Re: [PATCH 0/2] Support the new PPC476 processor

Thiago Jung Bauermann
2009-12-17T14:19:41Z

On Thu 17 Dec 2009 02:42:12 Joel Brobecker wrote:
> I'm very excited to see hardware-accelerated condition evaluation.
> I'll take a look at the patches for sure.

Great!

> Regarding the need for very recent kernel headers, it might be an issue.
> I assume the missing pieces are for the special kinds of watchpoints and
> breakpoints. Is there a way to disable just this code if the kernel
> is not recent enough?

We do intend that GDB keeps compiling and working as before when the kernel is
not recent enough. But then none of the new features this patch adds will be
available. The current ptrace interface for BookE debug registers
is an ugly hack, and GDB already does everything that can be done with it,
namely support just one hardware watchpoint, and no hardware breakpoint.

That is because the current ptrace interface was designed for server Power
processors, which only have one hardware watchpoint anyway.

By the way, the kernel patch implementing the new interface used by this
patch series is here:

http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-December/078805.html
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[]'s
Thiago Jung Bauermann
IBM Linux Technology Center