i386-stub and exception 16,17,19

[Fernando Nasser]

Wolfram Faul wrote:
> 
> Hallo all,
> I am working with a i386-stub on a PentiumIII machine. I want to use MMX
> and SIMD instructions on this machine, so i am interested in exception
> 19 handling streaming SIMD errors. This exception and as well 16
> (floatingpoint error) and 17 (alignemet check) are not supported yet.
> It's easy to add the chatching functions but which signals do I have to
> assign in the function computeSignal(int exceptionVector).
> Does gdb support these (new?) signals ?
> 

First of all, your stub is the one that will have to read the SSE registers (the
MMX registers are already accessible because they are mapped into the FP registers).
Also, your stub is the one that has to catch the exception and report it to gdb 
AS A UNIX SIGNAL.

The current version of gdb does not handle the SSE registers for embedded targets
(I know nothing about i386 native support, but this is not your case anyway).
I have a working version of it and I will be submitting it to be incorporated
later this year (it is being tested by Intel at the moment).  It will include access
to Pentium MSR registers that can be used to debug SSE (among other things).  Again,
your stub will have to be able to read MSR registers.


-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
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