rt0_freebsd_arm64.s

     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  #include "cgo/abi_arm64.h"
     7  
     8  // On FreeBSD argc/argv are passed in R0, not RSP
     9  TEXT _rt0_arm64_freebsd(SB),NOSPLIT|NOFRAME,$0
    10  	ADD	$8, R0, R1	// argv
    11  	MOVD	0(R0), R0	// argc
    12  	BL	main(SB)
    13  
    14  // When building with -buildmode=c-shared, this symbol is called when the shared
    15  // library is loaded.
    16  TEXT _rt0_arm64_freebsd_lib(SB),NOSPLIT,$184
    17  	// Preserve callee-save registers.
    18  	SAVE_R19_TO_R28(24)
    19  	SAVE_F8_TO_F15(104)
    20  
    21  	// Initialize g as null in case of using g later e.g. sigaction in cgo_sigaction.go
    22  	MOVD	ZR, g
    23  
    24  	MOVD	R0, _rt0_arm64_freebsd_lib_argc<>(SB)
    25  	MOVD	R1, _rt0_arm64_freebsd_lib_argv<>(SB)
    26  
    27  	// Synchronous initialization.
    28  	MOVD	$runtime·libpreinit(SB), R4
    29  	BL	(R4)
    30  
    31  	// Create a new thread to do the runtime initialization and return.
    32  	MOVD	_cgo_sys_thread_create(SB), R4
    33  	CBZ	R4, nocgo
    34  	MOVD	$_rt0_arm64_freebsd_lib_go(SB), R0
    35  	MOVD	$0, R1
    36  	SUB	$16, RSP	// reserve 16 bytes for sp-8 where fp may be saved.
    37  	BL	(R4)
    38  	ADD	$16, RSP
    39  	B	restore
    40  
    41  nocgo:
    42  	MOVD	$0x800000, R0                     // stacksize = 8192KB
    43  	MOVD	$_rt0_arm64_freebsd_lib_go(SB), R1
    44  	MOVD	R0, 8(RSP)
    45  	MOVD	R1, 16(RSP)
    46  	MOVD	$runtime·newosproc0(SB),R4
    47  	BL	(R4)
    48  
    49  restore:
    50  	// Restore callee-save registers.
    51  	RESTORE_R19_TO_R28(24)
    52  	RESTORE_F8_TO_F15(104)
    53  	RET
    54  
    55  TEXT _rt0_arm64_freebsd_lib_go(SB),NOSPLIT,$0
    56  	MOVD	_rt0_arm64_freebsd_lib_argc<>(SB), R0
    57  	MOVD	_rt0_arm64_freebsd_lib_argv<>(SB), R1
    58  	MOVD	$runtime·rt0_go(SB),R4
    59  	B       (R4)
    60  
    61  DATA _rt0_arm64_freebsd_lib_argc<>(SB)/8, $0
    62  GLOBL _rt0_arm64_freebsd_lib_argc<>(SB),NOPTR, $8
    63  DATA _rt0_arm64_freebsd_lib_argv<>(SB)/8, $0
    64  GLOBL _rt0_arm64_freebsd_lib_argv<>(SB),NOPTR, $8
    65  
    66  
    67  TEXT main(SB),NOSPLIT|NOFRAME,$0
    68  	MOVD	$runtime·rt0_go(SB), R2
    69  	BL	(R2)
    70  exit:
    71  	MOVD	$0, R0
    72  	MOVD	$1, R8	// SYS_exit
    73  	SVC
    74  	B	exit
    75
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