text: /*-
   * 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
   * $FreeBSD$
   */
  
  #pragma once
  
  /*
   * 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)
  