RFA: Add readelf --unwind support for ARM

[Nick Clifton]

Hi Daniel,

>>> +  if (elf_header.e_machine == EM_ARM)
>>> +    addr.offset&= ~1;
>>
>> I suspect that this behaviour might be needed for other architectures
>> as well (MIPS16 maybe ?).  So you might as well use a macro that
>> tests e_machine and returns an unmangled offset.
>
> Could you give me an example of what you mean?  Something like this?
>
> #define REMOVE_ARCH_BITS(ADDR) do { \
>    if (elf_header.e_machine == EM_ARM) \
>      ADDR&= ~1; \
>    } while (0)

Yeah, exactly that.


>> Just curious - are there any ARM binaries that use REL relocations
>> and have unwind tables ?
>
> In practice, I'm not sure.  I know there are REL ARM binaries -
> VxWorks uses REL, but last I checked it wasn't on the EABI yet.

Hmm, well no reason to penalize them if they do change, so I guess 
supporting both types of relocation is worthwhile.

Cheers
   Nick