1/*	$NetBSD: rtld_start.S,v 1.17 2011/09/26 01:52:22 mrg Exp $	*/
2
3/*-
4 * Copyright (c) 2014 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 of 3am Software Foundry.
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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <machine/asm.h>
33
34	.globl	_rtld_start
35	.globl	_rtld
36
37#define	CF_LEN		(3*__SIZEOF_POINTER__)
38#define	CF_OBJ		(2*__SIZEOF_POINTER__)
39#define	CF_CLEANUP	(1*__SIZEOF_POINTER__)
40
41	/*
42	 * void ___start(void (*cleanup)(void), const Obj_Entry *obj,
43	 *    struct ps_strings *ps_strings);
44	 */
45ENTRY_NP(_rtld_start)
46	l.sw	CF_LEN(r1), r1		# reserve some stack space
47#if 0
48	l.ori	r26, r3, 0		# obj		(should be 0)
49	l.ori	r28, r4, 0		# cleanup	(should be 0)
50#endif
51	l.ori	r30, r5, 0		# ps_strings
52	l.addi	r1, r1, -CF_LEN
53
54	PIC_GOTSETUP(r16)
55
56	l.movhi	r3, gotoffhi(_DYNAMIC)	# get _DYNAMIC gotoff address
57	l.ori	r3, r3, gotofflo(_DYNAMIC)
58
59	l.lwz	r7, 0(r16)		# get base-relative &_DYNAMIC
60	l.add	r3, r3, r16		# r3 = _DYNAMIC actual address
61	l.sub	r24, r3, r7		# r24 = relocbase
62	l.ori	r4, r24, 0		# r4 = relocbase
63	l.jal	_C_LABEL(_rtld_relocate_nonplt_self)
64	l.nop
65
66	l.addi	r3, r1, CF_CLEANUP
67	l.ori	r4, r24, 0		# r4 = relocbase
68	l.jal	_C_LABEL(_rtld)		# _start = _rtld(sp, relocbase)
69	l.nop
70
71	l.lwz	r3, CF_OBJ(r1)		# obj
72	l.lwz	r4, CF_CLEANUP(r1)	# cleanup
73	l.ori	r5, r30, 0		# ps_strings
74
75	l.addi	r1, r1, CF_LEN		# pop stack
76	l.jalr	r11			# _start(obj, cleanup, ps_strings)
77
78	l.ori	r13, r0, 1		# _exit()
79	l.sys	0
80
81END(_rtld_start)
82
83	.globl	_rtld_bind
84
85/*
86 * r11 = rela offset
87 * r12 = GOT[1] (&obj)
88 * r15 = GOT[2] (&_rtld_bind_start)
89 */
90ENTRY_NP(_rtld_bind_start)
91
92	l.sw	-4(r1), r9		# save lr
93	l.sw	-8(r1), r8		# save arg5
94	l.sw	-12(r1), r7		# save arg4
95	l.sw	-16(r1), r6		# save arg3
96	l.sw	-20(r1), r5		# save arg2
97	l.sw	-24(r1), r4		# save arg1
98	l.sw	-28(r1), r3		# save arg0
99	l.sw	-32(r1), r1		# establish stack frame
100	l.addi	r1, r1, -32
101
102	l.ori	r3, r12, 0		# obj
103	l.ori	r4, r11, 0		# reloff
104	l.jal	_C_LABEL(_rtld_bind)	# _rtld_bind(obj, reloff)
105	l.nop
106
107	l.addi	r1, r1, 32		# pop stack frame
108	l.lwz	r3, -28(r1)		# restore arg0
109	l.lwz	r4, -24(r1)		# restore arg1
110	l.lwz	r5, -20(r1)		# restore arg2
111	l.lwz	r6, -16(r1)		# restore arg3
112	l.lwz	r7, -12(r1)		# restore arg4
113	l.lwz	r8, -8(r1)		# restore arg5
114	l.lwz	r9, -4(r1)		# restore lr
115
116	l.jr	r11			# jump to routine
117	l.nop
118END(_rtld_bind_start)
119