xref: /openbsd/lib/csu/amd64/md_init.h (revision 73471bf0)
1 /* $OpenBSD: md_init.h,v 1.8 2020/10/15 16:30:23 deraadt Exp $ */
2 
3 /*-
4  * Copyright (c) 2001 Ross Harvey
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by the NetBSD
18  *      Foundation, Inc. and its contributors.
19  * 4. Neither the name of The NetBSD Foundation nor the names of its
20  *    contributors may be used to endorse or promote products derived
21  *    from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #define MD_SECT_CALL_FUNC(section, func) \
37 	__asm (".section "#section", \"ax\"\n"	\
38 	"	call " #func "\n"		\
39 	"	.previous")
40 
41 /*
42  * Align is after because we want the function to start at the first
43  * address of the section, but overall we want the section to be
44  * aligned by the align amount.
45  */
46 #define MD_SECTION_PROLOGUE(sect, entry_pt)	\
47 	__asm (					\
48 	".section "#sect",\"ax\",@progbits	\n" \
49 	"	.globl " #entry_pt "		\n" \
50 	"	.type " #entry_pt ",@function	\n" \
51 	#entry_pt":				\n" \
52 	"	.align 16			\n" \
53 	"	subq	$8,%rsp			\n" \
54 	"	.previous")
55 
56 
57 #define MD_SECTION_EPILOGUE(sect)		\
58 	__asm (					\
59 	".section "#sect",\"ax\",@progbits	\n" \
60 	"	addq	$8,%rsp			\n" \
61 	"	ret				\n" \
62 	"	.previous")
63 
64 
65 #define	MD_CRT0_START				\
66 	__asm(					\
67 	".text					\n" \
68 	"	.align	8			\n" \
69 	"	.globl	__start			\n" \
70 	"	.globl	_start			\n" \
71 	"_start:				\n" \
72 	"__start:				\n" \
73 	"	movq	%rdx,%rcx		\n" \
74 	"	movq	(%rsp),%rdi		\n" \
75 	"	leaq	16(%rsp,%rdi,8),%rdx	\n" \
76 	"	leaq	8(%rsp),%rsi		\n" \
77 	"	subq	$8,%rsp			\n" \
78 	"	andq	$~15,%rsp		\n" \
79 	"	addq	$8,%rsp			\n" \
80 	"	jmp	___start		\n" \
81 	"	.previous")
82 
83 #define	MD_RCRT0_START					\
84 	__asm(						\
85 	".text						\n" \
86 	"	.align	8				\n" \
87 	"	.globl	__start				\n" \
88 	"	.type	__start,@function		\n" \
89 	"_start:					\n" \
90 	"__start:					\n" \
91 	"	movq	%rsp, %r12			\n" \
92 	"	subq	$8, %rsp			\n" \
93 	"	andq	$~15, %rsp			\n" \
94 	"	addq	$8, %rsp			\n" \
95 	"	pushq	%rbx				\n" \
96 	"	subq	$(16*8), %rsp			\n" \
97 	"	leaq	_DYNAMIC(%rip),%rdx		\n" \
98 	"	movq	%rsp, %rsi			\n" \
99 	"	movq	%r12, %rdi			\n" \
100 	"	call	_dl_boot_bind@PLT		\n" \
101 	"						\n" \
102 	"	movq	$0, %rcx			\n" \
103 	"	movq	%r12, %rsp			\n" \
104 	"	movq	(%rsp),%rdi			\n" \
105 	"	leaq	16(%rsp,%rdi,8),%rdx		\n" \
106 	"	leaq	8(%rsp),%rsi			\n" \
107 	"	subq	$8,%rsp				\n" \
108 	"	andq	$~15,%rsp			\n" \
109 	"	addq	$8,%rsp				\n" \
110 	"	jmp	___start			\n" \
111 	"						\n" \
112 	"	.global	_dl_exit			\n" \
113 	"	.type	_dl_exit,@function		\n" \
114 	"	.align	8				\n" \
115 	"_dl_exit:					\n" \
116 	"	movl	$ " STR(SYS_exit) ", %eax	\n" \
117 	"	syscall					\n" \
118 	"	int3					\n" \
119 	"	.previous")
120