1 files changed, 649 insertions, 0 deletions
diff --git a/src/runtime/sys_linux_mips64x.s b/src/runtime/sys_linux_mips64x.s
new file mode 100644
index 0000000..e38f444
--- /dev/null
+++ b/src/runtime/sys_linux_mips64x.s
@@ -0,0 +1,649 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build linux && (mips64 || mips64le)
+
+//
+// System calls and other sys.stuff for mips64, Linux
+//
+
+#include "go_asm.h"
+#include "go_tls.h"
+#include "textflag.h"
+
+#define AT_FDCWD -100
+
+#define SYS_exit		5058
+#define SYS_read		5000
+#define SYS_write		5001
+#define SYS_close		5003
+#define SYS_getpid		5038
+#define SYS_kill		5060
+#define SYS_fcntl		5070
+#define SYS_mmap		5009
+#define SYS_munmap		5011
+#define SYS_setitimer		5036
+#define SYS_clone		5055
+#define SYS_nanosleep		5034
+#define SYS_sched_yield		5023
+#define SYS_rt_sigreturn	5211
+#define SYS_rt_sigaction	5013
+#define SYS_rt_sigprocmask	5014
+#define SYS_sigaltstack		5129
+#define SYS_madvise		5027
+#define SYS_mincore		5026
+#define SYS_gettid		5178
+#define SYS_futex		5194
+#define SYS_sched_getaffinity	5196
+#define SYS_exit_group		5205
+#define SYS_epoll_create	5207
+#define SYS_epoll_ctl		5208
+#define SYS_timer_create	5216
+#define SYS_timer_settime	5217
+#define SYS_timer_delete	5220
+#define SYS_tgkill		5225
+#define SYS_openat		5247
+#define SYS_epoll_pwait		5272
+#define SYS_clock_gettime	5222
+#define SYS_epoll_create1	5285
+#define SYS_brk			5012
+#define SYS_pipe2		5287
+
+TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	code+0(FP), R4
+	MOVV	$SYS_exit_group, R2
+	SYSCALL
+	RET
+
+// func exitThread(wait *atomic.Uint32)
+TEXT runtime·exitThread(SB),NOSPLIT|NOFRAME,$0-8
+	MOVV	wait+0(FP), R1
+	// We're done using the stack.
+	MOVW	$0, R2
+	SYNC
+	MOVW	R2, (R1)
+	SYNC
+	MOVW	$0, R4	// exit code
+	MOVV	$SYS_exit, R2
+	SYSCALL
+	JMP	0(PC)
+
+TEXT runtime·open(SB),NOSPLIT|NOFRAME,$0-20
+	// This uses openat instead of open, because Android O blocks open.
+	MOVW	$AT_FDCWD, R4 // AT_FDCWD, so this acts like open
+	MOVV	name+0(FP), R5
+	MOVW	mode+8(FP), R6
+	MOVW	perm+12(FP), R7
+	MOVV	$SYS_openat, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	MOVW	$-1, R2
+	MOVW	R2, ret+16(FP)
+	RET
+
+TEXT runtime·closefd(SB),NOSPLIT|NOFRAME,$0-12
+	MOVW	fd+0(FP), R4
+	MOVV	$SYS_close, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	MOVW	$-1, R2
+	MOVW	R2, ret+8(FP)
+	RET
+
+TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0-28
+	MOVV	fd+0(FP), R4
+	MOVV	p+8(FP), R5
+	MOVW	n+16(FP), R6
+	MOVV	$SYS_write, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+24(FP)
+	RET
+
+TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
+	MOVW	fd+0(FP), R4
+	MOVV	p+8(FP), R5
+	MOVW	n+16(FP), R6
+	MOVV	$SYS_read, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+24(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
+	MOVV	$r+8(FP), R4
+	MOVW	flags+0(FP), R5
+	MOVV	$SYS_pipe2, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, errno+16(FP)
+	RET
+
+TEXT runtime·usleep(SB),NOSPLIT,$16-4
+	MOVWU	usec+0(FP), R3
+	MOVV	R3, R5
+	MOVW	$1000000, R4
+	DIVVU	R4, R3
+	MOVV	LO, R3
+	MOVV	R3, 8(R29)
+	MOVW	$1000, R4
+	MULVU	R3, R4
+	MOVV	LO, R4
+	SUBVU	R4, R5
+	MOVV	R5, 16(R29)
+
+	// nanosleep(&ts, 0)
+	ADDV	$8, R29, R4
+	MOVW	$0, R5
+	MOVV	$SYS_nanosleep, R2
+	SYSCALL
+	RET
+
+TEXT runtime·gettid(SB),NOSPLIT,$0-4
+	MOVV	$SYS_gettid, R2
+	SYSCALL
+	MOVW	R2, ret+0(FP)
+	RET
+
+TEXT runtime·raise(SB),NOSPLIT|NOFRAME,$0
+	MOVV	$SYS_getpid, R2
+	SYSCALL
+	MOVW	R2, R16
+	MOVV	$SYS_gettid, R2
+	SYSCALL
+	MOVW	R2, R5	// arg 2 tid
+	MOVW	R16, R4	// arg 1 pid
+	MOVW	sig+0(FP), R6	// arg 3
+	MOVV	$SYS_tgkill, R2
+	SYSCALL
+	RET
+
+TEXT runtime·raiseproc(SB),NOSPLIT|NOFRAME,$0
+	MOVV	$SYS_getpid, R2
+	SYSCALL
+	MOVW	R2, R4	// arg 1 pid
+	MOVW	sig+0(FP), R5	// arg 2
+	MOVV	$SYS_kill, R2
+	SYSCALL
+	RET
+
+TEXT ·getpid(SB),NOSPLIT|NOFRAME,$0-8
+	MOVV	$SYS_getpid, R2
+	SYSCALL
+	MOVV	R2, ret+0(FP)
+	RET
+
+TEXT ·tgkill(SB),NOSPLIT|NOFRAME,$0-24
+	MOVV	tgid+0(FP), R4
+	MOVV	tid+8(FP), R5
+	MOVV	sig+16(FP), R6
+	MOVV	$SYS_tgkill, R2
+	SYSCALL
+	RET
+
+TEXT runtime·setitimer(SB),NOSPLIT|NOFRAME,$0-24
+	MOVW	mode+0(FP), R4
+	MOVV	new+8(FP), R5
+	MOVV	old+16(FP), R6
+	MOVV	$SYS_setitimer, R2
+	SYSCALL
+	RET
+
+TEXT runtime·timer_create(SB),NOSPLIT,$0-28
+	MOVW	clockid+0(FP), R4
+	MOVV	sevp+8(FP), R5
+	MOVV	timerid+16(FP), R6
+	MOVV	$SYS_timer_create, R2
+	SYSCALL
+	MOVW	R2, ret+24(FP)
+	RET
+
+TEXT runtime·timer_settime(SB),NOSPLIT,$0-28
+	MOVW	timerid+0(FP), R4
+	MOVW	flags+4(FP), R5
+	MOVV	new+8(FP), R6
+	MOVV	old+16(FP), R7
+	MOVV	$SYS_timer_settime, R2
+	SYSCALL
+	MOVW	R2, ret+24(FP)
+	RET
+
+TEXT runtime·timer_delete(SB),NOSPLIT,$0-12
+	MOVW	timerid+0(FP), R4
+	MOVV	$SYS_timer_delete, R2
+	SYSCALL
+	MOVW	R2, ret+8(FP)
+	RET
+
+TEXT runtime·mincore(SB),NOSPLIT|NOFRAME,$0-28
+	MOVV	addr+0(FP), R4
+	MOVV	n+8(FP), R5
+	MOVV	dst+16(FP), R6
+	MOVV	$SYS_mincore, R2
+	SYSCALL
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+24(FP)
+	RET
+
+// func walltime() (sec int64, nsec int32)
+TEXT runtime·walltime(SB),NOSPLIT,$16-12
+	MOVV	R29, R16	// R16 is unchanged by C code
+	MOVV	R29, R1
+
+	MOVV	g_m(g), R17	// R17 = m
+
+	// Set vdsoPC and vdsoSP for SIGPROF traceback.
+	// Save the old values on stack and restore them on exit,
+	// so this function is reentrant.
+	MOVV	m_vdsoPC(R17), R2
+	MOVV	m_vdsoSP(R17), R3
+	MOVV	R2, 8(R29)
+	MOVV	R3, 16(R29)
+
+	MOVV	$ret-8(FP), R2 // caller's SP
+	MOVV	R31, m_vdsoPC(R17)
+	MOVV	R2, m_vdsoSP(R17)
+
+	MOVV	m_curg(R17), R4
+	MOVV	g, R5
+	BNE	R4, R5, noswitch
+
+	MOVV	m_g0(R17), R4
+	MOVV	(g_sched+gobuf_sp)(R4), R1	// Set SP to g0 stack
+
+noswitch:
+	SUBV	$16, R1
+	AND	$~15, R1	// Align for C code
+	MOVV	R1, R29
+
+	MOVW	$0, R4 // CLOCK_REALTIME
+	MOVV	$0(R29), R5
+
+	MOVV	runtime·vdsoClockgettimeSym(SB), R25
+	BEQ	R25, fallback
+
+	JAL	(R25)
+	// check on vdso call return for kernel compatibility
+	// see https://golang.org/issues/39046
+	// if we get any error make fallback permanent.
+	BEQ	R2, R0, finish
+	MOVV	R0, runtime·vdsoClockgettimeSym(SB)
+	MOVW	$0, R4 // CLOCK_REALTIME
+	MOVV	$0(R29), R5
+	JMP	fallback
+
+finish:
+	MOVV	0(R29), R3	// sec
+	MOVV	8(R29), R5	// nsec
+
+	MOVV	R16, R29	// restore SP
+	// Restore vdsoPC, vdsoSP
+	// We don't worry about being signaled between the two stores.
+	// If we are not in a signal handler, we'll restore vdsoSP to 0,
+	// and no one will care about vdsoPC. If we are in a signal handler,
+	// we cannot receive another signal.
+	MOVV	16(R29), R1
+	MOVV	R1, m_vdsoSP(R17)
+	MOVV	8(R29), R1
+	MOVV	R1, m_vdsoPC(R17)
+
+	MOVV	R3, sec+0(FP)
+	MOVW	R5, nsec+8(FP)
+	RET
+
+fallback:
+	MOVV	$SYS_clock_gettime, R2
+	SYSCALL
+	JMP finish
+
+TEXT runtime·nanotime1(SB),NOSPLIT,$16-8
+	MOVV	R29, R16	// R16 is unchanged by C code
+	MOVV	R29, R1
+
+	MOVV	g_m(g), R17	// R17 = m
+
+	// Set vdsoPC and vdsoSP for SIGPROF traceback.
+	// Save the old values on stack and restore them on exit,
+	// so this function is reentrant.
+	MOVV	m_vdsoPC(R17), R2
+	MOVV	m_vdsoSP(R17), R3
+	MOVV	R2, 8(R29)
+	MOVV	R3, 16(R29)
+
+	MOVV	$ret-8(FP), R2 // caller's SP
+	MOVV	R31, m_vdsoPC(R17)
+	MOVV	R2, m_vdsoSP(R17)
+
+	MOVV	m_curg(R17), R4
+	MOVV	g, R5
+	BNE	R4, R5, noswitch
+
+	MOVV	m_g0(R17), R4
+	MOVV	(g_sched+gobuf_sp)(R4), R1	// Set SP to g0 stack
+
+noswitch:
+	SUBV	$16, R1
+	AND	$~15, R1	// Align for C code
+	MOVV	R1, R29
+
+	MOVW	$1, R4 // CLOCK_MONOTONIC
+	MOVV	$0(R29), R5
+
+	MOVV	runtime·vdsoClockgettimeSym(SB), R25
+	BEQ	R25, fallback
+
+	JAL	(R25)
+	// see walltime for detail
+	BEQ	R2, R0, finish
+	MOVV	R0, runtime·vdsoClockgettimeSym(SB)
+	MOVW	$1, R4 // CLOCK_MONOTONIC
+	MOVV	$0(R29), R5
+	JMP	fallback
+
+finish:
+	MOVV	0(R29), R3	// sec
+	MOVV	8(R29), R5	// nsec
+
+	MOVV	R16, R29	// restore SP
+	// Restore vdsoPC, vdsoSP
+	// We don't worry about being signaled between the two stores.
+	// If we are not in a signal handler, we'll restore vdsoSP to 0,
+	// and no one will care about vdsoPC. If we are in a signal handler,
+	// we cannot receive another signal.
+	MOVV	16(R29), R1
+	MOVV	R1, m_vdsoSP(R17)
+	MOVV	8(R29), R1
+	MOVV	R1, m_vdsoPC(R17)
+
+	// sec is in R3, nsec in R5
+	// return nsec in R3
+	MOVV	$1000000000, R4
+	MULVU	R4, R3
+	MOVV	LO, R3
+	ADDVU	R5, R3
+	MOVV	R3, ret+0(FP)
+	RET
+
+fallback:
+	MOVV	$SYS_clock_gettime, R2
+	SYSCALL
+	JMP	finish
+
+TEXT runtime·rtsigprocmask(SB),NOSPLIT|NOFRAME,$0-28
+	MOVW	how+0(FP), R4
+	MOVV	new+8(FP), R5
+	MOVV	old+16(FP), R6
+	MOVW	size+24(FP), R7
+	MOVV	$SYS_rt_sigprocmask, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	MOVV	R0, 0xf1(R0)	// crash
+	RET
+
+TEXT runtime·rt_sigaction(SB),NOSPLIT|NOFRAME,$0-36
+	MOVV	sig+0(FP), R4
+	MOVV	new+8(FP), R5
+	MOVV	old+16(FP), R6
+	MOVV	size+24(FP), R7
+	MOVV	$SYS_rt_sigaction, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+32(FP)
+	RET
+
+TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
+	MOVW	sig+8(FP), R4
+	MOVV	info+16(FP), R5
+	MOVV	ctx+24(FP), R6
+	MOVV	fn+0(FP), R25
+	JAL	(R25)
+	RET
+
+TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$64
+	// initialize REGSB = PC&0xffffffff00000000
+	BGEZAL	R0, 1(PC)
+	SRLV	$32, R31, RSB
+	SLLV	$32, RSB
+
+	// this might be called in external code context,
+	// where g is not set.
+	MOVB	runtime·iscgo(SB), R1
+	BEQ	R1, 2(PC)
+	JAL	runtime·load_g(SB)
+
+	MOVW	R4, 8(R29)
+	MOVV	R5, 16(R29)
+	MOVV	R6, 24(R29)
+	MOVV	$runtime·sigtrampgo(SB), R1
+	JAL	(R1)
+	RET
+
+TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0
+	JMP	runtime·sigtramp(SB)
+
+TEXT runtime·mmap(SB),NOSPLIT|NOFRAME,$0
+	MOVV	addr+0(FP), R4
+	MOVV	n+8(FP), R5
+	MOVW	prot+16(FP), R6
+	MOVW	flags+20(FP), R7
+	MOVW	fd+24(FP), R8
+	MOVW	off+28(FP), R9
+
+	MOVV	$SYS_mmap, R2
+	SYSCALL
+	BEQ	R7, ok
+	MOVV	$0, p+32(FP)
+	MOVV	R2, err+40(FP)
+	RET
+ok:
+	MOVV	R2, p+32(FP)
+	MOVV	$0, err+40(FP)
+	RET
+
+TEXT runtime·munmap(SB),NOSPLIT|NOFRAME,$0
+	MOVV	addr+0(FP), R4
+	MOVV	n+8(FP), R5
+	MOVV	$SYS_munmap, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	MOVV	R0, 0xf3(R0)	// crash
+	RET
+
+TEXT runtime·madvise(SB),NOSPLIT|NOFRAME,$0
+	MOVV	addr+0(FP), R4
+	MOVV	n+8(FP), R5
+	MOVW	flags+16(FP), R6
+	MOVV	$SYS_madvise, R2
+	SYSCALL
+	MOVW	R2, ret+24(FP)
+	RET
+
+// int64 futex(int32 *uaddr, int32 op, int32 val,
+//	struct timespec *timeout, int32 *uaddr2, int32 val2);
+TEXT runtime·futex(SB),NOSPLIT|NOFRAME,$0
+	MOVV	addr+0(FP), R4
+	MOVW	op+8(FP), R5
+	MOVW	val+12(FP), R6
+	MOVV	ts+16(FP), R7
+	MOVV	addr2+24(FP), R8
+	MOVW	val3+32(FP), R9
+	MOVV	$SYS_futex, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+40(FP)
+	RET
+
+// int64 clone(int32 flags, void *stk, M *mp, G *gp, void (*fn)(void));
+TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0
+	MOVW	flags+0(FP), R4
+	MOVV	stk+8(FP), R5
+
+	// Copy mp, gp, fn off parent stack for use by child.
+	// Careful: Linux system call clobbers ???.
+	MOVV	mp+16(FP), R16
+	MOVV	gp+24(FP), R17
+	MOVV	fn+32(FP), R18
+
+	MOVV	R16, -8(R5)
+	MOVV	R17, -16(R5)
+	MOVV	R18, -24(R5)
+	MOVV	$1234, R16
+	MOVV	R16, -32(R5)
+
+	MOVV	$SYS_clone, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+
+	// In parent, return.
+	BEQ	R2, 3(PC)
+	MOVW	R2, ret+40(FP)
+	RET
+
+	// In child, on new stack.
+	MOVV	-32(R29), R16
+	MOVV	$1234, R1
+	BEQ	R16, R1, 2(PC)
+	MOVV	R0, 0(R0)
+
+	// Initialize m->procid to Linux tid
+	MOVV	$SYS_gettid, R2
+	SYSCALL
+
+	MOVV	-24(R29), R18		// fn
+	MOVV	-16(R29), R17		// g
+	MOVV	-8(R29), R16		// m
+
+	BEQ	R16, nog
+	BEQ	R17, nog
+
+	MOVV	R2, m_procid(R16)
+
+	// TODO: setup TLS.
+
+	// In child, set up new stack
+	MOVV	R16, g_m(R17)
+	MOVV	R17, g
+	//CALL	runtime·stackcheck(SB)
+
+nog:
+	// Call fn
+	JAL	(R18)
+
+	// It shouldn't return.	 If it does, exit that thread.
+	MOVW	$111, R4
+	MOVV	$SYS_exit, R2
+	SYSCALL
+	JMP	-3(PC)	// keep exiting
+
+TEXT runtime·sigaltstack(SB),NOSPLIT|NOFRAME,$0
+	MOVV	new+0(FP), R4
+	MOVV	old+8(FP), R5
+	MOVV	$SYS_sigaltstack, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	MOVV	R0, 0xf1(R0)	// crash
+	RET
+
+TEXT runtime·osyield(SB),NOSPLIT|NOFRAME,$0
+	MOVV	$SYS_sched_yield, R2
+	SYSCALL
+	RET
+
+TEXT runtime·sched_getaffinity(SB),NOSPLIT|NOFRAME,$0
+	MOVV	pid+0(FP), R4
+	MOVV	len+8(FP), R5
+	MOVV	buf+16(FP), R6
+	MOVV	$SYS_sched_getaffinity, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+24(FP)
+	RET
+
+// int32 runtime·epollcreate(int32 size);
+TEXT runtime·epollcreate(SB),NOSPLIT|NOFRAME,$0
+	MOVW    size+0(FP), R4
+	MOVV	$SYS_epoll_create, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+8(FP)
+	RET
+
+// int32 runtime·epollcreate1(int32 flags);
+TEXT runtime·epollcreate1(SB),NOSPLIT|NOFRAME,$0
+	MOVW	flags+0(FP), R4
+	MOVV	$SYS_epoll_create1, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+8(FP)
+	RET
+
+// func epollctl(epfd, op, fd int32, ev *epollEvent) int
+TEXT runtime·epollctl(SB),NOSPLIT|NOFRAME,$0
+	MOVW	epfd+0(FP), R4
+	MOVW	op+4(FP), R5
+	MOVW	fd+8(FP), R6
+	MOVV	ev+16(FP), R7
+	MOVV	$SYS_epoll_ctl, R2
+	SYSCALL
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+24(FP)
+	RET
+
+// int32 runtime·epollwait(int32 epfd, EpollEvent *ev, int32 nev, int32 timeout);
+TEXT runtime·epollwait(SB),NOSPLIT|NOFRAME,$0
+	// This uses pwait instead of wait, because Android O blocks wait.
+	MOVW	epfd+0(FP), R4
+	MOVV	ev+8(FP), R5
+	MOVW	nev+16(FP), R6
+	MOVW	timeout+20(FP), R7
+	MOVV	$0, R8
+	MOVV	$SYS_epoll_pwait, R2
+	SYSCALL
+	BEQ	R7, 2(PC)
+	SUBVU	R2, R0, R2	// caller expects negative errno
+	MOVW	R2, ret+24(FP)
+	RET
+
+// void runtime·closeonexec(int32 fd);
+TEXT runtime·closeonexec(SB),NOSPLIT|NOFRAME,$0
+	MOVW    fd+0(FP), R4  // fd
+	MOVV    $2, R5  // F_SETFD
+	MOVV    $1, R6  // FD_CLOEXEC
+	MOVV	$SYS_fcntl, R2
+	SYSCALL
+	RET
+
+// func sbrk0() uintptr
+TEXT runtime·sbrk0(SB),NOSPLIT|NOFRAME,$0-8
+	// Implemented as brk(NULL).
+	MOVV	$0, R4
+	MOVV	$SYS_brk, R2
+	SYSCALL
+	MOVV	R2, ret+0(FP)
+	RET
+
+TEXT runtime·access(SB),$0-20
+	MOVV	R0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP) // for vet
+	RET
+
+TEXT runtime·connect(SB),$0-28
+	MOVV	R0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+24(FP) // for vet
+	RET
+
+TEXT runtime·socket(SB),$0-20
+	MOVV	R0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP) // for vet
+	RET