[Buildroot] ARM OABI build broken with current buildroot tip

[Buildroot] ARM OABI build broken with current buildroot tip

[David J. Fiddes]

Hi,

I'm trying to build an up to date ARM OABI toolchain with uClibc 0.9.32. 
The build fails with a missing stack unwind symobl.

The toolchain I'm trying to configure is pretty straight forward. From a 
"make distclean" I configure:
  - ARM processor
  - OABI
  - Disable busybox and filesystem image generation

Switching uClibc to 0.9.31 allows the build to succeed.

I'm using buildroot: bef98b7c10a9969bc3f8b977dd9e0bdafba684a3

The build error is:

/usr/bin/make -j1 -C 
/home/dave/source/cvs-versions/buildroot/output/toolchain/uClibc-0.9.32 \
	ARCH="arm" \
	PREFIX=/home/dave/source/cvs-versions/buildroot/output/host/usr/arm-unknown-linux-uclibc/sysroot \
	DEVEL_PREFIX=/usr/ \
	RUNTIME_PREFIX=/ \
	install_runtime install_dev
make[1]: Entering directory 
`/home/dave/source/cvs-versions/buildroot/output/toolchain/uClibc-0.9.32'
   LD libuClibc-0.9.32.so
libc/libc_so.a(close.oS):(.ARM.exidx+0x0): undefined reference to 
`__aeabi_unwind_cpp_pr0'
collect2: ld returned 1 exit status
make[1]: *** [lib/libc.so] Error 1
make[1]: Leaving directory 
`/home/dave/source/cvs-versions/buildroot/output/toolchain/uClibc-0.9.32'
make: *** 
[/home/dave/source/cvs-versions/buildroot/output/host/usr/arm-unknown-linux-uclibc/sysroot/usr/lib/libc.a] 
Error 2

It seems like this is a uClibc bug but I'm not sure how best to separate 
the toolchain build form the uClibc build.

Dave

[Buildroot] ARM OABI build broken with current buildroot tip

[Peter Korsgaard]

>>>>> "David" == David J Fiddes <D.J@fiddes.net> writes:

 David> Hi,
 David> I'm trying to build an up to date ARM OABI toolchain with uClibc
 David> 0.9.32. The build fails with a missing stack unwind symobl.

 David> The toolchain I'm trying to configure is pretty straight forward. From
 David> a "make distclean" I configure:
 David>  - ARM processor
 David>  - OABI
 David>  - Disable busybox and filesystem image generation

 David> Switching uClibc to 0.9.31 allows the build to succeed.

The problem is NPTL threading support. A quick look in
libpthread/nptl/sysdeps/arm shows a number of EABI references. It seems
like NPTL on ARM is only supported with EABI.

And indeed, OABI / uClibc 0.9.32  / linuxthreads-old builds fine.

I'll adjust Buildroot so you cannot select NTPL together with OABI.

 David> It seems like this is a uClibc bug but I'm not sure how best to
 David> separate the toolchain build form the uClibc build.

It looks pretty independent of anything Buildroot related. You are
welcome to ask them regarding non-EABI NPTL support, but I would imagine
that such an uncommon configuration has fairly low priority.

May I ask why you want to use a new C library / NPTL together with the
obsolete OABI?

-- 
Bye, Peter Korsgaard

[Buildroot] ARM OABI build broken with current buildroot tip

[David J. Fiddes]

Hi Peter,

> The problem is NPTL threading support. A quick look in
> libpthread/nptl/sysdeps/arm shows a number of EABI references. It seems
> like NPTL on ARM is only supported with EABI.

Ah. That's a bit of a show stopper.

> May I ask why you want to use a new C library / NPTL together with the
> obsolete OABI?

I have a very large multi-threaded C++ app and a custom embedded Linux 
platform that have historically been developed at different times. The 
SW is now over 10 years old and I fear change so just stuck to the ABI 
that has always worked...

Probably time to bite the bullet and move our kernel to EABI for our 
next major release.

thanks,

Dave