github.com/hbdrawn/golang@v0.0.0-20141214014649-6b835209aba2/src/syscall/asm_linux_arm.s (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include "textflag.h"
     6  #include "funcdata.h"
     7  
     8  //
     9  // System calls for arm, Linux
    10  //
    11  
    12  // TODO(kaib): handle error returns
    13  
    14  // func Syscall(syscall uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
    15  
    16  TEXT	·Syscall(SB),NOSPLIT,$0-28
    17  	BL		runtime·entersyscall(SB)
    18  	MOVW	4(SP), R7
    19  	MOVW	8(SP), R0
    20  	MOVW	12(SP), R1
    21  	MOVW	16(SP), R2
    22  	MOVW	$0, R3
    23  	MOVW	$0, R4
    24  	MOVW	$0, R5
    25  	SWI		$0
    26  	MOVW	$0xfffff001, R1
    27  	CMP		R1, R0
    28  	BLS		ok
    29  	MOVW	$-1, R1
    30  	MOVW	R1, 20(SP)	// r1
    31  	MOVW	$0, R2
    32  	MOVW	R2, 24(SP)	// r2
    33  	RSB		$0, R0, R0
    34  	MOVW	R0, 28(SP)	// errno
    35  	BL		runtime·exitsyscall(SB)
    36  	RET
    37  ok:
    38  	MOVW	R0, 20(SP) // r1
    39  	MOVW	$0, R0
    40  	MOVW	R0, 24(SP)	// r2
    41  	MOVW	R0, 28(SP)	// errno
    42  	BL		runtime·exitsyscall(SB)
    43  	RET
    44  
    45  // func Syscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
    46  // Actually Syscall5 but the rest of the code expects it to be named Syscall6.
    47  TEXT	·Syscall6(SB),NOSPLIT,$0-40
    48  	BL		runtime·entersyscall(SB)
    49  	MOVW	4(SP), R7	// syscall entry
    50  	MOVW	8(SP), R0
    51  	MOVW	12(SP), R1
    52  	MOVW	16(SP), R2
    53  	MOVW	20(SP), R3
    54  	MOVW	24(SP), R4
    55  	MOVW	28(SP), R5
    56  	SWI		$0
    57  	MOVW	$0xfffff001, R6
    58  	CMP		R6, R0
    59  	BLS		ok6
    60  	MOVW	$-1, R1
    61  	MOVW	R1, 32(SP)	// r1
    62  	MOVW	$0, R2
    63  	MOVW	R2, 36(SP)	// r2
    64  	RSB		$0, R0, R0
    65  	MOVW	R0, 40(SP)	// errno
    66  	BL		runtime·exitsyscall(SB)
    67  	RET
    68  ok6:
    69  	MOVW	R0, 32(SP) // r1
    70  	MOVW	R1, 36(SP)	// r2
    71  	MOVW	$0, R0
    72  	MOVW	R0, 40(SP)	// errno
    73  	BL		runtime·exitsyscall(SB)
    74  	RET
    75  
    76  // func RawSyscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
    77  // Actually RawSyscall5 but the rest of the code expects it to be named RawSyscall6.
    78  TEXT	·RawSyscall6(SB),NOSPLIT,$0-40
    79  	MOVW	4(SP), R7	// syscall entry
    80  	MOVW	8(SP), R0
    81  	MOVW	12(SP), R1
    82  	MOVW	16(SP), R2
    83  	MOVW	20(SP), R3
    84  	MOVW	24(SP), R4
    85  	MOVW	28(SP), R5
    86  	SWI		$0
    87  	MOVW	$0xfffff001, R6
    88  	CMP		R6, R0
    89  	BLS		ok2
    90  	MOVW	$-1, R1
    91  	MOVW	R1, 32(SP)	// r1
    92  	MOVW	$0, R2
    93  	MOVW	R2, 36(SP)	// r2
    94  	RSB		$0, R0, R0
    95  	MOVW	R0, 40(SP)	// errno
    96  	RET
    97  ok2:
    98  	MOVW	R0, 32(SP) // r1
    99  	MOVW	R1, 36(SP)	// r2
   100  	MOVW	$0, R0
   101  	MOVW	R0, 40(SP)	// errno
   102  	RET
   103  
   104  #define SYS__LLSEEK 140  /* from zsysnum_linux_arm.go */
   105  // func seek(fd int, offset int64, whence int) (newoffset int64, errno int)
   106  // Implemented in assembly to avoid allocation when
   107  // taking the address of the return value newoffset.
   108  // Underlying system call is
   109  //	llseek(int fd, int offhi, int offlo, int64 *result, int whence)
   110  TEXT ·seek(SB),NOSPLIT,$0-32
   111  	BL	runtime·entersyscall(SB)
   112  	MOVW	$SYS__LLSEEK, R7	// syscall entry
   113  	MOVW	4(SP), R0	// fd
   114  	MOVW	12(SP), R1	// offset-high
   115  	MOVW	8(SP), R2	// offset-low
   116  	MOVW	$20(SP), R3
   117  	MOVW	16(SP), R4	// whence
   118  	SWI	$0
   119  	MOVW	$0xfffff001, R6
   120  	CMP	R6, R0
   121  	BLS	okseek
   122  	MOVW	$0, R1
   123  	MOVW	R1, 20(SP)
   124  	MOVW	R1, 24(SP)
   125  	RSB	$0, R0, R0
   126  	MOVW	R0, 28(SP)	// errno
   127  	BL	runtime·exitsyscall(SB)
   128  	RET
   129  okseek:
   130  	// system call filled in newoffset already
   131  	MOVW	$0, R0
   132  	MOVW	R0, 28(SP)	// errno
   133  	BL	runtime·exitsyscall(SB)
   134  	RET	
   135  
   136  // func RawSyscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
   137  TEXT ·RawSyscall(SB),NOSPLIT,$0-28
   138  	MOVW	4(SP), R7	// syscall entry
   139  	MOVW	8(SP), R0
   140  	MOVW	12(SP), R1
   141  	MOVW	16(SP), R2
   142  	SWI		$0
   143  	MOVW	$0xfffff001, R1
   144  	CMP		R1, R0
   145  	BLS		ok1
   146  	MOVW	$-1, R1
   147  	MOVW	R1, 20(SP)	// r1
   148  	MOVW	$0, R2
   149  	MOVW	R2, 24(SP)	// r2
   150  	RSB		$0, R0, R0
   151  	MOVW	R0, 28(SP)	// errno
   152  	RET
   153  ok1:
   154  	MOVW	R0, 20(SP) // r1
   155  	MOVW	$0, R0
   156  	MOVW	R0, 24(SP)	// r2
   157  	MOVW	R0, 28(SP)	// errno
   158  	RET
   159