rtld_start.S revision 1.8 
1/*	$NetBSD: rtld_start.S,v 1.8 2004/08/21 11:12:03 rearnsha Exp $	*/
2
3/*-
4 * Copyright (c) 1998, 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Matt Thomas and by Charles M. Hannum.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *        This product includes software developed by the NetBSD
21 *        Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#include <machine/asm.h>
40
41	.text
42	.align	0
43	.globl	_rtld_start
44	.type	_rtld_start,%function
45_rtld_start:
46	sub	sp, sp, #8		/* make room for obj_main & exit proc */
47	mov	r4, r0			/* save ps_strings */
48
49	ldr	sl, .L2
50	ldr	r5, .L2+4
51	ldr	r0, .L2+8
52.L1:
53	add	sl, pc, sl
54	ldr	r5, [sl, r5]
55	ldr	r0, [sl, r0]
56
57	sub	r1, sl, r5		/* relocbase */
58	add	r0, r1, r0		/* &_DYNAMIC */
59	bl	_rtld_relocate_nonplt_self
60
61	sub	r1, sl, r5		/* relocbase */
62	mov	r0, sp			/* sp */
63	bl	_rtld			/* call the shared loader */
64	mov	r3, r0			/* save entry point */
65
66	ldr	r2, [sp, #0]		/* r2 = cleanup */
67	ldr	r1, [sp, #4]		/* r1 = obj_main */
68	add	sp, sp, #8		/* restore stack */
69	mov	r0, r4			/* restore ps_strings */
70#ifdef _ARM_ARCH_4T
71	bx	r3			/* jump to the entry point */
72#else
73	mov	pc, r3			/* jump to the entry point */
74#endif
75.L2:
76	.word	_GLOBAL_OFFSET_TABLE_ - (.L1+8)
77	.word	_GLOBAL_OFFSET_TABLE_(GOT)
78	.word	_DYNAMIC(GOT)
79
80	.align	0
81	.globl	_rtld_bind_start
82	.type	_rtld_bind_start,%function
83/*
84 *	stack[0] = RA
85 *	ip = &GOT[n+3]
86 *	lr = &GOT[2]
87 */
88_rtld_bind_start:
89	stmdb	sp!,{r0-r4,sl,fp}
90
91	sub	r1, ip, lr		/* r1 = 4 * (n + 1) */
92	sub	r1, r1, #4		/* r1 = 4 * n */
93	add	r1, r1, r1		/* r1 = 8 * n */
94
95	ldr	r0, [lr, #-4]		/* get obj ptr from GOT[1] */
96	mov	r4, ip			/* save GOT location */
97
98	bl	_rtld_bind		/* Call the binder */
99
100	str	r0, [r4]		/* save address in GOT */
101	mov	ip, r0			/* save new address */
102
103	ldmia	sp!,{r0-r4,sl,fp,lr}	/* restore the stack */
104#ifdef _ARM_ARCH_4T
105	bx	ip			/* jump to the new address */
106#else
107	mov	pc, ip			/* jump to the new address */
108#endif
109
110