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/*-
* 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.
* 4. 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: head/sys/x86/include/psl.h 258135 2013-11-14 15:37:20Z emaste $
*/
#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_ */
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