_nodb_trap
#define MACHINE_KDEBUG_TRAP_FALLBACK(t, f) _nodb_trap((t), (f))
int _nodb_trap(int, struct trapframe *);
#define MACHINE_KDEBUG_TRAP_FALLBACK(t, f) _nodb_trap((t), (f))
int _nodb_trap(int, struct trapframe *);