xref: /openbsd-src/lib/csu/arm/md_init.h (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /* $OpenBSD: md_init.h,v 1.4 2013/12/03 06:21:40 guenther 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 #ifdef __PIC__
37 	/* This nastyness derived from gcc3 output */
38 #define MD_SECT_CALL_FUNC(section, func) \
39 	__asm (".section "#section", \"ax\"		\n" \
40 	"	bl " #func "(PLT)			\n" \
41 	"	.previous")
42 #else
43 #define MD_SECT_CALL_FUNC(section, func) \
44 	__asm (".section "#section", \"ax\"	\n" \
45 	"	adr r0, 1f			\n" \
46 	"	ldr r0, [r0]			\n" \
47 	"	adr lr, 2f			\n" \
48 	"	mov pc,	r0			\n" \
49 	"1:	.word " #func "			\n" \
50 	"2:					\n" \
51 	"	.previous")
52 #endif
53 
54 #define MD_SECTION_PROLOGUE(sect, entry_pt)	\
55 	__asm (					\
56 	".section "#sect",\"ax\",%progbits	\n" \
57 	"	.globl " #entry_pt "		\n" \
58 	"	.type " #entry_pt ",%function	\n" \
59 	"	.align 4			\n" \
60 	#entry_pt":				\n" \
61 	"	mov ip, sp			\n" \
62 	"	stmfd sp!, {fp, ip, lr, pc}	\n" \
63 	"	sub fp, ip, #4			\n" \
64 	"	/* fall thru */			\n" \
65 	"	.previous")
66 
67 
68 #define MD_SECTION_EPILOGUE(sect)		\
69 	__asm (					\
70 	".section "#sect",\"ax\",%progbits	\n" \
71 	"	ldmea	fp, {fp, sp, pc}	\n" \
72 	"	.previous")
73 
74 
75 #define	MD_CRT0_START				\
76 	__asm(					\
77 	".text					\n" \
78 	"	.align	0			\n" \
79 	"	.globl	_start			\n" \
80 	"	.globl	__start			\n" \
81 	"_start:				\n" \
82 	"__start:				\n" \
83 	"	mov	r3, r0	/* cleanup */	\n" \
84 	"/* Get argc/argv/envp from stack */	\n" \
85 	"	ldr	r0, [sp, #0x0000]	\n" \
86 	"	add	r1, sp, #0x0004		\n" \
87 	"	add	r2, r1, r0, lsl #2	\n" \
88 	"	add	r2, r2, #0x0004		\n" \
89 	"					\n" \
90 	"/*					\n" \
91 	" * Ensure the stack is properly	\n" \
92 	" * aligned before calling C code.	\n" \
93 	" */					\n" \
94 	/* #if 1 */				\
95 	"	bic	sp, sp, #7" /*__STRING(STACKALIGNBYTES)*/ "	\n" \
96 	/* #endif */				\
97 	"	sub	sp, sp, #8		\n" \
98 	"	str	r5, [sp, #4]		\n" \
99 	"	str	r4, [sp, #0]		\n" \
100 	"					\n" \
101 	"	b	___start		\n" \
102 	".previous");
103