Jeremy Fitzhardinge suggested the use of -freg-struct-return, which does
structure-returns (such as when using pte_t) in registers instead of on
the stack.

that is indeed so, and this option reduced the kernel size a bit:

    text    data     bss     dec     hex filename
 4799506  543456 3760128 9103090  8ae6f2 vmlinux.before
 4798117  543456 3760128 9101701  8ae185 vmlinux.after

the resulting kernel booted fine on my testbox. Lets go for it.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

-mregparm=3 has been enabled by default for some time on i386, and AFAIK
there aren't any problems with it left.

This patch removes the REGPARM config option and sets -mregparm=3
unconditionally.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch modifies the i386 kernel so that if CONFIG_RELOCATABLE is
selected it will be able to be loaded at any 4K aligned address below
1G.  The technique used is to compile the decompressor with -fPIC and
modify it so the decompressor is fully relocatable.  For the main
kernel relocations are generated.  Resulting in a kernel that is relocatable
with no runtime overhead and no need to modify the source code.

A reserved 32bit word in the parameters has been assigned
to serve as a stack so we figure out where are running.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This avoids some problems with gcc 4.x and earlier generating
invalid unwind information. In 4.1 the option is default
when unwind information is enabled.

And it seems to generate smaller code too, so it's probably
a good thing on its own. With gcc 4.0:

i386:
4683198  902112  480868 6066178  5c9002 vmlinux (before)
4449895  902112  480868 5832875  5900ab vmlinux (after)

x86-64:
4939761 1449584  648216 7037561  6b6279 vmlinux (before)
4854193 1449584  648216 6951993  6a1439 vmlinux (after)

On 4.1 it shouldn't make much difference because it is
default when unwind is enabled anyways.

Suggested by Michael Matz and Jan Beulich

Cc: jbeulich@novell.com
Signed-off-by: NAndi Kleen <ak@suse.de>

This was copied, pasted but not edited.

Cc: Andi Kleen <ak@muc.de>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Current gcc generates calls not jumps to noreturn functions. When that happens the
return address can point to the next function, which confuses the unwinder.

This patch works around it by marking asynchronous exception
frames in contrast normal call frames in the unwind information.  Then teach
the unwinder to decode this.

For normal call frames the unwinder now subtracts one from the address which avoids
this problem.  The standard libgcc unwinder uses the same trick.

It doesn't include adjustment of the printed address (i.e. for the original
example, it'd still be kernel_math_error+0 that gets displayed, but the
unwinder wouldn't get confused anymore.

This only works with binutils 2.6.17+ and some versions of H.J.Lu's 2.6.16
unfortunately because earlier binutils don't support .cfi_signal_frame

[AK: added automatic detection of the new binutils and wrote description]
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

... instead of using a CONFIG option. The config option still controls
if the resulting executable actually has unwind information.

This is useful to prevent compilation errors when users select
CONFIG_STACK_UNWIND on old binutils and also allows to use
CFI in the future for non kernel debugging applications.

Cc: jbeulich@novell.com
Cc: sam@ravnborg.org
Signed-off-by: NAndi Kleen <ak@suse.de>

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>

gcc should handle this anyways, and it causes problems when
sprintf is turned into strcpy by gcc behind our backs and
the C fallback version of strcpy is actually defining __builtin_strcpy

Then drop -ffreestanding from the main Makefile because it isn't
needed anymore and implies -fno-builtin, which is wrong now.
(it was only added for x86-64, so dropping it should be safe)

Noticed by Roman Zippel

Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The kbuild system takes advantage of an incorrect behavior in GNU make.
Once this behavior is fixed, all files in the kernel rebuild every time,
even if nothing has changed.  This patch ensures kbuild works with both
the incorrect and correct behaviors of GNU make.

For more details on the incorrect behavior, see:

http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html

Changes in this patch:
  - Keep all targets that are to be marked .PHONY in a variable, PHONY.
  - Add .PHONY: $(PHONY) to mark them properly.
  - Remove any $(PHONY) files from the $? list when determining whether
    targets are up-to-date or not.
Signed-off-by: NPaul Smith <psmith@gnu.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Since we do no longer support any gcc < 3.0, there's no need to check
for it..
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Allow gcc4 compilers to optimize unit-at-a-time.

This flag enables gcc to "see" the entire C file before making optimisation
decisions such as inline, which results in gcc making better decisions.  One
of the immediate effects of this is that static functions that are used only
once now get inlined.

gcc 3.4 has this flag as well, however gcc 3.x have a problem with inlining
and stacks and as a result, enabling this flag there would cause excessive and
unacceptable stack use.  This problem is fixed in the gcc 4.x series.  The
x86-64 architecture already enables this feature so it's well tested already.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Acked-by: NJeff Garzik <jgarzik@pobox.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
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 various things which were checking for gcc-1.x and gcc-2.x compilers.

From: Adrian Bunk <bunk@stusta.de>

    Some documentation updates and removes some code paths for gcc < 3.2.
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This was causing some ordering problems.  Remove the up-front evaluation
and just revaluate the compiler version each time we need it.

(The up-front evaluation was problematic because some architectures modify
the value of $(CC)).
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Make UML share the underlying cpu-specific tuning done on i386.

Actually, for now many config options aren't used a lot - but that can be done
later.  Also, UML relies on GCC optimization for things like memcpy and such
more than i386, so specifying the correct -march and -mtune should be enough.
Later, we may want to correct some other stuff.

For instance, since FPU context switching, for us, is done (at least
partially, i.e.  between our kernelspace and userspace) by the host, we may
allow usage of FPU operations by GCC.  This doesn't hold for kernelspace vs.
kernelspace, but we don't support preemption.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Building asm-offsets.h has been moved to a seperate Kbuild file
located in the top-level directory. This allow us to share the
functionality across the architectures.

The old rules in architecture specific Makefiles will die
in subsequent patches.

Furhtermore the usual kbuild dependency tracking is now used
when deciding to rebuild asm-offsets.s. So we no longer risk
to fail a rebuild caused by asm-offsets.c dependencies being touched.

With this common rule-set we now force the same name across
all architectures. Following patches will fix the rest.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

This allows the i386 architecture to be built on a system with a biarch
compiler that defaults to x86-64, merely by specifying ARCH=i386.

As previously discussed, this uses the equivalent logic to the ppc port.
Signed-Off-By: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- Changed Name/defines from "Geode GX" to "Geode GX1" for clarification

- Dropped "-march=i586" in favor of "-march=i486"

- Dopped X86_OOSTORE support for Geode GX1
Signed-off-by: NKianusch Sayah Karadji <kianusch@sk-tech.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Removing the dependency on vmlinux for the install target raised a few
complaints, so instead a new target i added: kernel_install.

kernel_install will install the kernel just like the ordinary install target.
The only difference is that install has a dependency on vmlinux,
kernel_install does not. Therefore kernel_install is the best choice
when accessing the kernel over a NFS mount or as another user.

kernel_install is similar to modules_install in the fact that neither does
a full kernel compile before performing the install.
In this way they are good for root use. Also added back the
dependency on vmlinux for the install target so peoples scripts are no
longer broken.
Signed-off-by: NSam Ravnborg <sam@ravnborg.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!