I had a surprise when I tried to debug a user process on the raspberry pi. The first time it hit a breakpoint, the kernel panicked. Oops.
It turns out than on armv6 (and armv7, I think) the breakpoint instruction causes a Prefetch Abort exception, instead of Undefined Instruction as on previous arm architectures. I've updated the rpi kernel source to deal with this. I wonder if somebody with plan 9 on an armv7 system (omap or teg2) could check whether the same panic occurs there too?
