Teach powerpc64 ddb to x, w, break, step, trace.

Copy and adapt db_memrw.c from amd64, so ddb can read and write kernel
memory.  It can now insert breakpoints in the kernel text.  Change
__syncicache() to prevent an infinite loop when len isn't a multiple
of cacheline_size.

Get breakpoints and single-stepping to work.
Single-stepping uses msr bit PSL_SE (single-step trace enable).

Adapt db_trace.c db_stack_trace_print() from powerpc 32, but without
all its features.  For now, powerpc64 trace doesn't print function
arguments and doesn't recognize traps.

"go for it" kettenis@

0 files changed, 0 insertions, 0 deletions