When gcc with -pg, it'll add _mcount stub in every function. We need
implement the _mcount in kernel and ftrace depends on stackstrace.
To do: call-graph, dynamic ftrace
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
The gcc option "-mbacktrace" will push fp(r8),lr into stack and we could
unwind the stack with:
fp = *fp
lr = (unsigned int *)fp[1]
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Guo Ren