size_t size;
	int err;

	SIGFILLSET(ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);

	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {
		fatalf("pthread_create failed: %s", strerror(err));

	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);

	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {
		fatalf("pthread_create failed: %s", strerror(err));

	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	size = pthread_get_stacksize_np(pthread_self());
	pthread_attr_init(&attr);
	pthread_attr_setstacksize(&attr, size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {

	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {
		fatalf("pthread_create failed: %s", strerror(err));

		tf_stack: uintptr(stk) - goarch.PtrSize,
	}

	var oset sigset
	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
	ret := retryOnEAGAIN(func() int32 {
		errno := tfork(&param, unsafe.Sizeof(param), mp, mp.g0, abi.FuncPCABI0(mstart))
		// tfork returns negative errno
		return -errno
	})
	sigprocmask(_SIG_SETMASK, &oset, nil)

	if ret != 0 {
		print("runtime: failed to create new OS thread (have ", mcount()-1, " already; errno=", ret, ")\n")

	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {
		fatalf("pthread_create failed: %s", strerror(err));

	// UnsafePointRestart1(2) apply on a sequence of instructions, within
	// which if an async preemption happens, we should back off the PC
	// to the start of the sequence when resuming.
	// We need two so we can distinguish the start/end of the sequence
	// in case that two sequences are next to each other.
	UnsafePointRestart1 = -3
	UnsafePointRestart2 = -4

	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	size = pthread_get_stacksize_np(pthread_self());
	pthread_attr_init(&attr);
	pthread_attr_setstacksize(&attr, size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {

// signal stack here before calling the regular mstart. It's a bit
// baroque to remove a signal stack here only to add one in minit, but
// it's a simple change that keeps NetBSD working like other OS's.
// At this point all signals are blocked, so there is no race.
//
//go:nosplit
func netbsdMstart0() {
	st := stackt{ss_flags: _SS_DISABLE}
	sigaltstack(&st, nil)
	mstart0()
}

func osinit() {
	ncpu = getncpu()

	// be systemstack_switch if the G stack is scanned.
	MOVD $runtime·systemstack_switch(SB), g_sched+gobuf_pc(g)

	MOVD SP, g_sched+gobuf_sp(g)

	// switch to g0
	MOVD R2, g

	// make it look like mstart called systemstack on g0, to stop traceback
	I64Load (g_sched+gobuf_sp)(R2)
	I64Const $8
	I64Sub
	Set R3

	MOVD $runtime·mstart(SB), 0(R3)
	MOVD R3, SP

	// call fn
	MOVD R0, CTXT