github.com/zxy12/golang151_with_comment@v0.0.0-20190507085033-721809559d3c/runtime/rt0_darwin_arm64.s (about)

     1  // Copyright 2015 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  
     7  // No need for _rt0_arm64_darwin as darwin/arm64 only
     8  // supports external linking.
     9  TEXT _rt0_arm64_darwin(SB),NOSPLIT,$-8
    10  	MOVD	$42, R0
    11  	MOVD	$1, R16	// SYS_exit
    12  	SVC	$0x80
    13  
    14  // When linking with -buildmode=c-archive or -buildmode=c-shared,
    15  // this symbol is called from a global initialization function.
    16  //
    17  // Note that all currently shipping darwin/arm64 platforms require
    18  // cgo and do not support c-shared.
    19  TEXT _rt0_arm64_darwin_lib(SB),NOSPLIT,$0
    20  	// R27 is REGTMP, reserved for liblink. It is used below to
    21  	// move R0/R1 into globals. However in the standard ARM64 calling
    22  	// convention, it is a callee-saved register. So we save it to a
    23  	// temporary register.
    24  	MOVD  R27, R7
    25  
    26  	MOVD  R0, _rt0_arm64_darwin_lib_argc<>(SB)
    27  	MOVD  R1, _rt0_arm64_darwin_lib_argv<>(SB)
    28  	// Create a new thread to do the runtime initialization and return.
    29  	MOVD  _cgo_sys_thread_create(SB), R4
    30  	MOVD  $_rt0_arm64_darwin_lib_go(SB), R0
    31  	MOVD  $0, R1
    32  	BL    (R4)
    33  
    34  	MOVD  R7, R27
    35  	RET
    36  
    37  TEXT _rt0_arm64_darwin_lib_go(SB),NOSPLIT,$0
    38  	MOVD  _rt0_arm64_darwin_lib_argc<>(SB), R0
    39  	MOVD  _rt0_arm64_darwin_lib_argv<>(SB), R1
    40  	MOVD  $runtime·rt0_go(SB), R4
    41  	B     (R4)
    42  
    43  DATA  _rt0_arm64_darwin_lib_argc<>(SB)/8, $0
    44  GLOBL _rt0_arm64_darwin_lib_argc<>(SB),NOPTR, $8
    45  DATA  _rt0_arm64_darwin_lib_argv<>(SB)/8, $0
    46  GLOBL _rt0_arm64_darwin_lib_argv<>(SB),NOPTR, $8
    47  
    48  TEXT main(SB),NOSPLIT,$-8
    49  	MOVD	$runtime·rt0_go(SB), R2
    50  	BL	(R2)
    51  exit:
    52  	MOVD	$0, R0
    53  	MOVD	$1, R16	// sys_exit
    54  	SVC	$0x80
    55  	B	exit