rtems gdb stub with virtex issue

[Tim Cussins]

On Tue, 05 Feb 2008 11:12:27 -0800, "Till Straumann"
<strauman at slac.stanford.edu> said:
> > Question: I've set a breakpoint, my thread has hit it and stopped.
> > At this point the breakpoint is 'disabled' by the stub.
> What makes you believe that? The stub only sets/removes
> breakpoints on behalf of gdb.

You're dead right - I should've turned on the DEBUG_COMM switch...

> The only exception being when
> it is asked to single-step over an existing breakpoint.
> In that case, the breakpoint is repaced by the original
> instruction which is subsequently executed and again
> replaced by the breakpoint.
> 
> gdb usually lets the stub insert breakpoints before
> issuing 'cont' or 'step' and removes them from the target
> as soon as it gains control (but would re-insert them
> before issuing 'cont' again).

This is true. gdb is setting the breakpoint before continuing,
the trap is being patched in by the stub, but the thread fails to
stick on it the next time around...

> 
> What version of gdb are you using?
> 

GNU gdb 6.6
This GDB was configured as "--host=i486-linux-gnu
--target=powerpc-ssrl-rtems".

Cheers,
Tim