xref: /freebsd/sys/i386/include/specialreg.h (revision afe61c15161c324a7af299a9b8457aba5afc92db)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	from: @(#)specialreg.h	7.1 (Berkeley) 5/9/91
34  *	$Id: specialreg.h,v 1.2 1993/10/16 14:39:32 rgrimes Exp $
35  */
36 
37 #ifndef _MACHINE_SPECIALREG_H_
38 #define _MACHINE_SPECIALREG_H_ 1
39 
40 /*
41  * Bits in 386 special registers:
42  */
43 
44 #define	CR0_PE	0x00000001	/* Protected mode Enable */
45 #define	CR0_MP	0x00000002	/* "Math" Present (NPX or NPX emulator) */
46 #ifdef notused
47 #define	CR0_EM	0x00000004	/* EMulate non-NPX coproc. (trap ESC only) */
48 #endif
49 #define	CR0_TS	0x00000008	/* Task Switched (if MP, trap ESC and WAIT) */
50 #ifdef notused
51 #define	CR0_ET	0x00000010	/* Extension Type (387 (if set) vs 287) */
52 #endif
53 #define	CR0_PG	0x80000000	/* PaGing enable */
54 
55 /*
56  * Bits in 486 special registers:
57  */
58 
59 #define CR0_NE	0x00000020	/* Numeric Error enable (EX16 vs IRQ13) */
60 #define CR0_WP	0x00010000	/* Write Protect (honor ~PG_W in all modes) */
61 #ifdef notyet
62 #define CR0_AM	0x00040000	/* Alignment Mask (set to enable AC flag) */
63 #endif
64 #endif /* _MACHINE_SPECIALREG_H_ */
65