xref: /freebsd/sys/i386/include/asm.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
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  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	from: @(#)DEFS.h	5.1 (Berkeley) 4/23/90
35  * $FreeBSD$
36  */
37 
38 #ifndef _MACHINE_ASM_H_
39 #define	_MACHINE_ASM_H_
40 
41 #include <sys/cdefs.h>
42 
43 #ifdef PIC
44 #define	PIC_PROLOGUE	\
45 	pushl	%ebx;	\
46 	call	1f;	\
47 1:			\
48 	popl	%ebx;	\
49 	addl	$_GLOBAL_OFFSET_TABLE_+[.-1b],%ebx
50 #define	PIC_EPILOGUE	\
51 	popl	%ebx
52 #define	PIC_PLT(x)	x@PLT
53 #define	PIC_GOT(x)	x@GOT(%ebx)
54 #define	PIC_GOTOFF(x)	x@GOTOFF(%ebx)
55 #else
56 #define	PIC_PROLOGUE
57 #define	PIC_EPILOGUE
58 #define	PIC_PLT(x)	x
59 #define	PIC_GOTOFF(x)	x
60 #endif
61 
62 /*
63  * CNAME and HIDENAME manage the relationship between symbol names in C
64  * and the equivalent assembly language names.  CNAME is given a name as
65  * it would be used in a C program.  It expands to the equivalent assembly
66  * language name.  HIDENAME is given an assembly-language name, and expands
67  * to a possibly-modified form that will be invisible to C programs.
68  */
69 #define CNAME(csym)		csym
70 #define HIDENAME(asmsym)	.asmsym
71 
72 /* XXX should use .p2align 4,0x90 for -m486. */
73 #define _START_ENTRY	.text; .p2align 2,0x90
74 
75 #define _ENTRY(x)	_START_ENTRY; \
76 			.globl CNAME(x); .type CNAME(x),@function; CNAME(x): \
77 			.cfi_startproc
78 #define	END(x)		.cfi_endproc; .size x, . - x
79 
80 #ifdef PROF
81 #define	ALTENTRY(x)	_ENTRY(x); \
82 			pushl %ebp; \
83 			.cfi_def_cfa_offset 8; \
84 			.cfi_offset %ebp, -8; \
85 			movl %esp,%ebp; \
86 			call PIC_PLT(HIDENAME(mcount)); \
87 			popl %ebp; \
88 			.cfi_restore %ebp; \
89 			.cfi_def_cfa_offset 4; \
90 			jmp 9f
91 #define	ENTRY(x)	_ENTRY(x); \
92 			pushl %ebp; \
93 			.cfi_def_cfa_offset 8; \
94 			.cfi_offset %ebp, -8; \
95 			movl %esp,%ebp; \
96 			call PIC_PLT(HIDENAME(mcount)); \
97 			popl %ebp; \
98 			.cfi_restore %ebp; \
99 			.cfi_def_cfa_offset 4; \
100 			9:
101 #else
102 #define	ALTENTRY(x)	_ENTRY(x)
103 #define	ENTRY(x)	_ENTRY(x)
104 #endif
105 
106 /*
107  * WEAK_REFERENCE(): create a weak reference alias from sym.
108  * The macro is not a general asm macro that takes arbitrary names,
109  * but one that takes only C names. It does the non-null name
110  * translation inside the macro.
111  */
112 
113 #define	WEAK_REFERENCE(sym, alias)					\
114 	.weak CNAME(alias);						\
115 	.equ CNAME(alias),CNAME(sym)
116 
117 /*
118  * STRONG_ALIAS: create a strong alias.
119  */
120 #define	STRONG_ALIAS(alias,sym)						\
121 	.globl alias;							\
122 	alias = sym
123 
124 #define RCSID(x)	.text; .asciz x
125 
126 #undef __FBSDID
127 #if !defined(STRIP_FBSDID)
128 #define __FBSDID(s)	.ident s
129 #else
130 #define __FBSDID(s)	/* nothing */
131 #endif /* not STRIP_FBSDID */
132 
133 #endif /* !_MACHINE_ASM_H_ */
134