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) {

	var wg sync.WaitGroup
	wg.Add(2)

	for i := 0; i < 2; i++ {
		go func() {
			for time.Now().Before(start) {
			}

			// Add work to the local runq to trigger early startm
			// in handoffp.
			go func() {}()

			runtime.LockOSThread()
			runtime.Gosched() // add a preemption point.
			wg.Done()
		}()
	}

	wg.Wait()

	// 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

#include "textflag.h"

#define CLOCK_REALTIME	$0
#define	CLOCK_MONOTONIC	$3

// mstart_stub is the first function executed on a new thread started by pthread_create.
// It just does some low-level setup and then calls mstart.
// Note: called with the C calling convention.
TEXT runtime·mstart_stub(SB),NOSPLIT,$32
	// R3 points to the m.
	// We are already on m's g0 stack.

	// Go relies on R0 being $0.
	XOR	R0, R0

#include "cgo/abi_arm64.h"

#define CLOCK_REALTIME	$0
#define	CLOCK_MONOTONIC	$3

// mstart_stub is the first function executed on a new thread started by pthread_create.
// It just does some low-level setup and then calls mstart.
// Note: called with the C calling convention.
TEXT runtime·mstart_stub(SB),NOSPLIT,$144
	// R0 points to the m.
	// We are already on m's g0 stack.

	// Save callee-save registers.
	SAVE_R19_TO_R28(8)

#include "textflag.h"

#define CLOCK_REALTIME	$0
#define	CLOCK_MONOTONIC	$3

// mstart_stub is the first function executed on a new thread started by pthread_create.
// It just does some low-level setup and then calls mstart.
// Note: called with the C calling convention.
TEXT runtime·mstart_stub(SB),NOSPLIT,$200
	// X10 points to the m.
	// We are already on m's g0 stack.

	// Save callee-save registers (X8, X9, X18..X27, F8, F9, F18..F27)

		// including C code called via cgo, calls a
		// TSAN-intercepted function such as malloc.
		//
		// We check this condition last as g0.stack.lo
		// may be not very accurate (see mstart).
		st := stackt{ss_size: mp.g0.stack.hi - mp.g0.stack.lo}
		setSignalstackSP(&st, mp.g0.stack.lo)
		setGsignalStack(&st, gsigStack)
		return true
	}

	// Nothing to do, pthread already set thread-local storage up.
	RET

// mstart_stub is the first function executed on a new thread started by pthread_create.
// It just does some low-level setup and then calls mstart.
// Note: called with the C calling convention.
TEXT runtime·mstart_stub(SB),NOSPLIT,$0
	// DI points to the m.
	// We are already on m's g0 stack.

	// Transition from C ABI to Go ABI.
	PUSH_REGS_HOST_TO_ABI0()

	BL	notok<>(SB)
#endif
	RET

// Thread related functions

// mstart_stub is the first function executed on a new thread started by pthread_create.
// It just does some low-level setup and then calls mstart.
// Note: called with the C calling convention.
TEXT runtime·mstart_stub(SB),NOSPLIT,$160
	// R0 points to the m.
	// We are already on m's g0 stack.

	// Save callee-save registers.
	SAVE_R19_TO_R28(8)

	MOVL	$-1, AX
noerr:
	MOVL	AX, 12(BX)
	MOVL	DX, 16(BX)
	RET

// mstart_stub is the first function executed on a new thread started by pthread_create.
// It just does some low-level setup and then calls mstart.
// Note: called with the C calling convention.
TEXT runtime·mstart_stub(SB),NOSPLIT|NOFRAME,$0
	// DI points to the m.
	// We are already on m's g0 stack.

	// Transition from C ABI to Go ABI.