sys/cpu/i386/include/psl.h

   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  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      from: @(#)psl.h 5.2 (Berkeley) 1/18/91
  37  * $FreeBSD: src/sys/i386/include/psl.h,v 1.10.2.1 2001/11/22 08:53:35 sobomax Exp $
  38  * $DragonFly: src/sys/cpu/i386/include/psl.h,v 1.3 2006/11/07 06:43:22 dillon Exp $
  39  */
  40
  41 #ifndef _CPU_PSL_H_
  42 #define _CPU_PSL_H_
  43
  44 /*
  45  * 386 processor status longword.
  46  */
  47 #define PSL_C           0x00000001      /* carry bit */
  48 #define PSL_PF          0x00000004      /* parity bit */
  49 #define PSL_AF          0x00000010      /* bcd carry bit */
  50 #define PSL_Z           0x00000040      /* zero bit */
  51 #define PSL_N           0x00000080      /* negative bit */
  52 #define PSL_T           0x00000100      /* trace enable bit */
  53 #define PSL_I           0x00000200      /* interrupt enable bit */
  54 #define PSL_D           0x00000400      /* string instruction direction bit */
  55 #define PSL_V           0x00000800      /* overflow bit */
  56 #define PSL_IOPL        0x00003000      /* i/o privilege level */
  57 #define PSL_NT          0x00004000      /* nested task bit */
  58 #define PSL_RF          0x00010000      /* resume flag bit */
  59 #define PSL_VM          0x00020000      /* virtual 8086 mode bit */
  60 #define PSL_AC          0x00040000      /* alignment checking */
  61 #define PSL_VIF         0x00080000      /* virtual interrupt enable */
  62 #define PSL_VIP         0x00100000      /* virtual interrupt pending */
  63 #define PSL_ID          0x00200000      /* identification bit */
  64
  65 /*
  66  * The i486 manual says that we are not supposed to change reserved flags,
  67  * but this is too much trouble since the reserved flags depend on the cpu
  68  * and setting them to their historical values works in practice.
  69  */
  70 #define PSL_RESERVED_DEFAULT    0x00000002
  71
  72 /*
  73  * Initial flags for kernel and user mode.  The kernel later inherits
  74  * PSL_I and some other flags from user mode.
  75  */
  76 #define PSL_KERNEL      PSL_RESERVED_DEFAULT
  77 #define PSL_USER        (PSL_RESERVED_DEFAULT | PSL_I)
  78
  79 /*
  80  * Bits that can be changed in user mode on 486's.  We allow these bits
  81  * to be changed using ptrace(), sigreturn() and procfs.  Setting PS_NT
  82  * is undesirable but it may as well be allowed since users can inflict
  83  * it on the kernel directly.  Changes to PSL_AC are silently ignored on
  84  * 386's.
  85  */
  86 #define PSL_USERCHANGE (PSL_C | PSL_PF | PSL_AF | PSL_Z | PSL_N | PSL_T \
  87                         | PSL_D | PSL_V | PSL_NT | PSL_AC | PSL_ID)
  88
  89 #endif /* !_CPU_PSL_H_ */