rt0_freebsd_arm64.s

Documentation: runtime

     1  // Copyright 2019 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  // On FreeBSD argc/argv are passed in R0, not RSP
     8  TEXT _rt0_arm64_freebsd(SB),NOSPLIT|NOFRAME,$0
     9  	ADD	$8, R0, R1	// argv
    10  	MOVD	0(R0), R0	// argc
    11  	BL	main(SB)
    12  
    13  // When building with -buildmode=c-shared, this symbol is called when the shared
    14  // library is loaded.
    15  TEXT _rt0_arm64_freebsd_lib(SB),NOSPLIT,$184
    16  	// Preserve callee-save registers.
    17  	MOVD R19, 24(RSP)
    18  	MOVD R20, 32(RSP)
    19  	MOVD R21, 40(RSP)
    20  	MOVD R22, 48(RSP)
    21  	MOVD R23, 56(RSP)
    22  	MOVD R24, 64(RSP)
    23  	MOVD R25, 72(RSP)
    24  	MOVD R26, 80(RSP)
    25  	MOVD R27, 88(RSP)
    26  	FMOVD F8, 96(RSP)
    27  	FMOVD F9, 104(RSP)
    28  	FMOVD F10, 112(RSP)
    29  	FMOVD F11, 120(RSP)
    30  	FMOVD F12, 128(RSP)
    31  	FMOVD F13, 136(RSP)
    32  	FMOVD F14, 144(RSP)
    33  	FMOVD F15, 152(RSP)
    34  	MOVD g, 160(RSP)
    35  
    36  	// Initialize g as null in case of using g later e.g. sigaction in cgo_sigaction.go
    37  	MOVD	ZR, g
    38  
    39  	MOVD	R0, _rt0_arm64_freebsd_lib_argc<>(SB)
    40  	MOVD	R1, _rt0_arm64_freebsd_lib_argv<>(SB)
    41  
    42  	// Synchronous initialization.
    43  	MOVD	$runtime·libpreinit(SB), R4
    44  	BL	(R4)
    45  
    46  	// Create a new thread to do the runtime initialization and return.
    47  	MOVD	_cgo_sys_thread_create(SB), R4
    48  	CBZ	R4, nocgo
    49  	MOVD	$_rt0_arm64_freebsd_lib_go(SB), R0
    50  	MOVD	$0, R1
    51  	SUB	$16, RSP	// reserve 16 bytes for sp-8 where fp may be saved.
    52  	BL	(R4)
    53  	ADD	$16, RSP
    54  	B	restore
    55  
    56  nocgo:
    57  	MOVD	$0x800000, R0                     // stacksize = 8192KB
    58  	MOVD	$_rt0_arm64_freebsd_lib_go(SB), R1
    59  	MOVD	R0, 8(RSP)
    60  	MOVD	R1, 16(RSP)
    61  	MOVD	$runtime·newosproc0(SB),R4
    62  	BL	(R4)
    63  
    64  restore:
    65  	// Restore callee-save registers.
    66  	MOVD 24(RSP), R19
    67  	MOVD 32(RSP), R20
    68  	MOVD 40(RSP), R21
    69  	MOVD 48(RSP), R22
    70  	MOVD 56(RSP), R23
    71  	MOVD 64(RSP), R24
    72  	MOVD 72(RSP), R25
    73  	MOVD 80(RSP), R26
    74  	MOVD 88(RSP), R27
    75  	FMOVD 96(RSP), F8
    76  	FMOVD 104(RSP), F9
    77  	FMOVD 112(RSP), F10
    78  	FMOVD 120(RSP), F11
    79  	FMOVD 128(RSP), F12
    80  	FMOVD 136(RSP), F13
    81  	FMOVD 144(RSP), F14
    82  	FMOVD 152(RSP), F15
    83  	MOVD 160(RSP), g
    84  	RET
    85  
    86  TEXT _rt0_arm64_freebsd_lib_go(SB),NOSPLIT,$0
    87  	MOVD	_rt0_arm64_freebsd_lib_argc<>(SB), R0
    88  	MOVD	_rt0_arm64_freebsd_lib_argv<>(SB), R1
    89  	MOVD	$runtime·rt0_go(SB),R4
    90  	B       (R4)
    91  
    92  DATA _rt0_arm64_freebsd_lib_argc<>(SB)/8, $0
    93  GLOBL _rt0_arm64_freebsd_lib_argc<>(SB),NOPTR, $8
    94  DATA _rt0_arm64_freebsd_lib_argv<>(SB)/8, $0
    95  GLOBL _rt0_arm64_freebsd_lib_argv<>(SB),NOPTR, $8
    96  
    97  
    98  TEXT main(SB),NOSPLIT|NOFRAME,$0
    99  	MOVD	$runtime·rt0_go(SB), R2
   100  	BL	(R2)
   101  exit:
   102  	MOVD	$0, R0
   103  	MOVD	$1, R8	// SYS_exit
   104  	SVC
   105  	B	exit
   106
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