xref: /illumos-gate/usr/src/boot/sys/x86/include/psl.h (revision 55fea89dcaa64928bed4327112404dcb3e07b79f)
1*199767f8SToomas Soome /*-
2*199767f8SToomas Soome  * Copyright (c) 1990 The Regents of the University of California.
3*199767f8SToomas Soome  * All rights reserved.
4*199767f8SToomas Soome  *
5*199767f8SToomas Soome  * This code is derived from software contributed to Berkeley by
6*199767f8SToomas Soome  * William Jolitz.
7*199767f8SToomas Soome  *
8*199767f8SToomas Soome  * Redistribution and use in source and binary forms, with or without
9*199767f8SToomas Soome  * modification, are permitted provided that the following conditions
10*199767f8SToomas Soome  * are met:
11*199767f8SToomas Soome  * 1. Redistributions of source code must retain the above copyright
12*199767f8SToomas Soome  *    notice, this list of conditions and the following disclaimer.
13*199767f8SToomas Soome  * 2. Redistributions in binary form must reproduce the above copyright
14*199767f8SToomas Soome  *    notice, this list of conditions and the following disclaimer in the
15*199767f8SToomas Soome  *    documentation and/or other materials provided with the distribution.
16*199767f8SToomas Soome  * 4. Neither the name of the University nor the names of its contributors
17*199767f8SToomas Soome  *    may be used to endorse or promote products derived from this software
18*199767f8SToomas Soome  *    without specific prior written permission.
19*199767f8SToomas Soome  *
20*199767f8SToomas Soome  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21*199767f8SToomas Soome  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22*199767f8SToomas Soome  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23*199767f8SToomas Soome  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24*199767f8SToomas Soome  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25*199767f8SToomas Soome  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26*199767f8SToomas Soome  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27*199767f8SToomas Soome  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28*199767f8SToomas Soome  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29*199767f8SToomas Soome  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30*199767f8SToomas Soome  * SUCH DAMAGE.
31*199767f8SToomas Soome  *
32*199767f8SToomas Soome  *	from: @(#)psl.h	5.2 (Berkeley) 1/18/91
33*199767f8SToomas Soome  * $FreeBSD$
34*199767f8SToomas Soome  */
35*199767f8SToomas Soome 
36*199767f8SToomas Soome #ifndef _MACHINE_PSL_H_
37*199767f8SToomas Soome #define	_MACHINE_PSL_H_
38*199767f8SToomas Soome 
39*199767f8SToomas Soome /*
40*199767f8SToomas Soome  * 386 processor status longword.
41*199767f8SToomas Soome  */
42*199767f8SToomas Soome #define	PSL_C		0x00000001	/* carry bit */
43*199767f8SToomas Soome #define	PSL_PF		0x00000004	/* parity bit */
44*199767f8SToomas Soome #define	PSL_AF		0x00000010	/* bcd carry bit */
45*199767f8SToomas Soome #define	PSL_Z		0x00000040	/* zero bit */
46*199767f8SToomas Soome #define	PSL_N		0x00000080	/* negative bit */
47*199767f8SToomas Soome #define	PSL_T		0x00000100	/* trace enable bit */
48*199767f8SToomas Soome #define	PSL_I		0x00000200	/* interrupt enable bit */
49*199767f8SToomas Soome #define	PSL_D		0x00000400	/* string instruction direction bit */
50*199767f8SToomas Soome #define	PSL_V		0x00000800	/* overflow bit */
51*199767f8SToomas Soome #define	PSL_IOPL	0x00003000	/* i/o privilege level */
52*199767f8SToomas Soome #define	PSL_NT		0x00004000	/* nested task bit */
53*199767f8SToomas Soome #define	PSL_RF		0x00010000	/* resume flag bit */
54*199767f8SToomas Soome #define	PSL_VM		0x00020000	/* virtual 8086 mode bit */
55*199767f8SToomas Soome #define	PSL_AC		0x00040000	/* alignment checking */
56*199767f8SToomas Soome #define	PSL_VIF		0x00080000	/* virtual interrupt enable */
57*199767f8SToomas Soome #define	PSL_VIP		0x00100000	/* virtual interrupt pending */
58*199767f8SToomas Soome #define	PSL_ID		0x00200000	/* identification bit */
59*199767f8SToomas Soome 
60*199767f8SToomas Soome /*
61*199767f8SToomas Soome  * The i486 manual says that we are not supposed to change reserved flags,
62*199767f8SToomas Soome  * but this is too much trouble since the reserved flags depend on the cpu
63*199767f8SToomas Soome  * and setting them to their historical values works in practice.
64*199767f8SToomas Soome  */
65*199767f8SToomas Soome #define	PSL_RESERVED_DEFAULT	0x00000002
66*199767f8SToomas Soome 
67*199767f8SToomas Soome /*
68*199767f8SToomas Soome  * Initial flags for kernel and user mode.  The kernel later inherits
69*199767f8SToomas Soome  * PSL_I and some other flags from user mode.
70*199767f8SToomas Soome  */
71*199767f8SToomas Soome #define	PSL_KERNEL	PSL_RESERVED_DEFAULT
72*199767f8SToomas Soome #define	PSL_USER	(PSL_RESERVED_DEFAULT | PSL_I)
73*199767f8SToomas Soome 
74*199767f8SToomas Soome /*
75*199767f8SToomas Soome  * Bits that can be changed in user mode on 486's.  We allow these bits
76*199767f8SToomas Soome  * to be changed using ptrace(), sigreturn() and procfs.  Setting PS_NT
77*199767f8SToomas Soome  * is undesirable but it may as well be allowed since users can inflict
78*199767f8SToomas Soome  * it on the kernel directly.  Changes to PSL_AC are silently ignored on
79*199767f8SToomas Soome  * 386's.
80*199767f8SToomas Soome  *
81*199767f8SToomas Soome  * Users are allowed to change the privileged flag PSL_RF.  The cpu sets PSL_RF
82*199767f8SToomas Soome  * in tf_eflags for faults.  Debuggers should sometimes set it there too.
83*199767f8SToomas Soome  * tf_eflags is kept in the signal context during signal handling and there is
84*199767f8SToomas Soome  * no other place to remember it, so the PSL_RF bit may be corrupted by the
85*199767f8SToomas Soome  * signal handler without us knowing.  Corruption of the PSL_RF bit at worst
86*199767f8SToomas Soome  * causes one more or one less debugger trap, so allowing it is fairly
87*199767f8SToomas Soome  * harmless.
88*199767f8SToomas Soome  */
89*199767f8SToomas Soome #define	PSL_USERCHANGE (PSL_C | PSL_PF | PSL_AF | PSL_Z | PSL_N | PSL_T \
90*199767f8SToomas Soome 			| PSL_D | PSL_V | PSL_NT | PSL_RF | PSL_AC | PSL_ID)
91*199767f8SToomas Soome 
92*199767f8SToomas Soome #endif /* !_MACHINE_PSL_H_ */
93