Re: arm core analysis on x86 host

[Daniel Jacobowitz <drow@false.org>]

On Wed, Mar 30, 2005 at 08:01:56PM +0200, Mark Kettenis wrote:
>    It looks to me from tracing this through on i386, that the reason
>    it works is because foo-*-linux* configurations default to
>    GDB_OSABI_LINUX and none of the OS/ABI sniffers trigger on the core
>    file.  An accident, basically.
> 
> Not completely accidental.  If we don't have the means to determine
> the OS/ABI it makes sense to default to the target (implicitly)
> selected by the user.

Well, yes.  This is one of the reasons I added the default osabi
mechanism.  At least I think it was me :-)

>    The reason this doesn't work for ARM is because the sniffer tags
>    the core file as GDB_OSABI_ARM_APCS.  I've been meaning to change
>    the way ARM OS/ABI detection works, which will "fix" this as a side
>    effect; I will move that up my list and try to do it today.
> 
> Well, if there is some sort of standard ARM APCS core file this is
> perfectly OK.  In that case we shouldn't think about this as a Linux
> core file, but an ARM APCS core file.  There should be an ARM APCS
> architecture vector with a regset_from_core_section() that knows how
> to interpret it.
> 
> But i guess that's not the case.

Right.  APCS is simply the default for "unknown" ABIs; the sniffer is
being over-eager.  Patch forthcoming.

> There are several possibilities.  Yes, sniffers should be as clever as
> they can possibly be.  But the regset_from_core_section() functions
> can be made cleverer too.  And the core file reading code in BFD can
> help too by generating core file sections with meaningful names.

I wonder if we should fall back to the executable's OSABI in some case?
Anyway, not an urgent question.

-- 
Daniel Jacobowitz
CodeSourcery, LLC