xref: /freebsd/sys/i386/include/asm.h (revision 1d386b48a555f61cb7325543adbbb5c3f3407a66)
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  */
36 
37 #ifndef _MACHINE_ASM_H_
38 #define	_MACHINE_ASM_H_
39 
40 #include <sys/cdefs.h>
41 
42 #ifdef PIC
43 #define	PIC_PROLOGUE	\
44 	pushl	%ebx;	\
45 	call	1f;	\
46 1:			\
47 	popl	%ebx;	\
48 	addl	$_GLOBAL_OFFSET_TABLE_+[.-1b],%ebx
49 #define	PIC_EPILOGUE	\
50 	popl	%ebx
51 #define	PIC_PLT(x)	x@PLT
52 #define	PIC_GOT(x)	x@GOT(%ebx)
53 #define	PIC_GOTOFF(x)	x@GOTOFF(%ebx)
54 #else
55 #define	PIC_PROLOGUE
56 #define	PIC_EPILOGUE
57 #define	PIC_PLT(x)	x
58 #define	PIC_GOTOFF(x)	x
59 #endif
60 
61 /*
62  * CNAME and HIDENAME manage the relationship between symbol names in C
63  * and the equivalent assembly language names.  CNAME is given a name as
64  * it would be used in a C program.  It expands to the equivalent assembly
65  * language name.  HIDENAME is given an assembly-language name, and expands
66  * to a possibly-modified form that will be invisible to C programs.
67  */
68 #define CNAME(csym)		csym
69 #define HIDENAME(asmsym)	.asmsym
70 
71 /* XXX should use .p2align 4,0x90 for -m486. */
72 #define _START_ENTRY	.text; .p2align 2,0x90
73 
74 #define _ENTRY(x)	_START_ENTRY; \
75 			.globl CNAME(x); .type CNAME(x),@function; CNAME(x): \
76 			.cfi_startproc
77 #define	END(x)		.cfi_endproc; .size x, . - x
78 
79 #ifdef PROF
80 #define	ALTENTRY(x)	_ENTRY(x); \
81 			pushl %ebp; \
82 			.cfi_def_cfa_offset 8; \
83 			.cfi_offset %ebp, -8; \
84 			movl %esp,%ebp; \
85 			call PIC_PLT(HIDENAME(mcount)); \
86 			popl %ebp; \
87 			.cfi_restore %ebp; \
88 			.cfi_def_cfa_offset 4; \
89 			jmp 9f
90 #define	ENTRY(x)	_ENTRY(x); \
91 			pushl %ebp; \
92 			.cfi_def_cfa_offset 8; \
93 			.cfi_offset %ebp, -8; \
94 			movl %esp,%ebp; \
95 			call PIC_PLT(HIDENAME(mcount)); \
96 			popl %ebp; \
97 			.cfi_restore %ebp; \
98 			.cfi_def_cfa_offset 4; \
99 			9:
100 #else
101 #define	ALTENTRY(x)	_ENTRY(x)
102 #define	ENTRY(x)	_ENTRY(x)
103 #endif
104 
105 /*
106  * WEAK_REFERENCE(): create a weak reference alias from sym.
107  * The macro is not a general asm macro that takes arbitrary names,
108  * but one that takes only C names. It does the non-null name
109  * translation inside the macro.
110  */
111 
112 #define	WEAK_REFERENCE(sym, alias)					\
113 	.weak CNAME(alias);						\
114 	.equ CNAME(alias),CNAME(sym)
115 
116 /*
117  * STRONG_ALIAS: create a strong alias.
118  */
119 #define	STRONG_ALIAS(alias,sym)						\
120 	.globl alias;							\
121 	alias = sym
122 
123 #define RCSID(x)	.text; .asciz x
124 
125 #undef __FBSDID
126 #if !defined(STRIP_FBSDID)
127 #define __FBSDID(s)	.ident s
128 #else
129 #define __FBSDID(s)	/* nothing */
130 #endif /* not STRIP_FBSDID */
131 
132 #endif /* !_MACHINE_ASM_H_ */
133