RET

	// In child, on new stack.
	// initialize essential registers
	BL	runtime·reginit(SB)
	MOVD	-32(R1), R7
	CMP	R7, $1234
	BEQ	2(PC)
	MOVD	R0, 0(R0)

	// Initialize m->procid to Linux tid
	SYSCALL $SYS_gettid

	MOVD	-24(R1), R12       // fn
	MOVD	-16(R1), R8        // g
	MOVD	-8(R1), R7         // m

	CMP	R7, $0
	BEQ	nog
	CMP	R8, $0
	BEQ	nog

	INVOKE_SYSCALL

	MOVL	0(SP), BX	    // m
	MOVL	4(SP), DX	    // g
	MOVL	8(SP), SI	    // fn

	CMPL	BX, $0
	JEQ	nog
	CMPL	DX, $0
	JEQ	nog

	MOVL	AX, m_procid(BX)	// save tid as m->procid

	// set up ldt 7+id to point at m->tls.
	LEAL	m_tls(BX), BP
	MOVL	m_id(BX), DI
	ADDL	$7, DI	// m0 is LDT#7. count up.
	// setldt(tls#, &tls, sizeof tls)
	PUSHAL	// save registers
	PUSHL	$32	// sizeof tls

	RET
child:

	// In child, on new stack.
	MOVD	-32(RSP), R10
	MOVD	$1234, R0
	CMP	R0, R10
	BEQ	good
	MOVD	$0, R0
	MOVD	R0, (R0)	// crash

good:
	// Initialize m->procid to Linux tid
	MOVD	$SYS_gettid, R8
	SVC

	MOVD	-24(RSP), R12     // fn
	MOVD	-16(RSP), R11     // g
	MOVD	-8(RSP), R10      // m

	CMP	$0, R10
	BEQ	nog
	CMP	$0, R11
	BEQ	nog

//
// Must be called with a valid P.
func (tl traceLocker) GoSysCall() {
	// Scribble down the M that the P is currently attached to.
	pp := tl.mp.p.ptr()
	pp.trace.mSyscallID = int64(tl.mp.procid)
	tl.eventWriter(traceGoRunning, traceProcRunning).commit(traceEvGoSyscallBegin, pp.trace.nextSeq(tl.gen), tl.stack(1))
}

// GoSysExit emits a GoSyscallEnd event, possibly along with a GoSyscallBlocked event

			// that's running for the first time in this generation. Therefore,
			// this should be relatively fast.
			s := suspendG(gp)
			if !s.dead {
				ug.goid = s.g.goid
				if s.g.m != nil {
					ug.mid = int64(s.g.m.procid)
				}
				ug.status = readgstatus(s.g) &^ _Gscan
				ug.waitreason = s.g.waitreason
				ug.inMarkAssist = s.g.inMarkAssist
				ug.stackID = traceStack(0, gp, gen)
			}
			resumeG(s)

	morebuf gobuf  // gobuf arg to morestack
	divmod  uint32 // div/mod denominator for arm - known to liblink
	_       uint32 // align next field to 8 bytes

	// Fields not known to debuggers.
	procid        uint64            // for debuggers, but offset not hard-coded
	gsignal       *g                // signal-handling g
	goSigStack    gsignalStack      // Go-allocated signal handling stack

	// destroyed respectively. The m then might get reused with a different procid but
	// still with a reference to oldp, and still with the same syscalltick. The next
	// time a G is "created" in needm, it'll return and quietly reacquire its P from a
	// different m with a different procid, which will confuse the trace parser. By
	// trashing syscalltick, we ensure that it'll appear as if we lost the P to the