// that is always passing a new M from needm.

		// Stack is bogus, but reset the bounds anyway so we can print.
		hi := g0.stack.hi
		lo := g0.stack.lo
		g0.stack.hi = sp + 1024
		g0.stack.lo = sp - 32*1024
		g0.stackguard0 = g0.stack.lo + stackGuard
		g0.stackguard1 = g0.stackguard0

		print("M ", mp.id, " procid ", mp.procid, " runtime: cgocallback with sp=", hex(sp), " out of bounds [", hex(lo), ", ", hex(hi), "]")

	gp := getg()
	if gp != gp.m.g0 {
		throw("notetsleep not on g0")
	}
	semacreate(gp.m)
	return notetsleep_internal(n, ns, nil, 0)
}

// same as runtime·notetsleep, but called on user g (not g0)
// calls only nosplit functions between entersyscallblock/exitsyscall.
func notetsleepg(n *note, ns int64) bool {
	gp := getg()
	if gp == gp.m.g0 {
		throw("notetsleepg on g0")
	}
	semacreate(gp.m)

	}
	if go1Dot5Fields {
		g0.Disposal = make([]byte, len(g0.Image))
		for i := range g0.Disposal {
			g0.Disposal[i] = DisposalNone
		}
		g0.Config = image.Config{
			ColorModel: globalColorModel,
			Width:      width,
			Height:     height,
		}
		g0.BackgroundIndex = backgroundIndex
	}

	var buf bytes.Buffer
	if err := EncodeAll(&buf, g0); err != nil {
		t.Fatal("EncodeAll:", err)
	}

	gp := getg()
	if gp != gp.m.g0 && gp.m.preemptoff != "" {
		throw("notetsleep not on g0")
	}

	return notetsleep_internal(n, ns)
}

// same as runtime·notetsleep, but called on user g (not g0)
// calls only nosplit functions between entersyscallblock/exitsyscall.
func notetsleepg(n *note, ns int64) bool {
	gp := getg()
	if gp == gp.m.g0 {
		throw("notetsleepg on g0")
	}

	entersyscallblock()

	LEAL	fn+0(FP), BX	// caller's SP
	MOVL	BX, (g_sched+gobuf_sp)(AX)

	// switch to m->g0 & its stack, call fn
	MOVL	g(DX), BX
	MOVL	g_m(BX), BX
	MOVL	m_g0(BX), SI
	CMPL	SI, AX	// if g == m->g0 call badmcall
	JNE	3(PC)
	MOVL	$runtime·badmcall(SB), AX
	JMP	AX
	MOVL	SI, g(DX)	// g = m->g0
	MOVL	(g_sched+gobuf_sp)(SI), SP	// sp = m->g0->sched.sp
	PUSHL	AX
	MOVL	DI, DX
	MOVL	0(DI), DI
	CALL	DI
	POPL	AX

	MOVW	g, R2

	// Figure out if we need to switch to m->g0 stack.
	// We get called to create new OS threads too, and those
	// come in on the m->g0 stack already. Or we might already
	// be on the m->gsignal stack.
	MOVW	g_m(g), R5
	MOVW	m_gsignal(R5), R6
	BEQ	R6, g, g0
	MOVW	m_g0(R5), R6
	BEQ	R6, g, g0

	JAL	gosave_systemstack_switch<>(SB)
	MOVW	R6, g
	JAL	runtime·save_g(SB)

//
// Ensure mayMoreStackPreempt can be called for all ABIs.
//
//go:nosplit
//go:linkname mayMoreStackPreempt
func mayMoreStackPreempt() {
	// Don't do anything on the g0 or gsignal stack.
	gp := getg()
	if gp == gp.m.g0 || gp == gp.m.gsignal {
		return
	}
	// Force a preemption, unless the stack is already poisoned.
	if gp.stackguard0 < stackPoisonMin {
		gp.stackguard0 = stackPreempt
	}
}

	MOVV	R3, R12	// save original stack pointer
	MOVV	g, R13

	// Figure out if we need to switch to m->g0 stack.
	// We get called to create new OS threads too, and those
	// come in on the m->g0 stack already.
	MOVV	g_m(g), R5
	MOVV	m_gsignal(R5), R6
	BEQ	R6, g, g0
	MOVV	m_g0(R5), R6
	BEQ	R6, g, g0

	JAL	gosave_systemstack_switch<>(SB)
	MOVV	R6, g
	JAL	runtime·save_g(SB)
	MOVV	(g_sched+gobuf_sp)(g), R3

	JMP	racecall<>(SB)

// Switches SP to g0 stack and calls R1. Arguments are already set.
TEXT	racecall<>(SB), NOSPLIT, $0-0
	BL	runtime·save_g(SB)		// Save g for callbacks.
	MOVD	R15, R7				// Save SP.
	MOVD	g_m(g), R8			// R8 = thread.
	MOVD	m_g0(R8), R8			// R8 = g0.
	CMPBEQ	R8, g, call			// Already on g0?
	MOVD	(g_sched+gobuf_sp)(R8), R15	// Switch SP to g0.
call:	SUB	$160, R15			// Allocate C frame.

	MOVQ	arg3+32(FP), RARG3
	JMP	racecall<>(SB)

// Switches SP to g0 stack and calls (AX). Arguments already set.
TEXT	racecall<>(SB), NOSPLIT|NOFRAME, $0-0
	MOVQ	g_m(R14), R13
	// Switch to g0 stack.
	MOVQ	SP, R12		// callee-saved, preserved across the CALL
	MOVQ	m_g0(R13), R10
	CMPQ	R10, R14
	JE	call	// already on g0
	MOVQ	(g_sched+gobuf_sp)(R10), SP
call:
	ANDQ	$~15, SP	// alignment for gcc ABI