Robert Smith wrote:
> I have now solved this problem.  It seems that there were some
> bugs in /src/sys/arch/mips/mips/trap.c which led to incorrect
> memory accesses when attempting to read/decode instructions
> for the purpose of single stepping.
> 
> If anyone is interested I can send them the fix.  Alternatively, if
> someone can give me some guidance, I will submit the fix into
> the maintained code.

Excellent work! You can either post it here, or send-pr the diff.
The latter is probably better, so that committer won't need
to dig archives to get the patch.

Jaromir
-- 
Jaromir Dolecek <jdolecek@NetBSD.org>      http://www.ics.muni.cz/~dolecek/
NetBSD - just plain best OS! -=*=- Got spare MCA cards or docs? Hand me them!