[Buildroot] problems compiling uclibc for Geode (i386)

[Buildroot] problems compiling uclibc for Geode (i386)

[Sven Neumann]

Hi,

I am currently trying to update our buildroot system to the latest
version that I pulled from your git repository yesterday. Things work
reasonably well and I have everything compiling fine for the ARM
platform. The Geode platform however is causing trouble when it comes to
compiling uclibc 0.9.32.

First I had to fix a compile problem by pulling in this patch from the
uclibc repository:
http://git.uclibc.org/uClibc/patch/?id=8245f3b4638fdff2011c2657af1bb211def704bc


But now I am stuck with this linker error:

  LD libuClibc-0.9.32.so
libc/libc_so.a(err.os):(.text.vwarn_work+0x127): undefined reference to
`__lll_unlock_wake_private'
collect2: ld returned 1 exit status
make[1]: *** [lib/libc.so] Error 1
make[1]: Leaving directory
`/home/sven/git/buildroot/output/toolchain/uClibc-0.9.32'

Any ideas?


Thanks in advance,
Sven

[Buildroot] problems compiling uclibc for Geode (i386)

[Sven Neumann]

On Tue, 2011-06-28 at 22:02 +0200, Sven Neumann wrote:
> Hi,
> 
> I am currently trying to update our buildroot system to the latest
> version that I pulled from your git repository yesterday. Things work
> reasonably well and I have everything compiling fine for the ARM
> platform. The Geode platform however is causing trouble when it comes to
> compiling uclibc 0.9.32.
> 
> First I had to fix a compile problem by pulling in this patch from the
> uclibc repository:
> http://git.uclibc.org/uClibc/patch/?id=8245f3b4638fdff2011c2657af1bb211def704bc
> 
> 
> But now I am stuck with this linker error:
> 
>   LD libuClibc-0.9.32.so
> libc/libc_so.a(err.os):(.text.vwarn_work+0x127): undefined reference to
> `__lll_unlock_wake_private'
> collect2: ld returned 1 exit status
> make[1]: *** [lib/libc.so] Error 1
> make[1]: Leaving directory
> `/home/sven/git/buildroot/output/toolchain/uClibc-0.9.32'

Looks like NPTL support is broken for the generic 386 target. I've
changed the uclibc configuration to i586 now (in the hope that this will
work for a Geode processor) and that has fixed above problem for me.


Sven

[Buildroot] problems compiling uclibc for Geode (i386)

[Michael S. Zick]

On Wed June 29 2011, Sven Neumann wrote:
> On Tue, 2011-06-28 at 22:02 +0200, Sven Neumann wrote:
> > Hi,
> > 
> > I am currently trying to update our buildroot system to the latest
> > version that I pulled from your git repository yesterday. Things work
> > reasonably well and I have everything compiling fine for the ARM
> > platform. The Geode platform however is causing trouble when it comes to
> > compiling uclibc 0.9.32.
> > 
> > First I had to fix a compile problem by pulling in this patch from the
> > uclibc repository:
> > http://git.uclibc.org/uClibc/patch/?id=8245f3b4638fdff2011c2657af1bb211def704bc
> > 
> > 
> > But now I am stuck with this linker error:
> > 
> >   LD libuClibc-0.9.32.so
> > libc/libc_so.a(err.os):(.text.vwarn_work+0x127): undefined reference to
> > `__lll_unlock_wake_private'
> > collect2: ld returned 1 exit status
> > make[1]: *** [lib/libc.so] Error 1
> > make[1]: Leaving directory
> > `/home/sven/git/buildroot/output/toolchain/uClibc-0.9.32'
> 
> Looks like NPTL support is broken for the generic 386 target. I've
> changed the uclibc configuration to i586 now (in the hope that this will
> work for a Geode processor) and that has fixed above problem for me.
> 

Probably a good starting point although you don't mention __which__ Geode
processor your using.

An older sort of reference but depending on your processor, might still apply:
http://www.larwe.com/technical/geode_linux.html

Mike
> 
> Sven
> 
> 
> 
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot
> 
> 

[Buildroot] problems compiling uclibc for Geode (i386)

[Thomas Petazzoni]

Le Wed, 29 Jun 2011 14:29:34 +0200,
Sven Neumann <s.neumann@raumfeld.com> a ?crit :

> >   LD libuClibc-0.9.32.so
> > libc/libc_so.a(err.os):(.text.vwarn_work+0x127): undefined
> > reference to `__lll_unlock_wake_private'
> > collect2: ld returned 1 exit status
> > make[1]: *** [lib/libc.so] Error 1
> > make[1]: Leaving directory
> > `/home/sven/git/buildroot/output/toolchain/uClibc-0.9.32'
> 
> Looks like NPTL support is broken for the generic 386 target. I've
> changed the uclibc configuration to i586 now (in the hope that this
> will work for a Geode processor) and that has fixed above problem for
> me.

This function is implemented in
libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S, so
presumably, i386 does not work, but i486 should.

My understanding is that the futex mechanism uses the cmpxchgl
instruction, which is only available on 486+ processors.

Maybe someone should send a patch to the uClibc configuration system to
make sure that NPTL cannot be selected on i386.

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] problems compiling uclibc for Geode (i386)

[Thomas Petazzoni]

Hello,

Please don't reply to me directly, but rather to the Buildroot list.

Le Wed, 29 Jun 2011 15:48:29 +0100,
Dominic Newton <dominic.newton@in-2-technology.co.uk> a ?crit :

> uclibc menuconfig correctly shows that the i386 sub-architecture does 
> not support NPTL. For some reason this is not picked up in the main 
> buildroot config options. I've not had time to see why. I normally
> run uclicb-menuconfig and see what is supported their as a double
> check at the moment.

Ah, then it's Buildroot that needs to be fixed.

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] problems compiling uclibc for Geode (i386)

[Peter Korsgaard]

>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni@free-electrons.com> writes:

 Thomas> Hello,
 Thomas> Please don't reply to me directly, but rather to the Buildroot list.

 Thomas> Le Wed, 29 Jun 2011 15:48:29 +0100,
 Thomas> Dominic Newton <dominic.newton@in-2-technology.co.uk> a ?crit :

 >> uclibc menuconfig correctly shows that the i386 sub-architecture does 
 >> not support NPTL. For some reason this is not picked up in the main 
 >> buildroot config options. I've not had time to see why. I normally
 >> run uclicb-menuconfig and see what is supported their as a double
 >> check at the moment.

 Thomas> Ah, then it's Buildroot that needs to be fixed.

I've fixed it now. Perhaps we should consider defaulting to something
slightly less ancient than i386.

-- 
Bye, Peter Korsgaard

[Buildroot] problems compiling uclibc for Geode (i386)

[Thomas Petazzoni]

Le Tue, 05 Jul 2011 09:00:15 +0200,
Peter Korsgaard <jacmet@uclibc.org> a ?crit :

> I've fixed it now. Perhaps we should consider defaulting to something
> slightly less ancient than i386.

Agreed. At least i486 or i586 seems like a good default.

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] problems compiling uclibc for Geode (i386)

[Yann E. MORIN]

Sven, Thomas, All,

On Wednesday 29 June 2011 16:43:30 Thomas Petazzoni wrote:
> Le Wed, 29 Jun 2011 14:29:34 +0200,
> Sven Neumann <s.neumann@raumfeld.com> a ?crit :
> 
> > >   LD libuClibc-0.9.32.so
> > > libc/libc_so.a(err.os):(.text.vwarn_work+0x127): undefined
> > > reference to `__lll_unlock_wake_private'
> > > collect2: ld returned 1 exit status
> > > make[1]: *** [lib/libc.so] Error 1
> > > make[1]: Leaving directory
> > > `/home/sven/git/buildroot/output/toolchain/uClibc-0.9.32'
> > 
> > Looks like NPTL support is broken for the generic 386 target. I've
> > changed the uclibc configuration to i586 now (in the hope that this
> > will work for a Geode processor) and that has fixed above problem for
> > me.
> 
> This function is implemented in
> libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S, so
> presumably, i386 does not work, but i486 should.
> 
> My understanding is that the futex mechanism uses the cmpxchgl
> instruction, which is only available on 486+ processors.

I confirm Thomas' explanations.

NPTL on x86 requires i486+ because of the cmpxchg opcode.
NPTL will never be implemented for i386.

IIRC, Geode is at least an i586, so you should be OK by selecting i586
instead of generic i386.

Regards,
Yann E. MORIN.

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
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'------------------------------^-------^------------------^--------------------'

[Buildroot] problems compiling uclibc for Geode (i386)

[Khem Raj]

On (29/06/11 16:43), Thomas Petazzoni wrote:
> Le Wed, 29 Jun 2011 14:29:34 +0200,
> Sven Neumann <s.neumann@raumfeld.com> a ?crit :
> 
> > >   LD libuClibc-0.9.32.so
> > > libc/libc_so.a(err.os):(.text.vwarn_work+0x127): undefined
> > > reference to `__lll_unlock_wake_private'
> > > collect2: ld returned 1 exit status
> > > make[1]: *** [lib/libc.so] Error 1
> > > make[1]: Leaving directory
> > > `/home/sven/git/buildroot/output/toolchain/uClibc-0.9.32'
> > 
> > Looks like NPTL support is broken for the generic 386 target. I've
> > changed the uclibc configuration to i586 now (in the hope that this
> > will work for a Geode processor) and that has fixed above problem for
> > me.
> 
> This function is implemented in
> libpthread/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S, so
> presumably, i386 does not work, but i486 should.
> 
> My understanding is that the futex mechanism uses the cmpxchgl
> instruction, which is only available on 486+ processors.

yes

> 
> Maybe someone should send a patch to the uClibc configuration system to
> make sure that NPTL cannot be selected on i386.

yes that will be the correct fix.

> 
> Regards,
> 
> Thomas
> -- 
> Thomas Petazzoni, Free Electrons
> Kernel, drivers, real-time and embedded Linux
> development, consulting, training and support.
> http://free-electrons.com
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot

-- 
-Khem

[Buildroot] problems compiling uclibc for Geode (i386)

[Peter Korsgaard]

>>>>> "Sven" == Sven Neumann <s.neumann@raumfeld.com> writes:

Hi,

 Sven> Looks like NPTL support is broken for the generic 386 target. I've
 Sven> changed the uclibc configuration to i586 now (in the hope that this will
 Sven> work for a Geode processor) and that has fixed above problem for me.

I've committed a fix so you cannot enable NPTL if you choose i386.

-- 
Bye, Peter Korsgaard