1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 .text 29 .align 4 30 .type _start,#function 31 .globl _start 32 33 # this is the small startup code that is first run when 34 # any executable that is statically-linked with Bionic 35 # runs. 36 # 37 # it's purpose is to call __libc_init with appropriate 38 # arguments, which are: 39 # 40 # - the address of the raw data block setup by the Linux 41 # kernel ELF loader 42 # 43 # - address of an "onexit" function, not used on any 44 # platform supported by Bionic 45 # 46 # - address of the "main" function of the program. We 47 # can't hard-code it in the adr pseudo instruction 48 # so we use a tiny trampoline that will get relocated 49 # by the dynamic linker before this code runs 50 # 51 # - address of the constructor list 52 # 53 _start: 54 mov r0, sp 55 mov r1, #0 56 adr r2, 0f 57 adr r3, 1f 58 b __libc_init 59 60 0: b main 61 62 1: .long __PREINIT_ARRAY__ 63 .long __INIT_ARRAY__ 64 .long __FINI_ARRAY__ 65 .long __CTOR_LIST__ 66 67 # the .ctors section contains a list of pointers to "constructor" 68 # functions that need to be called in order during C library initialization, 69 # just before the program is being run. This is a C++ requirement 70 # 71 # the last entry shall be 0, and is defined in crtend.S 72 # 73 .section .preinit_array, "aw" 74 .globl __PREINIT_ARRAY__ 75 __PREINIT_ARRAY__: 76 .long -1 77 78 .section .init_array, "aw" 79 .globl __INIT_ARRAY__ 80 __INIT_ARRAY__: 81 .long -1 82 83 .section .fini_array, "aw" 84 .globl __FINI_ARRAY__ 85 __FINI_ARRAY__: 86 .long -1 87 88 .section .ctors, "aw" 89 .globl __CTOR_LIST__ 90 __CTOR_LIST__: 91 .long -1 92 93
