[Buildroot] Problem building latest arm

[michael.miller at prga.com]

>-----Original Message-----
>From: Bernhard Fischer [mailto:rep.dot.nop at gmail.com] 
>Sent: Wednesday, June 27, 2007 11:20 AM
>To: Michael D. Miller
>Cc: buildroot at uclibc.org
>Subject: Re: [Buildroot] Problem building latest arm
>
>On Wed, Jun 27, 2007 at 07:45:02AM -0500, michael.miller at prga.com
wrote:
>>>-----Original Message-----
>>>From: Bernhard Fischer [mailto:rep.dot.nop at gmail.com]
>>>Sent: Tuesday, June 26, 2007 1:22 AM
>>>To: Michael D. Miller
>>>Cc: buildroot at uclibc.org
>>>Subject: Re: [Buildroot] Problem building latest arm
>>>
>>>On Mon, Jun 25, 2007 at 10:04:44PM -0500, michael.miller at prga.com
>>wrote:
>>>>I'm trying to build for an Xscale (ARM), EABI, NPTL with binutils 
>>>>2.17.50.0.16, software floating point, and target options bash,
bzip2 
>>>>and diffutils.  All other options are default (gcc 4.2.0).  I'm
using 
>>>>the latest snapshot for uclibc, and have tried buildroot snapshots
>>>from
>>>>6/20, 6/21 and 6/23.
>>>>
>>>>If I use 6/20, 6/21 or 6/23 buildroot snapshots then the build fails
>>in
>>>>pthreads because sysdep-cancel.h is not found.  Looking in the 
>>>>linuxthreads/sysdeps/unix/sysv/linux directory, I see subdirectories

>>>>for i386, mips, etc. but not for arm.
>>>>
>>>>Searching recent mailing list archives, Bernhard says things that 
>>>>make
>>
>>>>me think this configuration should work.  He hints that helptext
will
>>>
>>>I was talking about eabi. Threading is a different issue (but even 
>>>that
>>one has a nice, >IMHO descriptive help-text).
>>
>>I tried just building for "old" Linux threads instead of POSIX
threads.
>>In that case I got an error because
build_arm_nofpu/staging_dir/include
>
>this area changed recently. You may need to erase build_* toolchain_*

I've been doing clean builds by removing the entire buildroot directory
and starting over each time.

>>didn't exist.  I manually created the directory and restarted the
build.
>>Things continued without further incident and completed with a tool 
>>chain.  A quick test seems to indicate the generated cross compiler 
>>works, checked with a simple "Hello world" compiled after exporting
the 
>>staging_dir/usr/bin.
>>
>>So, NPTL seems broken for ARM.  I've tried using an old ecos version
of
>
>you're better off to ask the uclibc list about the state of NTPL
support.

This really seems more of a buildroot issue since the problem is the
gcc-final stage.  I'll query the uclibc list if you think it might help,
but I expect I'll get one of Rob's famous flames for being off topic.

I'm not sure why the pthread test is failing, so I'll poke around a
little more there.  A check via -dumpspecs of xgcc indicates that the
pthread support is there.  Maybe configure is looking for the library.

>>sysdep-cancel.h and things reach the point that during the gcc-final 
>>stage libgomp blows up because the pthread library can't be found.  
>>This is a configure error saying that pthreads are required for 
>>libgomp.  I'd say I don't even want libgomp.  Is there an easy way to 
>>prevent this from even being attempted?  I'm thinking of some 
>>additional build flag I can pass in to buildroot.
>
>See menuconfig. ()  Additional gcc options

On more reflection, I can't decide for sure if libgomp support is needed
in the final gcc.  It seems to me that OpenMP and POSIX threads are
different beasts.  I can understand OpenMP requiring pthreads, but it
doesn't' seem like pthreads should really require OpenMP.  That's a vote
for getting libgomp out of the final gcc.  We're talking about the cross
tool that runs on a x686 platform here, not the final ARM target.  I'll
give --disable-libgomp a try and see if that gets me further.

	Regards,
	Mike