1 /*
2  * Copyright (C) 2012 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 <stdint.h>
30 #include <sys/cdefs.h>
31 
32 extern unsigned __linker_init(void* raw_args);
33 
_start()34 __LIBC_HIDDEN__ void _start() {
35   void (*start)(void);
36 
37   void* raw_args = (void*) ((uintptr_t) __builtin_frame_address(0) + sizeof(void*));
38   start = (void(*)(void))__linker_init(raw_args);
39 
40   /* linker init returns (%eax) the _entry address in the main image */
41   /* entry point expects sp to point to raw_args */
42 
43   __asm__ (
44      "mov %0, %%esp\n\t"
45      "jmp *%1\n\t"
46      : : "r"(raw_args), "r"(start) :
47   );
48 
49   /* Unreachable */
50 }
51 
52 /* Since linker has its own version of crtbegin (this file) it should have */
53 /* own version of __stack_chk_fail_local for the case when it's built with */
54 /* stack protector feature */
55 
56 #include "arch-x86/bionic/__stack_chk_fail_local.h"
57