[PATCH revised] enable make ARCH=x86 (and stay backward compatible)

[Sam Ravnborg <sam@ravnborg.org>]

This revised patchset does the followings things:

o unify the i386 and x86_64 Kconfig files
o introduce support for K64BIT to set CONFIG_64BIT on command line
o introdue support for "make ARCH=x86"
o degraded ARCH={i386,x86_64} to select between 32/64 for all*targets
  and otherwise just selecting the x86 architecture

I suggest we should merge this despite being at -rc2 so we can start
teaching distributors to use "ARCH=x86" - but I leave it to the
x86 Maintainers to decide.

I have always thought that the x86 merge could not be considered ready
until we could do a "make ARCH=x86" becasue it is so intuitive
if you have not typed "make ARCH=i386" one thousand times.


Based on feedback from previous submissions the following have changed:
- The backwards compatibility links are kept
- The backwards compatibility ARCH={i386,x86_64} are kept but degraded
  to select 32/64 bit during configuration for all*config targets.
- ARCH={i386,x86_64} are not broken by any patches so bisect will
  not choke
- patchset shrinked to 13 logical patches


With this change we have a setup where we have a common Kconfig
for 32-bit and 64-bit x86 like all other architectures.
And we can configure and build a kernel using ARCH="name of arch dir"

As an added bonus "make update-po-config" is fixed :-)

The diffstat tells it own story:
 19 files changed, 684 insertions(+), 1235 deletions(-)

And this is with new functionality added...

The patches explained...

Unification of Kconfig.i386 + Kconfig.x86_64:
      x86: unification of cfufreq/Kconfig
      x86: start unification of arch/x86/Kconfig.*
      x86: arch/x86/Kconfig.cpu unification
      x86: add X86_32 dependency to i386 specific symbols in Kconfig.i386
      x86: add X86_64 dependency to x86_64 specific symbols in Kconfig.x86_64
      x86: copy x86_64 specific Kconfig symbols to Kconfig.i386
      x86: move all simple arch settings to Kconfig
      x86: move the rest of the menu's to Kconfig

Adding support for K64BIT=y on commandline
      kconfig: factor out code in confdata.c
      kconfig: add helper to set config symbol from environment variable
      kconfig: use $K64BIT to set 64BIT with all*config targets

Preparational patch that just clean up a few bits in x86:
      x86: do not use $(ARCH) when not needed

Introducing "make ARCH=x86"
      x86: enable "make ARCH=x86"

After the preparation then introducing "make ARCH=x86" actually
deleted more lines than is added (last patch):
    5 files changed, 19 insertions(+), 49 deletions(-)


The patchset is available at:

	git://git.kernel.org/pub/scm/linux/kernel/git/sam/x86.git

Patches will be sent to lkml for another review round.

	Sam


Diffstat:

 Makefile                                           |   13 +-
 README                                             |    2 +
 arch/x86/{Kconfig.i386 => Kconfig}                 |  567 ++++++++++----
 arch/x86/Kconfig.cpu                               |  121 ++--
 arch/x86/Kconfig.x86_64                            |  839 --------------------
 arch/x86/Makefile                                  |   10 +-
 arch/x86/Makefile_32                               |    8 +-
 arch/x86/Makefile_64                               |    8 +-
 arch/x86/boot/Makefile                             |    6 +-
 arch/x86/boot/cpucheck.c                           |    6 -
 arch/x86/kernel/Makefile_32                        |    3 +-
 arch/x86/kernel/Makefile_64                        |    2 +
 .../x86/kernel/cpu/cpufreq/{Kconfig_32 => Kconfig} |   69 ++-
 arch/x86/kernel/cpu/cpufreq/Kconfig_64             |  108 ---
 arch/x86/vdso/Makefile                             |    2 +-
 scripts/kconfig/Makefile                           |    7 +-
 scripts/kconfig/conf.c                             |    1 +
 scripts/kconfig/confdata.c                         |  146 +++--
 scripts/kconfig/lkc_proto.h                        |    1 +
 19 files changed, 684 insertions(+), 1235 deletions(-)