Re: Debugging the MIPS processor using GDB

["Maciej W. Rozycki" <macro@xxxxxxxxxxxxxx>]

On Wed, 13 Aug 2008, Brian Foster wrote:

>   Re the FS²:  When it works, my (somewhat limited)
>  experience to-date is it works Ok.  And the use of
>  TCL on the Host workstation side allows some neat
>  tricks.  However, at least one thing doesn't work
>  reliably for me, albeit I've never investigated:
>  Breakpoints in the Linux kernel.  They do detonate.
>  Then, sometimes, I can â??câ??(ontinue) or â??sâ??(tep) Ok.
>  But other times, when I â??câ?? or â??sâ??, the breakpoint
>  detonates again and I'm stuck.  I cannot proceed.
>  (The same breakpoint might even work once or twice
>  and then fail.)   Any ideas?   AFAICR, this can also
>  happen if I try to use the â??sysnavâ?? console instead
>  of â??gdbâ??.

 Hmm, odd.  It looks like a cache coherence issue.  It could be a bug in
your version of FS2 software -- did you raise the issue with them?  
Anyway, as a workaround try setting "coherent=on" (quoting from memory) in
fs2.ini (just an idea -- it may not work and you will lose some
performance though) or use hardware breakpoints.

  Maciej