// 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 ·seek(SB),NOSPLIT,$0-28

BL runtime·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·exitsyscall(SB)

RET

okseek:

// system call filled in newoffset already

MOVW $0, R0

MOVW R0, err+24(FP)

BL runtime·exitsyscall(SB)

RET

// func rawVforkSyscall(trap, a1, a2, a3 uintptr) (r1, err uintptr)

TEXT ·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 ·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