xref: /openbsd/lib/csu/arm/md_init.h (revision 76d0caae)
1 /* $OpenBSD: md_init.h,v 1.17 2020/10/19 17:57:40 naddy 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 /*
37  * arm overrides these because it uses %progbits instead of @progbits
38  */
39 #define MD_DATA_SECTION_FLAGS_SYMBOL(section, flags, type, symbol)	\
40 	extern __dso_hidden type symbol[];				\
41 	__asm("	.section "section",\""flags"\",%progbits		\n" \
42 	"	.balign 4						\n" \
43 	#symbol":							\n" \
44 	"	.previous")
45 #define MD_DATA_SECTION_SYMBOL_VALUE(section, type, symbol, value)	\
46 	extern __dso_hidden type symbol[];				\
47 	__asm("	.section "section",\"aw\",%progbits			\n" \
48 	"	.balign 4						\n" \
49 	#symbol":							\n" \
50 	"	.int "#value"						\n" \
51 	"	.previous")
52 #define MD_DATA_SECTION_FLAGS_VALUE(section, flags, value)		\
53 	__asm("	.section "section",\""flags"\",%progbits		\n" \
54 	"	.balign 4						\n" \
55 	"	.int "#value"						\n" \
56 	"	.previous")
57 
58 #define MD_SECT_CALL_FUNC(section, func) \
59 	__asm (".section "#section", \"ax\"		\n" \
60 	"	movw	r0, #:lower16:" #func "- 1f - 8	\n" \
61 	"	movt	r0, #:upper16:" #func "- 1f - 8	\n" \
62 	"1:	add	r0, r0, pc			\n" \
63 	"	blx	r0				\n" \
64 	"	.previous")
65 
66 #define MD_SECTION_PROLOGUE(sect, entry_pt)	\
67 	__asm (					\
68 	".section "#sect",\"ax\",%progbits	\n" \
69 	"	.globl " #entry_pt "		\n" \
70 	"	.type " #entry_pt ",%function	\n" \
71 	"	.align 4			\n" \
72 	#entry_pt":				\n" \
73 	"	push	{r4, lr}		\n" \
74 	"	/* fall thru */			\n" \
75 	"	.previous")
76 
77 
78 #define MD_SECTION_EPILOGUE(sect)		\
79 	__asm (					\
80 	".section "#sect",\"ax\",%progbits	\n" \
81 	"	pop	{r4, pc}		\n" \
82 	"	.previous")
83 
84 
85 /*
86  * The definitions of environ and __progname prevent the creation
87  * of COPY relocations for WEAK symbols.
88  */
89 #define	MD_CRT0_START				\
90 	char **environ, *__progname;		\
91 	__asm(					\
92 	".text					\n" \
93 	"	.align	0			\n" \
94 	"	.globl	_start			\n" \
95 	"	.globl	__start			\n" \
96 	"_start:				\n" \
97 	"__start:				\n" \
98 	"	mov	r3, r0	/* cleanup */	\n" \
99 	"/* Get argc/argv/envp from stack */	\n" \
100 	"	ldr	r0, [sp, #0]		\n" \
101 	"	add	r1, sp, #4		\n" \
102 	"	add	r2, r1, r0, lsl #2	\n" \
103 	"	add	r2, r2, #4		\n" \
104 	"					\n" \
105 	"/*					\n" \
106 	" * Ensure the stack is properly	\n" \
107 	" * aligned before calling C code.	\n" \
108 	" */					\n" \
109 	"	bic	sp, sp, #7" /*__STRING(STACKALIGNBYTES)*/ "	\n" \
110 	"	b	___start		\n" \
111 	".previous");
112 
113 #define	MD_RCRT0_START				\
114 	char **environ, *__progname;		\
115 	__asm(					\
116 	".text					\n" \
117 	"	.align	0			\n" \
118 	"	.globl	_start			\n" \
119 	"	.globl	__start			\n" \
120 	"_start:				\n" \
121 	"__start:				\n" \
122 	"	mov	fp, sp			\n" \
123 	"	mov	r0, fp			\n" \
124 	"					\n" \
125 	"	sub	sp, sp, #4+4+(16*4)	\n" \
126 	"	add	r1, sp, #4		\n" \
127 	"					\n" \
128 	"	ldr	r8, .L_GOT		\n" \
129 	"1:	add	r8, pc, r8		\n" \
130 	"	ldr	r2, .L__DYNAMIC		\n" \
131 	"	add	r2, r2, r8		\n" \
132 	"					\n" \
133 	"	bl	_dl_boot_bind		\n" \
134 	"					\n" \
135 	"	mov	sp, fp			\n" \
136 	"	mov	fp, #0			\n" \
137 	"					\n" \
138 	"	mov	r3, #0	/* cleanup */	\n" \
139 	"/* Get argc/argv/envp from stack */	\n" \
140 	"	ldr	r0, [sp, #0]		\n" \
141 	"	add	r1, sp, #4		\n" \
142 	"	add	r2, r1, r0, lsl #2	\n" \
143 	"	add	r2, r2, #4		\n" \
144 	"					\n" \
145 	"/*					\n" \
146 	" * Ensure the stack is properly	\n" \
147 	" * aligned before calling C code.	\n" \
148 	" */					\n" \
149 	"	bic	sp, sp, #7" /*__STRING(STACKALIGNBYTES)*/ "	\n" \
150 	"	b	___start		\n" \
151 	"					\n" \
152 	".L_GOT:				\n" \
153 	"	.long	_GLOBAL_OFFSET_TABLE_-(1b+8)	\n" \
154 	".L__DYNAMIC:				\n" \
155 	"	.long	_DYNAMIC(GOTOFF)	\n" \
156 	"					\n" \
157 	"_dl_exit:				\n" \
158 	"	mov	r12, #" STR(SYS_exit) " \n" \
159 	"	swi	#0			\n" \
160 	"	dsb	nsh			\n" \
161 	"	isb				\n" \
162 	"	udf	#0			\n" \
163 	".previous");
164