Re: hardware watchpoints for ppc

[Wolfgang Schmieder <wolfgang dot schmieder at onlinehome dot de>]

Hello Cal,

thanks for the hint. I caught the problem in the meanwhile by checking the 
respective address in piece of code which is called very often. It took a lot 
of time and luck.
This way of catching bugs is really hard. Do you know  how I could
obtain the know how to implement hardware watchpoints into the gdb ?

Regards
	Wolfgang


Am Dienstag, 6. Juli 2004 22:31 schrieben Sie:
> Wolfgang,
> We had a similar problem here with some benchmarks we were doing. A
> particular address was being changed at random and we had to find
> what was doing it. So we put a watchpoint on the address and when
> it changed we stopped the process and did a bt to find the culprit.
> It took a while but it worked. This was on a PPC 860 target board
> using a cross built gdb and gdbserver. So it can be done it just
> takes time and patience.
>
> The only processor family that I know that has hardware watchpoints is
> x86. We work here with x86, ppc, mips, arm, xscale, crusoe, and sh.
>
> Cal
>
> Wolfgang Schmieder wrote:
> > Hello Cal,
> >
> > thanks for your anwer, even if it's bad news for me !
> >
> >
> > Regards
> > 	Wolfgang
> >
> > Am Dienstag, 6. Juli 2004 16:45 schrieb Cal Erickson:
> >>Wolfgang,
> >> From what I know there are no hardware watchpoints available on the PPC
> >>target boards. You might just try watch which will create a software
> >>watchpoint. These do work on PPC processors.
> >>
> >>Cal
> >>
> >>Wolfgang Schmieder wrote:
> >>>Hello,
> >>>
> >>>is there anybody who knows how I can set hardware watchpoints on ppc
> >>>boards ? I have a mpc855 board running a multithreaded application. It
> >>>appears that one thread (always the same thread) has a corrupted stack
> >>>(always at the same address). I guess I need to set a hardware
> >>> watchpoint in a remote debugging session to find the piece of code
> >>> which is corrupting the stack.
> >>>
> >>>There is one gdb mailing list thread about "supporting hw break/watch
> >>> for embedded ppc", which makes me think that there is at least a patch
> >>> or workaround available to set hardware watchpoints on a ppc board.
> >>>
> >>>Thanks,
> >>>
> >>>Wolfgang