1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22/* 23 * Copyright (c) 1988 AT&T 24 * All Rights Reserved 25 * 26 * 27 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31/* 32 * Bootstrap routine for run-time linker. 33 * We get control from exec which has loaded our text and 34 * data into the process' address space and created the process 35 * stack. 36 * 37 * On entry, the process stack looks like this: 38 * 39 * # # <- %rsp 40 * #_______________________# high addresses 41 * # strings # 42 * #_______________________# 43 * # 0 word # 44 * #_______________________# 45 * # Auxiliary # 46 * # entries # 47 * # ... # 48 * # (size varies) # 49 * #_______________________# 50 * # 0 word # 51 * #_______________________# 52 * # Environment # 53 * # pointers # 54 * # ... # 55 * # (one word each) # 56 * #_______________________# 57 * # 0 word # 58 * #_______________________# 59 * # Argument # low addresses 60 * # pointers # 61 * # Argc words # 62 * #_______________________# 63 * # argc # 64 * #_______________________# <- %rbp 65 * 66 * 67 * We must calculate the address at which ld.so was loaded, 68 * find the addr of the dynamic section of ld.so, of argv[0], and of 69 * the process' environment pointers - and pass the thing to _setup 70 * to handle. We then call _rtld - on return we jump to the entry 71 * point for the executable. 72 */ 73 74#if defined(lint) 75 76extern unsigned long _setup(); 77extern void atexit_fini(); 78void 79main() 80{ 81 (void) _setup(); 82 atexit_fini(); 83} 84 85#else 86 87#include <link.h> 88 89 .file "boot.s" 90 .text 91 .globl _rt_boot 92 .globl _setup 93 .globl _GLOBAL_OFFSET_TABLE_ 94 .type _rt_boot,@function 95 .align 4 96 97_rt_alias: 98 / in case we were invoked from libc.so 99 jmp .get_got 100_rt_boot: 101 / save for referencing args 102 movq %rsp,%rbp 103 / make room for a max sized boot vector 104 subq $EB_MAX_SIZE64,%rsp 105 / use esi as a pointer to &eb[0] 106 movq %rsp,%rsi 107 / set up tag for argv 108 movq $EB_ARGV,0(%rsi) 109 / get address of argv 110 leaq 8(%rbp),%rax 111 / put after tag 112 movq %rax,8(%rsi) 113 / set up tag for envp 114 movq $EB_ENVP,16(%rsi) 115 / get # of args 116 movq (%rbp),%rax 117 / one for the zero & one for argc 118 addq $2,%rax 119 / now points past args & @ envp 120 leaq (%rbp,%rax,8),%rdi 121 / set envp 122 movq %rdi,24(%rsi) 123 / next 124.L0: addq $8,%rdi 125 / search for 0 at end of env 126 cmpq $0,-8(%rdi) 127 jne .L0 128 / set up tag for auxv 129 movq $EB_AUXV,32(%rsi) 130 / point to auxv 131 movq %rdi,40(%rsi) 132 / set up NULL tag 133 movq $EB_NULL,48(%rsi) 134 135 / arg1 - address of &eb[0] 136 movq %rsi, %rdi 137.get_got: 138 leaq _GLOBAL_OFFSET_TABLE_(%rip), %rbx 139 / addq $_GLOBAL_OFFSET_TABLE_, %rbx 140 movq %rbx,%r9 141 // addq $[.L2-.L1], %rbx 142 movq %rbx,%r10 143 144 movq (%rbx),%rsi 145 146 / _setup(&eb[0], _DYNAMIC) 147 call _setup@PLT 148 / release stack frame 149 movq %rbp,%rsp 150 151 movq atexit_fini@GOTPCREL(%rip), %rdx 152 / transfer control to the executable 153 jmp *%rax 154 .size _rt_boot,.-_rt_boot 155#endif 156