[Buildroot] Problems building for ucLinux/ARM with elf2flt enabled

[Thomas De Schampheleire]

On Thu, Jul 25, 2013 at 11:45 AM, Anna Fischer (novero/Bochum)
<Anna.Fischer at novero.com> wrote:
>> Subject: Re: [Buildroot] Problems building for ucLinux/ARM with elf2flt
>> enabled
>>
>> On Wed, Jul 24, 2013 at 1:39 PM, Anna Fischer (novero/Bochum)
>> <Anna.Fischer at novero.com> wrote:
>> >> Subject: Re: [Buildroot] Problems building for ucLinux/ARM with
>> >> elf2flt enabled
>> >>
>> >> Hi Anna,
>> >>
>> >> On Wed, Jul 24, 2013 at 12:02 PM, Anna Fischer (novero/Bochum)
>> >> <Anna.Fischer at novero.com> wrote:
>> >> > I'm trying to build a ucLinux system for an ARM platform (no-MMU),
>> >> but when trying to enabled elf2flt in the menuconfig I get the
>> >> following error:
>> >> >
>> >> > /home/buildroot-2013.05/output/build/host-binutils-
>> >> 2.21.1/bfd/libbfd.a(compress.o): In function
>> >> `bfd_compress_section_contents':
>> >> > compress.c:(.text+0x25): undefined reference to `compressBound'
>> >> > /home//buildroot-2013.05/output/build/host-binutils-
>> >> 2.21.1/bfd/libbfd.a(compress.o): In function
>> >> `bfd_get_full_section_contents':
>> >> > compress.c:(.text+0x226): undefined reference to `inflateEnd'
>> >> > compress.c:(.text+0x37a): undefined reference to `inflateInit_'
>> >> > compress.c:(.text+0x3b0): undefined reference to `inflate'
>> >> > compress.c:(.text+0x3bf): undefined reference to `inflateReset'
>> >> > collect2: ld returned 1 exit status
>> >> > make[1]: *** [elf2flt] Error 1
>> >> > make[1]: Leaving directory `/home/buildroot-
>> >> 2013.05/output/toolchain/elf2flt'
>> >> > make: ***
>> >> > [/home/buildroot-2013.05/output/toolchain/elf2flt/elf2flt]
>> >> > Error 2
>> >> >
>> >> > It seems like it is missing libz? But I don't quite understand
>> why,
>> >> because I definitely have it installed on the system. Anyone ever
>> >> seen this before?
>> >> >
>> >> > I'm using the buildroot internal toolchain, uClibc-0.9.33.2, gcc-
>> >> 4.7.3, linux-3.8, and this is buildroot-2013.05. I have attached my
>> >> .config as well. My build host is Ubuntu 64-bit.
>> >>
>> >> Do you have the -dev package of zlib? Also for 64-bit?
>> >>
>> >> On a CentOS system, I have seen a problem with the static version of
>> >> zlib missing, when building a static toolchain with crosstool-ng. On
>> >> CentOS, the static version (libz.a) is distributed as a separate
>> >> package. I don't know if this is the case on your system.
>> >
>> > libz.a and libz.so are installed in output/host/usr/lib in the
>> buildroot system, so apart from the fact that I have it installed as
>> part of my Ubuntu distribution (yes, I have the -dev package
>> installed), it is present in the buildroot output directory. The
>> elf2flt Makefile also references this folder in LDFLAGS. It is not
>> clear to me though if the problem is in elf2flt or in the binutils
>> itself under build/host-binutils-2.21.1/bfd (as referenced by the error
>> message I printed out above)?
>>
>> Where exactly can you find libz in output/ ?
>> Since the error is in a host package, there should be such files in
>> output/host/ Any libz files in output/staging are irrelevant, as these
>> are for the target, not for the host.
>>
>> If there is no libz in output/host, there may be a missing dependency
>> to host-zlib in binutils. You could verify this by running 'make host-
>> zlib' manually first, and then retrying the binutils build.
>
> I have fixed the problem now by adding the -lz to the end of the gcc command in the elf2flt Makefile.
> Now the whole system builds without errors.
>
> However, in the target folder I'm still getting ELF files compiled, not FLAT format binaries. Is there any way I can tell the build system to change the binary format to FLAT by using the elf2flt tool at the end of each build process for binaries (or by adding -elf2flt to the build command)? I was hoping that by enabling elf2flt support it would do that automatically for target binaries.
>
> Any pointers would be really appreciated.

I'm afraid I'm not the person to help you here, I don't have any
experience with flat binaries in buildroot.
Others may be better suited. Thomas Petazzoni maybe?

Best regards,
Thomas