why gcc/objdump not recognize binary object file format

[Bridge Wu]

Oh, sorry. The binutils version number in 3.4.4 is 2.15.96, and the
one in 4.1.0 is 2.16.92. Thanks your hints.

On 6/7/06, Nick Clifton <nickc@redhat.com> wrote:
> Hi Bridge,
>
> > I got two ARM EABI toolchain and want to test their compatibility. One
> > is 3.4.4 (GCC version), the other is 4.1.0. The result is 4.1.0 can
> > link the binary code built by 3.4.4, but on the contrary, 3.4.4 cannot
> > recognize binary file format built by 4.1.0.
>
> This does not actually tell us which version of the binutils is being
> used.  3.4.4 is a GCC version number, not a binutils version number.
>
> > I took a look at the binutils source code. I found it's
> > bfd_check_format_matches that check the   file format. If target type
> > is not explicitly speicifed, bfd_target_vector list will be traversed
> > to check which target is matched. It seems this check was failed, so
> > the "File format not recognized" error appeared. I found below macro
> > do the checking.
> >
> >     temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
> >
> > But I didn't find abfd->xvec->_bfd_check_format[] for ARM. I cannot
> > know what happened in the bfd_check_format function. Any hints?
>
> Use a debugger to follow the execution path through this pointer.
>
> For most ELF targets you will probably end up in
> bfd/elfcode.h:elf_object_p().  I suspect that you will find that the
> checks of the machine code values are the problem.  Otherwise look at
> the function bfd/elf32-arm.c:elf32_arm_object_p() and see if that is
> unable to recognise the 4.1.0 generated files.
>
> Cheers
>    Nick
>
>
>


-- 
best regards,
-Bridge