Various console drivers are able to resize the screen via the con_resize()
hook.  This hook is also visible in userspace via the TIOCWINSZ, VT_RESIZE and
VT_RESIZEX ioctl's.  One particular utility, SVGATextMode, expects that
con_resize() of the VGA console will always return success even if the
resulting screen is not compatible with the hardware.  However, this
particular behavior of the VGA console, as reported in Kernel Bugzilla Bug
7513, can cause undefined behavior if the user starts with a console size
larger than 80x25.

To work around this problem, add an extra parameter to con_resize().  This
parameter is ignored by drivers except for vgacon.  If this parameter is
non-zero, then the resize request came from a VT_RESIZE or VT_RESIZEX ioctl
and vgacon will always return success.  If this parameter is zero, vgacon will
return -EINVAL if the requested size is not compatible with the hardware.  The
latter is the more correct behavior.

With this change, SVGATextMode should still work correctly while in-kernel and
stty resize calls can expect correct behavior from vgacon.
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix following section mismatch warning:
WARNING: vmlinux.o(.text+0x121e62): Section mismatch: reference to .init.text:__alloc_bootmem (between 'vgacon_startup' and 'vgacon_scrolldelta')

Browsing the code it seems that vgacon_scrollback_startup() is only called
during the init phase so the reference to the .init.text section is OK.

Teach modpost not to warn using ___init_refok.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Acked-by: N"Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Refine SCREEN_INFO sanity check for vgacon initialization.

Checking video mode field only to see whenever SCREEN_INFO is
initialized is not enougth, in some cases it is zero although
a vga card is present.  Lets additionally check cols and lines.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reported by James Pearson as:

	 boot to run level 3

	 if not root, then make sure /dev/console is writeable

	 login and type:

	 setterm -blank 0

	 start X

	 type into an xterm:

	 while true; do echo "" > /dev/console; usleep 100000; done

	 while the above loop is running switch to the text console and back
	 again (Ctrl-Alt-F1 then Ctrl-Alt-F7)

	 ... and the screen will be shifting (and wrapping) to the left.

This problem stems from continuously writing text to the system console (which
is in KD_TEXT mode) while the foreground console is in KD_GRAPHICS
mode. Somewhere along the way, console printing got confused and omitted the
KD_GRAPHICS/KD_TEXT test.  Thus, vgacon attempted to scroll the screen of X,
which causes X to shift.

Fix by disallowing vgacon to touch the hardware when the vc is in KD_GRAPHICS
mode. A definitive fix entails a full audit of the console code.
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add color support to the "underline" and "italic" attributes as in
OpenBSD/NetBSD-style (vt220) and xterm.
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Acked-by: N"Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Avoid trying to set up vgacon if there's no vga hardware present.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Alan <alan@lxorguk.ukuu.org.uk>
Acked-by: NIngo Molnar <mingo@elte.hu>

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- annotate some variables from vgacon.c and fbmem.c as __read_mostly
- move the mask[] array in fb_set_logo_truepalette() into the .rodata section
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

screen_info.h doesn't have anything to do with the tty layer and shouldn't be
included by tty.h.  This patches removes the include and modifies all users to
directly include screen_info.h.  struct screen_info is mainly used to
communicate with the console drivers in drivers/video/console.  Note that this
patch touches every arch and I have no way of testing it.  If there is a
mistake the worst thing that will happen is a compile error.

[akpm@osdl.org: fix arm build]
[akpm@osdl.org: fix alpha build]
Signed-off-by: NJon Smirl <jonsmir@gmail.com>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

MAX_NR_CONSOLES, fg_console, want_console and last_console are more of a
function of the VT layer than the TTY one.  Moving these to vt.h and vt_kern.h
allows all of the framebuffer and VT console drivers to remove their
dependency on tty.h.

[akpm@osdl.org: fix alpha build]
Signed-off-by: NJon Smirl <jonsmir@gmail.com>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Based on an original patch from Ralf Baechle <ralf@linux-mips.org> and
Vivek Goyal <vgoyal@in.ibm.com>.  This is needed in order to prepare for
changing the size of resources.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

One of the limitations of the framebuffer console system is its inablity to
unload or detach itself from the console layer.  And once it loads, it also
locks in framebuffer drivers preventing their unload. Although the con2fbmap
utility does provide a means to unload individual drivers, it requires that at
least one framebuffer driver is loaded for use by fbcon.

With this change, it is possible to detach fbcon from the console layer. If it
is detached, it will reattach the boot console driver (which is permanently
loaded) back to the console layer so the system can continue to work.  As a
consequence, fbcon will also decrement its reference count of individual
framebuffer drivers, allowing all of these drivers to be unloaded even if
fbcon is still loaded.

Unless you use drivers that restores the display to text mode (rivafb and
i810fb, for example), detaching fbcon does require assistance from userspace
tools (ie, vbetools) for text mode to be restored completely.  Without the
help of these tools, fbcon will leave the VGA console corrupted. The methods
that can be used will be described in Documentation/fb/fbcon.txt.

Because the vt layer also increments the module reference count for each
console driver, fbcon cannot be directly unloaded.  It must be detached first
prior to unload.

Similarly, fbcon can be reattached to the console layer without having to
reload the module.  A nice feature if fbcon is compiled statically.

Attaching and detaching fbcon is done via sysfs attributes. A class device
entry for fbcon is created in /sys/class/graphics. The two attributes that
controls this feature are detach and attach. Two other attributes that are
piggybacked under /sys/class/graphics/fb[n] that are fbcon-specific,
'con_rotate' and 'con_rotate_all' are moved to fbcon.  They are renamed as
'rotate' and 'rotate_all' respectively.

Overall, this feature is a great help for developers working in the
framebuffer or console layer.  There is not need to continually reboot the
kernel for every small change. It is also useful for regular users who wants
to choose between a graphical console or a text console without having to
reboot.

Example usage for x86:

/* start in text mode */
modprobe xxxfb
modprobe fbcon
/* graphical mode with fbcon using xxxfb */
echo 1 > /sys/class/graphics/fbcon/detach
/* back to text mode, will produce corrupt display unless vbetool is used */
rmmod xxxfb
modprobe yyyfb
/* back to graphical mode with fbcon using yyyfb */

Before trying out this feature, please read Documentation/fb/fbcon.txt.

This patch:

In order for fbcon to detach itself from the console layer, vgacon, which is a
boot console driver, must be fixed so it can retake the console multiple
times, not just during init.  The following needs to be done:

- remove __init from the vgacon_startup, this is called again by
  take_over_console().

- vc->rows and vc->cols are set manually by vgacon during init. After init,
  vc_resize() can be used

- make sure the scrollback_buffer is not reallocated
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

VGA_MAP_MEM translates to ioremap() on some architectures.  It makes sense
to do this to vga_vram_base, because we're going to access memory between
vga_vram_base and vga_vram_end.

But it doesn't really make sense to map starting at vga_vram_end, because
we aren't going to access memory starting there.  On ia64, which always has
to be different, ioremapping vga_vram_end gives you something completely
incompatible with ioremapped vga_vram_start, so vga_vram_size ends up being
nonsense.

As a bonus, we often know the size up front, so we can use ioremap()
correctly, rather than giving it a zero size.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The scrollback buffer of the VGA console is located in VGA RAM.  This RAM
is fixed in size and is very small.  To make the scrollback buffer larger,
it must be placed instead in System RAM.

This patch adds this feature.  The feature and the size of the buffer are
made as a kernel config option.  Besides consuming kernel memory, this
feature will slow down the console by approximately 20%.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Cc: Jindrich Makovicka <makovick@kmlinux.fjfi.cvut.cz>
Cc: Martin Mares <mj@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This corrects cursor resize on ega boards: registers are write-only, so we
shouldn't even try to read them.  And on ega, 31/30 produces a flat cursor.
Using 31/31 is better: except with 32 pixels high fonts, it shouldn't show
up.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

EGA boards suck: they mostly have write-only registers.  This is
particularly problematic for the overflow register: for being able to write
to it, we would have to handle vertical sync & such too, which (I'd say)
would potentially break a lot of configurations.  Instead, just disabling
vertical resize for EGA boards is just nice enough (horizontal resize still
works).

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=6106Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Rafal Olearski <olearski@mail2.kim.net.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Reported from Redhat Bugzilla Bug 170450

"I updated to the development kernel and now during boot only the top of the
text is visable. For example the monitor screen the is the lines and I can
only see text in the asterisk area.

When doublescan mode is in use, scanlines must be doubled.

Thanks to Jason Dravet <dravet@hotmail.com> for reporting and testing.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Reported by: Wayne E. Harlan

"[1.] One line summary of the problem:
When the kernel option "vga=1" is used, additional tty's (alt+control+Fx
with x=2,3,4,5, etc) do not provide the full 50 lines of output.  The first
one does have 50 lines, however.

[2.] Full description of the problem/report:
These addtitional tty's show only 39 lines plus the top pixel of the 40-th
line.  The remaining lines are black and not shown.  Kernel version
2.6.13.4 does not show this problem."

This bug is caused by using a stale font height value on vgacon_init.

Booting with vga=1 gives an 80x50 screen with an 8x8 font.  Somewhere
during the initialization, the font was changed to 8x9 and the first
vc was correctly resized to 80x44.  However, the rest of the vc's were
not allocated yet, and when they were subsequently initialized, they
still used a font height of 8 (instead of 9) causing the mentioned bug.

Fix by saving the new font height to vga_video_font_height.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some visually impaired people use hardware devices which directly read
the vga screen. When newt for instance asks to hide the cursor for
better visual aspect, the kernel puts the vga cursor out of the screen,
so that the cursor position can't be read by the hardware device. This
is a great loss for such people.

Here is a patch which uses the same technique as CUR_NONE for hiding the
cursor while still moving it.

Mario, you should apply it to the speakup kernel for access floppies
asap. I'll submit a 2.4 patch too.

Signed-off-by: samuel.thibault@ens-lyon.org
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch fixes a long-standing vgacon bug: characters with the bright bit
set were left on the screen and not blacked out.  All I did was that I
lookuped up some examples on the net about setting the vga palette, and
added the call missing from the linux kernel, but included in all other
ones.  It works for me.

You can test this by writing something with the bright set to the
console, for example:
  echo -e "\e[1;31mhello there\e[0m"
and then wait for the console to blank itself (by default, after 10 mins
of inactivity), maybe making it faster using
  setterm -blank 1
so you only have to wait 1 minute.
Signed-off-by: NPozsar Balazs <pozsy@uhulinux.hu>
Cc: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix bug 5441.

I didn't know about messy programs like svgatextmode...  Couldn't this be
integrated in some linux/drivers/video/console/svgacon.c ?...  So because
of the existence of the svgatextmode program, the kernel is not supposed to
touch to CRT_OVERFLOW/SYNC_END/DISP/DISP_END/OFFSET ?

Disabling the check in vgacon_resize() might help indeed, but I'm really
not sure whether it will work for any chipset: in my patch, CRT registers
are set at each console switch, since stty rows/cols apply to consoles
separately...

The attached solution is to keep the test, but if it fails, we assume that
the caller knows what it does (i.e.  it is svgatextmode) and then disable
any further call to vgacon_doresize.  Svgatextmode is usually used to
_expand_ the display, not to shrink it.  And it is harmless in the case of
a too big stty rows/cols: the display will just be cropped.  I tested it on
my laptop, and it works fine with svgatextmode.

A better solution would be that svgatextmode explicitely tells the kernel
not to care about video timing, but for this an interface needs be defined
and svgatextmode be patched.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Reported by: walt <wa1ter@myrealbox.com>

"I routinely switch the console font during bootup to
8x8 so I can get 50 lines per screen.  Until 09 Sept,
just changing to the small font automatically gave me
all 50 lines -- but now I'm only getting 25 lines even
with the small font.  The bottom half of the screen
displays the text that already scrolled off the top."

This bug is due to an erroneous check in the recently added hook,
vgacon_resize(). It checks the new height against the original number of
rows of the console. Because the original number of rows depends on both
the scanline and the font height, check it instead against the
scanline/fontheight.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some people use 66-cells braille devices for reading the console, and hence
would like to reduce the width of the screen by using:

stty cols 66

However, the vga text console doesn't behave correctly: the 14 first
characters of the second line are put on the right of the first line and so
forth.

Here is a patch to correct that.  It corrects the disp_end and offset
registers of the vga board on console resize and console switch.

On usual screens, you then correctly get a right and/or bottom blank
margin.  On some laptop panels, the output is resized so that text actually
gets magnified, which can be great for some people (see
http://dept-info.labri.fr/~thibault/ls.jpg ).
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently when going from vgacon to fbcon the VT screenbuffer are often
different sizes.  In the case when they are different sizes a new VT
screenbuffer is allocated and the contents are copied into the new buffer.

Currently the amount copied from VGA text memory to the new screenbuf is
the size of the framebuffer console.  If the framebuffer console new VT
screen buffer is greater than the VGA text memory size then we get some of
the VGA BIOS contents as well.

This patch will only allow you to copy up to the size of VGA text memory
now.  The rest is filled with erase characters.

Initial patch by Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: NJames Simmons <jsimmons@www.infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When allocating a new VC with vgacon_init(), the font is shared across all
the VGA consoles.  However, the font mask was always set to the default
value of zero in visual_init(), even if we were using 512 character fonts
at the time.

Moreover, code in vgacon.c:vga_do_font_op() didn't reset the mask if the
console driver thinks it's already in 512 character mode.  This means that
to *fix* it, you'd actually have to take the console out of 512 character
mode and then set it back.

The attached sets vc_hi_font_mask in vgacon_init() for any new consoles
opened if the vgacon driver is already in 512 character mode, solving this.

This bug goes back to 2.4.18 at least, probably earlier.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!