Hardware Watchpoints with via gdbserver on PowerPC

[Stefan Roese <sr at denx dot de>]

Hi,

I'm currently testing hardware watchpoints on embedded PPC platforms (PPC4xx 
BookE, and PPC82xx). With the latest CVS GDB versions this seems to work fine 
with the native GDB (7.0.1 release doesn't work).

Then I tried to use the HW watchpoints via gdbserver running on the PPC target 
(GDB running on the x86 host). This doesn't work. I'm getting this error:

...
(gdb) watch global_x 
Hardware watchpoint 1: global_x
(gdb) c
Continuing.
Warning:
Could not insert hardware watchpoint 1.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.


After digging a bit into the gdbserver source, I noticed that the low level 
functionality for HW watchpoints is not implemented at all for PPC. It seems 
that "only" those platforms support this feature currently
(the_low_target->insert_point()):

  x86           gdb/gdbserver/linux-x86-low.c
  crisv32       gdb/gdbserver/linux-crisv32-low.c


I'm wondering why this isn't implemented for PowerPC in gdbserver. Is it that 
nobody needed this feature till now? Or are some technical reasons preventing 
this or making it harder to implement as done in the PowerPC native gdb 
version?

Comments really appreciated. Thanks.

Cheers,
Stefan

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