root/src/pkg/runtime/sys_freebsd_arm.s

// Copyright 2012 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.
//
// System calls and other sys.stuff for ARM, FreeBSD
// /usr/src/sys/kern/syscalls.master for syscall numbers.
//

#include "zasm_GOOS_GOARCH.h"
#include "../../cmd/ld/textflag.h"

// for EABI, as we don't support OABI
#define SYS_BASE 0x0

#define SYS_exit (SYS_BASE + 1)
#define SYS_read (SYS_BASE + 3)
#define SYS_write (SYS_BASE + 4)
#define SYS_open (SYS_BASE + 5)
#define SYS_close (SYS_BASE + 6)
#define SYS_sigaltstack (SYS_BASE + 53)
#define SYS_munmap (SYS_BASE + 73)
#define SYS_madvise (SYS_BASE + 75)
#define SYS_setitimer (SYS_BASE + 83)
#define SYS_fcntl (SYS_BASE + 92)
#define SYS_getrlimit (SYS_BASE + 194)
#define SYS___sysctl (SYS_BASE + 202)
#define SYS_nanosleep (SYS_BASE + 240)
#define SYS_clock_gettime (SYS_BASE + 232)
#define SYS_sched_yield (SYS_BASE + 331)
#define SYS_sigprocmask (SYS_BASE + 340)
#define SYS_kqueue (SYS_BASE + 362)
#define SYS_kevent (SYS_BASE + 363)
#define SYS_sigaction (SYS_BASE + 416)
#define SYS_thr_exit (SYS_BASE + 431)
#define SYS_thr_self (SYS_BASE + 432)
#define SYS_thr_kill (SYS_BASE + 433)
#define SYS__umtx_op (SYS_BASE + 454)
#define SYS_thr_new (SYS_BASE + 455)
#define SYS_mmap (SYS_BASE + 477) 
        
TEXT runtime·sys_umtx_op(SB),NOSPLIT,$0
        MOVW 0(FP), R0
        MOVW 4(FP), R1
        MOVW 8(FP), R2
        MOVW 12(FP), R3
        ADD $20, R13 // arg 5 is passed on stack
        MOVW $SYS__umtx_op, R7
        SWI $0
        SUB $20, R13
        // BCS error
        RET

TEXT runtime·thr_new(SB),NOSPLIT,$0
        MOVW 0(FP), R0
        MOVW 4(FP), R1
        MOVW $SYS_thr_new, R7
        SWI $0
        RET

TEXT runtime·thr_start(SB),NOSPLIT,$0
        MOVW R0, m

        // set up g
        MOVW m_g0(m), g
        BL runtime·emptyfunc(SB) // fault if stack check is wrong
        BL runtime·mstart(SB)

        MOVW $2, R8  // crash (not reached)
        MOVW R8, (R8)
        RET

// Exit the entire program (like C exit)
TEXT runtime·exit(SB),NOSPLIT,$-8
        MOVW 0(FP), R0  // arg 1 exit status
        MOVW $SYS_exit, R7
        SWI $0
        MOVW.CS $0, R8 // crash on syscall failure
        MOVW.CS R8, (R8)
        RET

TEXT runtime·exit1(SB),NOSPLIT,$-8
        MOVW 0(FP), R0  // arg 1 exit status
        MOVW $SYS_thr_exit, R7  
        SWI $0
        MOVW.CS $0, R8 // crash on syscall failure
        MOVW.CS R8, (R8)
        RET

TEXT runtime·open(SB),NOSPLIT,$-8
        MOVW 0(FP), R0  // arg 1 name
        MOVW 4(FP), R1  // arg 2 mode
        MOVW 8(FP), R2  // arg 3 perm
        MOVW $SYS_open, R7
        SWI $0
        RET

TEXT runtime·read(SB),NOSPLIT,$-8
        MOVW 0(FP), R0  // arg 1 fd
        MOVW 4(FP), R1  // arg 2 buf
        MOVW 8(FP), R2  // arg 3 count
        MOVW $SYS_read, R7
        SWI $0
        RET

TEXT runtime·write(SB),NOSPLIT,$-8
        MOVW 0(FP), R0  // arg 1 fd
        MOVW 4(FP), R1  // arg 2 buf
        MOVW 8(FP), R2  // arg 3 count
        MOVW $SYS_write, R7
        SWI $0
        RET

TEXT runtime·close(SB),NOSPLIT,$-8
        MOVW 0(FP), R0  // arg 1 fd
        MOVW $SYS_close, R7
        SWI $0
        RET

TEXT runtime·getrlimit(SB),NOSPLIT,$-8
        MOVW 0(FP), R0
        MOVW 4(FP), R1
        MOVW $SYS_getrlimit, R7
        SWI $0
        RET

TEXT runtime·raise(SB),NOSPLIT,$8
        // thr_self(&4(R13))
        MOVW $4(R13), R0 // arg 1 &4(R13)
        MOVW $SYS_thr_self, R7
        SWI $0
        // thr_kill(self, SIGPIPE)
        MOVW 4(R13), R0 // arg 1 id
        MOVW sig+0(FP), R1      // arg 2 - signal
        MOVW $SYS_thr_kill, R7
        SWI $0
        RET

TEXT runtime·setitimer(SB), NOSPLIT, $-8
        MOVW 0(FP), R0
        MOVW 4(FP), R1
        MOVW 8(FP), R2
        MOVW $SYS_setitimer, R7
        SWI $0
        RET

// func now() (sec int64, nsec int32)
TEXT time·now(SB), NOSPLIT, $32
        MOVW $0, R0 // CLOCK_REALTIME
        MOVW $8(R13), R1
        MOVW $SYS_clock_gettime, R7
        SWI $0

        MOVW 8(R13), R0 // sec.low
        MOVW 12(R13), R1 // sec.high
        MOVW 16(R13), R2 // nsec

        MOVW R0, 0(FP)
        MOVW R1, 4(FP)
        MOVW R2, 8(FP)
        RET

// int64 nanotime(void) so really
// void nanotime(int64 *nsec)
TEXT runtime·nanotime(SB), NOSPLIT, $32
        // We can use CLOCK_MONOTONIC_FAST here when we drop
        // support for FreeBSD 8-STABLE.
        MOVW $4, R0 // CLOCK_MONOTONIC
        MOVW $8(R13), R1
        MOVW $SYS_clock_gettime, R7
        SWI $0

        MOVW 8(R13), R0 // sec.low
        MOVW 12(R13), R4 // sec.high
        MOVW 16(R13), R2 // nsec

        MOVW $1000000000, R3
        MULLU R0, R3, (R1, R0)
        MUL R3, R4
        ADD.S R2, R0
        ADC R4, R1

        MOVW 0(FP), R3
        MOVW R0, 0(R3)
        MOVW R1, 4(R3)
        RET

TEXT runtime·sigaction(SB),NOSPLIT,$-8
        MOVW 0(FP), R0          // arg 1 sig
        MOVW 4(FP), R1          // arg 2 act
        MOVW 8(FP), R2          // arg 3 oact
        MOVW $SYS_sigaction, R7
        SWI $0
        MOVW.CS $0, R8 // crash on syscall failure
        MOVW.CS R8, (R8)
        RET

TEXT runtime·sigtramp(SB),NOSPLIT,$24
        // this might be called in external code context,
        // where g and m are not set.
        // first save R0, because runtime·load_gm will clobber it
        MOVW    R0, 4(R13) // signum
        MOVB    runtime·iscgo(SB), R0
        CMP     $0, R0
        BL.NE   runtime·load_gm(SB)

        CMP $0, m
        BNE 4(PC)
        // signal number is already prepared in 4(R13)
        MOVW $runtime·badsignal(SB), R11
        BL (R11)
        RET

        // save g
        MOVW g, R4
        MOVW g, 20(R13)

        // g = m->signal
        MOVW m_gsignal(m), g

        // R0 is already saved
        MOVW R1, 8(R13) // info
        MOVW R2, 12(R13) // context
        MOVW R4, 16(R13) // oldg

        BL runtime·sighandler(SB)

        // restore g
        MOVW 20(R13), g
        RET

TEXT runtime·mmap(SB),NOSPLIT,$16
        MOVW 0(FP), R0          // arg 1 addr
        MOVW 4(FP), R1          // arg 2 len
        MOVW 8(FP), R2          // arg 3 prot
        MOVW 12(FP), R3         // arg 4 flags
        // arg 5 (fid) and arg6 (offset_lo, offset_hi) are passed on stack
        // note the C runtime only passes the 32-bit offset_lo to us
        MOVW 16(FP), R4         // arg 5
        MOVW R4, 4(R13)
        MOVW 20(FP), R5         // arg 6 lower 32-bit
        // the word at 8(R13) is skipped due to 64-bit argument alignment.
        MOVW R5, 12(R13)
        MOVW $0, R6             // higher 32-bit for arg 6
        MOVW R6, 16(R13)
        ADD $4, R13
        MOVW $SYS_mmap, R7
        SWI $0
        SUB $4, R13
        // TODO(dfc) error checking ?
        RET

TEXT runtime·munmap(SB),NOSPLIT,$0
        MOVW 0(FP), R0          // arg 1 addr
        MOVW 4(FP), R1          // arg 2 len
        MOVW $SYS_munmap, R7
        SWI $0
        MOVW.CS $0, R8 // crash on syscall failure
        MOVW.CS R8, (R8)
        RET

TEXT runtime·madvise(SB),NOSPLIT,$0
        MOVW 0(FP), R0          // arg 1 addr
        MOVW 4(FP), R1          // arg 2 len
        MOVW 8(FP), R2          // arg 3 flags
        MOVW $SYS_madvise, R7
        SWI $0
        // ignore failure - maybe pages are locked
        RET
        
TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
        MOVW new+0(FP), R0
        MOVW old+4(FP), R1
        MOVW $SYS_sigaltstack, R7
        SWI $0
        MOVW.CS $0, R8 // crash on syscall failure
        MOVW.CS R8, (R8)
        RET

TEXT runtime·usleep(SB),NOSPLIT,$16
        MOVW usec+0(FP), R0
        MOVW R0, R2
        MOVW $1000000, R1
        DIV R1, R0
        // 0(R13) is the saved LR, don't use it
        MOVW R0, 4(R13) // tv_sec.low
        MOVW $0, R0
        MOVW R0, 8(R13) // tv_sec.high
        MOD R1, R2
        MOVW $1000, R1
        MUL R1, R2
        MOVW R2, 12(R13) // tv_nsec

        MOVW $4(R13), R0 // arg 1 - rqtp
        MOVW $0, R1      // arg 2 - rmtp
        MOVW $SYS_nanosleep, R7
        SWI $0
        RET

TEXT runtime·sysctl(SB),NOSPLIT,$0
        MOVW 0(FP), R0  // arg 1 - name
        MOVW 4(FP), R1  // arg 2 - namelen
        MOVW 8(FP), R2  // arg 3 - old
        MOVW 12(FP), R3 // arg 4 - oldlenp
        // arg 5 (newp) and arg 6 (newlen) are passed on stack
        ADD $20, R13
        MOVW $SYS___sysctl, R7
        SWI $0
        SUB.CS $0, R0, R0
        SUB $20, R13
        RET

TEXT runtime·osyield(SB),NOSPLIT,$-4
        MOVW $SYS_sched_yield, R7
        SWI $0
        RET

TEXT runtime·sigprocmask(SB),NOSPLIT,$0
        MOVW $3, R0     // arg 1 - how (SIG_SETMASK)
        MOVW 0(FP), R1  // arg 2 - set
        MOVW 4(FP), R2  // arg 3 - oset
        MOVW $SYS_sigprocmask, R7
        SWI $0
        MOVW.CS $0, R8 // crash on syscall failure
        MOVW.CS R8, (R8)
        RET

// int32 runtime·kqueue(void)
TEXT runtime·kqueue(SB),NOSPLIT,$0
        MOVW $SYS_kqueue, R7
        SWI $0
        RSB.CS $0, R0
        RET

// int32 runtime·kevent(int kq, Kevent *changelist, int nchanges, Kevent *eventlist, int nevents, Timespec *timeout)
TEXT runtime·kevent(SB),NOSPLIT,$0
        MOVW 0(FP), R0  // kq
        MOVW 4(FP), R1  // changelist
        MOVW 8(FP), R2  // nchanges
        MOVW 12(FP), R3 // eventlist
        ADD $20, R13    // pass arg 5 and 6 on stack
        MOVW $SYS_kevent, R7
        SWI $0
        RSB.CS $0, R0
        SUB $20, R13
        RET

// void runtime·closeonexec(int32 fd)
TEXT runtime·closeonexec(SB),NOSPLIT,$0
        MOVW 0(FP), R0  // fd
        MOVW $2, R1     // F_SETFD
        MOVW $1, R2     // FD_CLOEXEC
        MOVW $SYS_fcntl, R7
        SWI $0
        RET

TEXT runtime·casp(SB),NOSPLIT,$0
        B       runtime·cas(SB)

// TODO(minux): this is only valid for ARMv6+
// bool armcas(int32 *val, int32 old, int32 new)
// Atomically:
//      if(*val == old){
//              *val = new;
//              return 1;
//      }else
//              return 0;
TEXT runtime·cas(SB),NOSPLIT,$0
        B runtime·armcas(SB)

// TODO(minux): this only supports ARMv6K+.
TEXT runtime·read_tls_fallback(SB),NOSPLIT,$-4
        WORD $0xee1d0f70 // mrc p15, 0, r0, c13, c0, 3
        RET