psl.h revision 127914
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 *	from: @(#)psl.h	5.2 (Berkeley) 1/18/91
33 * $FreeBSD: head/sys/amd64/include/psl.h 127914 2004-04-05 21:29:41Z imp $
34 */
35
36#ifndef _MACHINE_PSL_H_
37#define	_MACHINE_PSL_H_
38
39/*
40 * 386 processor status longword.
41 */
42#define	PSL_C		0x00000001	/* carry bit */
43#define	PSL_PF		0x00000004	/* parity bit */
44#define	PSL_AF		0x00000010	/* bcd carry bit */
45#define	PSL_Z		0x00000040	/* zero bit */
46#define	PSL_N		0x00000080	/* negative bit */
47#define	PSL_T		0x00000100	/* trace enable bit */
48#define	PSL_I		0x00000200	/* interrupt enable bit */
49#define	PSL_D		0x00000400	/* string instruction direction bit */
50#define	PSL_V		0x00000800	/* overflow bit */
51#define	PSL_IOPL	0x00003000	/* i/o privilege level */
52#define	PSL_NT		0x00004000	/* nested task bit */
53#define	PSL_RF		0x00010000	/* resume flag bit */
54/* #define PSL_VM	0x00020000 */	/* virtual 8086 mode bit */
55#define	PSL_AC		0x00040000	/* alignment checking */
56/* #define PSL_VIF	0x00080000 */	/* virtual interrupt enable */
57/* #define PSL_VIP	0x00100000 */	/* virtual interrupt pending */
58#define	PSL_ID		0x00200000	/* identification bit */
59
60/*
61 * The i486 manual says that we are not supposed to change reserved flags,
62 * but this is too much trouble since the reserved flags depend on the cpu
63 * and setting them to their historical values works in practice.
64 */
65#define	PSL_RESERVED_DEFAULT	0x00000002
66
67/*
68 * Initial flags for kernel and user mode.  The kernel later inherits
69 * PSL_I and some other flags from user mode.
70 */
71#define	PSL_KERNEL	PSL_RESERVED_DEFAULT
72#define	PSL_USER	(PSL_RESERVED_DEFAULT | PSL_I)
73
74/*
75 * Bits that can be changed in user mode on 486's.  We allow these bits
76 * to be changed using ptrace(), sigreturn() and procfs.  Setting PS_NT
77 * is undesirable but it may as well be allowed since users can inflict
78 * it on the kernel directly.  Changes to PSL_AC are silently ignored on
79 * 386's.
80 */
81#define	PSL_USERCHANGE (PSL_C | PSL_PF | PSL_AF | PSL_Z | PSL_N | PSL_T \
82			| PSL_D | PSL_V | PSL_NT | PSL_AC | PSL_ID)
83
84#endif /* !_MACHINE_PSL_H_ */
85