1/*	$NetBSD: rtld_start.S,v 1.8 2010/12/05 00:56:07 joerg Exp $	*/
2
3/*
4 * Copyright (c) 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Frank van der Linden for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 *      This product includes software developed for the NetBSD Project by
20 *      Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 *    or promote products derived from this software without specific prior
23 *    written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38#include <machine/asm.h>
39
40	.text
41	.align	16
42	.globl	.rtld_start
43	.hidden	.rtld_start
44	.type	.rtld_start,@function
45.rtld_start:
46	subq	$16,%rsp		# make room of obj_main and exit proc
47	movq	%rsp,%r12		# stack pointer arg to _rtld
48	pushq	%rbx			# save ps_strings
49
50	andq	$~15,%rsp		# align rsp, to be restored from r12
51
52	leaq	_GLOBAL_OFFSET_TABLE_(%rip),%rax
53	leaq	_DYNAMIC(%rip),%rdi	# &_DYNAMIC
54	movq	%rdi,%rbx
55	subq	(%rax),%rbx		# relocbase
56
57	movq	%rbx,%rsi
58	call	_rtld_relocate_nonplt_self
59
60	movq	%r12,%rdi
61	movq	%rbx,%rsi
62	call	_rtld			# _rtld(sp, relocbase)
63
64	leaq	-8(%r12),%rsp		# restore saved rsp, including %rbx
65	popq	%rbx			# %rbx = ps_strings
66	popq	%rdx			# %rdx = cleanup
67	popq	%rcx			# %rcx = obj_main
68	jmp	*%rax
69
70	.align	4
71	.globl	_rtld_bind_start
72	.hidden	_rtld_bind_start
73	.type	_rtld_bind_start,@function
74_rtld_bind_start:	# (obj, reloff)
75	# This function is called with a misaligned stack from the PLT
76	# due to the additional argument pushed.
77	# At this point %rsp % 16 == 8.
78	pushfq				# save caller-saved registers
79	pushq	%rax
80	pushq	%rcx
81	pushq	%rdx
82	pushq	%rsi
83	pushq	%rdi
84	pushq	%r8
85	pushq	%r9
86	pushq	%r10
87	pushq	%r11
88
89	movq	80(%rsp),%rdi
90	movq	88(%rsp),%rsi
91
92	call	_rtld_bind		# call the binder
93	movq	%rax,88(%rsp)		# store function in obj
94
95	popq	%r11
96	popq	%r10
97	popq	%r9
98	popq	%r8
99	popq	%rdi
100	popq	%rsi
101	popq	%rdx
102	popq	%rcx
103	popq	%rax
104	popfq
105
106	leaq	8(%rsp),%rsp
107
108	ret
109