begin.S revision 1a5db57d5a0f633a83f20e667a4698757a63413e 
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 <private/bionic_asm.h>
30
31#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
32#define ELF_DYNSZ       8
33#define ELF_DYN_TAG     0
34#define ELF_DYN_VAL     4
35#define GOTENT_SZ       4
36#else
37#define ELF_DYNSZ       16
38#define ELF_DYN_TAG     0
39#define ELF_DYN_VAL     8
40#define GOTENT_SZ       8
41#endif
42
43    .text
44    .align	4
45    .type	__start,@function
46
47    .ent	__start
48    .globl	__start
49    .globl	_start
50__start:
51_start:
52    .set	noreorder
53    bal		1f
54     nop
551:
56#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
57    .cpload	ra
58#else
59    .cpsetup	ra, $0, 1b
60#endif
61    .set	reorder
62
63    /* Discover the load address */
64    LA		t0, 1b
65    PTR_SUBU	t0, ra, t0
66
67#define DT_PLTGOT 3
68#define DT_MIPS_LOCAL_GOTNO 0x7000000a
69
70    /* Search dynamic table for DT_MIPS_LOCAL_GOTNO and DT_PLTGOT values */
71    LA		t1, _DYNAMIC
72    PTR_ADDU	t1, t0
73    LI		t3, DT_PLTGOT
74    LI		ta0, DT_MIPS_LOCAL_GOTNO
750:
76    REG_L	t2, ELF_DYN_TAG(t1)
77    beqz	t2, .Lrelocate_local_got
78
79    bne		t2, t3, 1f	/* DT_PLTGOT? */
80    REG_L	s0, ELF_DYN_VAL(t1)
81    PTR_ADDU	s0, t0
82    b		2f
83
841:
85    bne		t2, ta0, 2f    /* DT_MIPS_LOCAL_GOTNO? */
86    REG_L	s1, ELF_DYN_VAL(t1)
87
882:  PTR_ADDU    t1, ELF_DYNSZ
89    b		0b
90
91.Lrelocate_local_got:
92    /*
93     * Relocate the local GOT entries
94     * got[0] is address of lazy resolver function
95     * got[1] may be used for a GNU extension
96     */
97
98    PTR_ADDU	s0, GOTENT_SZ
99    SUBU	s1, 1
100    PTR_L	t1, (s0)
101    bgez	t1, 9f
102    PTR_ADDU	s0, GOTENT_SZ
103    SUBU	s1, 1
104    b		9f
105
1061:  PTR_L	t1, (s0)
107    PTR_ADDU	t1, t0
108    PTR_S	t1, (s0)
109    PTR_ADDU	s0, GOTENT_SZ
1109:  SUBU	s1, 1
111    bgez	s1, 1b
112
113    /* call linker_init */
114    move	a0, sp
115#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
116    PTR_SUBU	sp, 4*REGSZ       /* space for arg saves in linker_init */
117#endif
118    jal		__linker_init
119#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
120    PTR_ADDU	sp, 4*REGSZ        /* restore sp */
121#endif
122    move	t9, v0
123    j		t9
124    .end    __start
125