[Buildroot] [PATCH 1/1] Fix elf2flt build

[Douglas RAILLARD <public.douglas.raillard@gmail.com>]

Thomas,

On Friday 28 August 2015 10:09:32, Thomas Petazzoni wrote:
> Douglas,
> 
> Please do not reply to me directly: keep the list in Cc so that others
> can continue to participate to the discussion. Thanks!
> 
Sorry, messed up with my mailer, previous email here for reference: 
http://lists.busybox.net/pipermail/buildroot/2015-August/138057.html


> > > However the build of an ARM Cortex-M3 toolchain fails during the uClibc
> > > build (which takes place *after* host-elf2flt is built).
> > 
> > There are indeed problems when some toolchain options are selected,
> > so I managed to leave them out for the moment to focus on getting
> > something built. Here is my buildroot configuration generated with
> > make savedefconfig:
> > BR2_arm=y
> > BR2_cortex_m3=y
> > BR2_ARM_INSTRUCTIONS_THUMB2=y
> > BR2_GLOBAL_PATCH_DIR="../patch"
> > BR2_UCLIBC_VERSION_0_9_33=y
> > BR2_UCLIBC_CONFIG="package/uclibc/uClibc-ng.config"
> 
> This seems weird: using uClibc 0.9.33 with the configuration file for
> uClibc-ng. Have you had any problem with uClibc-ng that made you go
> back to uClibc 0.9.33 ?

Indeed, I did not pay attention to it in the first place as I wanted to use as 
much default as possible.
uClibc-ng does not compile with my configuration (same as before but with
uClibc-ng instead of uClibc 0.9.33), I have not tried to investigate this issue yet:

make[1]: Entering directory '/working_dir/buildroot/output/build/uclibc-1.0.5'
/working_dir/buildroot/output/host/usr/bin/arm-buildroot-uclinux-uclibcgnueabi-gcc -c libc/sysdeps/linux/arm/setcontext.S -o libc/sysdeps/linux/arm/setcontext.os -Wall -Wstrict-prototypes -Wstrict-aliasing -funsigned-char -fno-builtin -fno-asm -fmerge-all-constants -msoft-float -mlittle-endian -fstack-protector -nostdinc -I./include -I./include -include libc-symbols.h -I./libc/sysdeps/linux/arm -I./libc/sysdeps/linux -I./ldso/ldso/arm -I./ldso/include -I. -DSTATIC -Os -fstrict-aliasing -I./libc/sysdeps/linux/common -isystem /working_dir/buildroot/output/host/usr/lib/gcc/arm-buildroot-uclinux-uclibcgnueabi/4.9.3/include-fixed -isystem /working_dir/buildroot/output/host/usr/lib/gcc/arm-buildroot-uclinux-uclibcgnueabi/4.9.3/include -I/working_dir/buildroot/output/build/linux-headers-4.1.4/usr/include/ -DNDEBUG -DIN_LIB=libc -fPIC -MT libc/sysdeps/linux/arm/setcontext.os -MD -MP -MF libc/sysdeps/linux/arm/.setcontext.os.dep -D__ASSEMBLER__ -Wa,--noexecstack    
libc/sysdeps/linux/arm/setcontext.S: Assembler messages:
libc/sysdeps/linux/arm/setcontext.S:63: Error: LR and PC should not both be in register list -- `ldmia r14,{r14,pc}'
Makerules:386: recipe for target 'libc/sysdeps/linux/arm/setcontext.os' failed
make[1]: *** [libc/sysdeps/linux/arm/setcontext.os] Error 1
make[1]: Leaving directory '/working_dir/buildroot/output/build/uclibc-1.0.5'
package/pkg-generic.mk:156: recipe for target '/working_dir/buildroot/output/build/uclibc-1.0.5/.stamp_built' failed
make: *** [/working_dir/buildroot/output/build/uclibc-1.0.5/.stamp_built] Error 2


> > BR2_TOOLCHAIN_BUILDROOT_INET_RPC=y
> > BR2_TOOLCHAIN_BUILDROOT_WCHAR=y
> > BR2_PTHREADS_NONE=y
> 
> Any reason to disable thread support?
It fails  with NPTL thread support enabled (and also with every other threading backend).
Same configuration with uClibc 0.9.33 and NPTL thread, I did not try to solve this 
issue yet:

make[1]: Entering directory '/working_dir/buildroot/output/build/uclibc-0.9.33.2'
  AR cr lib/libcrypt.a
  STRIP -x -R .note -R .comment lib/libcrypt.a
  AR cr lib/libm.a
  STRIP -x -R .note -R .comment lib/libm.a
  AR cr lib/libnsl.a
  STRIP -x -R .note -R .comment lib/libnsl.a
  AR cr lib/libresolv.a
  STRIP -x -R .note -R .comment lib/libresolv.a
  AR cr lib/libutil.a
  STRIP -x -R .note -R .comment lib/libutil.a
  AS libpthread/nptl/sysdeps/arm/pthread_spin_lock.os -DSTATIC -DHAVE_FORCED_UNWIND -DNDEBUG -D__USE_STDIO_FUTEXES__ -D__ASSEMBLER__ -DNOT_IN_libc -DIS_IN_libpthread
libpthread/nptl/sysdeps/arm/pthread_spin_lock.S: Assembler messages:
libpthread/nptl/sysdeps/arm/pthread_spin_lock.S:26: Error: selected processor does not support Thumb mode `swp r2,r1,[r0]'
libpthread/nptl/sysdeps/arm/pthread_spin_lock.S:27: Error: instruction not supported in Thumb16 mode -- `teq r2,#0'
Makerules:362: recipe for target 'libpthread/nptl/sysdeps/arm/pthread_spin_lock.os' failed
make[1]: *** [libpthread/nptl/sysdeps/arm/pthread_spin_lock.os] Error 1
make[1]: Leaving directory '/working_dir/buildroot/output/build/uclibc-0.9.33.2'
package/pkg-generic.mk:156: recipe for target '/working_dir/buildroot/output/build/uclibc-0.9.33.2/.stamp_built' failed
make: *** [/working_dir/buildroot/output/build/uclibc-0.9.33.2/.stamp_built] Error 2

> To tell the truth, ARM noMMU support in Buildroot is very much a work
> in progress. We have had only some initial Cortex-M3 patches, and a lot
> of work remain to be done to make it really usable. Your
> patches/reports are definitely welcome!

I plan to add support the smt32f429-discovery board with as much new
stuff as possible (new kernel, new toolchain, new Busybox, new U-boot), because
I started from this: https://github.com/jserv/stm32f429-linux-builder and after some
research, I felt that Buildroot was in the same vein, but much more integrated and also
widespread so this was the way to go for that kind of job.

Best regards,

Douglas

-- 

Douglas RAILLARD