rt0_linux_arm64.s

Documentation: runtime

     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#include "cgo/abi_arm64.h"
     7
     8TEXT _rt0_arm64_linux(SB),NOSPLIT|NOFRAME,$0
     9	MOVD	0(RSP), R0	// argc
    10	ADD	$8, RSP, R1	// argv
    11	BL	main(SB)
    12
    13// When building with -buildmode=c-shared, this symbol is called when the shared
    14// library is loaded.
    15TEXT _rt0_arm64_linux_lib(SB),NOSPLIT,$184
    16	// Preserve callee-save registers.
    17	SAVE_R19_TO_R28(24)
    18	SAVE_F8_TO_F15(104)
    19
    20	// Initialize g as null in case of using g later e.g. sigaction in cgo_sigaction.go
    21	MOVD	ZR, g
    22
    23	MOVD	R0, _rt0_arm64_linux_lib_argc<>(SB)
    24	MOVD	R1, _rt0_arm64_linux_lib_argv<>(SB)
    25
    26	// Synchronous initialization.
    27	MOVD	$runtime·libpreinit(SB), R4
    28	BL	(R4)
    29
    30	// Create a new thread to do the runtime initialization and return.
    31	MOVD	_cgo_sys_thread_create(SB), R4
    32	CBZ	R4, nocgo
    33	MOVD	$_rt0_arm64_linux_lib_go(SB), R0
    34	MOVD	$0, R1
    35	SUB	$16, RSP		// reserve 16 bytes for sp-8 where fp may be saved.
    36	BL	(R4)
    37	ADD	$16, RSP
    38	B	restore
    39
    40nocgo:
    41	MOVD	$0x800000, R0                     // stacksize = 8192KB
    42	MOVD	$_rt0_arm64_linux_lib_go(SB), R1
    43	MOVD	R0, 8(RSP)
    44	MOVD	R1, 16(RSP)
    45	MOVD	$runtime·newosproc0(SB),R4
    46	BL	(R4)
    47
    48restore:
    49	// Restore callee-save registers.
    50	RESTORE_R19_TO_R28(24)
    51	RESTORE_F8_TO_F15(104)
    52	RET
    53
    54TEXT _rt0_arm64_linux_lib_go(SB),NOSPLIT,$0
    55	MOVD	_rt0_arm64_linux_lib_argc<>(SB), R0
    56	MOVD	_rt0_arm64_linux_lib_argv<>(SB), R1
    57	MOVD	$runtime·rt0_go(SB),R4
    58	B       (R4)
    59
    60DATA _rt0_arm64_linux_lib_argc<>(SB)/8, $0
    61GLOBL _rt0_arm64_linux_lib_argc<>(SB),NOPTR, $8
    62DATA _rt0_arm64_linux_lib_argv<>(SB)/8, $0
    63GLOBL _rt0_arm64_linux_lib_argv<>(SB),NOPTR, $8
    64
    65
    66TEXT main(SB),NOSPLIT|NOFRAME,$0
    67	MOVD	$runtime·rt0_go(SB), R2
    68	BL	(R2)
    69exit:
    70	MOVD $0, R0
    71	MOVD	$94, R8	// sys_exit
    72	SVC
    73	B	exit
View as plain text