config automatically switches from 32-bit to 64-bit for x86

config automatically switches from 32-bit to 64-bit for x86

[Jaswinder Singh Rajput]

Hello,

I am trying to build 32 bit kernel image on 64-bit machine but after
'make menuconfig' it automatically switches 32-bit to 64-bit.

Is this a BUG or did intentionally.

How can I fix this issue.


.config (before)
#
# Automatically generated make config: don't edit
# Linux kernel version: 2.6.34
# Wed May 26 03:40:31 2010
#
# CONFIG_64BIT is not set
CONFIG_X86_32=y
# CONFIG_X86_64 is not set
CONFIG_X86=y
CONFIG_INSTRUCTION_DECODER=y
CONFIG_OUTPUT_FORMAT="elf32-i386"
CONFIG_ARCH_DEFCONFIG="arch/x86/configs/i386_defconfig"
CONFIG_GENERIC_TIME=y

.config (after 'make menuconfig' on 64-bit box)
#
# Automatically generated make config: don't edit
# Linux kernel version: 2.6.34
# Wed May 26 23:49:18 2010
#
CONFIG_64BIT=y
# CONFIG_X86_32 is not set
CONFIG_X86_64=y
CONFIG_X86=y
CONFIG_INSTRUCTION_DECODER=y
CONFIG_OUTPUT_FORMAT="elf64-x86-64"
CONFIG_ARCH_DEFCONFIG="arch/x86/configs/x86_64_defconfig"
CONFIG_GENERIC_TIME=y

Thanks,
--
Jaswinder Singh.

Re: config automatically switches from 32-bit to 64-bit for x86

[Rafael J. Wysocki]

On Thursday 27 May 2010, Jaswinder Singh Rajput wrote:
> Hello,
> 
> I am trying to build 32 bit kernel image on 64-bit machine but after
> 'make menuconfig' it automatically switches 32-bit to 64-bit.

Try 'linux32 make menuconfig' and 'linux32 make'.

Rafael

Re: config automatically switches from 32-bit to 64-bit for x86

[Jaswinder Singh Rajput]

Hello Rafael,

On Thu, May 27, 2010 at 5:43 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> On Thursday 27 May 2010, Jaswinder Singh Rajput wrote:
>> Hello,
>>
>> I am trying to build 32 bit kernel image on 64-bit machine but after
>> 'make menuconfig' it automatically switches 32-bit to 64-bit.
>
> Try 'linux32 make menuconfig' and 'linux32 make'.
>

Yes, this works :-)

But I wonder then what is the point/use of CONFIG_X86_32 if compiler
is not listening to it.

Logically compiler should set appropriate flags based on .config settings.

Thanks,
--
Jaswinder Singh.

Re: config automatically switches from 32-bit to 64-bit for x86

[Américo Wang]

On Thu, May 27, 2010 at 09:39:51AM +0530, Jaswinder Singh Rajput wrote:
>Hello Rafael,
>
>On Thu, May 27, 2010 at 5:43 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
>> On Thursday 27 May 2010, Jaswinder Singh Rajput wrote:
>>> Hello,
>>>
>>> I am trying to build 32 bit kernel image on 64-bit machine but after
>>> 'make menuconfig' it automatically switches 32-bit to 64-bit.
>>
>> Try 'linux32 make menuconfig' and 'linux32 make'.
>>
>
>Yes, this works :-)


I think 'make ARCH=i386 menuconfig' also works.

>
>But I wonder then what is the point/use of CONFIG_X86_32 if compiler
>is not listening to it.
>
>Logically compiler should set appropriate flags based on .config settings.
>

It's not compiler, it's kbuild, kbuild tries to determine the arch
by 'uname -m'.

Re: config automatically switches from 32-bit to 64-bit for x86

[Jaswinder Singh Rajput]

On Thu, May 27, 2010 at 10:01 AM, Américo Wang <xiyou.wangcong@gmail.com> wrote:
> On Thu, May 27, 2010 at 09:39:51AM +0530, Jaswinder Singh Rajput wrote:
>>
>>But I wonder then what is the point/use of CONFIG_X86_32 if compiler
>>is not listening to it.
>>
>>Logically compiler should set appropriate flags based on .config settings.
>>
>
> It's not compiler, it's kbuild, kbuild tries to determine the arch
> by 'uname -m'.
>

Ahh, then kbuild is buggy, kbuild should check .config instead of
'uname -m' and verify from user if it mismatches.

Thanks,
--
Jaswinder Singh.

Re: config automatically switches from 32-bit to 64-bit for x86

[Américo Wang]

On Thu, May 27, 2010 at 10:53:41AM +0530, Jaswinder Singh Rajput wrote:
>On Thu, May 27, 2010 at 10:01 AM, Américo Wang <xiyou.wangcong@gmail.com> wrote:
>> On Thu, May 27, 2010 at 09:39:51AM +0530, Jaswinder Singh Rajput wrote:
>>>
>>>But I wonder then what is the point/use of CONFIG_X86_32 if compiler
>>>is not listening to it.
>>>
>>>Logically compiler should set appropriate flags based on .config settings.
>>>
>>
>> It's not compiler, it's kbuild, kbuild tries to determine the arch
>> by 'uname -m'.
>>
>
>Ahh, then kbuild is buggy, kbuild should check .config instead of
>'uname -m' and verify from user if it mismatches.
>

Why? You didn't use 'make oldconfig', why shoud it check?

Re: config automatically switches from 32-bit to 64-bit for x86

[Randy Dunlap]

On Thu, 27 May 2010 12:31:23 +0800 Américo Wang wrote:

> On Thu, May 27, 2010 at 09:39:51AM +0530, Jaswinder Singh Rajput wrote:
> >Hello Rafael,
> >
> >On Thu, May 27, 2010 at 5:43 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> On Thursday 27 May 2010, Jaswinder Singh Rajput wrote:
> >>> Hello,
> >>>
> >>> I am trying to build 32 bit kernel image on 64-bit machine but after
> >>> 'make menuconfig' it automatically switches 32-bit to 64-bit.
> >>
> >> Try 'linux32 make menuconfig' and 'linux32 make'.
> >>
> >
> >Yes, this works :-)
> 
> 
> I think 'make ARCH=i386 menuconfig' also works.

Yes, that's what I use.  I wasn't familiar with the "linux32 make ..." usage.


> >But I wonder then what is the point/use of CONFIG_X86_32 if compiler
> >is not listening to it.
> >
> >Logically compiler should set appropriate flags based on .config settings.
> >
> 
> It's not compiler, it's kbuild, kbuild tries to determine the arch
> by 'uname -m'.
> --


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: config automatically switches from 32-bit to 64-bit for x86

[Geert Uytterhoeven]

On Thu, May 27, 2010 at 07:31, Randy Dunlap <rdunlap@xenotime.net> wrote:
> On Thu, 27 May 2010 12:31:23 +0800 Américo Wang wrote:
>> On Thu, May 27, 2010 at 09:39:51AM +0530, Jaswinder Singh Rajput wrote:
>> >On Thu, May 27, 2010 at 5:43 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
>> >> On Thursday 27 May 2010, Jaswinder Singh Rajput wrote:
>> >>> Hello,
>> >>>
>> >>> I am trying to build 32 bit kernel image on 64-bit machine but after
>> >>> 'make menuconfig' it automatically switches 32-bit to 64-bit.
>> >>
>> >> Try 'linux32 make menuconfig' and 'linux32 make'.
>> >>
>> >
>> >Yes, this works :-)
>>
>>
>> I think 'make ARCH=i386 menuconfig' also works.
>
> Yes, that's what I use.  I wasn't familiar with the "linux32 make ..." usage.

Doesn't the linux32 trick run the (possibly slower due to x86 register pressure)
32-bit compiler instead of running the 64-bit compiler in -m32 mode?

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Re: config automatically switches from 32-bit to 64-bit for x86

[Rafael J. Wysocki]

On Thursday 27 May 2010, Geert Uytterhoeven wrote:
> On Thu, May 27, 2010 at 07:31, Randy Dunlap <rdunlap@xenotime.net> wrote:
> > On Thu, 27 May 2010 12:31:23 +0800 Américo Wang wrote:
> >> On Thu, May 27, 2010 at 09:39:51AM +0530, Jaswinder Singh Rajput wrote:
> >> >On Thu, May 27, 2010 at 5:43 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> >> On Thursday 27 May 2010, Jaswinder Singh Rajput wrote:
> >> >>> Hello,
> >> >>>
> >> >>> I am trying to build 32 bit kernel image on 64-bit machine but after
> >> >>> 'make menuconfig' it automatically switches 32-bit to 64-bit.
> >> >>
> >> >> Try 'linux32 make menuconfig' and 'linux32 make'.
> >> >>
> >> >
> >> >Yes, this works :-)
> >>
> >>
> >> I think 'make ARCH=i386 menuconfig' also works.
> >
> > Yes, that's what I use.  I wasn't familiar with the "linux32 make ..." usage.
> 
> Doesn't the linux32 trick run the (possibly slower due to x86 register pressure)
> 32-bit compiler instead of running the 64-bit compiler in -m32 mode?

You're probably right, but I haven't noticed a difference yet. :-)

Rafael

Re: config automatically switches from 32-bit to 64-bit for x86

[Matthias Schniedermeyer]

On 27.05.2010 02:13, Rafael J. Wysocki wrote:
> On Thursday 27 May 2010, Jaswinder Singh Rajput wrote:
> > Hello,
> > 
> > I am trying to build 32 bit kernel image on 64-bit machine but after
> > 'make menuconfig' it automatically switches 32-bit to 64-bit.
> 
> Try 'linux32 make menuconfig' and 'linux32 make'.

I personally use the third ARCH (i386 and x86_64 beeing the first two):
make ARCH=x86
that way the bitness isn't implied but an actual configuration-point.
CONFIG_64BIT (The very first menu-point with menuconfig)

And i'm still wondering what the hell the problem is with ARCH=x86 that 
prevents it from beeing the default.



Bis denn

-- 
Real Programmers consider "what you see is what you get" to be just as 
bad a concept in Text Editors as it is in women. No, the Real Programmer
wants a "you asked for it, you got it" text editor -- complicated, 
cryptic, powerful, unforgiving, dangerous.

Re: config automatically switches from 32-bit to 64-bit for x86

[Christoph Hellwig]

On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
> Hello,
> 
> I am trying to build 32 bit kernel image on 64-bit machine but after
> 'make menuconfig' it automatically switches 32-bit to 64-bit.
> 
> Is this a BUG or did intentionally.

I think it's intentional, but I'm really annoyed by this behaviour.
I really don't want my config to change from a normal make depending
on uname output.  We do have a CONFIG_64BIT in .config which should
be respected.  uname output is a good indicator for a previously
unconfigured kernel, but shouldn't change settings for a fully
congigured build.  Forgetting the linux32 command happens at least two
dozen times to me everyday, leading to a few lost seconds that add
up in the end.

Re: config automatically switches from 32-bit to 64-bit for x86

[Matthias Schniedermeyer]

On 27.05.2010 11:49, Christoph Hellwig wrote:
> On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
> > Hello,
> > 
> > I am trying to build 32 bit kernel image on 64-bit machine but after
> > 'make menuconfig' it automatically switches 32-bit to 64-bit.
> > 
> > Is this a BUG or did intentionally.
> 
> I think it's intentional, but I'm really annoyed by this behaviour.
> I really don't want my config to change from a normal make depending
> on uname output.  We do have a CONFIG_64BIT in .config which should
> be respected.  uname output is a good indicator for a previously
> unconfigured kernel, but shouldn't change settings for a fully
> congigured build.  Forgetting the linux32 command happens at least two
> dozen times to me everyday, leading to a few lost seconds that add
> up in the end.

Just use ARCH=x86. That ARCH respects CONFIG_64BIT from .config and 
"CONFIG_64BIT" is a config-option (the very first in menuconfig)





Bis denn

-- 
Real Programmers consider "what you see is what you get" to be just as 
bad a concept in Text Editors as it is in women. No, the Real Programmer
wants a "you asked for it, you got it" text editor -- complicated, 
cryptic, powerful, unforgiving, dangerous.

Re: config automatically switches from 32-bit to 64-bit for x86

[Christoph Hellwig]

On Thu, May 27, 2010 at 06:11:34PM +0200, Matthias Schniedermeyer wrote:
> Just use ARCH=x86. That ARCH respects CONFIG_64BIT from .config and 
> "CONFIG_64BIT" is a config-option (the very first in menuconfig)

Which is an obsolute pain to type, even worse than doing a linux32 call
first.  Really, a simple

	make

should default to do the right thing.

Re: config automatically switches from 32-bit to 64-bit for x86

[Matthias Schniedermeyer]

On 27.05.2010 12:13, Christoph Hellwig wrote:
> On Thu, May 27, 2010 at 06:11:34PM +0200, Matthias Schniedermeyer wrote:
> > Just use ARCH=x86. That ARCH respects CONFIG_64BIT from .config and 
> > "CONFIG_64BIT" is a config-option (the very first in menuconfig)
> 
> Which is an obsolute pain to type, even worse than doing a linux32 call
> first.  Really, a simple
> 
> 	make
> 
> should default to do the right thing.

In my case it's wonderful, i compile several kernels with different 
bitnesses for differnt machines and with ARCH=x86 i don't have to 
differentiate between an i386 or x86_64 target.

for dat in a b c d; do make ARCH=x86 O=../$dat ; done





Bis denn

-- 
Real Programmers consider "what you see is what you get" to be just as 
bad a concept in Text Editors as it is in women. No, the Real Programmer
wants a "you asked for it, you got it" text editor -- complicated, 
cryptic, powerful, unforgiving, dangerous.

Re: config automatically switches from 32-bit to 64-bit for x86

[Sam Ravnborg]

On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote:
> On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
> > Hello,
> > 
> > I am trying to build 32 bit kernel image on 64-bit machine but after
> > 'make menuconfig' it automatically switches 32-bit to 64-bit.
> > 
> > Is this a BUG or did intentionally.
> 
> I think it's intentional, but I'm really annoyed by this behaviour.

The request when we did the merge of 32 and 64 bit was that we
should continue to build 64bit kernels on 64 bit machines.
And likewise for 32bit.
Because this was what the users where used to.

We could simplify metters by defining new rules.
As you suggest that uname on an intel box always resulted in ARCH=x86.
But then people would complain why a 32 bit kernel is default when
the box is 64 bit.

Something like this:
[The escape chars align nicely in the patched Makefile]

	Sam

diff --git a/Makefile b/Makefile
index ebc8225..e7f97a5 100644
--- a/Makefile
+++ b/Makefile
@@ -161,10 +161,11 @@ export srctree objtree VPATH
 # then ARCH is assigned, getting whatever value it gets normally, and 
 # SUBARCH is subsequently ignored.
 
-SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
-				  -e s/arm.*/arm/ -e s/sa110/arm/ \
+SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/        \
+				  -e s/sun4u/sparc64/                    \
+				  -e s/arm.*/arm/ -e s/sa110/arm/        \
 				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
-				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
+				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/  \
 				  -e s/sh[234].*/sh/ )
 
 # Cross compiling and selecting different set of gcc/bin-utils

Re: config automatically switches from 32-bit to 64-bit for x86

[Jaswinder Singh Rajput]

Hello Sam,

On Fri, May 28, 2010 at 12:16 AM, Sam Ravnborg <sam@ravnborg.org> wrote:
> On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote:
>> On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
>> > Hello,
>> >
>> > I am trying to build 32 bit kernel image on 64-bit machine but after
>> > 'make menuconfig' it automatically switches 32-bit to 64-bit.
>> >
>> > Is this a BUG or did intentionally.
>>
>> I think it's intentional, but I'm really annoyed by this behaviour.
>
> The request when we did the merge of 32 and 64 bit was that we
> should continue to build 64bit kernels on 64 bit machines.
> And likewise for 32bit.
> Because this was what the users where used to.
>
> We could simplify metters by defining new rules.
> As you suggest that uname on an intel box always resulted in ARCH=x86.
> But then people would complain why a 32 bit kernel is default when
> the box is 64 bit.
>
> Something like this:
> [The escape chars align nicely in the patched Makefile]
>
>        Sam
>
> diff --git a/Makefile b/Makefile
> index ebc8225..e7f97a5 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -161,10 +161,11 @@ export srctree objtree VPATH
>  # then ARCH is assigned, getting whatever value it gets normally, and
>  # SUBARCH is subsequently ignored.
>
> -SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
> -                                 -e s/arm.*/arm/ -e s/sa110/arm/ \
> +SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/        \
> +                                 -e s/sun4u/sparc64/                    \
> +                                 -e s/arm.*/arm/ -e s/sa110/arm/        \
>                                  -e s/s390x/s390/ -e s/parisc64/parisc/ \
> -                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
> +                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/  \
>                                  -e s/sh[234].*/sh/ )
>
>  # Cross compiling and selecting different set of gcc/bin-utils
>
>

Thanks, this patch fixes the issue. Now 'make menuconfig' is following .config.

Thanks,
--
Jaswinder Singh.

Re: config automatically switches from 32-bit to 64-bit for x86

[Sam Ravnborg]

On Fri, May 28, 2010 at 03:37:00AM +0530, Jaswinder Singh Rajput wrote:
> Hello Sam,
> 
> On Fri, May 28, 2010 at 12:16 AM, Sam Ravnborg <sam@ravnborg.org> wrote:
> > On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote:
> >> On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
> >> > Hello,
> >> >
> >> > I am trying to build 32 bit kernel image on 64-bit machine but after
> >> > 'make menuconfig' it automatically switches 32-bit to 64-bit.
> >> >
> >> > Is this a BUG or did intentionally.
> >>
> >> I think it's intentional, but I'm really annoyed by this behaviour.
> >
> > The request when we did the merge of 32 and 64 bit was that we
> > should continue to build 64bit kernels on 64 bit machines.
> > And likewise for 32bit.
> > Because this was what the users where used to.
> >
> > We could simplify metters by defining new rules.
> > As you suggest that uname on an intel box always resulted in ARCH=x86.
> > But then people would complain why a 32 bit kernel is default when
> > the box is 64 bit.
> >
> > Something like this:
> > [The escape chars align nicely in the patched Makefile]
> >
> >        Sam
> >
> > diff --git a/Makefile b/Makefile
> > index ebc8225..e7f97a5 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -161,10 +161,11 @@ export srctree objtree VPATH
> >  # then ARCH is assigned, getting whatever value it gets normally, and
> >  # SUBARCH is subsequently ignored.
> >
> > -SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
> > -                                 -e s/arm.*/arm/ -e s/sa110/arm/ \
> > +SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/        \
> > +                                 -e s/sun4u/sparc64/                    \
> > +                                 -e s/arm.*/arm/ -e s/sa110/arm/        \
> >                                  -e s/s390x/s390/ -e s/parisc64/parisc/ \
> > -                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
> > +                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/  \
> >                                  -e s/sh[234].*/sh/ )
> >
> >  # Cross compiling and selecting different set of gcc/bin-utils
> >
> >
> 
> Thanks, this patch fixes the issue. Now 'make menuconfig' is following .config.

If you think this is the right way to do things you can take it up
with the x86 maintainers.

Although the patch touches only a generic file this is x86 specific.

	Sam

Re: config automatically switches from 32-bit to 64-bit for x86

[Jaswinder Singh Rajput]

Hello Sam and Américo,

On Sat, May 29, 2010 at 4:49 PM, Sam Ravnborg <sam@ravnborg.org> wrote:
> On Fri, May 28, 2010 at 03:37:00AM +0530, Jaswinder Singh Rajput wrote:
>> Hello Sam,
>>
>> On Fri, May 28, 2010 at 12:16 AM, Sam Ravnborg <sam@ravnborg.org> wrote:
>> > On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote:
>> >> On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
>> >> > Hello,
>> >> >
>> >> > I am trying to build 32 bit kernel image on 64-bit machine but after
>> >> > 'make menuconfig' it automatically switches 32-bit to 64-bit.
>> >> >
>> >> > Is this a BUG or did intentionally.
>> >>
>> >> I think it's intentional, but I'm really annoyed by this behaviour.
>> >
>> > The request when we did the merge of 32 and 64 bit was that we
>> > should continue to build 64bit kernels on 64 bit machines.
>> > And likewise for 32bit.
>> > Because this was what the users where used to.
>> >
>> > We could simplify metters by defining new rules.
>> > As you suggest that uname on an intel box always resulted in ARCH=x86.
>> > But then people would complain why a 32 bit kernel is default when
>> > the box is 64 bit.
>> >
>> > Something like this:
>> > [The escape chars align nicely in the patched Makefile]
>> >
>> >        Sam
>> >
>> > diff --git a/Makefile b/Makefile
>> > index ebc8225..e7f97a5 100644
>> > --- a/Makefile
>> > +++ b/Makefile
>> > @@ -161,10 +161,11 @@ export srctree objtree VPATH
>> >  # then ARCH is assigned, getting whatever value it gets normally, and
>> >  # SUBARCH is subsequently ignored.
>> >
>> > -SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
>> > -                                 -e s/arm.*/arm/ -e s/sa110/arm/ \
>> > +SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/        \
>> > +                                 -e s/sun4u/sparc64/                    \
>> > +                                 -e s/arm.*/arm/ -e s/sa110/arm/        \
>> >                                  -e s/s390x/s390/ -e s/parisc64/parisc/ \
>> > -                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
>> > +                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/  \
>> >                                  -e s/sh[234].*/sh/ )
>> >
>> >  # Cross compiling and selecting different set of gcc/bin-utils
>> >
>> >
>>
>> Thanks, this patch fixes the issue. Now 'make menuconfig' is following .config.
>
> If you think this is the right way to do things you can take it up
> with the x86 maintainers.
>
> Although the patch touches only a generic file this is x86 specific.
>

Américo Wang, Do you mind handle this kconfig patch.

Thanks,
--
Jaswinder Singh.

Re: config automatically switches from 32-bit to 64-bit for x86

[Américo Wang]

On Sat, May 29, 2010 at 10:49:25PM +0530, Jaswinder Singh Rajput wrote:
>Hello Sam and Américo,
>
>On Sat, May 29, 2010 at 4:49 PM, Sam Ravnborg <sam@ravnborg.org> wrote:
>> On Fri, May 28, 2010 at 03:37:00AM +0530, Jaswinder Singh Rajput wrote:
>>> Hello Sam,
>>>
>>> On Fri, May 28, 2010 at 12:16 AM, Sam Ravnborg <sam@ravnborg.org> wrote:
>>> > On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote:
>>> >> On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
>>> >> > Hello,
>>> >> >
>>> >> > I am trying to build 32 bit kernel image on 64-bit machine but after
>>> >> > 'make menuconfig' it automatically switches 32-bit to 64-bit.
>>> >> >
>>> >> > Is this a BUG or did intentionally.
>>> >>
>>> >> I think it's intentional, but I'm really annoyed by this behaviour.
>>> >
>>> > The request when we did the merge of 32 and 64 bit was that we
>>> > should continue to build 64bit kernels on 64 bit machines.
>>> > And likewise for 32bit.
>>> > Because this was what the users where used to.
>>> >
>>> > We could simplify metters by defining new rules.
>>> > As you suggest that uname on an intel box always resulted in ARCH=x86.
>>> > But then people would complain why a 32 bit kernel is default when
>>> > the box is 64 bit.
>>> >
>>> > Something like this:
>>> > [The escape chars align nicely in the patched Makefile]
>>> >
>>> >        Sam
>>> >
>>> > diff --git a/Makefile b/Makefile
>>> > index ebc8225..e7f97a5 100644
>>> > --- a/Makefile
>>> > +++ b/Makefile
>>> > @@ -161,10 +161,11 @@ export srctree objtree VPATH
>>> >  # then ARCH is assigned, getting whatever value it gets normally, and
>>> >  # SUBARCH is subsequently ignored.
>>> >
>>> > -SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
>>> > -                                 -e s/arm.*/arm/ -e s/sa110/arm/ \
>>> > +SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/        \
>>> > +                                 -e s/sun4u/sparc64/                    \
>>> > +                                 -e s/arm.*/arm/ -e s/sa110/arm/        \
>>> >                                  -e s/s390x/s390/ -e s/parisc64/parisc/ \
>>> > -                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
>>> > +                                 -e s/ppc.*/powerpc/ -e s/mips.*/mips/  \
>>> >                                  -e s/sh[234].*/sh/ )
>>> >
>>> >  # Cross compiling and selecting different set of gcc/bin-utils
>>> >
>>> >
>>>
>>> Thanks, this patch fixes the issue. Now 'make menuconfig' is following .config.
>>
>> If you think this is the right way to do things you can take it up
>> with the x86 maintainers.
>>
>> Although the patch touches only a generic file this is x86 specific.
>>
>
>Américo Wang, Do you mind handle this kconfig patch.
>


Sorry for the delay.

Usually Michal should take this patch. Cc'ing him.

Re: config automatically switches from 32-bit to 64-bit for x86

[Sam Ravnborg]

> >>
> >> Although the patch touches only a generic file this is x86 specific.
> >>
> >
> >Américo Wang, Do you mind handle this kconfig patch.
> >
> 
> 
> Sorry for the delay.
> 
> Usually Michal should take this patch. Cc'ing him.

This is not generic functionality. The patch changes default
behaviour when building x86 kernes only.
So IMO it requires ack from the x86 maintainers.

	Sam

Re: config automatically switches from 32-bit to 64-bit for x86

[Michal Marek]

On Thu, May 27, 2010 at 08:46:53PM +0200, Sam Ravnborg wrote:
> On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote:
> > On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
> > > Hello,
> > > 
> > > I am trying to build 32 bit kernel image on 64-bit machine but after
> > > 'make menuconfig' it automatically switches 32-bit to 64-bit.
> > > 
> > > Is this a BUG or did intentionally.
> > 
> > I think it's intentional, but I'm really annoyed by this behaviour.
> 
> The request when we did the merge of 32 and 64 bit was that we
> should continue to build 64bit kernels on 64 bit machines.
> And likewise for 32bit.
> Because this was what the users where used to.
> 
> We could simplify metters by defining new rules.
> As you suggest that uname on an intel box always resulted in ARCH=x86.
> But then people would complain why a 32 bit kernel is default when
> the box is 64 bit.

Which is not acceptable, IMO. An x86_64 distro typically has a complete
64bit userspace including /sbin/init, so the default kernel has to be
64bit.

What about always making the prompt visible, so that the previously set
value gets reused? The downside is that 'make ARCH=i386 menuconfig' in a
clean tree on x86_64 will default to 64bit, because it will find the
setting in the config of the running 64bit kernel :(. But after manually
turning CONFIG_64BIT off, the setting will be preserved.

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index dcb0593..05ec418 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -3,7 +3,7 @@ mainmenu "Linux Kernel Configuration for x86"
 
 # Select 32 or 64 bit
 config 64BIT
-	bool "64-bit kernel" if ARCH = "x86"
+	bool "64-bit kernel"
 	default ARCH = "x86_64"
 	---help---
 	  Say yes to build a 64-bit kernel - formerly known as x86_64

Re: config automatically switches from 32-bit to 64-bit for x86

[Jaswinder Singh Rajput]

Hello Michal and Sam,

On Thu, Jun 3, 2010 at 7:00 PM, Michal Marek <mmarek@suse.cz> wrote:
> On Thu, May 27, 2010 at 08:46:53PM +0200, Sam Ravnborg wrote:
>> On Thu, May 27, 2010 at 11:49:16AM -0400, Christoph Hellwig wrote:
>> > On Thu, May 27, 2010 at 05:37:36AM +0530, Jaswinder Singh Rajput wrote:
>> > > Hello,
>> > >
>> > > I am trying to build 32 bit kernel image on 64-bit machine but after
>> > > 'make menuconfig' it automatically switches 32-bit to 64-bit.
>> > >
>> > > Is this a BUG or did intentionally.
>> >
>> > I think it's intentional, but I'm really annoyed by this behaviour.
>>
>> The request when we did the merge of 32 and 64 bit was that we
>> should continue to build 64bit kernels on 64 bit machines.
>> And likewise for 32bit.
>> Because this was what the users where used to.
>>
>> We could simplify metters by defining new rules.
>> As you suggest that uname on an intel box always resulted in ARCH=x86.
>> But then people would complain why a 32 bit kernel is default when
>> the box is 64 bit.
>
> Which is not acceptable, IMO. An x86_64 distro typically has a complete
> 64bit userspace including /sbin/init, so the default kernel has to be
> 64bit.
>
> What about always making the prompt visible, so that the previously set
> value gets reused? The downside is that 'make ARCH=i386 menuconfig' in a
> clean tree on x86_64 will default to 64bit, because it will find the
> setting in the config of the running 64bit kernel :(. But after manually
> turning CONFIG_64BIT off, the setting will be preserved.
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index dcb0593..05ec418 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -3,7 +3,7 @@ mainmenu "Linux Kernel Configuration for x86"
>
>  # Select 32 or 64 bit
>  config 64BIT
> -       bool "64-bit kernel" if ARCH = "x86"
> +       bool "64-bit kernel"
>        default ARCH = "x86_64"
>        ---help---
>          Say yes to build a 64-bit kernel - formerly known as x86_64
>

This patch works !!

Thanks,
--
Jaswinder Singh.

Re: config automatically switches from 32-bit to 64-bit for x86

[Michal Marek]

On 4.6.2010 08:23, Jaswinder Singh Rajput wrote:
> Hello Michal and Sam,
> 
> On Thu, Jun 3, 2010 at 7:00 PM, Michal Marek <mmarek@suse.cz> wrote:
>> What about always making the prompt visible, so that the previously set
>> value gets reused? The downside is that 'make ARCH=i386 menuconfig' in a
>> clean tree on x86_64 will default to 64bit, because it will find the
>> setting in the config of the running 64bit kernel :(. But after manually
>> turning CONFIG_64BIT off, the setting will be preserved.
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index dcb0593..05ec418 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -3,7 +3,7 @@ mainmenu "Linux Kernel Configuration for x86"
>>
>>  # Select 32 or 64 bit
>>  config 64BIT
>> -       bool "64-bit kernel" if ARCH = "x86"
>> +       bool "64-bit kernel"
>>        default ARCH = "x86_64"
>>        ---help---
>>          Say yes to build a 64-bit kernel - formerly known as x86_64
>>
> 
> This patch works !!

Does
$ make mrproper
$ make ARCH=i386 menuconfig
on x86_64 also work for you? Here, it takes CONFIG_64BIT=y from
/boot/config-`uname -r`. I see no easy way to solve this atm.

Michal

Re: config automatically switches from 32-bit to 64-bit for x86

[Jaswinder Singh Rajput]

Hello Michal,

On Fri, Jun 4, 2010 at 1:23 PM, Michal Marek <mmarek@suse.cz> wrote:
> On 4.6.2010 08:23, Jaswinder Singh Rajput wrote:
>> Hello Michal and Sam,
>>
>> On Thu, Jun 3, 2010 at 7:00 PM, Michal Marek <mmarek@suse.cz> wrote:
>>> What about always making the prompt visible, so that the previously set
>>> value gets reused? The downside is that 'make ARCH=i386 menuconfig' in a
>>> clean tree on x86_64 will default to 64bit, because it will find the
>>> setting in the config of the running 64bit kernel :(. But after manually
>>> turning CONFIG_64BIT off, the setting will be preserved.
>>>
>>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>>> index dcb0593..05ec418 100644
>>> --- a/arch/x86/Kconfig
>>> +++ b/arch/x86/Kconfig
>>> @@ -3,7 +3,7 @@ mainmenu "Linux Kernel Configuration for x86"
>>>
>>>  # Select 32 or 64 bit
>>>  config 64BIT
>>> -       bool "64-bit kernel" if ARCH = "x86"
>>> +       bool "64-bit kernel"
>>>        default ARCH = "x86_64"
>>>        ---help---
>>>          Say yes to build a 64-bit kernel - formerly known as x86_64
>>>
>>
>> This patch works !!
>
> Does
> $ make mrproper
> $ make ARCH=i386 menuconfig
> on x86_64 also work for you? Here, it takes CONFIG_64BIT=y from
> /boot/config-`uname -r`. I see no easy way to solve this atm.
>

Yes, this also works.

Thanks,
--
Jaswinder Singh.