| // 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 *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 |
