1bf21cd93STycho Nightingale /*- 2bf21cd93STycho Nightingale * Copyright (c) 1990 The Regents of the University of California. 3bf21cd93STycho Nightingale * All rights reserved. 4bf21cd93STycho Nightingale * 5bf21cd93STycho Nightingale * This code is derived from software contributed to Berkeley by 6bf21cd93STycho Nightingale * William Jolitz. 7bf21cd93STycho Nightingale * 8bf21cd93STycho Nightingale * Redistribution and use in source and binary forms, with or without 9bf21cd93STycho Nightingale * modification, are permitted provided that the following conditions 10bf21cd93STycho Nightingale * are met: 11bf21cd93STycho Nightingale * 1. Redistributions of source code must retain the above copyright 12bf21cd93STycho Nightingale * notice, this list of conditions and the following disclaimer. 13bf21cd93STycho Nightingale * 2. Redistributions in binary form must reproduce the above copyright 14bf21cd93STycho Nightingale * notice, this list of conditions and the following disclaimer in the 15bf21cd93STycho Nightingale * documentation and/or other materials provided with the distribution. 16bf21cd93STycho Nightingale * 4. Neither the name of the University nor the names of its contributors 17bf21cd93STycho Nightingale * may be used to endorse or promote products derived from this software 18bf21cd93STycho Nightingale * without specific prior written permission. 19bf21cd93STycho Nightingale * 20bf21cd93STycho Nightingale * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21bf21cd93STycho Nightingale * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22bf21cd93STycho Nightingale * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23bf21cd93STycho Nightingale * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24bf21cd93STycho Nightingale * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25bf21cd93STycho Nightingale * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26bf21cd93STycho Nightingale * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27bf21cd93STycho Nightingale * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28bf21cd93STycho Nightingale * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29bf21cd93STycho Nightingale * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30bf21cd93STycho Nightingale * SUCH DAMAGE. 31bf21cd93STycho Nightingale * 32bf21cd93STycho Nightingale * from: @(#)psl.h 5.2 (Berkeley) 1/18/91 33bf21cd93STycho Nightingale * $FreeBSD: head/sys/x86/include/psl.h 258135 2013-11-14 15:37:20Z emaste $ 34bf21cd93STycho Nightingale */ 35bf21cd93STycho Nightingale 36bf21cd93STycho Nightingale #ifndef _MACHINE_PSL_H_ 37bf21cd93STycho Nightingale #define _MACHINE_PSL_H_ 38bf21cd93STycho Nightingale 39bf21cd93STycho Nightingale /* 40bf21cd93STycho Nightingale * 386 processor status longword. 41bf21cd93STycho Nightingale */ 42bf21cd93STycho Nightingale #define PSL_C 0x00000001 /* carry bit */ 43bf21cd93STycho Nightingale #define PSL_PF 0x00000004 /* parity bit */ 44bf21cd93STycho Nightingale #define PSL_AF 0x00000010 /* bcd carry bit */ 45bf21cd93STycho Nightingale #define PSL_Z 0x00000040 /* zero bit */ 46bf21cd93STycho Nightingale #define PSL_N 0x00000080 /* negative bit */ 47bf21cd93STycho Nightingale #define PSL_T 0x00000100 /* trace enable bit */ 48bf21cd93STycho Nightingale #define PSL_I 0x00000200 /* interrupt enable bit */ 49bf21cd93STycho Nightingale #define PSL_D 0x00000400 /* string instruction direction bit */ 50bf21cd93STycho Nightingale #define PSL_V 0x00000800 /* overflow bit */ 51bf21cd93STycho Nightingale #define PSL_IOPL 0x00003000 /* i/o privilege level */ 52bf21cd93STycho Nightingale #define PSL_NT 0x00004000 /* nested task bit */ 53bf21cd93STycho Nightingale #define PSL_RF 0x00010000 /* resume flag bit */ 54bf21cd93STycho Nightingale #define PSL_VM 0x00020000 /* virtual 8086 mode bit */ 55bf21cd93STycho Nightingale #define PSL_AC 0x00040000 /* alignment checking */ 56bf21cd93STycho Nightingale #define PSL_VIF 0x00080000 /* virtual interrupt enable */ 57bf21cd93STycho Nightingale #define PSL_VIP 0x00100000 /* virtual interrupt pending */ 58bf21cd93STycho Nightingale #define PSL_ID 0x00200000 /* identification bit */ 59bf21cd93STycho Nightingale 60bf21cd93STycho Nightingale /* 61bf21cd93STycho Nightingale * The i486 manual says that we are not supposed to change reserved flags, 62bf21cd93STycho Nightingale * but this is too much trouble since the reserved flags depend on the cpu 63bf21cd93STycho Nightingale * and setting them to their historical values works in practice. 64bf21cd93STycho Nightingale */ 65bf21cd93STycho Nightingale #define PSL_RESERVED_DEFAULT 0x00000002 66bf21cd93STycho Nightingale 67bf21cd93STycho Nightingale /* 68bf21cd93STycho Nightingale * Initial flags for kernel and user mode. The kernel later inherits 69bf21cd93STycho Nightingale * PSL_I and some other flags from user mode. 70bf21cd93STycho Nightingale */ 71bf21cd93STycho Nightingale #define PSL_KERNEL PSL_RESERVED_DEFAULT 72bf21cd93STycho Nightingale #define PSL_USER (PSL_RESERVED_DEFAULT | PSL_I) 73bf21cd93STycho Nightingale 74bf21cd93STycho Nightingale /* 75bf21cd93STycho Nightingale * Bits that can be changed in user mode on 486's. We allow these bits 76bf21cd93STycho Nightingale * to be changed using ptrace(), sigreturn() and procfs. Setting PS_NT 77bf21cd93STycho Nightingale * is undesirable but it may as well be allowed since users can inflict 78bf21cd93STycho Nightingale * it on the kernel directly. Changes to PSL_AC are silently ignored on 79bf21cd93STycho Nightingale * 386's. 80bf21cd93STycho Nightingale * 81bf21cd93STycho Nightingale * Users are allowed to change the privileged flag PSL_RF. The cpu sets PSL_RF 82bf21cd93STycho Nightingale * in tf_eflags for faults. Debuggers should sometimes set it there too. 83bf21cd93STycho Nightingale * tf_eflags is kept in the signal context during signal handling and there is 84bf21cd93STycho Nightingale * no other place to remember it, so the PSL_RF bit may be corrupted by the 85bf21cd93STycho Nightingale * signal handler without us knowing. Corruption of the PSL_RF bit at worst 86bf21cd93STycho Nightingale * causes one more or one less debugger trap, so allowing it is fairly 87bf21cd93STycho Nightingale * harmless. 88bf21cd93STycho Nightingale */ 89bf21cd93STycho Nightingale #define PSL_USERCHANGE (PSL_C | PSL_PF | PSL_AF | PSL_Z | PSL_N | PSL_T \ 90bf21cd93STycho Nightingale | PSL_D | PSL_V | PSL_NT | PSL_RF | PSL_AC | PSL_ID) 91bf21cd93STycho Nightingale 92bf21cd93STycho Nightingale #endif /* !_MACHINE_PSL_H_ */ 93