freebsd-dev/sys/x86/include/psl.h
Warner Losh fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

93 lines
4.0 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)psl.h 5.2 (Berkeley) 1/18/91
* $FreeBSD$
*/
#ifndef _MACHINE_PSL_H_
#define _MACHINE_PSL_H_
/*
* 386 processor status longword.
*/
#define PSL_C 0x00000001 /* carry bit */
#define PSL_PF 0x00000004 /* parity bit */
#define PSL_AF 0x00000010 /* bcd carry bit */
#define PSL_Z 0x00000040 /* zero bit */
#define PSL_N 0x00000080 /* negative bit */
#define PSL_T 0x00000100 /* trace enable bit */
#define PSL_I 0x00000200 /* interrupt enable bit */
#define PSL_D 0x00000400 /* string instruction direction bit */
#define PSL_V 0x00000800 /* overflow bit */
#define PSL_IOPL 0x00003000 /* i/o privilege level */
#define PSL_NT 0x00004000 /* nested task bit */
#define PSL_RF 0x00010000 /* resume flag bit */
#define PSL_VM 0x00020000 /* virtual 8086 mode bit */
#define PSL_AC 0x00040000 /* alignment checking */
#define PSL_VIF 0x00080000 /* virtual interrupt enable */
#define PSL_VIP 0x00100000 /* virtual interrupt pending */
#define PSL_ID 0x00200000 /* identification bit */
/*
* The i486 manual says that we are not supposed to change reserved flags,
* but this is too much trouble since the reserved flags depend on the cpu
* and setting them to their historical values works in practice.
*/
#define PSL_RESERVED_DEFAULT 0x00000002
/*
* Initial flags for kernel and user mode. The kernel later inherits
* PSL_I and some other flags from user mode.
*/
#define PSL_KERNEL PSL_RESERVED_DEFAULT
#define PSL_USER (PSL_RESERVED_DEFAULT | PSL_I)
/*
* Bits that can be changed in user mode on 486's. We allow these bits
* to be changed using ptrace(), sigreturn() and procfs. Setting PS_NT
* is undesirable but it may as well be allowed since users can inflict
* it on the kernel directly. Changes to PSL_AC are silently ignored on
* 386's.
*
* Users are allowed to change the privileged flag PSL_RF. The cpu sets PSL_RF
* in tf_eflags for faults. Debuggers should sometimes set it there too.
* tf_eflags is kept in the signal context during signal handling and there is
* no other place to remember it, so the PSL_RF bit may be corrupted by the
* signal handler without us knowing. Corruption of the PSL_RF bit at worst
* causes one more or one less debugger trap, so allowing it is fairly
* harmless.
*/
#define PSL_USERCHANGE (PSL_C | PSL_PF | PSL_AF | PSL_Z | PSL_N | PSL_T \
| PSL_D | PSL_V | PSL_NT | PSL_RF | PSL_AC | PSL_ID)
#endif /* !_MACHINE_PSL_H_ */