Re: ppc64 altivec registers?

Paul Gilliam
2005-09-07T19:06:39Z

On Wednesday 07 September 2005 06:30, Daniel Jacobowitz wrote:
> On Wed, Sep 07, 2005 at 08:26:57AM -0500, Reynolds, Terry (Contractor-SIMTECH) wrote:
> > Hi,
> >
> > Does anyone here know how to fix the configuration of the kernel so that
> > gdb can find the altivec registers? The last time I heard from Andrew
> > Cagney he said :
> >
> > "At the time the code was written it was for a special altivec kernel /
> > build / config. Hence it was only enabled when built powerpc-*-*altivec.
> > Time has passed and that restriction no longer applies. I'll see about
> > removing it."
>
> Probably, the clean way to do this is through the "optional register
> set" interface we defined a couple of months ago. But I haven't had
> time to implement that yet.
>

(One of) The problem(s) with Altivec is with the kernel and not with GDB. The kernel (not sure which version, but I think all) just left out the GETVRREGS
and PUTVRREGS parts of the ptrace system call. Even with a patched kernel, there seems to be some problems with Altivec. I am working on them. I
hope to turn all the 'FAILS' to 'PASSES' in the the Altivec part of the testsuite (gdb.arch/altivec-abi.exp and gdb.arch/altivec-regs.exp)

Here is a link to a experimental patch to the 64-bit kernel that seems to fix the ptrace part of the problem(s):