File size: 1,808 Bytes
e36aeda | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 | // Copyright 2009 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.
#include "textflag.h"
#include "funcdata.h"
//
// System calls for arm, Linux
//
#define SYS__LLSEEK 140 /* from zsysnum_linux_arm.go */
// func seek(fd int, offset int64, whence int) (newoffset int64, errno int)
// Implemented in assembly to avoid allocation when
// taking the address of the return value newoffset.
// Underlying system call is
// llseek(int fd, int offhi, int offlo, int64 *result, int whence)
TEXT 路seek(SB),NOSPLIT,$0-28
BL runtime路entersyscall(SB)
MOVW $SYS__LLSEEK, R7 // syscall entry
MOVW fd+0(FP), R0
MOVW offset_hi+8(FP), R1
MOVW offset_lo+4(FP), R2
MOVW $newoffset_lo+16(FP), R3
MOVW whence+12(FP), R4
SWI $0
MOVW $0xfffff001, R6
CMP R6, R0
BLS okseek
MOVW $0, R1
MOVW R1, newoffset_lo+16(FP)
MOVW R1, newoffset_hi+20(FP)
RSB $0, R0, R0
MOVW R0, err+24(FP)
BL runtime路exitsyscall(SB)
RET
okseek:
// system call filled in newoffset already
MOVW $0, R0
MOVW R0, err+24(FP)
BL runtime路exitsyscall(SB)
RET
// func rawVforkSyscall(trap, a1, a2, a3 uintptr) (r1, err uintptr)
TEXT 路rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-24
MOVW trap+0(FP), R7 // syscall entry
MOVW a1+4(FP), R0
MOVW a2+8(FP), R1
MOVW a3+12(FP), R2
SWI $0
MOVW $0xfffff001, R1
CMP R1, R0
BLS ok
MOVW $-1, R1
MOVW R1, r1+16(FP)
RSB $0, R0, R0
MOVW R0, err+20(FP)
RET
ok:
MOVW R0, r1+16(FP)
MOVW $0, R0
MOVW R0, err+20(FP)
RET
// func rawSyscallNoError(trap uintptr, a1, a2, a3 uintptr) (r1, r2 uintptr);
TEXT 路rawSyscallNoError(SB),NOSPLIT,$0-24
MOVW trap+0(FP), R7 // syscall entry
MOVW a1+4(FP), R0
MOVW a2+8(FP), R1
MOVW a3+12(FP), R2
SWI $0
MOVW R0, r1+16(FP)
MOVW $0, R0
MOVW R0, r2+20(FP)
RET
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