gdbstub_state
extern int gdbstub_state(struct kgdb_state *ks, char *cmd);
gdbstub_state(ks, "s");
gdbstub_state(ks, "c");
kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e");
gdbstub_state(kdb_ks, buf);