1 /* 2 * Copyright (C) 2013 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 29 #include <stddef.h> 30 #include <stdint.h> 31 #include <sys/cdefs.h> 32 33 extern int main(int argc, char** argv, char** env); 34 35 typedef struct 36 { 37 void (**preinit_array)(void); 38 void (**init_array)(void); 39 void (**fini_array)(void); 40 void (**ctor_list)(void); 41 void (**dtor_list)(void); 42 } structors_array_t; 43 44 __attribute__ ((section (".preinit_array"))) 45 void (*__PREINIT_ARRAY__)(void) = (void (*)(void)) -1; 46 47 __attribute__ ((section (".init_array"))) 48 void (*__INIT_ARRAY__)(void) = (void (*)(void)) -1; 49 50 __attribute__ ((section (".fini_array"))) 51 void (*__FINI_ARRAY__)(void) = (void (*)(void)) -1; 52 53 __attribute__ ((section (".ctors"))) 54 void (*__CTOR_LIST__)(void) = (void (*)(void)) -1; 55 56 __attribute__ ((section (".dtors"))) 57 void (*__DTOR_LIST__)(void) = (void (*)(void)) -1; 58 59 __LIBC_HIDDEN__ void do_mips_start(void *raw_args) { 60 structors_array_t array; 61 array.preinit_array = &__PREINIT_ARRAY__; 62 array.init_array = &__INIT_ARRAY__; 63 array.fini_array = &__FINI_ARRAY__; 64 array.ctor_list = &__CTOR_LIST__; 65 array.dtor_list = &__DTOR_LIST__; 66 67 __libc_init(raw_args, NULL, &main, &array); 68 } 69 70 /* 71 * This function prepares the return address with a branch-and-link 72 * instruction (bal) and then uses a .cpload to compute the Global 73 * Offset Table (GOT) pointer ($gp). The $gp is then used to load 74 * the address of _do_start() into $t9 just before calling it. 75 * Terminating the stack with a NULL return address. 76 */ 77 __asm__ ( 78 " .set push \n" 79 " \n" 80 " .text \n" 81 " .align 4 \n" 82 " .type __start,@function \n" 83 " .globl __start \n" 84 " .globl _start \n" 85 " \n" 86 " .ent __start \n" 87 "__start: \n" 88 " _start: \n" 89 " .frame $sp,32,$ra \n" 90 " .mask 0x80000000,-4 \n" 91 " \n" 92 " .set noreorder \n" 93 " bal 1f \n" 94 " nop \n" 95 "1: \n" 96 " .cpload $ra \n" 97 " .set reorder \n" 98 " \n" 99 " move $a0, $sp \n" 100 " addiu $sp, $sp, (-32) \n" 101 " sw $0, 28($sp) \n" 102 " la $t9, do_mips_start \n" 103 " jalr $t9 \n" 104 " \n" 105 "2: b 2b \n" 106 " .end __start \n" 107 " \n" 108 " .set pop \n" 109 ); 110 111 #include "__dso_handle.h" 112 #include "atexit.h" 113
