We have historically hard-coded entry points in head.S just so it's easy
to build the executable/bzImage headers with references to them.

Unfortunately, this leads to boot loaders abusing these "known" addresses
even when they are *explicitly* told that they "should look at the ELF
header to find this address, as it may change in the future". And even
when the address in question *has* actually been changed in the past,
without fanfare or thought to compatibility.

Thus we have bootloaders doing stunningly broken things like jumping
to offset 0x200 in the kernel startup code in 64-bit mode, *hoping*
that startup_64 is still there (it has moved at least once
before). And hoping that it's actually a 64-bit kernel despite the
fact that we don't give them any indication of that fact.

This patch should hopefully remove the temptation to abuse internal
addresses in future, where sternly worded comments have not sufficed.
Instead of having hard-coded addresses and saying "please don't abuse
these", we actually pull the addresses out of the ELF payload into
zoffset.h, and make build.c shove them back into the right places in
the bzImage header.

Rather than including zoffset.h into build.c and thus having to rebuild
the tool for every kernel build, we parse it instead. The parsing code
is small and simple.

This patch doesn't actually move any of the interesting entry points, so
any offending bootloader will still continue to "work" after this patch
is applied. For some version of "work" which includes jumping into the
compressed payload and crashing, if the bzImage it's given is a 32-bit
kernel. No change there then.

[ hpa: some of the issues in the description are addressed or
  retconned by the 2.12 boot protocol.  This patch has been edited to
  only remove fixed addresses that were *not* thus retconned. ]
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>

The hostprogs need access to the CONFIG_* symbols found in
include/generated/autoconf.h.  But commit abbf1590 ("UAPI: Partition
the header include path sets and add uapi/ header directories") replaced
$(LINUXINCLUDE) with $(USERINCLUDE) which doesn't contain the necessary
include paths.

This has the undesirable effect of breaking the EFI boot stub because
the #ifdef CONFIG_EFI_STUB code in arch/x86/boot/tools/build.c is
never compiled.

It should also be noted that because $(USERINCLUDE) isn't exported by
the top-level Makefile it's actually empty in arch/x86/boot/Makefile.

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Partition the header include path flags into two sets, one for kernelspace
builds and one for userspace builds.

Add the following directories to build after the ordinary include directories
so that #include will pick up the UAPI header directly if the kernel header
has been moved there.

The userspace set (represented by the USERINCLUDE make variable) contains:

	-I $(srctree)/arch/$(hdr-arch)/include/uapi
	-I arch/$(hdr-arch)/include/generated/uapi
	-I $(srctree)/include/uapi
	-I include/generated/uapi
	-include $(srctree)/include/linux/kconfig.h

and the kernelspace set (represented by the LINUXINCLUDE make variable)
contains:

	-I $(srctree)/arch/$(hdr-arch)/include
	-I arch/$(hdr-arch)/include/generated
	-I $(srctree)/include
	-I include		--- if not building in the source tree

plus everything in the USERINCLUDE set.

Then use USERINCLUDE in building the x86 boot code.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

GCC built with nonstandard options can enable -fpic by default.
We never want this for 32-bit kernels and it will break the build.

[ hpa: Notably the Android toolchain apparently does this. ]

Change-Id: Iaab7d66e598b1c65ac4a4f0229eca2cd3d0d2898
Signed-off-by: NAndrew Boie <andrew.p.boie@intel.com>
Link: http://lkml.kernel.org/r/1344624546-29691-1-git-send-email-andrew.p.boie@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

This is a partial revert of commit:
    d40f8336 "Restrict CFLAGS for hostprogs"

The endian-manipulation macros in tools/include need <linux/types.h>,
but the hostprogs in arch/x86/boot need several headers from the
kernel build tree, which means we have to add the kernel headers to
the include path.  This picks up <linux/types.h> from the kernel tree,
which gives a warning.

Since this use of <linux/types.h> is intentional, add
-D__EXPORTED_HEADERS__ to the command line to silence the warning.

A better way to fix this would be to always install the exported
kernel headers into $(objtree)/usr/include as a standard part of the
kernel build, but that is a lot more involved.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NMatt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1330436245-24875-5-git-send-email-matt@console-pimps.orgSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

Currently tools/build has access to all the kernel headers in
$(srctree). This is unnecessary and could potentially allow
tools/build to erroneously include kernel headers when it should only
be including userspace-exported headers.

Unfortunately, mkcpustr still needs access to some of the asm kernel
headers, so explicitly special case that hostprog.

Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1330436245-24875-5-git-send-email-matt@console-pimps.orgSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

This has been obsoleted by the root= commandline and the rdev utility
for many, many years.  People who still depend on this will surely
have a copy of the rdev utility around, the rest of the world gets rid
of another piece of buildhost-dependent data in the build. Thanks to
Paul Bolle for the build.c cleanup.

Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: NMichal Marek <mmarek@suse.cz>
Link: http://lkml.kernel.org/r/1302607824-24699-1-git-send-email-mmarek@suse.czSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Separate early_serial_console from tty.c

This allows for reuse of
early_serial_console.c/string.c/printf.c/cmdline.c in boot/compressed/.

-v2: according to hpa, don't include string.c etc
-v3: compressed/misc.c must have early_serial_base as static, so move it back to tty.c
     for setup code
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C568D2B.205@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Enable gcov profiling of the entire kernel on x86_64. Required changes
include disabling profiling for:

* arch/kernel/acpi/realmode and arch/kernel/boot/compressed:
  not linked to main kernel
* arch/vdso, arch/kernel/vsyscall_64 and arch/kernel/hpet:
  profiling causes segfaults during boot (incompatible context)
Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Correct the calculation of ZO_INIT_SIZE (the amount of memory we need
during decompression).  One symbol (ZO_startup_32) was missing from
zoffset.h, and another (ZO_z_extract_offset) was misspelled.

[ Impact: build fix ]
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Make symbols from the main vmlinux, as opposed to just
compressed/vmlinux, available to header.S.  Also, export a few
additional symbols.

This will be used in a subsequent patch to export the total memory
footprint of the kernel.

[ Impact: enable future enhancement ]
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: new interfaces (not yet used)

For all the platforms out there, there is an infinite number of buggy
BIOSes.  This adds infrastructure to treat BIOS interrupts more like
toxic waste and "glove box" them -- we switch out the register set,
perform the BIOS interrupt, and then restore the previous state.

LKML-Reference: <49DE7F79.4030106@zytor.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rjw@sisk.pl>

Impact: code size reduction (possibly critical)

The x86 boot and decompression code has no use of the branch profiling
constructs, so disable them.  This would bloat the setup code by as
much as 14K, eating up a fairly large chunk of the 32K area we are
guaranteed to have.
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

Instead of using CLEAN_FILES in arch/x86/Makefile, add generated files
to targets in arch/x86/boot/Makefile, so they will get naturally
cleaned up by "make clean".

Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: cleanup

Remove targets that were used for zImage only, and Makefile
infrastructure that was there to support the zImage/bzImage split.
Reported-by: NPaul Bolle <pebolle@tiscali.nl>
LKML-Reference: <1236879901.24144.26.camel@test.thuisdomein>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: obsolete feature removal

The zImage kernel format has been functionally unused for a very long
time.  It is just barely possible to build a modern kernel that still
fits within the zImage size limit, but it is highly unlikely that
anyone ever uses it.  Furthermore, although it is still supported by
most bootloaders, it has been at best poorly tested (or not tested at
all); some bootloaders are even known to not support zImage at all and
not having even noticed.

Also remove some really obsolete constants that no longer have any
meaning.

LKML-Reference: <49B703D4.1000008@zytor.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Impact: remove unused/broken code

The Voyager subarch last built successfully on the v2.6.26 kernel
and has been stale since then and does not build on the v2.6.27,
v2.6.28 and v2.6.29-rc5 kernels.

No actual users beyond the maintainer reported this breakage.
Patches were sent and most of the fixes were accepted but the
discussion around how to do a few remaining issues cleanly
fizzled out with no resolution and the code remained broken.

In the v2.6.30 x86 tree development cycle 32-bit subarch support
has been reworked and removed - and the Voyager code, beyond the
build problems already known, needs serious and significant
changes and probably a rewrite to support it.

CONFIG_X86_VOYAGER has been marked BROKEN then. The maintainer has
been notified but no patches have been sent so far to fix it.

While all other subarchs have been converted to the new scheme,
voyager is still broken. We'd prefer to receive patches which
clean up the current situation in a constructive way, but even in
case of removal there is no obstacle to add that support back
after the issues have been sorted out in a mutually acceptable
fashion.

So remove this inactive code for now.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

After commit 968de4f0 ("i386: Relocatable kernel support") IMAGE_OFFSET wasn't
actually used anymore in the (current) X86 build system. Now remove its last
traces.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

When building image.iso (make isoimage), use the isohybrid tool if it
exists.  isohybrid is a script included with Syslinux 3.72 and higher,
which creates an image that can be booted either as a hard disk
(including removable, e.g. USB disk) or as a CD-ROM.

If isohybrid doesn't exist, then this has no effect.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Move wakeup code to .c, so that video mode setting code can be shared
between boot and wakeup. Remove nasty assembly code in 64-bit case by
re-using trampoline code. Stack setup was fixed to clear high 16bits
of %esp, maybe that fixes some machines.

.c code sharing and morse code was done H. Peter Anvin, Sam Ravnborg
reviewed kbuild related stuff, and it seems okay to him. Rafael did
some cleanups.

[rjw:
* Made the patch stop breaking compilation on x86-32
* Added arch/x86/kernel/acpi/sleep.h
* Got rid of compiler warnings in arch/x86/kernel/acpi/sleep.c
* Fixed 32-bit compilation on x86-64 systems
* Added include/asm-x86/trampoline.h and fixed the non-SMP
  compilation on 64-bit x86
* Removed arch/x86/kernel/acpi/sleep_32.c which was not used
* Fixed some breakage caused by the integration of smpboot.c done
  under us in the meantime]
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIan Campbell <ijc@hellion.org.uk>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Instead of obscure numbers, print the list of missing CPU features in
cleartext.  To conserve space, use a host program (mkcpustr.c) to
produce a compact list of mandatory features only.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Do this rather than defining a global version and overriding it in
almost all cases in order to make subsequent patches simpler.
Signed-off-by: NIan Campbell <ijc@hellion.org.uk>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Previously the complete files were #ifdef'ed, but now handle that in the
Makefile.

May save a minor bit of compilation time.

[ Stephen Rothwell <sfr@canb.auug.org.au>: build dependency fix ]
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

There were no reason to mess around with CC, AS and LD.
Fixing this up avoided duplicated option for ld.

A small fixlet were needed in boot/Makefile which assumed
that CC were modified.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

For x86 ARCH may say i386 or x86_64 and soon x86.
Rely on CONFIG_X64_32 to select between 32/64 or just
hardcode the value as appropriate.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>

Instead of using magic macros for boot_params access, simply use the
boot_params structure.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

x86 uses target specific assignment of EXTRA_AFLAGS,
EXTRA_CFLAGS - this caused troubles with
introducing asflags-y, ccflags-y.

Fixed the target specific assignments in arch/x86/boot/Makefile
and auditted the rest of the kernel for similar usage.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

The variable AFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of AFLAGS with KBUILD_AFLAGS all over
the tree.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k, s390
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

The variable CFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of CFLAGS with KBUILD_CFLAGS all over the
tree and enabling one to use:
make CFLAGS=...
to specify additional gcc commandline options.

One usecase is when trying to find gcc bugs but other
use cases has been requested too.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k

Test was simple to do a defconfig build, apply the patch and check
that nothing got rebuild.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Keep the arch/i386/boot directory from being rebuilt every time.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

This patch hooks the new x86 setup code into the Makefile machinery.  It
also adapts boot/tools/build.c to a two-file (as opposed to three-file)
universe, and simplifies it substantially.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Needed for followon patch
Signed-off-by: NAndi Kleen <ak@suse.de>

It's like this on SUSE systems.

Cc: hpa@zytor.com
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a "make isoimage" to i386 and x86-64, which allows the automatic
creation of a bootable CD image.  It also adds an option FDINITRD= to
include an initrd of the user's choice in generated floppy- or CD boot
images.  Finally, some minor cleanups of the image generation code.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Removing the dependency on the boot image build was good, but it also
meant that the $< expansion by make needed to be done explicitly.

Noted by Stephen Hemminger.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This removes the dependency from vmlinux to install, thus avoiding the
current situation where "make install" has a nasty tendency to leave
root-turds in the working directory.

It also updates x86-64 to be in sync with i386.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Remove some of the unnecessary differences between arch/i386 and
arch/x86_64.  This patch fixes more whitespace issues, some miscellaneous
typos, a wrong URL and a factually incorrect statement about the current
boot sector code.
Signed-off-by: NDomen Puncer <domen@coderock.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I am always trying to make sure I've booted the right kernel after a new
install.  Too paranoid maybe.  But I guess there're other people like me.
So let's make kbuild display the compile version number at the end to give
us a hint.  I know we may be booting vmlinux someday, but don't care about
it for now.
Signed-off-by: NCoywolf Qi Hunt <coywolf@lovecn.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>