally the
placement constraint by the physical address range of
memory allocations. A value of 0 disables CMA
altogether. For more information, see
include/linux/dma-contiguous.h
cmo_free_hint= [PPC] Format: { yes | no }
Specify whether pages are marked as being inactive
when they are freed. This is used in CMO environments
to determine OS memory pressure for page stealing by
a hypervisor.
Default: yes
coherent_pool=nn[KMG] [ARM,KNL]
Sets the size of memory pool for coherent, atomic dma
allocations, by default set to 256K.
code_bytes [X86] How many bytes of object code to print
in an oops report.
Range: 0 - 8192
Default: 64
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
Format: <io>[,<irq>]
com90xx= [HW,NET]
ARCnet - COM90xx chipset (memory-mapped buffers)
Format: <io>[,<irq>[,<memstart>]]
condev= [HW,S390] console device
conmode=
console= [KNL] Output console device and options.
tty<n> Use the virtual console device <n>.
ttyS<n>[,options]
ttyUSB0[,options]
Use the specified serial port. The options are of
the form "bbbbpnf", where "bbbb" is the baud rate,
"p" is parity ("n", "o", or "e"), "n" is number of
bits, and "f" is flow control ("r" for RTS or
omit it). Default is "9600n8".
See Documentation/admin-guide/serial-console.rst for more
information. See
Documentation/networking/netconsole.txt for an
alternative.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio16,<addr>[,options]
uart[8250],mmio32,<addr>[,options]
uart[8250],0x<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address,
switching to the matching ttyS device later.
MMIO inter-register address stride is either 8-bit
(mmio), 16-bit (mmio16), or 32-bit (mmio32).
If none of [io|mmio|mmio16|mmio32], <addr> is assumed
to be equivalent to 'mmio'. 'options' are specified in
the same format described for ttyS above; if unspecified,
the h/w is not re-initialized.
hvc<n> Use the hypervisor console device <n>. This is for
both Xen and PowerPC hypervisors.
If the device connected to the port is not a TTY but a braille
device, prepend "brl," before the device type, for instance
console=brl,ttyS0
For now, only VisioBraille is supported.
consoleblank= [KNL] The console blank (screen saver) timeout in
seconds. Defaults to 10*60 = 10mins. A value of 0
disables the blank timer.
coredump_filter=
[KNL] Change the default value for
/proc/<pid>/coredump_filter.
See also Documentation/filesystems/proc.txt.
cpuidle.off=1 [CPU_IDLE]
disable the cpuidle sub-system
cpu_init_udelay=N
[X86] Delay for N microsec between assert and de-assert
of APIC INIT to start processors. This delay occurs
on every CPU online, such as boot, and resume from suspend.
Default: 10000
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
crashkernel=size[KMG][@offset[KMG]]
[KNL] Using kexec, Linux can switch to a 'crash kernel'
upon panic. This parameter reserves the physical
memory region [offset, offset + size] for that kernel
image. If '@offset' is omitted, then a suitable offset
is selected automatically. Check
Documentation/kdump/kdump.txt for further details.
crashkernel=range1:size1[,range2:size2,...][@offset]
[KNL] Same as above, but depends on the memory
in the running system. The syntax of range is
start-[end] where start and end are both
a memory unit (amount[KMG]). See also
Documentation/kdump/kdump.txt for an example.
crashkernel=size[KMG],high
[KNL, x86_64] range could be above 4G. Allow kernel
to allocate physical memory region from top, so could
be above 4G if system have more than 4G ram installed.
Otherwise memory region will be allocated below 4G, if
available.
It will be ignored if crashkernel=X is specified.
crashkernel=size[KMG],low
[KNL, x86_64] range under 4G. When crashkernel=X,high
is passed, kernel could allocate physical memory region
above 4G, that cause second kernel crash on system
that require some amount of low memory, e.g. swiotlb
requires at least 64M+32K low memory, also enough extra
low memory is needed to make sure DMA buffers for 32-bit
devices won't run out. Kernel would try to allocate at
at least 256M below 4G automatically.
This one let user to specify own low range under 4G
for second kernel instead.
0: to disable low allocation.
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
cryptomgr.notests
[KNL] Disable crypto self-tests
cs89x0_dma= [HW,NET]
Format: <dma>
cs89x0_media= [HW,NET]
Format: { rj45 | aui | bnc }
dasd= [HW,NET]
See header of drivers/s390/block/dasd_devmap.c.
db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
(one device per port)
Format: <port#>,<type>
See also Documentation/input/joystick-parport.txt
ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
time. See Documentation/dynamic-debug-howto.txt for
details. Deprecated, see dyndbg.
debug [KNL] Enable kernel debugging (events log level).
debug_locks_verbose=
[KNL] verbose self-tests
Format=<0|1>
Print debugging info while doing the locking API
self-tests.
We default to 0 (no extra messages), setting it to
1 will print _a lot_ more information - normally
only useful to kernel developers.
debug_objects [KNL] Enable object debugging
no_debug_objects
[KNL] Disable object debugging
debug_guardpage_minorder=
[KNL] When CONFIG_DEBUG_PAGEALLOC is set, this
parameter allows control of the order of pages that will
be intentionally kept free (and hence protected) by the
buddy allocator. Bigger value increase the probability
of catching random memory corruption, but reduce the
amount of memory for normal system use. The maximum
possible value is MAX_ORDER/2. Setting this parameter
to 1 or 2 should be enough to identify most random
memory corruption problems caused by bugs in kernel or
driver code when a CPU writes to (or reads from) a
random memory location. Note that there exists a class
of memory corruptions problems caused by buggy H/W or
F/W or by drivers badly programing DMA (basically when
memory is written at bus level and the CPU MMU is
bypassed) which are not detectable by
CONFIG_DEBUG_PAGEALLOC, hence this option will not help
tracking down these problems.
debug_pagealloc=
[KNL] When CONFIG_DEBUG_PAGEALLOC is set, this
parameter enables the feature at boot time. In
default, it is disabled. We can avoid allocating huge
chunk of memory for debug pagealloc if we don't enable
it at boot time and the system will work mostly same
with the kernel built without CONFIG_DEBUG_PAGEALLOC.
on: enable the feature
debugpat [X86] Enable PAT debugging
decnet.addr= [HW,NET]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
default_hugepagesz=
[same as hugepagesz=] The size of the default
HugeTLB page size. This is the size represented by
the legacy /proc/ hugepages APIs, used for SHM, and
default size when mounting hugetlbfs filesystems.
Defaults to the default architecture's huge page size
if not specified.
dhash_entries= [KNL]
Set number of hash buckets for dentry cache.
disable_1tb_segments [PPC]
Disables the use of 1TB hash page table segments. This
causes the kernel to fall back to 256MB segments which
can be useful when debugging issues that require an SLB
miss to occur.
disable= [IPV6]
See Documentation/networking/ipv6.txt.
disable_radix [PPC]
Disable RADIX MMU mode on POWER9
disable_cpu_apicid= [X86,APIC,SMP]
Format: <int>
The number of initial APIC ID for the
corresponding CPU to be disabled at boot,
mostly used for the kdump 2nd kernel to
disable BSP to wake up multiple CPUs without
causing system reset or hang due to sending
INIT from AP to BSP.
disable_ddw [PPC/PSERIES]
Disable Dynamic DMA Window support. Use this if
to workaround buggy firmware.
disable_ipv6= [IPV6]
See Documentation/networking/ipv6.txt.
disable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
entry later. This parameter disables that.
disable_mtrr_trim [X86, Intel and AMD only]
By default the kernel will trim any uncacheable
memory out of your available memory pool based on
MTRR settings. This parameter disables that behavior,
possibly causing your machine to run very slowly.
disable_timer_pin_1 [X86]
Disable PIN 1 of APIC timer
Can be useful to work around chipset bugs.
dis_ucode_ldr [X86] Disable the microcode loader.
dma_debug=off If the kernel is compiled with DMA_API_DEBUG support,
this option disables the debugging code at boot.
dma_debug_entries=<number>
This option allows to tune the number of preallocated
entries for DMA-API debugging code. One entry is
required per DMA-API allocation. Use this if the
DMA-API debugging code disables itself because the
architectural default is too low.
dma_debug_driver=<driver_name>
With this option the DMA-API debugging driver
filter feature can be enabled at boot time. Just
pass the driver to filter for as the parameter.
The filter can be disabled or changed to another
driver later using sysfs.
drm_kms_helper.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
Broken monitors, graphic adapters, KVMs and EDIDless
panels may send no or incorrect EDID data sets.
This parameter allows to specify an EDID data sets
in the /lib/firmware directory that are used instead.
Generic built-in EDID data sets are used, if one of
edid/1024x768.bin, edid/1280x1024.bin,
edid/1680x1050.bin, or edid/1920x1080.bin is given
and no file with the same name exists. Details and
instructions how to build your own EDID data are
available in Documentation/EDID/HOWTO.txt. An EDID
data set will only be used for a particular connector,
if its name and a colon are prepended to the EDID
name. Each connector may use a unique EDID data
set by separating the files with a comma. An EDID
data set with no connector name will be used for
any connectors not explicitly specified.
dscc4.setup= [NET]
dyndbg[="val"] [KNL,DYNAMIC_DEBUG]
module.dyndbg[="val"]
Enable debug messages at boot time. See
Documentation/dynamic-debug-howto.txt for details.
nompx [X86] Disables Intel Memory Protection Extensions.
See Documentation/x86/intel_mpx.txt for more
information about the feature.
nopku [X86] Disable Memory Protection Keys CPU feature found
in some Intel CPUs.
eagerfpu= [X86]
on enable eager fpu restore
off disable eager fpu restore
auto selects the default scheme, which automatically
enables eagerfpu restore for xsaveopt.
module.async_probe [KNL]
Enable asynchronous probe on this module.
early_ioremap_debug [KNL]
Enable debug messages in early_ioremap support. This
is useful for tracking down temporary early mappings
which are not unmapped.
earlycon= [KNL] Output early console device and options.
When used with no options, the early console is
determined by the stdout-path property in device
tree's chosen node.
cdns,<addr>[,options]
Start an early, polled-mode console on a Cadence
(xuartps) serial port at the specified address. Only
supported option is baud rate. If baud rate is not
specified, the serial port must already be setup and
configured.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio32,<addr>[,options]
uart[8250],mmio32be,<addr>[,options]
uart[8250],0x<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
MMIO inter-register address stride is either 8-bit
(mmio) or 32-bit (mmio32 or mmio32be).
If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
to be equivalent to 'mmio'. 'options' are specified
in the same format described for "console=ttyS<n>"; if
unspecified, the h/w is not initialized.
pl011,<addr>
pl011,mmio32,<addr>
Start an early, polled-mode console on a pl011 serial
port at the specified address. The pl011 serial port
must already be setup and configured. Options are not
yet supported. If 'mmio32' is specified, then only
the driver will use only 32-bit accessors to read/write
the device registers.
meson,<addr>
Start an early, polled-mode console on a meson serial
port at the specified address. The serial port must
already be setup and configured. Options are not yet
supported.
msm_serial,<addr>
Start an early, polled-mode console on an msm serial
port at the specified address. The serial port
must already be setup and configured. Options are not
yet supported.
msm_serial_dm,<addr>
Start an early, polled-mode console on an msm serial
dm port at the specified address. The serial port
must already be setup and configured. Options are not
yet supported.
smh Use ARM semihosting calls for early console.
s3c2410,<addr>
s3c2412,<addr>
s3c2440,<addr>
s3c6400,<addr>
s5pv210,<addr>
exynos4210,<addr>
Use early console provided by serial driver available
on Samsung SoCs, requires selecting proper type and
a correct base address of the selected UART port. The
serial port must already be setup and configured.
Options are not yet supported.
lpuart,<addr>
lpuart32,<addr>
Use early console provided by Freescale LP UART driver
found on Freescale Vybrid and QorIQ LS1021A processors.
A valid base address must be provided, and the serial
port must already be setup and configured.
armada3700_uart,<addr>
Start an early, polled-mode console on the
Armada 3700 serial port at the specified
address. The serial port must already be setup
and configured. Options are not yet supported.
earlyprintk= [X86,SH,BLACKFIN,ARM,M68k]
earlyprintk=vga
earlyprintk=efi
earlyprintk=xen
earlyprintk=serial[,ttySn[,baudrate]]
earlyprintk=serial[,0x...[,baudrate]]
earlyprintk=ttySn[,baudrate]
earlyprintk=dbgp[debugController#]
earlyprintk=pciserial,bus:device.function[,baudrate]
earlyprintk is useful when the kernel crashes before
the normal console is initialized. It is not enabled by
default because it has some cosmetic problems.
Append ",keep" to not disable it when the real console
takes over.
Only one of vga, efi, serial, or usb debug port can
be used at a time.
Currently only ttyS0 and ttyS1 may be specified by
name. Other I/O ports may be explicitly specified
on some architectures (x86 and arm at least) by
replacing ttySn with an I/O port address, like this:
earlyprintk=serial,0x1008,115200
You can find the port for a given device in
/proc/tty/driver/serial:
2: uart:ST16650V2 port:00001008 irq:18 ...
Interaction with the standard serial driver is not
very good.
The VGA and EFI output is eventually overwritten by
the real console.
The xen output can only be used by Xen PV guests.
edac_report= [HW,EDAC] Control how to report EDAC event
Format: {"on" | "off" | "force"}
on: enable EDAC to report H/W event. May be overridden
by other higher priority error reporting module.
off: disable H/W event reporting through EDAC.
force: enforce the use of EDAC to report H/W event.
default: on.
ekgdboc= [X86,KGDB] Allow early kernel console debugging
ekgdboc=kbd
This is designed to be used in conjunction with
the boot argument: earlyprintk=vga
edd= [EDD]
Format: {"off" | "on" | "skip[mbr]"}
efi= [EFI]
Format: { "old_map", "nochunk", "noruntime", "debug" }
old_map [X86-64]: switch to the old ioremap-based EFI
runtime services mapping. 32-bit still uses this one by
default.
nochunk: disable reading files in "chunks" in the EFI
boot stub, as chunking can cause problems with some
firmware implementations.
noruntime : disable EFI runtime services support
debug: enable misc debug output
efi_no_storage_paranoia [EFI; X86]
Using this parameter you can use more than 50% of
your efi variable storage. Use this parameter only if
you are really sure that your UEFI does sane gc and
fulfills the spec otherwise your board may brick.
efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86]
Add arbitrary attribute to specific memory range by
updating original EFI memory map.
Region of memory which aa attribute is added to is
from ss to ss+nn.
If efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000
is specified, EFI_MEMORY_MORE_RELIABLE(0x10000)
attribute is added to range 0x100000000-0x180000000 and
0x10a0000000-0x1120000000.
Using this parameter you can do debugging of EFI memmap
related feature. For example, you can do debugging of
Address Range Mirroring feature even if your box
doesn't support it.
efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT
that is to be dynamically loaded by Linux. If there are
multiple variables with the same name but with different
vendor GUIDs, all of them will be loaded. See
Documentation/acpi/ssdt-overlays.txt for details.
eisa_irq_edge= [PARISC,HW]
See header of drivers/parisc/eisa.c.
elanfreq= [X86-32]
See comment before function elanfreq_setup() in
arch/x86/kernel/cpu/cpufreq/elanfreq.c.
elevator= [IOSCHED]
Format: {"cfq" | "deadline" | "noop"}
See Documentation/block/cfq-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390]
Specifies physical address of start of kernel core
image elf header and optionally the size. Generally
kexec loader will pass this option to capture kernel.
See Documentation/kdump/kdump.txt for details.
enable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
entry later. This parameter enables that.
enable_timer_pin_1 [X86]
Enable PIN 1 of APIC timer
Can be useful to work around chipset bugs
(in particular on some ATI chipsets).
The kernel tries to set a reasonable default.
enforcing [SELINUX] Set initial enforcing status.
Format: {"0" | "1"}
See security/selinux/Kconfig help text.
0 -- permissive (log only, no denials).
1 -- enforcing (deny and log).
Default value is 0.
Value can be changed at runtime via /selinux/enforce.
erst_disable [ACPI]
Disable Error Record Serialization Table (ERST)
support.
ether= [HW,NET] Ethernet cards parameters
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
evm= [EVM]
Format: { "fix" }
Permit 'security.evm' to be updated regardless of
current integrity status.
failslab=
fail_page_alloc=
fail_make_request=[KNL]
General fault injection mechanism.
Format: <interval>,<probability>,<space>,<times>
See also Documentation/fault-injection/.
floppy= [HW]
See Documentation/blockdev/floppy.txt.
force_pal_cache_flush
[IA-64] Avoid check_sal_cache_flush which may hang on
buggy SAL_CACHE_FLUSH implementations. Using this
parameter will force ia64_sal_cache_flush to call
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
forcepae [X86-32]
Forcefully enable Physical Address Extension (PAE).
Many Pentium M systems disable PAE but may have a
functionally usable PAE implementation.
Warning: use of this parameter will taint the kernel
and may cause unknown problems.
ftrace=[tracer]
[FTRACE] will set and start the specified tracer
as early as possible in order to facilitate early
boot debugging.
ftrace_dump_on_oops[=orig_cpu]
[FTRACE] will dump the trace buffers on oops.
If no parameter is passed, ftrace will dump
buffers of all CPUs, but if you pass orig_cpu, it will
dump only the buffer of the CPU that triggered the
oops.
ftrace_filter=[function-list]
[FTRACE] Limit the functions traced by the function
tracer at boot up. function-list is a comma separated
list of functions. This list can be changed at run
time by the set_ftrace_filter file in the debugfs
tracing directory.
ftrace_notrace=[function-list]
[FTRACE] Do not trace the functions specified in
function-list. This list can be changed at run time
by the set_ftrace_notrace file in the debugfs
tracing directory.
ftrace_graph_filter=[function-list]
[FTRACE] Limit the top level callers functions traced
by the function graph tracer at boot up.
function-list is a comma separated list of functions
that can be changed at run time by the
set_graph_function file in the debugfs tracing directory.
ftrace_graph_notrace=[function-list]
[FTRACE] Do not trace from the functions specified in
function-list. This list is a comma separated list of
functions that can be changed at run time by the
set_graph_notrace file in the debugfs tracing directory.
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
See also Documentation/input/joystick-parport.txt
gamma= [HW,DRM]
gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
Format: off | on
default: on
gcov_persist= [GCOV] When non-zero (default), profiling data for
kernel modules is saved and remains accessible via
debugfs, even when the module is unloaded/reloaded.
When zero, profiling data is discarded and associated
debugfs files are removed at module unload time.
gpt [EFI] Forces disk with valid GPT signature but
invalid Protective MBR to be treated as GPT. If the
primary GPT is corrupted, it enables the backup/alternate
GPT to be used instead.
grcan.enable0= [HW] Configuration of physical interface 0. Determines
the "Enable 0" bit of the configuration register.
Format: 0 | 1
Default: 0
grcan.enable1= [HW] Configuration of physical interface 1. Determines
the "Enable 0" bit of the configuration register.
Format: 0 | 1
Default: 0
grcan.select= [HW] Select which physical interface to use.
Format: 0 | 1
Default: 0
grcan.txsize= [HW] Sets the size of the tx buffer.
Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0.
Default: 1024
grcan.rxsize= [HW] Sets the size of the rx buffer.
Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0.
Default: 1024
gpio-mockup.gpio_mockup_ranges
[HW] Sets the ranges of gpiochip of for this device.
Format: <start1>,<end1>,<start2>,<end2>...
hardlockup_all_cpu_backtrace=
[KNL] Should the hard-lockup detector generate
backtraces on all cpus.
Format: <integer>
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
for 64-bit NUMA, off otherwise.
Format: 0 | 1 (for off | on)
hcl= [IA-64] SGI's Hardware Graph compatibility layer
hd= [EIDE] (E)IDE hard drive subsystem geometry
Format: <cyl>,<head>,<sect>
hest_disable [ACPI]
Disable Hardware Error Source Table (HEST) support;
corresponding firmware-first mode error processing
logic will be disabled.
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
size of <nn>. This works even on boxes that have no
highmem otherwise. This also works to reduce highmem
size on bigger boxes.
highres= [KNL] Enable/disable high resolution timer mode.
Valid parameters: "on", "off"
Default: "on"
hisax= [HW,ISDN]
See Documentation/isdn/README.HiSax.
hlt [BUGS=ARM,SH]
hpet= [X86-32,HPET] option to control HPET usage
Format: { enable (default) | disable | force |
verbose }
disable: disable HPET and use PIT instead
force: allow force enabled of undocumented chips (ICH4,
VIA, nVidia)
verbose: show contents of HPET registers during setup
hpet_mmap= [X86, HPET_MMAP] Allow userspace to mmap HPET
registers. Default set by CONFIG_HPET_MMAP_DEFAULT.
hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
On x86-64 and powerpc, this option can be specified
multiple times interleaved with hugepages= to reserve
huge pages of different sizes. Valid pages sizes on
x86-64 are 2M (when the CPU supports "pse") and 1G
(when the CPU supports the "pdpe1gb" cpuinfo flag).
hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
terminal devices. Valid values: 0..8
hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
If specified, z/VM IUCV HVC accepts connections
from listed z/VM user IDs only.
hwthread_map= [METAG] Comma-separated list of Linux cpu id to
hardware thread id mappings.
Format: <cpu>:<hwthread>
keep_bootcon [KNL]
Do not unregister boot console at start. This is only
useful for debugging when something happens in the window
between unregistering the boot console and initializing
the real console.
i2c_bus= [HW] Override the default board specific I2C bus speed
or register an additional I2C bus that is not
registered from board initialization code.
Format:
<bus_id>,<clkrate>
i8042.debug [HW] Toggle i8042 debug mode
i8042.unmask_kbd_data
[HW] Enable printing of interrupt data from the KBD port
(disabled by default, and as a pre-condition
requires that i8042.debug=1 be enabled)
i8042.direct [HW] Put keyboard port into non-translated mode
i8042.dumbkbd [HW] Pretend that controller can only read data from
keyboard and cannot control its state
(Don't attempt to blink the leds)
i8042.noaux [HW] Don't check for auxiliary (== mouse) port
i8042.nokbd [HW] Don't check/create keyboard port
i8042.noloop [HW] Disable the AUX Loopback command while probing
for the AUX port
i8042.nomux [HW] Don't check presence of an active multiplexing
controller
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
controllers
i8042.notimeout [HW] Ignore timeout condition signalled by controller
i8042.reset [HW] Reset the controller during init, cleanup and
suspend-to-ram transitions, only during s2r
transitions, or never reset
Format: { 1 | Y | y | 0 | N | n }
1, Y, y: always reset controller
0, N, n: don't ever reset controller
Default: only on s2r transitions on x86; most other
architectures force reset to be always executed
i8042.unlock [HW] Unlock (ignore) the keylock
i8042.kbdreset [HW] Reset device connected to KBD port
i810= [HW,DRM]
i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
indicates that the driver is running on unsupported
hardware.
i8k.force [HW] Activate i8k driver even if SMM BIOS signature
does not match list of supported models.
i8k.power_status
[HW] Report power status in /proc/i8k
(disabled by default)
i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
capability is set.
i915.invert_brightness=
[DRM] Invert the sense of the variable that is used to
set the brightness of the panel backlight. Normally a
brightness value of 0 indicates backlight switched off,
and the maximum of the brightness value sets the backlight
to maximum brightness. If this parameter is set to 0
(default) and the machine requires it, or this parameter
is set to 1, a brightness value of 0 sets the backlight
to maximum brightness, and the maximum of the brightness
value switches the backlight off.
-1 -- never invert brightness
0 -- machine default
1 -- force brightness inversion
icn= [HW,ISDN]
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
ide-core.nodma= [HW] (E)IDE subsystem
Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
.vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr
.cdrom .chs .ignore_cable are additional options
See Documentation/ide/ide.txt.
ide-generic.probe-mask= [HW] (E)IDE subsystem
Format: <int>
Probe mask for legacy ISA IDE ports. Depending on
platform up to 6 ports are supported, enabled by
setting corresponding bits in the mask to 1. The
default value is 0x0, which has a special meaning.
On systems that have PCI, it triggers scanning the
PCI bus for the first and the second port, which
are then probed. On systems without PCI the value
of 0x0 enables probing the two first ports as if it
was 0x3.
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
Claim all unknown PCI IDE storage controllers.
idle= [X86]
Format: idle=poll, idle=halt, idle=nomwait
Poll forces a polling idle loop that can slightly
improve the performance of waking up a idle CPU, but
will use a lot of power and make the system run hot.
Not recommended.
idle=halt: Halt is forced to be used for CPU idle.
In such case C2/C3 won't be used again.
idle=nomwait: Disable mwait for CPU C-states
ieee754= [MIPS] Select IEEE Std 754 conformance mode
Format: { strict | legacy | 2008 | relaxed }
Default: strict
Choose which programs will be accepted for execution
based on the IEEE 754 NaN encoding(s) supported by
the FPU and the NaN encoding requested with the value
of an ELF file header flag individually set by each
binary. Hardware implementations are permitted to
support either or both of the legacy and the 2008 NaN
encoding mode.
Available settings are as follows:
strict accept binaries that request a NaN encoding
supported by the FPU
legacy only accept legacy-NaN binaries, if supported
by the FPU
2008 only accept 2008-NaN binaries, if supported
by the FPU
relaxed accept any binaries regardless of whether
supported by the FPU
The FPU emulator is always able to support both NaN
encodings, so if no FPU hardware is present or it has
been disabled with 'nofpu', then the settings of
'legacy' and '2008' strap the emulator accordingly,
'relaxed' straps the emulator for both legacy-NaN and
2008-NaN, whereas 'strict' enables legacy-NaN only on
legacy processors and both NaN encodings on MIPS32 or
MIPS64 CPUs.
The setting for ABS.fmt/NEG.fmt instruction execution
mode generally follows that for the NaN encoding,
except where unsupported by hardware.
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
kernel messages to the console. Useful for debugging.
We also add it as printk module parameter, so users
could change it dynamically, usually by
/sys/module/printk/parameters/ignore_loglevel.
ignore_rlimit_data
Ignore RLIMIT_DATA setting for data mappings,
print warning at first misuse. Can be changed via
/sys/module/kernel/parameters/ignore_rlimit_data.
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
ima_appraise= [IMA] appraise integrity measurements
Format: { "off" | "enforce" | "fix" | "log" }
default: "enforce"
ima_appraise_tcb [IMA]
The builtin appraise policy appraises all files
owned by uid=0.
ima_hash= [IMA]
Format: { md5 | sha1 | rmd160 | sha256 | sha384
| sha512 | ... }
default: "sha1"
The list of supported hash algorithms is defined
in crypto/hash_info.h.
ima_policy= [IMA]
The builtin measurement policy to load during IMA
setup. Specyfing "tcb" as the value, measures all
programs exec'd, files mmap'd for exec, and all files
opened with the read mode bit set by either the
effective uid (euid=0) or uid=0.
Format: "tcb"
ima_tcb [IMA] Deprecated. Use ima_policy= instead.
Load a policy which meets the needs of the Trusted
Computing Base. This means IMA will measure all
programs exec'd, files mmap'd for exec, and all files
opened for read by uid=0.
ima_template= [IMA]
Select one of defined IMA measurements template formats.
Formats: { "ima" | "ima-ng" | "ima-sig" }
Default: "ima-ng"
ima_template_fmt=
[IMA] Define a custom template format.
Format: { "field1|...|fieldN" }
ima.ahash_minsize= [IMA] Minimum file size for asynchronous hash usage
Format: <min_file_size>
Set the minimal file size for using asynchronous hash.
If left unspecified, ahash usage is disabled.
ahash performance varies for different data sizes on
different crypto accelerators. This option can be used
to achieve the best performance for a particular HW.
ima.ahash_bufsize= [IMA] Asynchronous hash buffer size
Format: <bufsize>
Set hashing buffer size. Default: 4k.
ahash performance varies for different chunk sizes on
different crypto accelerators. This option can be used
to achieve best performance for particular HW.
init= [KNL]
Format: <full_path>
Run specified binary instead of /sbin/init as init
process.
initcall_debug [KNL] Trace initcalls as they are executed. Useful
for working out where the kernel is dying during
startup.
initcall_blacklist= [KNL] Do not execute a comma-separated list of
initcall functions. Useful for debugging built-in
modules and initcalls.
initrd= [BOOT] Specify the location of the initial ramdisk
init_pkru= [x86] Specify the default memory protection keys rights
register contents for all processes. 0x55555554 by
default (disallow access to all but pkey 0). Can
override in debugfs after boot.
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
int_pln_enable [x86] Enable power limit notification interrupt
integrity_audit=[IMA]
Format: { "0" | "1" }
0 -- basic integrity auditing messages. (Default)
1 -- additional integrity auditing messages.
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
on
Enable intel iommu driver.
off
Disable intel iommu driver.
igfx_off [Default Off]
By default, gfx is mapped as normal device. If a gfx
device has a dedicated DMAR unit, the DMAR unit is
bypassed by not enabling DMAR with this option. In
this case, gfx device will use physical address for
DMA.
forcedac [x86_64]
With this option iommu will not optimize to look
for io virtual address below 32-bit forcing dual
address cycle on pci bus for cards supporting greater
than 32-bit addressing. The default is to look
for translation below 32-bit and if not available
then look in the higher range.
strict [Default Off]
With this option on every unmap_single operation will
result in a hardware IOTLB flush operation as opposed
to batching them for performance.
sp_off [Default Off]
By default, super page will be supported if Intel IOMMU
has the capability. With this option, super page will
not be supported.
ecs_off [Default Off]
By default, extended context tables will be supported if
the hardware advertises that it has support both for the
extended tables themselves, and also PASID support. With
this option set, extended tables will not be used even
on hardware which claims to support them.
intel_idle.max_cstate= [KNL,HW,ACPI,X86]
0 disables intel_idle and fall back on acpi_idle.
1 to 9 specify maximum depth of C-state.
intel_pstate= [X86]
disable
Do not enable intel_pstate as the default
scaling driver for the supported processors
force
Enable intel_pstate on systems that prohibit it by default
in favor of acpi-cpufreq. Forcing the intel_pstate driver
instead of acpi-cpufreq may disable platform features, such
as thermal controls and power capping, that rely on ACPI
P-States information being indicated to OSPM and therefore
should be used with caution. This option does not work with
processors that aren't supported by the intel_pstate driver
or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
no_hwp
Do not enable hardware P state control (HWP)
if available.
hwp_only
Only load intel_pstate on systems which support
hardware P state control (HWP) if available.
support_acpi_ppc
Enforce ACPI _PPC performance limits. If the Fixed ACPI
Description Table, specifies preferred power management
profile as "Enterprise Server" or "Performance Server",
then this feature is turned on by default.
intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
off disable Interrupt Remapping
nosid disable Source ID checking
no_x2apic_optout
BIOS x2APIC opt-out request will be ignored
nopost disable Interrupt Posting
iomem= Disable strict checking of access to MMIO memory
strict regions from userspace.
relaxed
iommu= [x86]
off
force
noforce
biomerge
panic
nopanic
merge
nomerge
forcesac
soft
pt [x86, IA-64]
nobypass [PPC/POWERNV]
Disable IOMMU bypass, using IOMMU for PCI devices.
io7= [HW] IO7 for Marvel based alpha systems
See comment before marvel_specify_io7 in
arch/alpha/kernel/core_marvel.c.
io_delay= [X86] I/O delay method
0x80
Standard port 0x80 based delay
0xed
Alternate port 0xed based delay (needed on some systems)
udelay
Simple two microseconds delay
none
No delay
ip= [IP_PNP]
See Documentation/filesystems/nfs/nfsroot.txt.
irqaffinity= [SMP] Set the default irq affinity mask
The argument is a cpu list, as described above.
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
firmware running.
irqpoll [HW]
When an interrupt is not handled search all handlers
for it. Also check all handlers each timer
interrupt. Intended to get systems with badly broken
firmware running.
isapnp= [ISAPNP]
Format: <RDP>,<reset>,<pci_scan>,<verbosity>
isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
The argument is a cpu list, as described above.
This option can be used to specify one or more CPUs
to isolate from the general SMP balancing and scheduling
algorithms. You can move a process onto or off an
"isolated" CPU via the CPU affinity syscalls or cpuset.
<cpu number> begins at 0 and the maximum value is
"number of CPUs in system - 1".
This option is the preferred way to isolate CPUs. The
alternative -- manually setting the CPU mask of all
tasks in the system -- can cause problems and
suboptimal load balancer performance.
iucv= [HW,NET]
ivrs_ioapic [HW,X86_64]
Provide an override to the IOAPIC-ID<->DEVICE-ID
mapping provided in the IVRS ACPI table. For
example, to map IOAPIC-ID decimal 10 to
PCI device 00:14.0 write the parameter as:
ivrs_ioapic[10]=00:14.0
ivrs_hpet [HW,X86_64]
Provide an override to the HPET-ID<->DEVICE-ID
mapping provided in the IVRS ACPI table. For
example, to map HPET-ID decimal 0 to
PCI device 00:14.0 write the parameter as:
ivrs_hpet[0]=00:14.0
ivrs_acpihid [HW,X86_64]
Provide an override to the ACPI-HID:UID<->DEVICE-ID
mapping provided in the IVRS ACPI table. For
example, to map UART-HID:UID AMD0020:0 to
PCI device 00:14.5 write the parameter as:
ivrs_acpihid[00:14.5]=AMD0020:0
js= [HW,JOY] Analog joystick
See Documentation/input/joystick.txt.
nokaslr [KNL]
When CONFIG_RANDOMIZE_BASE is set, this disables
kernel and module base offset ASLR (Address Space
Layout Randomization).
keepinitrd [HW,ARM]
kernelcore= [KNL,X86,IA-64,PPC]
Format: nn[KMGTPE] | "mirror"
This parameter
specifies the amount of memory usable by the kernel
for non-movable allocations. The requested amount is
spread evenly throughout all nodes in the system. The
remaining memory in each node is used for Movable
pages. In the event, a node is too small to have both
kernelcore and Movable pages, kernelcore pages will
take priority and other nodes will have a larger number
of Movable pages. The Movable zone is used for the
allocation of pages that may be reclaimed or moved
by the page migration subsystem. This means that
HugeTLB pages may not be allocated from this zone.
Note that allocations like PTEs-from-HighMem still
use the HighMem zone if it exists, and the Normal
zone if it does not.
Instead of specifying the amount of memory (nn[KMGTPE]),
you can specify "mirror" option. In case "mirror"
option is specified, mirrored (reliable) memory is used
for non-movable allocations and remaining memory is used
for Movable pages. nn[KMGTPE] and "mirror" are exclusive,
so you can NOT specify nn[KMGTPE] and "mirror" at the same
time.
kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
Format: <Controller#>[,poll interval]
The controller # is the number of the ehci usb debug
port as it is probed via PCI. The poll interval is
optional and is the number seconds in between
each poll cycle to the debug port in case you need
the functionality for interrupting the kernel with
gdb or control-c on the dbgp connection. When
not using this parameter you use sysrq-g to break into
the kernel debugger.
kgdboc= [KGDB,HW] kgdb over consoles.
Requires a tty driver that supports console polling,
or a supported polling keyboard driver (non-usb).
Serial only format: <serial_device>[,baud]
keyboard only format: kbd
keyboard and serial format: kbd,<serial_device>[,baud]
Optional Kernel mode setting:
kms, kbd format: kms,kbd
kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]
kgdbwait [KGDB] Stop kernel execution and enter the
kernel debugger at the earliest opportunity.
kmac= [MIPS] korina ethernet MAC address.
Configure the RouterBoard 532 series on-chip
Ethernet adapter MAC address.
kmemleak= [KNL] Boot-time kmemleak enable/disable
Valid arguments: on, off
Default: on
Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
the default is off.
kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode
Valid arguments: 0, 1, 2
kmemcheck=0 (disabled)
kmemcheck=1 (enabled)
kmemcheck=2 (one-shot mode)
Default: 2 (one-shot mode)
kstack=N [X86] Print N words from the kernel stack
in oops dumps.
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
Default is 0 (don't ignore, but inject #GP)
kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit
KVM MMU at runtime.
Default is 0 (off)
kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
Default is 1 (enabled)
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
for all guests.
Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
kvm-intel.ept= [KVM,Intel] Disable extended page tables
(virtualized MMU) support on capable Intel chips.
Default is 1 (enabled)
kvm-intel.emulate_invalid_guest_state=
[KVM,Intel] Enable emulation of invalid guest states
Default is 0 (disabled)
kvm-intel.flexpriority=
[KVM,Intel] Disable FlexPriority feature (TPR shadow).
Default is 1 (enabled)
kvm-intel.nested=
[KVM,Intel] Enable VMX nesting (nVMX).
Default is 0 (disabled)
kvm-intel.unrestricted_guest=
[KVM,Intel] Disable unrestricted guest feature
(virtualized real and unpaged mode) on capable
Intel chips. Default is 1 (enabled)
kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
feature (tagged TLBs) on capable Intel chips.
Default is 1 (enabled)
l2cr= [PPC]
l3cr= [PPC]
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline
value for LAPIC timer one-shot implementation. Default
back to the programmable timer unit in the LAPIC.
lapic_timer_c2_ok [X86,APIC] trust the local apic timer
in C2 power state.
libata.dma= [LIBATA] DMA control
libata.dma=0 Disable all PATA and SATA DMA
libata.dma=1 PATA and SATA Disk DMA only
libata.dma=2 ATAPI (CDROM) DMA only
libata.dma=4 Compact Flash DMA only
Combinations also work, so libata.dma=3 enables DMA
for disks and CDROMs, but not CFs.
libata.ignore_hpa= [LIBATA] Ignore HPA limit
libata.ignore_hpa=0 keep BIOS limits (default)
libata.ignore_hpa=1 ignore limits, using full disk
libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
when set.
Format: <int>
libata.force= [LIBATA] Force configurations. The format is comma
separated list of "[ID:]VAL" where ID is
PORT[.DEVICE]. PORT and DEVICE are decimal numbers
matching port, link or device. Basically, it matches
the ATA ID string printed on console by libata. If
the whole ID part is omitted, the last PORT and DEVICE
values are used. If ID hasn't been specified yet, the
configuration applies to all ports, links and devices.
If only DEVICE is omitted, the parameter applies to
the port and all links and devices behind it. DEVICE
number of 0 either selects the first device or the
first fan-out link behind PMP device. It does not
select the host link. DEVICE number of 15 selects the
host link and device attached to it.
The VAL specifies the configuration to force. As long
as there's no ambiguity shortcut notation is allowed.
For example, both 1.5 and 1.5G would work for 1.5Gbps.
The following configurations can be forced.
* Cable type: 40c, 80c, short40c, unk, ign or sata.
Any ID with matching PORT is used.
* SATA link speed limit: 1.5Gbps or 3.0Gbps.
* Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
udma[/][16,25,33,44,66,100,133] notation is also
allowed.
* [no]ncq: Turn on or off NCQ.
* [no]ncqtrim: Turn off queued DSM TRIM.
* nohrst, nosrst, norst: suppress hard, soft
and both resets.
* rstonce: only attempt one reset during
hot-unplug link recovery
* dump_id: dump IDENTIFY data.
* atapi_dmadir: Enable ATAPI DMADIR bridge support
* disable: Disable this device.
If there are multiple matching configurations changing
the same attribute, the last one is used.
memblock=debug [KNL] Enable memblock debug messages.
load_ramdisk= [RAM] List of ramdisks to load from floppy
See Documentation/blockdev/ramdisk.txt.
lockd.nlm_grace_period=P [NFS] Assign grace period.
Format: <integer>
lockd.nlm_tcpport=N [NFS] Assign TCP port.
Format: <integer>
lockd.nlm_timeout=T [NFS] Assign timeout value.
Format: <integer>
lockd.nlm_udpport=M [NFS] Assign UDP port.
Format: <integer>
locktorture.nreaders_stress= [KNL]
Set the number of locking read-acquisition kthreads.
Defaults to being automatically set based on the
number of online CPUs.
locktorture.nwriters_stress= [KNL]
Set the number of locking write-acquisition kthreads.
locktorture.onoff_holdoff= [KNL]
Set time (s) after boot for CPU-hotplug testing.
locktorture.onoff_interval= [KNL]
Set time (s) between CPU-hotplug operations, or
zero to disable CPU-hotplug testing.
locktorture.shuffle_interval= [KNL]
Set task-shuffle interval (jiffies). Shuffling
tasks allows some CPUs to go into dyntick-idle
mode during the locktorture test.
locktorture.shutdown_secs= [KNL]
Set time (s) after boot system shutdown. This
is useful for hands-off automated testing.
locktorture.stat_interval= [KNL]
Time (s) between statistics printk()s.
locktorture.stutter= [KNL]
Time (s) to stutter testing, for example,
specifying five seconds causes the test to run for
five seconds, wait for five seconds, and so on.
This tests the locking primitive's ability to
transition abruptly to and from idle.
locktorture.torture_runnable= [BOOT]
Start locktorture running at boot time.
locktorture.torture_type= [KNL]
Specify the locking implementation to test.
locktorture.verbose= [KNL]
Enable additional printk() statements.
logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
Format: <irq>
loglevel= All Kernel Messages with a loglevel smaller than the
console loglevel will be printed to the console. It can
also be changed with klogd or other programs. The
loglevels are defined as follows:
0 (KERN_EMERG) system is unusable
1 (KERN_ALERT) action must be taken immediately
2 (KERN_CRIT) critical conditions
3 (KERN_ERR) error conditions
4 (KERN_WARNING) warning conditions
5 (KERN_NOTICE) normal but significant condition
6 (KERN_INFO) informational
7 (KERN_DEBUG) debug-level messages
log_buf_len=n[KMG] Sets the size of the printk ring buffer,
in bytes. n must be a power of two and greater
than the minimal size. The minimal size is defined
by LOG_BUF_SHIFT kernel config parameter. There is
also CONFIG_LOG_CPU_MAX_BUF_SHIFT config parameter
that allows to increase the default size depending on
the number of CPUs. See init/Kconfig for more details.
logo.nologo [FB] Disables display of the built-in Linux logo.
This may be used to provide more screen space for
kernel log messages and is useful when debugging
kernel boot problems.
lp=0 [LP] Specify parallel ports to use, e.g,
lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
lp=reset first parallel port). 'lp=0' disables the
lp=auto printer driver. 'lp=reset' (which can be
specified in addition to the ports) causes
attached printers to be reset. Using
lp=port1,port2,... specifies the parallel ports
to associate lp devices with, starting with
lp0. A port specification may be 'none' to skip
that lp device, or a parport name such as
'parport0'. Specifying 'lp=auto' instead of a
port specification list means that device IDs
from each port should be examined, to see if
an IEEE 1284-compliant printer is attached; if
so, the driver will manage that printer.
See also header of drivers/char/lp.c.
lpj=n [KNL]
Sets loops_per_jiffy to given constant, thus avoiding
time-consuming boot-time autodetection (up to 250 ms per
CPU). 0 enables autodetection (default). To determine
the correct value for your kernel, boot with normal
autodetection and see what value is printed. Note that
on SMP systems the preset will be applied to all CPUs,
which is likely to cause problems if your CPUs need
significantly divergent settings. An incorrect value
will cause delays in the kernel to be wrong, leading to
unpredictable I/O errors and other breakage. Although
unlikely, in the extreme case this might damage your
hardware.
ltpc= [NET]
Format: <io>,<irq>,<dma>
machvec= [IA-64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
machtype= [Loongson] Share the same kernel image file between different
yeeloong laptop.
Example: machtype=lemote-yeeloong-2f-7inch
max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater
than or equal to this physical address is ignored.
maxcpus= [SMP] Maximum number of processors that an SMP kernel
will bring up during bootup. maxcpus=n : n >= 0 limits
the kernel to bring up 'n' processors. Surely after
bootup you can bring up the other plugged cpu by executing
"echo 1 > /sys/devices/system/cpu/cpuX/online". So maxcpus
only takes effect during system bootup.
While n=0 is a special case, it is equivalent to "nosmp",
which also disables the IO APIC.
max_loop= [LOOP] The number of loop block devices that get
(loop.max_loop) unconditionally pre-created at init time. The default
number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead
of statically allocating a predefined number, loop
devices can be requested on-demand with the
/dev/loop-control interface.
mce [X86-32] Machine Check Exception
mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt
md= [HW] RAID subsystems devices and level
See Documentation/admin-guide/md.rst.
mdacon= [MDA]
Format: <first>,<last>
Specifies range of consoles to be captured by the MDA.
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
Amount of memory to be used when the kernel is not able
to see the whole system memory or for test.
[X86] Work as limiting max address. Use together
with memmap= to avoid physical address space collisions.
Without memmap= PCI devices could be placed at addresses
belonging to unused RAM.
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.
memchunk=nn[KMG]
[KNL,SH] Allow user to override the default size for
per-device physically contiguous DMA buffers.
memhp_default_state=online/offline
[KNL] Set the initial state for the memory hotplug
onlining policy. If not specified, the default value is
set according to the
CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config
option.
See Documentation/memory-hotplug.txt.
memmap=exactmap [KNL,X86] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
BIOS output or other requirements. See the memmap=nn@ss
option description.
memmap=nn[KMG]@ss[KMG]
[KNL] Force usage of a specific region of memory.
Region of memory to be used is from ss to ss+nn.
memmap=nn[KMG]#ss[KMG]
[KNL,ACPI] Mark specific memory as ACPI data.
Region of memory to be marked is from ss to ss+nn.
memmap=nn[KMG]$ss[KMG]
[KNL,ACPI] Mark specific memory as reserved.
Region of memory to be reserved is from ss to ss+nn.
Example: Exclude memory from 0x18690000-0x1869ffff
memmap=64K$0x18690000
or
memmap=0x10000$0x18690000
memmap=nn[KMG]!ss[KMG]
[KNL,X86] Mark specific memory as protected.
Region of memory to be used, from ss to ss+nn.
The memory region may be marked as e820 type 12 (0xc)
and is NVDIMM or ADR memory.
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
Setting this option will scan the memory
looking for corruption. Enabling this will
both detect corruption and prevent the kernel
from using the memory being corrupted.
However, its intended as a diagnostic tool; if
repeatable BIOS-originated corruption always
affects the same memory, you can use memmap=
to prevent the kernel from using that memory.
memory_corruption_check_size=size [X86]
By default it checks for corruption in the low
64k, making this memory unavailable for normal
use. Use this parameter to scan for
corruption in more or less memory.
memory_corruption_check_period=seconds [X86]
By default it checks for corruption every 60
seconds. Use this parameter to check at some
other rate. 0 disables periodic checking.
memtest= [KNL,X86,ARM] Enable memtest
Format: <integer>
default : 0 <disable>
Specifies the number of memtest passes to be
performed. Each pass selects another test
pattern from a given set of patterns. Memtest
fills the memory with this pattern, validates
memory contents and reserves bad memory
regions that are detected.
meye.*= [HW] Set MotionEye Camera parameters
See Documentation/video4linux/meye.txt.
mfgpt_irq= [IA-32] Specify the IRQ to use for the
Multi-Function General Purpose Timers on AMD Geode
platforms.
mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
the BIOS has incorrectly applied a workaround. TinyBIOS
version 0.98 is known to be affected, 0.99 fixes the
problem by letting the user disable the workaround.
mga= [HW,DRM]
min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
physical address is ignored.
mini2440= [ARM,HW,KNL]
Format:[0..2][b][c][t]
Default: "0tb"
MINI2440 configuration specification:
0 - The attached screen is the 3.5" TFT
1 - The attached screen is the 7" TFT
2 - The VGA Shield is attached (1024x768)
Leaving out the screen size parameter will not load
the TFT driver, and the framebuffer will be left
unconfigured.
b - Enable backlight. The TFT backlight pin will be
linked to the kernel VESA blanking code and a GPIO
LED. This parameter is not necessary when using the
VGA shield.
c - Enable the s3c camera interface.
t - Reserved for enabling touchscreen support. The
touchscreen support is not enabled in the mainstream
kernel as of 2.6.30, a preliminary port can be found
in the "bleeding edge" mini2440 support kernel at
http://repo.or.cz/w/linux-2.6/mini2440.git
mminit_loglevel=
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
parameter allows control of the logging verbosity for
the additional memory initialisation checks. A value
of 0 disables mminit logging and a level of 4 will
log everything. Information is printed at KERN_DEBUG
so loglevel=8 may also need to be specified.
module.sig_enforce
[KNL] When CONFIG_MODULE_SIG is set, this means that
modules without (valid) signatures will fail to load.
Note that if CONFIG_MODULE_SIG_FORCE is set, that
is always true, so this option does nothing.
module_blacklist= [KNL] Do not load a comma-separated list of
modules. Useful for debugging problem modules.
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
a tap and be reported as a left button click (for
touchpads working in absolute mode only).
Format: <msecs>
mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
reporting absolute coordinates, such as tablets
mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
reporting absolute coordinates, such as tablets
movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
is similar to kernelcore except it specifies the
amount of memory used for migratable allocations.
If both kernelcore and movablecore is specified,
then kernelcore will be at *least* the specified
value but may be more. If movablecore on its own
is specified, the administrator must be careful
that the amount of memory usable for all allocations
is not too small.
movable_node [KNL,X86] Boot-time switch to enable the effects
of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>
MTD_Region= [MTD] Format:
<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
mtdparts= [MTD]
See drivers/mtd/cmdlinepart.c.
multitce=off [PPC] This parameter disables the use of the pSeries
firmware feature for updating multiple TCE entries
at a time.
onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
boundary - index of last SLC block on Flex-OneNAND.
The remaining blocks are configured as MLC blocks.
lock - Configure if Flex-OneNAND boundary should be locked.
Once locked, the boundary cannot be changed.
1 indicates lock status, 0 indicates unlock status.
mtdset= [ARM]
ARM/S3C2412 JIVE boot control
See arch/arm/mach-s3c2412/mach-jive.c
mtouchusb.raw_coordinates=
[HW] Make the MicroTouch USB driver use raw coordinates
('y', default) or cooked coordinates ('n')
mtrr_chunk_size=nn[KMG] [X86]
used for mtrr cleanup. It is largest continuous chunk
that could hold holes aka. UC entries.
mtrr_gran_size=nn[KMG] [X86]
Used for mtrr cleanup. It is granularity of mtrr block.
Default is 1.
Large value could prevent small alignment from
using up MTRRs.
mtrr_spare_reg_nr=n [X86]
Format: <integer>
Range: 0,7 : spare reg number
Default : 1
Used for mtrr cleanup. It is spare mtrr entries number.
Set to 2 or more if your graphical card needs more.
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
netdev= [NET] Network devices parameters
Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
Note that mem_start is often overloaded to mean
something different and driver-specific.
This usage is only documented in each driver source
file if at all.
nf_conntrack.acct=
[NETFILTER] Enable connection tracking flow accounting
0 to disable accounting
1 to enable accounting
Default value is 0.
nfsaddrs= [NFS] Deprecated. Use ip= instead.
See Documentation/filesystems/nfs/nfsroot.txt.
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
See Documentation/filesystems/nfs/nfsroot.txt.
nfsrootdebug [NFS] enable nfsroot debugging messages.
See Documentation/filesystems/nfs/nfsroot.txt.
nfs.callback_nr_threads=
[NFSv4] set the total number of threads that the
NFS client will assign to service NFSv4 callback
requests.
nfs.callback_tcpport=
[NFS] set the TCP port on which the NFSv4 callback
channel should listen.
nfs.cache_getent=
[NFS] sets the pathname to the program which is used
to update the NFS client cache entries.
nfs.cache_getent_timeout=
[NFS] sets the timeout after which an attempt to
update a cache entry is deemed to have failed.
nfs.idmap_cache_timeout=
[NFS] set the maximum lifetime for idmapper cache
entries.
nfs.enable_ino64=
[NFS] enable 64-bit inode numbers.
If zero, the NFS client will fake up a 32-bit inode
number for the readdir() and stat() syscalls instead
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.
nfs.max_session_cb_slots=
[NFSv4.1] Sets the maximum number of session
slots the client will assign to the callback
channel. This determines the maximum number of
callbacks the client will process in parallel for
a particular server.
nfs.max_session_slots=
[NFSv4.1] Sets the maximum number of session slots
the client will attempt to negotiate with the server.
This limits the number of simultaneous RPC requests
that the client can send to the NFSv4.1 server.
Note that there is little point in setting this
value higher than the max_tcp_slot_table_limit.
nfs.nfs4_disable_idmapping=
[NFSv4] When set to the default of '1', this option
ensures that both the RPC level authentication
scheme and the NFS level operations agree to use
numeric uids/gids if the mount is using the
'sec=sys' security flavour. In effect it is
disabling idmapping, which can make migration from
legacy NFSv2/v3 systems to NFSv4 easier.
Servers that do not support this mode of operation
will be autodetected by the client, and it will fall
back to using the idmapper.
To turn off this behaviour, set the value to '0'.
nfs.nfs4_unique_id=
[NFS4] Specify an additional fixed unique ident-
ification string that NFSv4 clients can insert into
their nfs_client_id4 string. This is typically a
UUID that is generated at system install time.
nfs.send_implementation_id =
[NFSv4.1] Send client implementation identification
information in exchange_id requests.
If zero, no implementation identification information
will be sent.
The default is to send the implementation identification
information.
nfs.recover_lost_locks =
[NFSv4] Attempt to recover locks that were lost due
to a lease timeout on the server. Please note that
doing this risks data corruption, since there are
no guarantees that the file will remain unchanged
after the locks are lost.
If you want to enable the kernel legacy behaviour of
attempting to recover these locks, then set this
parameter to '1'.
The default parameter value of '0' causes the kernel
not to attempt recovery of lost locks.
nfs4.layoutstats_timer =
[NFSv4.2] Change the rate at which the kernel sends
layoutstats to the pNFS metadata server.
Setting this to value to 0 causes the kernel to use
whatever value is the default set by the layout
driver. A non-zero value sets the minimum interval
in seconds between layoutstats transmissions.
nfsd.nfs4_disable_idmapping=
[NFSv4] When set to the default of '1', the NFSv4
server will return only numeric uids and gids to
clients using auth_sys, and will accept numeric uids
and gids from such clients. This is intended to ease
migration from NFSv2/v3.
objlayoutdriver.osd_login_prog=
[NFS] [OBJLAYOUT] sets the pathname to the program which
is used to automatically discover and login into new
osd-targets. Please see:
Documentation/filesystems/pnfs.txt for more explanations
nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
when a NMI is triggered.
Format: [state][,regs][,debounce][,die]
nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
Format: [panic,][nopanic,][num]
Valid num: 0 or 1
0 - turn hardlockup detector in nmi_watchdog off
1 - turn hardlockup detector in nmi_watchdog on
When panic is specified, panic when an NMI watchdog
timeout occurs (or 'nopanic' to override the opposite
default). To disable both hard and soft lockup detectors,
please see 'nowatchdog'.
This is useful when you use a panic=... timeout and
need the box quickly up again.
netpoll.carrier_timeout=
[NET] Specifies amount of time (in seconds) that
netpoll should wait for a carrier. By default netpoll
waits 4 seconds.
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
emulation library even if a 387 maths coprocessor
is present.
no_console_suspend
[HW] Never suspend the console
Disable suspending of consoles during suspend and
hibernate operations. Once disabled, debugging
messages can reach various consoles while the rest
of the system is being put to sleep (ie, while
debugging driver suspend/resume hooks). This may
not work reliably with all consoles, but is known
to work with serial and VGA consoles.
To facilitate more flexible debugging, we also add
console_suspend, a printk module parameter to control
it. Users could use console_suspend (usually
/sys/module/printk/parameters/console_suspend) to
turn on/off it dynamically.
noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
caches in the slab allocator. Saves per-node memory,
but will impact performance.
noalign [KNL,ARM]
noapic [SMP,APIC] Tells the kernel to not make use of any
IOAPICs that may be present in the system.
noautogroup Disable scheduler automatic task group creation.
nobats [PPC] Do not use BATs for mapping kernel lowmem
on "Classic" PPC cores.
nocache [ARM]
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
nodelayacct [KNL] Disable per-task delay accounting
nodsp [SH] Disable hardware DSP at boot time.
noefi Disable EFI runtime services support.
noexec [IA-64]
noexec [X86]
On X86-32 available only on PAE configured kernels.
noexec=on: enable non-executable mappings (default)
noexec=off: disable non-executable mappings
nosmap [X86]
Disable SMAP (Supervisor Mode Access Prevention)
even if it is supported by processor.
nosmep [X86]
Disable SMEP (Supervisor Mode Execution Prevention)
even if it is supported by processor.
noexec32 [X86-64]
This affects only 32-bit executables.
noexec32=on: enable non-executable mappings (default)
read doesn't imply executable mappings
noexec32=off: disable non-executable mappings
read implies executable mappings
nofpu [MIPS,SH] Disable hardware FPU at boot time.
nofxsr [BUGS=X86-32] Disables x86 floating point extended
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
nohugeiomap [KNL,x86] Disable kernel huge I/O mappings.
nosmt [KNL,S390] Disable symmetric multithreading (SMT).
Equivalent to smt=1.
noxsave [BUGS=X86] Disables x86 extended register state save
and restore using xsave. The kernel will fallback to
enabling legacy floating-point and sse state.
noxsaveopt [X86] Disables xsaveopt used in saving x86 extended
register states. The kernel will fall back to use
xsave to save the states. By using this parameter,
performance of saving the states is degraded because
xsave doesn't support modified optimization while
xsaveopt supports it on xsaveopt enabled systems.
noxsaves [X86] Disables xsaves and xrstors used in saving and
restoring x86 extended register state in compacted
form of xsave area. The kernel will fall back to use
xsaveopt and xrstor to save and restore the states
in standard form of xsave area. By using this
parameter, xsave area per process might occupy more
memory on xsaves enabled systems.
nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
wfi(ARM) instruction doesn't work correctly and not to
use it. This is also useful when using JTAG debugger.
no_file_caps Tells the kernel not to honor file capabilities. The
only way then for a file to be executed with privilege
is to be setuid root or executed by root.
nohalt [IA-64] Tells the kernel not to use the power saving
function PAL_HALT_LIGHT when idle. This increases
power-consumption. On the positive side, it reduces
interrupt wake-up latency, which may improve performance
in certain environments such as networked servers or
real-time systems.
nohibernate [HIBERNATION] Disable hibernation and resume.
nohz= [KNL] Boottime enable/disable dynamic ticks
Valid arguments: on, off
Default: on
nohz_full= [KNL,BOOT]
The argument is a cpu list, as described above.
In kernels built with CONFIG_NO_HZ_FULL=y, set
the specified list of CPUs whose tick will be stopped
whenever possible. The boot CPU will be forced outside
the range to maintain the timekeeping.
The CPUs in this range must also be included in the
rcu_nocbs= set.
noiotrap [SH] Disables trapped I/O port accesses.
noirqdebug [X86-32] Disables the code which attempts to detect and
disable unhandled interrupt sources.
no_timer_check [X86,APIC] Disables the code which tests for
broken timer IRQ sources.
noisapnp [ISAPNP] Disables ISA PnP code.
noinitrd [RAM] Tells the kernel not to load any configured
initial RAM disk.
nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
remapping.
[Deprecated - use intremap=off]
nointroute [IA-64]
noinvpcid [X86] Disable the INVPCID cpu feature.
nojitter [IA-64] Disables jitter checking for ITC timers.
no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
fault handling.
no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
steal time is computed, but won't influence scheduler
behaviour
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
noltlbs [PPC] Do not use large page/tlb entries for kernel
lowmem mapping on PPC40x and PPC8xx
nomca [IA-64] Disable machine check abort handling
nomce [X86-32] Disable Machine Check Exception
nomfgpt [X86-32] Disable Multi-Function General Purpose
Timer usage (for AMD Geode machines).
nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to
shutdown the other cpus. Instead use the REBOOT_VECTOR
irq.
nomodule Disable module load
nopat [X86] Disable PAT (page attribute table extension of
pagetables) support.
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
with UP alternatives
nordrand [X86] Disable kernel use of the RDRAND and
RDSEED instructions even if they are supported
by the processor. RDRAND and RDSEED are still
available to user space applications.
noresume [SWSUSP] Disables resume and restores original swap
space.
no-scroll [VGA] Disables scrollback.
This is required for the Braillex ib80-piezo Braille
reader made by F.H. Papenmeier (Germany).
nosbagart [IA-64]
nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
and disable the IO APIC. legacy for "maxcpus=0".
nosoftlockup [KNL] Disable the soft-lockup detector.
nosync [HW,M68K] Disables sync negotiation for all devices.
notsc [BUGS=X86-32] Disable Time Stamp Counter
nowatchdog [KNL] Disable both lockup detectors, i.e.
soft-lockup and NMI watchdog (hard-lockup).
nowb [ARM]
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off.
Some features depend on CPU0. Known dependencies are:
1. Resume from suspend/hibernate depends on CPU0.
Suspend/hibernate will fail if CPU0 is offline and you
need to online CPU0 before suspend/hibernate.
2. PIC interrupts also depend on CPU0. CPU0 can't be
removed if a PIC interrupt is detected.
It's said poweroff/reboot may depend on CPU0 on some
machines although I haven't seen such issues so far
after CPU0 is offline on a few tested machines.
If the dependencies are under your control, you can
turn on cpu0_hotplug.
nptcg= [IA-64] Override max number of concurrent global TLB
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
nr_cpus= [SMP] Maximum number of processors that an SMP kernel
could support. nr_cpus=n : n >= 1 limits the kernel to
support 'n' processors. It could be larger than the
number of already plugged CPU during bootup, later in
runtime you can physically add extra cpu until it reaches
n. So during boot up some boot time memory for per-cpu
variables need be pre-allocated for later physical cpu
hot plugging.
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing.
Allowed values are enable and disable
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
one of ['zone', 'node', 'default'] can be specified
This can be set from sysctl after boot.
See Documentation/sysctl/vm.txt for details.
ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
See Documentation/debugging-via-ohci1394.txt for more
info.
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
Rather than timing out after 20 ms if an EC
command is not properly ACKed, override the length
of the timeout. We have interrupts disabled while
waiting for the ACK, so if this is set too high
interrupts *may* be lost!
omap_mux= [OMAP] Override bootloader pin multiplexing.
Format: <mux_mode0.mode_name=value>...
For example, to override I2C bus2:
omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
oprofile.timer= [HW]
Use timer interrupt instead of performance counters
oprofile.cpu_type= Force an oprofile cpu type
This might be useful if you have an older oprofile
userland or if you want common events.
Format: { arch_perfmon }
arch_perfmon: [X86] Force use of architectural
perfmon on Intel CPUs instead of the
CPU specific event set.
timer: [X86] Force use of architectural NMI
timer mode (see also oprofile.timer
for generic hr timer mode)
oops=panic Always panic on oopses. Default is to just kill the
process, but there is a small probability of
deadlocking the machine.
This will also cause panics on machine check exceptions.
Useful together with panic=30 to trigger a reboot.
OSS [HW,OSS]
See Documentation/sound/oss/oss-parameters.txt
page_owner= [KNL] Boot-time page_owner enabling option.
Storage of the information about who allocated
each page is disabled in default. With this switch,
we can turn it on.
on: enable the feature
page_poison= [KNL] Boot-time parameter changing the state of
poisoning on the buddy allocator.
off: turn off poisoning
on: turn on poisoning
panic= [KNL] Kernel behaviour on panic: delay <timeout>
timeout > 0: seconds before rebooting
timeout = 0: wait forever
timeout < 0: reboot immediately
Format: <timeout>
panic_on_warn panic() instead of WARN(). Useful to cause kdump
on a WARN().
crash_kexec_post_notifiers
Run kdump after running panic-notifiers and dumping
kmsg. This only for the users who doubt kdump always
succeeds in any situation.
Note that this also increases risks of kdump failure,
because some panic notifiers can make the crashed
kernel more unstable.
parkbd.port= [HW] Parallel port number the keyboard adapter is
connected to, default is 0.
Format: <parport#>
parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
0 for XT, 1 for AT (default is AT).
Format: <mode>
parport= [HW,PPT] Specify parallel ports. 0 disables.
Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
Use 'auto' to force the driver to use any
IRQ/DMA settings detected (the default is to
ignore detected IRQ/DMA settings because of
possible conflicts). You can specify the base
address, IRQ, and DMA settings; IRQ and DMA
should be numbers, or 'auto' (for using detected
settings on that particular port), or 'nofifo'
(to avoid using a FIFO even if it is detected).
Parallel ports are assigned in the order they
are specified on the command line, starting
with parport0.
parport_init_mode= [HW,PPT]
Configure VIA parallel port to operate in
a specific mode. This is necessary on Pegasos
computer where firmware has no options for setting
up parallel port mode and sets it to spp.
Currently this function knows 686a and 8231 chips.
Format: [spp|ps2|epp|ecp|ecpepp]
pause_on_oops=
Halt all CPUs after the first oops has been printed for
the specified number of seconds. This is to be used if
your oopses keep scrolling off the screen.
pcbit= [HW,ISDN]
pcd. [PARIDE]
See header of drivers/block/paride/pcd.c.
See also Documentation/blockdev/paride.txt.
pci=option[,option...] [PCI] various PCI subsystem options:
earlydump [X86] dump PCI config space before the kernel
changes anything
off [X86] don't probe for the PCI bus
bios [X86-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
has a non-standard PCI host bridge.
nobios [X86-32] disallow use of PCI BIOS, only direct
hardware access methods are allowed. Use this
if you experience crashes upon bootup and you
suspect they are caused by the BIOS.
conf1 [X86] Force use of PCI Configuration Access
Mechanism 1 (config address in IO port 0xCF8,
data in IO port 0xCFC, both 32-bit).
conf2 [X86] Force use of PCI Configuration Access
Mechanism 2 (IO port 0xCF8 is an 8-bit port for
the function, IO port 0xCFA, also 8-bit, sets
bus number. The config space is then accessed
through ports 0xC000-0xCFFF).
See http://wiki.osdev.org/PCI for more info
on the configuration access mechanisms.
noaer [PCIE] If the PCIEAER kernel config parameter is
enabled, this kernel boot option can be used to
disable the use of PCIE advanced error reporting.
nodomains [PCI] Disable support for multiple PCI
root domains (aka PCI segments, in ACPI-speak).
nommconf [X86] Disable use of MMCONFIG for PCI
Configuration
check_enable_amd_mmconf [X86] check for and enable
properly configured MMIO access to PCI
config space on AMD family 10h CPU
nomsi [MSI] If the PCI_MSI kernel config parameter is
enabled, this kernel boot option can be used to
disable the use of MSI interrupts system-wide.
noioapicquirk [APIC] Disable all boot interrupt quirks.
Safety option to keep boot IRQs enabled. This
should never be necessary.
ioapicreroute [APIC] Enable rerouting of boot IRQs to the
primary IO-APIC for bridges that cannot disable
boot IRQs. This fixes a source of spurious IRQs
when the system masks IRQs.
noioapicreroute [APIC] Disable workaround that uses the
boot IRQ equivalent of an IRQ that connects to
a chipset where boot IRQs cannot be disabled.
The opposite of ioapicreroute.
biosirq [X86-32] Use PCI BIOS calls to get the interrupt
routing table. These calls are known to be buggy
on several machines and they hang the machine
when used, but on other computers it's the only
way to get the interrupt routing table. Try
this option if the kernel is unable to allocate
IRQs or discover secondary PCI buses on your
motherboard.
rom [X86] Assign address space to expansion ROMs.
Use with caution as certain devices share
address decoders between ROMs and other
resources.
norom [X86] Do not assign address space to
expansion ROMs that do not already have
BIOS assigned address ranges.
nobar [X86] Do not assign address space to the
BARs that weren't assigned by the BIOS.
irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
assigned automatically to PCI devices. You can
make the kernel exclude IRQs of your ISA cards
this way.
pirqaddr=0xAAAAA [X86] Specify the physical address
of the PIRQ table (normally generated
by the BIOS) if it is outside the
F0000h-100000h range.
lastbus=N [X86] Scan all buses thru bus #N. Can be
useful if the kernel is unable to find your
secondary buses and you want to tell it
explicitly which ones they are.
assign-busses [X86] Always assign all PCI bus
numbers ourselves, overriding
whatever the firmware may have done.
usepirqmask [X86] Honor the possible IRQ mask stored
in the BIOS $PIR table. This is needed on
some systems with broken BIOSes, notably
some HP Pavilion N5400 and Omnibook XE3
notebooks. This will have no effect if ACPI
IRQ routing is enabled.
noacpi [X86] Do not use ACPI for IRQ routing
or for PCI scanning.
use_crs [X86] Use PCI host bridge window information
from ACPI. On BIOSes from 2008 or later, this
is enabled by default. If you need to use this,
please report a bug.
nocrs [X86] Ignore PCI host bridge windows from ACPI.
If you need to use this, please report a bug.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
for broken drivers that don't call it.
skip_isa_align [X86] do not align io start addr, so can
handle more pci cards
noearly [X86] Don't do any early type 1 scanning.
This might help on some broken boards which
machine check when some devices' config space
is read. But various workarounds are disabled
and some IOMMU drivers will not work.
bfsort Sort PCI devices into breadth-first order.
This sorting is done to get a device
order compatible with older (<= 2.4) kernels.
nobfsort Don't sort PCI devices into breadth-first order.
pcie_bus_tune_off Disable PCIe MPS (Max Payload Size)
tuning and use the BIOS-configured MPS defaults.
pcie_bus_safe Set every device's MPS to the largest value
supported by all devices below the root complex.
pcie_bus_perf Set device MPS to the largest allowable MPS
based on its parent bus. Also set MRRS (Max
Read Request Size) to the largest supported
value (no larger than the MPS that the device
or bus can support) for best performance.
pcie_bus_peer2peer Set every device's MPS to 128B, which
every device is guaranteed to support. This
configuration allows peer-to-peer DMA between
any pair of devices, possibly at the cost of
reduced performance. This also guarantees
that hot-added devices will work.
cbiosize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's IO window.
The default value is 256 bytes.
cbmemsize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
resource_alignment=
Format:
[<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
[<order of align>@]pci:<vendor>:<device>\
[:<subvendor>:<subdevice>][; ...]
Specifies alignment and device to reassign
aligned memory resources.
If <order of align> is not specified,
PAGE_SIZE is used as alignment.
PCI-PCI bridge can be specified, if resource
windows need to be expanded.
To specify the alignment for several
instances of a device, the PCI vendor,
device, subvendor, and subdevice may be
specified, e.g., 4096@pci:8086:9c22:103c:198f
ecrc= Enable/disable PCIe ECRC (transaction layer
end-to-end CRC checking).
bios: Use BIOS/firmware settings. This is the
the default.
off: Turn ECRC off
on: Turn ECRC on.
hpiosize=nn[KMG] The fixed amount of bus space which is
reserved for hotplug bridge's IO window.
Default size is 256 bytes.
hpmemsize=nn[KMG] The fixed amount of bus space which is
reserved for hotplug bridge's memory window.
Default size is 2 megabytes.
hpbussize=nn The minimum amount of additional bus numbers
reserved for buses below a hotplug bridge.
Default is 1.
realloc= Enable/disable reallocating PCI bridge resources
if allocations done by BIOS are too small to
accommodate resources required by all child
devices.
off: Turn realloc off
on: Turn realloc on
realloc same as realloc=on
noari do not use PCIe ARI.
pcie_scan_all Scan all possible PCIe devices. Otherwise we
only look for one device below a PCIe downstream
port.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
off Disable ASPM.
force Enable ASPM even on devices that claim not to support it.
WARNING: Forcing ASPM on may cause system lockups.
pcie_hp= [PCIE] PCI Express Hotplug driver options:
nomsi Do not use MSI for PCI Express Native Hotplug (this
makes all PCIe ports use INTx for hotplug services).
pcie_ports= [PCIE] PCIe ports handling:
auto Ask the BIOS whether or not to use native PCIe services
associated with PCIe ports (PME, hot-plug, AER). Use
them only if that is allowed by the BIOS.
native Use native PCIe services associated with PCIe ports
unconditionally.
compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe
ports driver.
pcie_port_pm= [PCIE] PCIe port power management handling:
off Disable power management of all PCIe ports
force Forcibly enable power management of all PCIe ports
pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
nomsi Do not use MSI for native PCIe PME signaling (this makes
all PCIe root ports use INTx for all services).
pcmv= [HW,PCMCIA] BadgePAD 4
pd_ignore_unused
[PM]
Keep all power-domains already enabled by bootloader on,
even if no driver has claimed them. This is useful
for debug and development, but should not be
needed on a platform with proper driver support.
pd. [PARIDE]
See Documentation/blockdev/paride.txt.
pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
boot time.
Format: { 0 | 1 }
See arch/parisc/kernel/pdc_chassis.c
percpu_alloc= Select which percpu first chunk allocator to use.
Currently supported values are "embed" and "page".
Archs may support subset or none of the selections.
See comments in mm/percpu.c for details on each
allocator. This parameter is primarily for debugging
and performance comparison.
pf. [PARIDE]
See Documentation/blockdev/paride.txt.
pg. [PARIDE]
See Documentation/blockdev/paride.txt.
pirq= [SMP,APIC] Manual mp-table setup
See Documentation/x86/i386/IO-APIC.txt.
plip= [PPT,NET] Parallel port network link
Format: { parport<nr> | timid | 0 }
See also Documentation/parport.txt.
pmtmr= [X86] Manual setup of pmtmr I/O Port.
Override pmtimer IOPort with a hex value.
e.g. pmtmr=0x508
pnp.debug=1 [PNP]
Enable PNP debug messages (depends on the
CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
via /sys/module/pnp/parameters/debug. We always show
current resource usage; turning this on also shows
possible settings and some assignment information.
pnpacpi= [ACPI]
{ off }
pnpbios= [ISAPNP]
{ on | off | curr | res | no-curr | no-res }
pnp_reserve_irq=
[ISAPNP] Exclude IRQs for the autoconfiguration
pnp_reserve_dma=
[ISAPNP] Exclude DMAs for the autoconfiguration
pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Ranges are in pairs (I/O port base and size).
pnp_reserve_mem=
[ISAPNP] Exclude memory regions for the
autoconfiguration.
Ranges are in pairs (memory base and size).
ports= [IP_VS_FTP] IPVS ftp helper module
Default is 21.
Up to 8 (IP_VS_APP_MAX_PORTS) ports
may be specified.
Format: <port>,<port>....
ppc_strict_facility_enable
[PPC] This option catches any kernel floating point,
Altivec, VSX and SPE outside of regions specifically
allowed (eg kernel_enable_fpu()/kernel_disable_fpu()).
There is some performance impact when enabling this.
print-fatal-signals=
[KNL] debug: print fatal signals
If enabled, warn about various signal handling
related application anomalies: too many signals,
too many POSIX.1 timers, fatal signals causing a
coredump - etc.
If you hit the warning due to signal overflow,
you might want to try "ulimit -i unlimited".
default: off.
printk.always_kmsg_dump=
Trigger kmsg_dump for cases other than kernel oops or
panics
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
default: disabled
printk.devkmsg={on,off,ratelimit}
Control writing to /dev/kmsg.
on - unlimited logging to /dev/kmsg from userspace
off - logging to /dev/kmsg disabled
ratelimit - ratelimit the logging
Default: ratelimit
printk.time= Show timing data prefixed to each printk message line
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
processor.max_cstate= [HW,ACPI]
Limit processor to maximum C-state
max_cstate=9 overrides any DMI blacklist limit.
processor.nocst [HW,ACPI]
Ignore the _CST method to determine C-states,
instead using the legacy FADT method
profile= [KNL] Enable kernel profiling via /proc/profile
Format: [schedule,]<number>
Param: "schedule" - profile schedule points.
Param: <number> - step/bucket size as a power of 2 for
statistical time based profiling.
Param: "sleep" - profile D-state sleeping (millisecs).
Requires CONFIG_SCHEDSTATS
Param: "kvm" - profile VM exits.
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
before loading.
See Documentation/blockdev/ramdisk.txt.
psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
probe for; one of (bare|imps|exps|lifebook|any).
psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
per second.
psmouse.resetafter= [HW,MOUSE]
Try to reset the device after so many bad packets
(0 = never).
psmouse.resolution=
[HW,MOUSE] Set desired mouse resolution, in dpi.
psmouse.smartscroll=
[HW,MOUSE] Controls Logitech smartscroll autorepeat.
0 = disabled, 1 = enabled (default).
pstore.backend= Specify the name of the pstore backend to use
pt. [PARIDE]
See Documentation/blockdev/paride.txt.
pty.legacy_count=
[KNL] Number of legacy pty's. Overwrites compiled-in
default number.
quiet [KNL] Disable most log messages
r128= [HW,DRM]
raid= [HW,RAID]
See Documentation/admin-guide/md.rst.
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
See Documentation/blockdev/ramdisk.txt.
rcu_nocbs= [KNL]
The argument is a cpu list, as described above.
In kernels built with CONFIG_RCU_NOCB_CPU=y, set
the specified list of CPUs to be no-callback CPUs.
Invocation of these CPUs' RCU callbacks will
be offloaded to "rcuox/N" kthreads created for
that purpose, where "x" is "b" for RCU-bh, "p"
for RCU-preempt, and "s" for RCU-sched, and "N"
is the CPU number. This reduces OS jitter on the
offloaded CPUs, which can be useful for HPC and
real-time workloads. It can also improve energy
efficiency for asymmetric multiprocessors.
rcu_nocb_poll [KNL]
Rather than requiring that offloaded CPUs
(specified by rcu_nocbs= above) explicitly
awaken the corresponding "rcuoN" kthreads,
make these kthreads poll for callbacks.
This improves the real-time response for the
offloaded CPUs by relieving them of the need to
wake up the corresponding kthread, but degrades
energy efficiency by requiring that the kthreads
periodically wake up to do the polling.
rcutree.blimit= [KNL]
Set maximum number of finished RCU callbacks to
process in one batch.
rcutree.dump_tree= [KNL]
Dump the structure of the rcu_node combining tree
out at early boot. This is used for diagnostic
purposes, to verify correct tree setup.
rcutree.gp_cleanup_delay= [KNL]
Set the number of jiffies to delay each step of
RCU grace-period cleanup. This only has effect
when CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP is set.
rcutree.gp_init_delay= [KNL]
Set the number of jiffies to delay each step of
RCU grace-period initialization. This only has
effect when CONFIG_RCU_TORTURE_TEST_SLOW_INIT
is set.
rcutree.gp_preinit_delay= [KNL]
Set the number of jiffies to delay each step of
RCU grace-period pre-initialization, that is,
the propagation of recent CPU-hotplug changes up
the rcu_node combining tree. This only has effect
when CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT is set.
rcutree.rcu_fanout_exact= [KNL]
Disable autobalancing of the rcu_node combining
tree. This is used by rcutorture, and might
possibly be useful for architectures having high
cache-to-cache transfer latencies.
rcutree.rcu_fanout_leaf= [KNL]
Change the number of CPUs assigned to each
leaf rcu_node structure. Useful for very
large systems, which will choose the value 64,
and for NUMA systems with large remote-access
latencies, which will choose a value aligned
with the appropriate hardware boundaries.
rcutree.jiffies_till_sched_qs= [KNL]
Set required age in jiffies for a
given grace period before RCU starts
soliciting quiescent-state help from
rcu_note_context_switch().
rcutree.jiffies_till_first_fqs= [KNL]
Set delay from grace-period initialization to
first attempt to force quiescent states.
Units are jiffies, minimum value is zero,
and maximum value is HZ.
rcutree.jiffies_till_next_fqs= [KNL]
Set delay between subsequent attempts to force
quiescent states. Units are jiffies, minimum
value is one, and maximum value is HZ.
rcutree.kthread_prio= [KNL,BOOT]
Set the SCHED_FIFO priority of the RCU per-CPU
kthreads (rcuc/N). This value is also used for
the priority of the RCU boost threads (rcub/N)
and for the RCU grace-period kthreads (rcu_bh,
rcu_preempt, and rcu_sched). If RCU_BOOST is
set, valid values are 1-99 and the default is 1
(the least-favored priority). Otherwise, when
RCU_BOOST is not set, valid values are 0-99 and
the default is zero (non-realtime operation).
rcutree.rcu_nocb_leader_stride= [KNL]
Set the number of NOCB kthread groups, which
defaults to the square root of the number of
CPUs. Larger numbers reduces the wakeup overhead
on the per-CPU grace-period kthreads, but increases
that same overhead on each group's leader.
rcutree.qhimark= [KNL]
Set threshold of queued RCU callbacks beyond which
batch limiting is disabled.
rcutree.qlowmark= [KNL]
Set threshold of queued RCU callbacks below which
batch limiting is re-enabled.
rcutree.rcu_idle_gp_delay= [KNL]
Set wakeup interval for idle CPUs that have
RCU callbacks (RCU_FAST_NO_HZ=y).
rcutree.rcu_idle_lazy_gp_delay= [KNL]
Set wakeup interval for idle CPUs that have
only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y).
Lazy RCU callbacks are those which RCU can
prove do nothing more than free memory.
rcuperf.gp_exp= [KNL]
Measure performance of expedited synchronous
grace-period primitives.
rcuperf.holdoff= [KNL]
Set test-start holdoff period. The purpose of
this parameter is to delay the start of the
test until boot completes in order to avoid
interference.
rcuperf.nreaders= [KNL]
Set number of RCU readers. The value -1 selects
N, where N is the number of CPUs. A value
"n" less than -1 selects N-n+1, where N is again
the number of CPUs. For example, -2 selects N
(the number of CPUs), -3 selects N+1, and so on.
A value of "n" less than or equal to -N selects
a single reader.
rcuperf.nwriters= [KNL]
Set number of RCU writers. The values operate
the same as for rcuperf.nreaders.
N, where N is the number of CPUs
rcuperf.perf_runnable= [BOOT]
Start rcuperf running at boot time.
rcuperf.shutdown= [KNL]
Shut the system down after performance tests
complete. This is useful for hands-off automated
testing.
rcuperf.perf_type= [KNL]
Specify the RCU implementation to test.
rcuperf.verbose= [KNL]
Enable additional printk() statements.
rcutorture.cbflood_inter_holdoff= [KNL]
Set holdoff time (jiffies) between successive
callback-flood tests.
rcutorture.cbflood_intra_holdoff= [KNL]
Set holdoff time (jiffies) between successive
bursts of callbacks within a given callback-flood
test.
rcutorture.cbflood_n_burst= [KNL]
Set the number of bursts making up a given
callback-flood test. Set this to zero to
disable callback-flood testing.
rcutorture.cbflood_n_per_burst= [KNL]
Set the number of callbacks to be registered
in a given burst of a callback-flood test.
rcutorture.fqs_duration= [KNL]
Set duration of force_quiescent_state bursts
in microseconds.
rcutorture.fqs_holdoff= [KNL]
Set holdoff time within force_quiescent_state bursts
in microseconds.
rcutorture.fqs_stutter= [KNL]
Set wait time between force_quiescent_state bursts
in seconds.
rcutorture.gp_cond= [KNL]
Use conditional/asynchronous update-side
primitives, if available.
rcutorture.gp_exp= [KNL]
Use expedited update-side primitives, if available.
rcutorture.gp_normal= [KNL]
Use normal (non-expedited) asynchronous
update-side primitives, if available.
rcutorture.gp_sync= [KNL]
Use normal (non-expedited) synchronous
update-side primitives, if available. If all
of rcutorture.gp_cond=, rcutorture.gp_exp=,
rcutorture.gp_normal=, and rcutorture.gp_sync=
are zero, rcutorture acts as if is interpreted
they are all non-zero.
rcutorture.n_barrier_cbs= [KNL]
Set callbacks/threads for rcu_barrier() testing.
rcutorture.nfakewriters= [KNL]
Set number of concurrent RCU writers. These just
stress RCU, they don't participate in the actual
test, hence the "fake".
rcutorture.nreaders= [KNL]
Set number of RCU readers. The value -1 selects
N-1, where N is the number of CPUs. A value
"n" less than -1 selects N-n-2, where N is again
the number of CPUs. For example, -2 selects N
(the number of CPUs), -3 selects N+1, and so on.
rcutorture.object_debug= [KNL]
Enable debug-object double-call_rcu() testing.
rcutorture.onoff_holdoff= [KNL]
Set time (s) after boot for CPU-hotplug testing.
rcutorture.onoff_interval= [KNL]
Set time (s) between CPU-hotplug operations, or
zero to disable CPU-hotplug testing.
rcutorture.shuffle_interval= [KNL]
Set task-shuffle interval (s). Shuffling tasks
allows some CPUs to go into dyntick-idle mode
during the rcutorture test.
rcutorture.shutdown_secs= [KNL]
Set time (s) after boot system shutdown. This
is useful for hands-off automated testing.
rcutorture.stall_cpu= [KNL]
Duration of CPU stall (s) to test RCU CPU stall
warnings, zero to disable.
rcutorture.stall_cpu_holdoff= [KNL]
Time to wait (s) after boot before inducing stall.
rcutorture.stat_interval= [KNL]
Time (s) between statistics printk()s.
rcutorture.stutter= [KNL]
Time (s) to stutter testing, for example, specifying
five seconds causes the test to run for five seconds,
wait for five seconds, and so on. This tests RCU's
ability to transition abruptly to and from idle.
rcutorture.test_boost= [KNL]
Test RCU priority boosting? 0=no, 1=maybe, 2=yes.
"Maybe" means test if the RCU implementation
under test support RCU priority boosting.
rcutorture.test_boost_duration= [KNL]
Duration (s) of each individual boost test.
rcutorture.test_boost_interval= [KNL]
Interval (s) between each boost test.
rcutorture.test_no_idle_hz= [KNL]
Test RCU's dyntick-idle handling. See also the
rcutorture.shuffle_interval parameter.
rcutorture.torture_runnable= [BOOT]
Start rcutorture running at boot time.
rcutorture.torture_type= [KNL]
Specify the RCU implementation to test.
rcutorture.verbose= [KNL]
Enable additional printk() statements.
rcupdate.rcu_cpu_stall_suppress= [KNL]
Suppress RCU CPU stall warning messages.
rcupdate.rcu_cpu_stall_timeout= [KNL]
Set timeout for RCU CPU stall warning messages.
rcupdate.rcu_expedited= [KNL]
Use expedited grace-period primitives, for
example, synchronize_rcu_expedited() instead
of synchronize_rcu(). This reduces latency,
but can increase CPU utilization, degrade
real-time latency, and degrade energy efficiency.
No effect on CONFIG_TINY_RCU kernels.
rcupdate.rcu_normal= [KNL]
Use only normal grace-period primitives,
for example, synchronize_rcu() instead of
synchronize_rcu_expedited(). This improves
real-time latency, CPU utilization, and
energy efficiency, but can expose users to
increased grace-period latency. This parameter
overrides rcupdate.rcu_expedited. No effect on
CONFIG_TINY_RCU kernels.
rcupdate.rcu_normal_after_boot= [KNL]
Once boot has completed (that is, after
rcu_end_inkernel_boot() has been invoked), use
only normal grace-period primitives. No effect
on CONFIG_TINY_RCU kernels.
rcupdate.rcu_task_stall_timeout= [KNL]
Set timeout in jiffies for RCU task stall warning
messages. Disable with a value less than or equal
to zero.
rcupdate.rcu_self_test= [KNL]
Run the RCU early boot self tests
rcupdate.rcu_self_test_bh= [KNL]
Run the RCU bh early boot self tests
rcupdate.rcu_self_test_sched= [KNL]
Run the RCU sched early boot self tests
rdinit= [KNL]
Format: <full_path>
Run specified binary instead of /init from the ramdisk,
used for early userspace startup. See initrd.
reboot= [KNL]
Format (x86 or x86_64):
[w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \
[[,]s[mp]#### \
[[,]b[ios] | a[cpi] | k[bd] | t[riple] | e[fi] | p[ci]] \
[[,]f[orce]
Where reboot_mode is one of warm (soft) or cold (hard) or gpio,
reboot_type is one of bios, acpi, kbd, triple, efi, or pci,
reboot_force is either force or not specified,
reboot_cpu is s[mp]#### with #### being the processor
to be used for rebooting.
relax_domain_level=
[KNL, SMP] Set scheduler's default relax_domain_level.
See Documentation/cgroup-v1/cpusets.txt.
relative_sleep_states=
[SUSPEND] Use sleep state labeling where the deepest
state available other than hibernation is always "mem".
Format: { "0" | "1" }
0 -- Traditional sleep state labels.
1 -- Relative sleep state labels.
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
reservetop= [X86-32]
Format: nn[KMG]
Reserves a hole at the top of the kernel virtual
address space.
reservelow= [X86]
Format: nn[K]
Set the amount of memory to reserve for BIOS at
the bottom of the address space.
reset_devices [KNL] Force drivers to reset the underlying device
during initialization.
resume= [SWSUSP]
Specify the partition device for software suspend
Format:
{/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>}
resume_offset= [SWSUSP]
Specify the offset from the beginning of the partition
given by "resume=" at which the swap header is located,
in <PAGE_SIZE> units (needed only for swap files).
See Documentation/power/swsusp-and-swap-files.txt
resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to
read the resume files
resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up.
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
hibernate= [HIBERNATION]
noresume Don't check if there's a hibernation image
present during boot.
nocompress Don't compress/decompress hibernation images.
no Disable hibernation and resume.
protect_image Turn on image protection during restoration
(that will set all pages holding image data
during restoration read-only).
retain_initrd [RAM] Keep initrd memory after extraction
rfkill.default_state=
0 "airplane mode". All wifi, bluetooth, wimax, gps, fm,
etc. communication is blocked by default.
1 Unblocked.
rfkill.master_switch_mode=
0 The "airplane mode" button does nothing.
1 The "airplane mode" button toggles between everything
blocked and the previous configuration.
2 The "airplane mode" button toggles between everything
blocked and everything unblocked.
rhash_entries= [KNL,NET]
Set number of hash buckets for route cache
ro [KNL] Mount root device read-only on boot
rodata= [KNL]
on Mark read-only kernel memory as read-only (default).
off Leave read-only kernel memory writable for debugging.
rockchip.usb_uart
Enable the uart passthrough on the designated usb port
on Rockchip SoCs. When active, the signals of the
debug-uart get routed to the D+ and D- pins of the usb
port and the regular usb controller gets disabled.
root= [KNL] Root filesystem
See name_to_dev_t comment in init/do_mounts.c.
rootdelay= [KNL] Delay (in seconds) to pause before attempting to
mount the root filesystem
rootflags= [KNL] Set root filesystem mount option string
rootfstype= [KNL] Set root filesystem type
rootwait [KNL] Wait (indefinitely) for root device to show up.
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
rproc_mem=nn[KMG][@address]
[KNL,ARM,CMA] Remoteproc physical memory block.
Memory area to be used by remote processor image,
managed by CMA.
rw [KNL] Mount root device read-write on boot
S [KNL] Run init in single mode
s390_iommu= [HW,S390]
Set s390 IOTLB flushing mode
strict
With strict flushing every unmap operation will result in
an IOTLB flush. Default is lazy flushing before reuse,
which is faster.
sa1100ir [NET]
See drivers/net/irda/sa1100_ir.c.
sbni= [NET] Granch SBNI12 leased line adapter
sched_debug [KNL] Enables verbose scheduler debug messages.
schedstats= [KNL,X86] Enable or disable scheduled statistics.
Allowed values are enable and disable. This feature
incurs a small amount of overhead in the scheduler
but is useful for debugging and performance tuning.
skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
xtime_lock contention on larger systems, and/or RCU lock
contention on all systems with CONFIG_MAXSMP set.
Format: { "0" | "1" }
0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
1 -- enable.
Note: increases power consumption, thus should only be
enabled if running jitter sensitive (HPC/RT) workloads.
security= [SECURITY] Choose a security module to enable at boot.
If this boot parameter is not specified, only the first
security module asking for security registration will be
loaded. An invalid security module name will be treated
as if no module has been chosen.
selinux= [SELINUX] Disable or enable SELinux at boot time.
Format: { "0" | "1" }
See security/selinux/Kconfig help text.
0 -- disable.
1 -- enable.
Default value is set via kernel config option.
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
apparmor= [APPARMOR] Disable or enable AppArmor at boot time
Format: { "0" | "1" }
See security/apparmor/Kconfig help text
0 -- disable.
1 -- enable.
Default value is set via kernel config option.
serialnumber [BUGS=X86-32]
shapers= [NET]
Maximal number of shapers.
show_msr= [x86] show boot-time MSR settings
Format: { <integer> }
Show boot-time (BIOS-initialized) MSR settings.
The parameter means the number of CPUs to show,
for example 1 means boot CPU only.
simeth= [IA-64]
simscsi=
slram= [HW,MTD]
slab_nomerge [MM]
Disable merging of slabs with similar size. May be
necessary if there is some reason to distinguish
allocs to different slabs. Debug options disable
merging on their own.
For more information see Documentation/vm/slub.txt.
slab_max_order= [MM, SLAB]
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
fragmentation. Defaults to 1 for systems with
more than 32MB of RAM, 0 otherwise.
slub_debug[=options[,slabs]] [MM, SLUB]
Enabling slub_debug allows one to determine the
culprit if slab objects become corrupted. Enabling
slub_debug can create guard zones around objects and
may poison objects when not in use. Also tracks the
last alloc / free. For more information see
Documentation/vm/slub.txt.
slub_max_order= [MM, SLUB]
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
fragmentation. For more information see
Documentation/vm/slub.txt.
slub_min_objects= [MM, SLUB]
The minimum number of objects per slab. SLUB will
increase the slab order up to slub_max_order to
generate a sufficiently large slab able to contain
the number of objects indicated. The higher the number
of objects the smaller the overhead of tracking slabs
and the less frequently locks need to be acquired.
For more information see Documentation/vm/slub.txt.
slub_min_order= [MM, SLUB]
Determines the minimum page order for slabs. Must be
lower than slub_max_order.
For more information see Documentation/vm/slub.txt.
slub_nomerge [MM, SLUB]
Same with slab_nomerge. This is supported for legacy.
See slab_nomerge for more information.
smart2= [HW]
Format: <io1>[,<io2>[,...,<io8>]]
smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
smsc-ircc2.ircc_sir= [HW] SIR base I/O port
smsc-ircc2.ircc_fir= [HW] FIR base I/O port
smsc-ircc2.ircc_irq= [HW] IRQ line
smsc-ircc2.ircc_dma= [HW] DMA channel
smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
0: Toshiba Satellite 1800 (GP data pin select)
1: Fast pin select (default)
2: ATC IRMode
smt [KNL,S390] Set the maximum number of threads (logical
CPUs) to use per physical CPU on systems capable of
symmetric multithreading (SMT). Will be capped to the
actual hardware limit.
Format: <integer>
Default: -1 (no limit)
softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
Format: <integer>
softlockup_all_cpu_backtrace=
[KNL] Should the soft-lockup detector generate
backtraces on all cpus.
Format: <integer>
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/laptops/sonypi.txt
spia_io_base= [HW,MTD]
spia_fio_base=
spia_pedr=
spia_peddr=
stacktrace [FTRACE]
Enabled the stack tracer on boot up.
stacktrace_filter=[function-list]
[FTRACE] Limit the functions that the stack tracer
will trace at boot up. function-list is a comma separated
list of functions. This list can be changed at run
time by the stack_trace_filter file in the debugfs
tracing directory. Note, this enables stack tracing
and the stacktrace above is not needed.
sti= [PARISC,HW]
Format: <num>
Set the STI (builtin display/keyboard on the HP-PARISC
machines) console (graphic card) which should be used
as the initial boot-console.
See also comment in drivers/video/console/sticore.c.
sti_font= [HW]
See comment in drivers/video/console/sticore.c.
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
sunrpc.min_resvport=
sunrpc.max_resvport=
[NFS,SUNRPC]
SunRPC servers often require that client requests
originate from a privileged port (i.e. a port in the
range 0 < portnr < 1024).
An administrator who wishes to reserve some of these
ports for other uses may adjust the range that the
kernel's sunrpc client considers to be privileged
using these two parameters to set the minimum and
maximum port values.
sunrpc.svc_rpc_per_connection_limit=
[NFS,SUNRPC]
Limit the number of requests that the server will
process in parallel from a single connection.
The default value is 0 (no limit).
sunrpc.pool_mode=
[NFS]
Control how the NFS server code allocates CPUs to
service thread pools. Depending on how many NICs
you have and where their interrupts are bound, this
option will affect which CPUs will do NFS serving.
Note: this parameter cannot be changed while the
NFS server is running.
auto the server chooses an appropriate mode
automatically using heuristics
global a single global pool contains all CPUs
percpu one pool for each CPU
pernode one pool for each NUMA node (equivalent
to global on non-NUMA machines)
sunrpc.tcp_slot_table_entries=
sunrpc.udp_slot_table_entries=
[NFS,SUNRPC]
Sets the upper limit on the number of simultaneous
RPC calls that can be sent from the client to a
server. Increasing these values may allow you to
improve throughput, but will also increase the
amount of memory reserved for use by the client.
suspend.pm_test_delay=
[SUSPEND]
Sets the number of seconds to remain in a suspend test
mode before resuming the system (see
/sys/power/pm_test). Only available when CONFIG_PM_DEBUG
is set. Default value is 5.
swapaccount=[0|1]
[KNL] Enable accounting of swap in memory resource
controller if no parameter or 1 is given or disable
it if 0 is given (See Documentation/cgroup-v1/memory.txt)
swiotlb= [ARM,IA-64,PPC,MIPS,X86]
Format: { <int> | force }
<int> -- Number of I/O TLB slabs
force -- force using of bounce buffers even if they
wouldn't be automatically used by the kernel
switches= [HW,M68k]
sysfs.deprecated=0|1 [KNL]
Enable/disable old style sysfs layout for old udev
on older distributions. When this option is enabled
very new udev will not work anymore. When this option
is disabled (or CONFIG_SYSFS_DEPRECATED not compiled)
in older udev will not work anymore.
Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in
the kernel configuration.
sysrq_always_enabled
[KNL]
Ignore sysrq setting - this boot parameter will
neutralize any effect of /proc/sys/kernel/sysrq.
Useful for debugging.
tcpmhash_entries= [KNL,NET]
Set the number of tcp_metrics_hash slots.
Default value is 8192 or 16384 depending on total
ram pages. This is used to specify the TCP metrics
cache size. See Documentation/networking/ip-sysctl.txt
"tcp_no_metrics_save" section for more details.
tdfx= [HW,DRM]
test_suspend= [SUSPEND][,N]
Specify "mem" (for Suspend-to-RAM) or "standby" (for
standby suspend) or "freeze" (for suspend type freeze)
as the system sleep state during system startup with
the optional capability to repeat N number of times.
The system is woken from this state using a
wakeup-capable RTC alarm.
thash_entries= [KNL,NET]
Set number of hash buckets for TCP connection
thermal.act= [HW,ACPI]
-1: disable all active trip points in all thermal zones
<degrees C>: override all lowest active trip points
thermal.crt= [HW,ACPI]
-1: disable all critical trip points in all thermal zones
<degrees C>: override all critical trip points
thermal.nocrt= [HW,ACPI]
Set to disable actions on ACPI thermal zone
critical and hot trip points.
thermal.off= [HW,ACPI]
1: disable ACPI thermal control
thermal.psv= [HW,ACPI]
-1: disable all passive trip points
<degrees C>: override all passive trip points to this
value
thermal.tzp= [HW,ACPI]
Specify global default ACPI thermal zone polling rate
<deci-seconds>: poll all this frequency
0: no polling (default)
threadirqs [KNL]
Force threading of all interrupt handlers except those
marked explicitly IRQF_NO_THREAD.
tmem [KNL,XEN]
Enable the Transcendent memory driver if built-in.
tmem.cleancache=0|1 [KNL, XEN]
Default is on (1). Disable the usage of the cleancache
API to send anonymous pages to the hypervisor.
tmem.frontswap=0|1 [KNL, XEN]
Default is on (1). Disable the usage of the frontswap
API to send swap pages to the hypervisor. If disabled
the selfballooning and selfshrinking are force disabled.
tmem.selfballooning=0|1 [KNL, XEN]
Default is on (1). Disable the driving of swap pages
to the hypervisor.
tmem.selfshrinking=0|1 [KNL, XEN]
Default is on (1). Partial swapoff that immediately
transfers pages from Xen hypervisor back to the
kernel based on different criteria.
topology= [S390]
Format: {off | on}
Specify if the kernel should make use of the cpu
topology information if the hardware supports this.
The scheduler will make use of this information and
e.g. base its process migration decisions on it.
Default is on.
topology_updates= [KNL, PPC, NUMA]
Format: {off}
Specify if the kernel should ignore (off)
topology updates sent by the hypervisor to this
LPAR.
tp720= [HW,PS2]
tpm_suspend_pcr=[HW,TPM]
Format: integer pcr id
Specify that at suspend time, the tpm driver
should extend the specified pcr with zeros,
as a workaround for some chips which fail to
flush the last written pcr on TPM_SaveState.
This will guarantee that all the other pcrs
are saved.
trace_buf_size=nn[KMG]
[FTRACE] will set tracing buffer size on each cpu.
trace_event=[event-list]
[FTRACE] Set and start specified trace events in order
to facilitate early boot debugging. The event-list is a
comma separated list of trace events to enable. See
also Documentation/trace/events.txt
trace_options=[option-list]
[FTRACE] Enable or disable tracer options at boot.
The option-list is a comma delimited list of options
that can be enabled or disabled just as if you were
to echo the option name into
/sys/kernel/debug/tracing/trace_options
For example, to enable stacktrace option (to dump the
stack trace of each event), add to the command line:
trace_options=stacktrace
See also Documentation/trace/ftrace.txt "trace options"
section.
tp_printk[FTRACE]
Have the tracepoints sent to printk as well as the
tracing ring buffer. This is useful for early boot up
where the system hangs or reboots and does not give the
option for reading the tracing buffer or performing a
ftrace_dump_on_oops.
To turn off having tracepoints sent to printk,
echo 0 > /proc/sys/kernel/tracepoint_printk
Note, echoing 1 into this file without the
tracepoint_printk kernel cmdline option has no effect.
** CAUTION **
Having tracepoints sent to printk() and activating high
frequency tracepoints such as irq or sched, can cause
the system to live lock.
traceoff_on_warning
[FTRACE] enable this option to disable tracing when a
warning is hit. This turns off "tracing_on". Tracing can
be enabled again by echoing '1' into the "tracing_on"
file located in /sys/kernel/debug/tracing/
This option is useful, as it disables the trace before
the WARNING dump is called, which prevents the trace to
be filled with content caused by the warning output.
This option can also be set at run time via the sysctl
option: kernel/traceoff_on_warning
transparent_hugepage=
[KNL]
Format: [always|madvise|never]
Can be used to control the default behavior of the system
with respect to transparent hugepages.
See Documentation/vm/transhuge.txt for more details.
tsc= Disable clocksource stability checks for TSC.
Format: <string>
[x86] reliable: mark tsc clocksource as reliable, this
disables clocksource verification at runtime, as well
as the stability checks done at bootup. Used to enable
high-resolution timer mode on older hardware, and in
virtualized environment.
[x86] noirqtime: Do not use TSC to do irq accounting.
Used to run time disable IRQ_TIME_ACCOUNTING on any
platforms where RDTSC is slow and this accounting
can add overhead.
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
Format:
<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
See also Documentation/input/joystick-parport.txt
udbg-immortal [PPC] When debugging early kernel crashes that
happen after console_init() and before a proper
console driver takes over, this boot options might
help "seeing" what's going on.
uhash_entries= [KNL,NET]
Set number of hash buckets for UDP/UDP-Lite connections
uhci-hcd.ignore_oc=
[USB] Ignore overcurrent events (default N).
Some badly-designed motherboards generate lots of
bogus events, for ports that aren't wired to
anything. Set this parameter to avoid log spamming.
Note that genuine overcurrent events won't be
reported either.
unknown_nmi_panic
[X86] Cause panic on unknown NMI.
usbcore.authorized_default=
[USB] Default USB device authorization:
(default -1 = authorized except for wireless USB,
0 = not authorized, 1 = authorized)
usbcore.autosuspend=
[USB] The autosuspend time delay (in seconds) used
for newly-detected USB devices (default 2). This
is the time required before an idle device will be
autosuspended. Devices for which the delay is set
to a negative value won't be autosuspended at all.
usbcore.usbfs_snoop=
[USB] Set to log all usbfs traffic (default 0 = off).
usbcore.usbfs_snoop_max=
[USB] Maximum number of bytes to snoop in each URB
(default = 65536).
usbcore.blinkenlights=
[USB] Set to cycle leds on hubs (default 0 = off).
usbcore.old_scheme_first=
[USB] Start with the old device initialization
scheme (default 0 = off).
usbcore.usbfs_memory_mb=
[USB] Memory limit (in MB) for buffers allocated by
usbfs (default = 16, 0 = max = 2047).
usbcore.use_both_schemes=
[USB] Try the other device initialization scheme
if the first one fails (default 1 = enabled).
usbcore.initial_descriptor_timeout=
[USB] Specifies timeout for the initial 64-byte
USB_REQ_GET_DESCRIPTOR request in milliseconds
(default 5000 = 5.0 seconds).
usbcore.nousb [USB] Disable the USB subsystem
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.
usb-storage.delay_use=
[UMS] The delay in seconds before a new device is
scanned for Logical Units (default 1).
usb-storage.quirks=
[UMS] A list of quirks entries to supplement or
override the built-in unusual_devs list. List
entries are separated by commas. Each entry has
the form VID:PID:Flags where VID and PID are Vendor
and Product ID values (4-digit hex numbers) and
Flags is a set of characters, each corresponding
to a common usb-storage quirk flag as follows:
a = SANE_SENSE (collect more than 18 bytes
of sense data);
b = BAD_SENSE (don't collect more than 18
bytes of sense data);
c = FIX_CAPACITY (decrease the reported
device capacity by one sector);
d = NO_READ_DISC_INFO (don't use
READ_DISC_INFO command);
e = NO_READ_CAPACITY_16 (don't use
READ_CAPACITY_16 command);
f = NO_REPORT_OPCODES (don't use report opcodes
command, uas only);
g = MAX_SECTORS_240 (don't transfer more than
240 sectors at a time, uas only);
h = CAPACITY_HEURISTICS (decrease the
reported device capacity by one
sector if the number is odd);
i = IGNORE_DEVICE (don't bind to this
device);
j = NO_REPORT_LUNS (don't use report luns
command, uas only);
l = NOT_LOCKABLE (don't try to lock and
unlock ejectable media);
m = MAX_SECTORS_64 (don't transfer more
than 64 sectors = 32 KB at a time);
n = INITIAL_READ10 (force a retry of the
initial READ(10) command);
o = CAPACITY_OK (accept the capacity
reported by the device);
p = WRITE_CACHE (the device cache is ON
by default);
r = IGNORE_RESIDUE (the device reports
bogus residue values);
s = SINGLE_LUN (the device has only one
Logical Unit);
t = NO_ATA_1X (don't allow ATA(12) and ATA(16)
commands, uas only);
u = IGNORE_UAS (don't bind to the uas driver);
w = NO_WP_DETECT (don't test whether the
medium is write-protected).
y = ALWAYS_SYNC (issue a SYNCHRONIZE_CACHE
even if the device claims no cache)
Example: quirks=0419:aaf5:rl,0421:0433:rc
user_debug= [KNL,ARM]
Format: <int>
See arch/arm/Kconfig.debug help text.
1 - undefined instruction events
2 - system calls
4 - invalid data aborts
8 - SIGSEGV faults
16 - SIGBUS faults
Example: user_debug=31
userpte=
[X86] Flags controlling user PTE allocations.
nohigh = do not allocate PTE pages in
HIGHMEM regardless of setting
of CONFIG_HIGHPTE.
vdso= [X86,SH]
On X86_32, this is an alias for vdso32=. Otherwise:
vdso=1: enable VDSO (the default)
vdso=0: disable VDSO mapping
vdso32= [X86] Control the 32-bit vDSO
vdso32=1: enable 32-bit VDSO
vdso32=0 or vdso32=2: disable 32-bit VDSO
See the help text for CONFIG_COMPAT_VDSO for more
details. If CONFIG_COMPAT_VDSO is set, the default is
vdso32=0; otherwise, the default is vdso32=1.
For compatibility with older kernels, vdso32=2 is an
alias for vdso32=0.
Try vdso32=0 if you encounter an error that says:
dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
vector= [IA-64,SMP]
vector=percpu: enable percpu vector domain
video= [FB] Frame buffer configuration
See Documentation/fb/modedb.txt.
video.brightness_switch_enabled= [0,1]
If set to 1, on receiving an ACPI notify event
generated by hotkey, video driver will adjust brightness
level and then send out the event to user space through
the allocated input device; If set to 0, video driver
will only send out the event without touching backlight
brightness level.
default: 1
virtio_mmio.device=
[VMMIO] Memory mapped virtio (platform) device.
<size>@<baseaddr>:<irq>[:<id>]
where:
<size> := size (can use standard suffixes
like K, M and G)
<baseaddr> := physical base address
<irq> := interrupt number (as passed to
request_irq())
<id> := (optional) platform device id
example:
virtio_mmio.device=1K@0x100b0000:48:7
Can be used multiple times for multiple devices.
vga= [BOOT,X86-32] Select a particular video mode
See Documentation/x86/boot.txt and
Documentation/svga.txt.
Use vga=ask for menu.
This is actually a boot loader parameter; the value is
passed to the kernel using a special protocol.
vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
size of <nn>. This can be used to increase the
minimum size (128MB on x86). It can also be used to
decrease the size and leave more room for directly
mapped kernel RAM.
vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
Format: <command>
vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
Format: <command>
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
vsyscall= [X86-64]
Controls the behavior of vsyscalls (i.e. calls to
fixed addresses of 0xffffffffff600x00 from legacy
code). Most statically-linked binaries and older
versions of glibc use these calls. Because these
functions are at fixed addresses, they make nice
targets for exploits that can control RIP.
emulate [default] Vsyscalls turn into traps and are
emulated reasonably safely.
native Vsyscalls are native syscall instructions.
This is a little bit faster than trapping
and makes a few dynamic recompilers work
better than they would in emulation mode.
It also makes exploits much easier to write.
none Vsyscalls don't work at all. This makes
them quite hard to use for exploits but
might break your system.
vt.color= [VT] Default text color.
Format: 0xYX, X = foreground, Y = background.
Default: 0x07 = light gray on black.
vt.cur_default= [VT] Default cursor shape.
Format: 0xCCBBAA, where AA, BB, and CC are the same as
the parameters of the <Esc>[?A;B;Cc escape sequence;
see VGA-softcursor.txt. Default: 2 = underline.
vt.default_blu= [VT]
Format: <blue0>,<blue1>,<blue2>,...,<blue15>
Change the default blue palette of the console.
This is a 16-member array composed of values
ranging from 0-255.
vt.default_grn= [VT]
Format: <green0>,<green1>,<green2>,...,<green15>
Change the default green palette of the console.
This is a 16-member array composed of values
ranging from 0-255.
vt.default_red= [VT]
Format: <red0>,<red1>,<red2>,...,<red15>
Change the default red palette of the console.
This is a 16-member array composed of values
ranging from 0-255.
vt.default_utf8=
[VT]
Format=<0|1>
Set system-wide default UTF-8 mode for all tty's.
Default is 1, i.e. UTF-8 mode is enabled for all
newly opened terminals.
vt.global_cursor_default=
[VT]
Format=<-1|0|1>
Set system-wide default for whether a cursor
is shown on new VTs. Default is -1,
i.e. cursors will be created by default unless
overridden by individual drivers. 0 will hide
cursors, 1 will display them.
vt.italic= [VT] Default color for italic text; 0-15.
Default: 2 = green.
vt.underline= [VT] Default color for underlined text; 0-15.
Default: 3 = cyan.
watchdog timers [HW,WDT] For information on watchdog timers,
see Documentation/watchdog/watchdog-parameters.txt
or other driver-specific files in the
Documentation/watchdog/ directory.
workqueue.watchdog_thresh=
If CONFIG_WQ_WATCHDOG is configured, workqueue can
warn stall conditions and dump internal state to
help debugging. 0 disables workqueue stall
detection; otherwise, it's the stall threshold
duration in seconds. The default value is 30 and
it can be updated at runtime by writing to the
corresponding sysfs file.
workqueue.disable_numa
By default, all work items queued to unbound
workqueues are affine to the NUMA nodes they're
issued on, which results in better behavior in
general. If NUMA affinity needs to be disabled for
whatever reason, this option can be used. Note
that this also can be controlled per-workqueue for
workqueues visible under /sys/bus/workqueue/.
workqueue.power_efficient
Per-cpu workqueues are generally preferred because
they show better performance thanks to cache
locality; unfortunately, per-cpu workqueues tend to
be more power hungry than unbound workqueues.
Enabling this makes the per-cpu workqueues which
were observed to contribute significantly to power
consumption unbound, leading to measurably lower
power usage at the cost of small performance
overhead.
The default value of this parameter is determined by
the config option CONFIG_WQ_POWER_EFFICIENT_DEFAULT.
workqueue.debug_force_rr_cpu
Workqueue used to implicitly guarantee that work
items queued without explicit CPU specified are put
on the local CPU. This guarantee is no longer true
and while local CPU is still preferred work items
may be put on foreign CPUs. This debug option
forces round-robin CPU selection to flush out
usages which depend on the now broken guarantee.
When enabled, memory and cache locality will be
impacted.
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
default x2apic cluster mode on platforms
supporting x2apic.
x86_intel_mid_timer= [X86-32,APBT]
Choose timer option for x86 Intel MID platform.
Two valid options are apbt timer only and lapic timer
plus one apbt timer for broadcast timer.
x86_intel_mid_timer=apbt_only | lapic_and_apbt
xen_512gb_limit [KNL,X86-64,XEN]
Restricts the kernel running paravirtualized under Xen
to use only up to 512 GB of RAM. The reason to do so is
crash analysis tools and Xen tools for doing domain
save/restore/migration must be enabled to handle larger
domains.
xen_emul_unplug= [HW,X86,XEN]
Unplug Xen emulated devices
Format: [unplug0,][unplug1]
ide-disks -- unplug primary master IDE devices
aux-ide-disks -- unplug non-primary-master IDE devices
nics -- unplug network devices
all -- unplug all emulated devices (NICs and IDE disks)
unnecessary -- unplugging emulated devices is
unnecessary even if the host did not respond to
the unplug protocol
never -- do not unplug even if version check succeeds
xen_nopvspin [X86,XEN]
Disables the ticketlock slowpath using Xen PV
optimizations.
xen_nopv [X86]
Disables the PV optimizations forcing the HVM guest to
run as generic HVM guest with no PV drivers.
xirc2ps_cs= [NET,PCMCIA]
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Documentation/admin-guide/mono.rst
浏览文件 @ 63ac0cf9
...@@ -31,7 +31,9 @@ other program after you have done the following: ...@@ -31,7 +31,9 @@ other program after you have done the following:
more about the configuration process. more about the configuration process.
3) Add the following entries to ``/etc/rc.local`` or similar script 3) Add the following entries to ``/etc/rc.local`` or similar script
to be run at system startup:: to be run at system startup:
.. code-block:: sh
# Insert BINFMT_MISC module into the kernel # Insert BINFMT_MISC module into the kernel
if [ ! -e /proc/sys/fs/binfmt_misc/register ]; then if [ ! -e /proc/sys/fs/binfmt_misc/register ]; then
......
Documentation/admin-guide/ramoops.rst
浏览文件 @ 63ac0cf9
...@@ -78,7 +78,9 @@ Setting the ramoops parameters can be done in several different manners: ...@@ -78,7 +78,9 @@ Setting the ramoops parameters can be done in several different manners:
}; };
C. Use a platform device and set the platform data. The parameters can then C. Use a platform device and set the platform data. The parameters can then
be set through that platform data. An example of doing that is:: be set through that platform data. An example of doing that is:
.. code-block:: c
#include <linux/pstore_ram.h> #include <linux/pstore_ram.h>
[...] [...]
......
Documentation/conf.py
浏览文件 @ 63ac0cf9
...@@ -136,7 +136,7 @@ pygments_style = 'sphinx' ...@@ -136,7 +136,7 @@ pygments_style = 'sphinx'
todo_include_todos = False todo_include_todos = False
primary_domain = 'C' primary_domain = 'C'
highlight_language = 'guess' highlight_language = 'none'
# -- Options for HTML output ---------------------------------------------- # -- Options for HTML output ----------------------------------------------
...@@ -336,7 +336,7 @@ latex_elements = { ...@@ -336,7 +336,7 @@ latex_elements = {
# (source start file, target name, title, # (source start file, target name, title,
# author, documentclass [howto, manual, or own class]). # author, documentclass [howto, manual, or own class]).
latex_documents = [ latex_documents = [
('user/index', 'linux-user.tex', 'Linux Kernel User Documentation', ('admin-guide/index', 'linux-user.tex', 'Linux Kernel User Documentation',
'The kernel development community', 'manual'), 'The kernel development community', 'manual'),
('kernel-documentation', 'kernel-documentation.tex', 'The Linux Kernel Documentation', ('kernel-documentation', 'kernel-documentation.tex', 'The Linux Kernel Documentation',
'The kernel development community', 'manual'), 'The kernel development community', 'manual'),
......
Documentation/dev-tools/gcov.rst
浏览文件 @ 63ac0cf9
...@@ -201,7 +201,9 @@ Appendix A: gather_on_build.sh ...@@ -201,7 +201,9 @@ Appendix A: gather_on_build.sh
------------------------------ ------------------------------
Sample script to gather coverage meta files on the build machine Sample script to gather coverage meta files on the build machine
(see 6a):: (see 6a):
.. code-block:: sh
#!/bin/bash #!/bin/bash
...@@ -232,7 +234,9 @@ Appendix B: gather_on_test.sh ...@@ -232,7 +234,9 @@ Appendix B: gather_on_test.sh
----------------------------- -----------------------------
Sample script to gather coverage data files on the test machine Sample script to gather coverage data files on the test machine
(see 6b):: (see 6b):
.. code-block:: sh
#!/bin/bash -e #!/bin/bash -e
......
Documentation/dev-tools/kcov.rst
浏览文件 @ 63ac0cf9
...@@ -24,7 +24,9 @@ Profiling data will only become accessible once debugfs has been mounted:: ...@@ -24,7 +24,9 @@ Profiling data will only become accessible once debugfs has been mounted::
mount -t debugfs none /sys/kernel/debug mount -t debugfs none /sys/kernel/debug
The following program demonstrates kcov usage from within a test program:: The following program demonstrates kcov usage from within a test program:
.. code-block:: c
#include <stdio.h> #include <stdio.h>
#include <stddef.h> #include <stddef.h>
......
Documentation/gpu/drm-kms.rst
浏览文件 @ 63ac0cf9
...@@ -215,7 +215,7 @@ Connectors state change detection must be cleanup up with a call to ...@@ -215,7 +215,7 @@ Connectors state change detection must be cleanup up with a call to
Output discovery and initialization example Output discovery and initialization example
------------------------------------------- -------------------------------------------
:: .. code-block:: c
void intel_crt_init(struct drm_device *dev) void intel_crt_init(struct drm_device *dev)
{ {
......
Documentation/gpu/drm-mm.rst
浏览文件 @ 63ac0cf9
...@@ -45,7 +45,7 @@ the radeon_ttm.c file for an example of usage. ...@@ -45,7 +45,7 @@ the radeon_ttm.c file for an example of usage.
The ttm_global_reference structure is made up of several fields: The ttm_global_reference structure is made up of several fields:
:: .. code-block:: c
struct ttm_global_reference { struct ttm_global_reference {
enum ttm_global_types global_type; enum ttm_global_types global_type;
......
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