psl.h revision 50477
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: head/sys/i386/include/psl.h 50477 1999-08-28 01:08:13Z peter $ 38 */ 39 40#ifndef _MACHINE_PSL_H_ 41#define _MACHINE_PSL_H_ 42 43/* 44 * 386 processor status longword. 45 */ 46#define PSL_C 0x00000001 /* carry bit */ 47#define PSL_PF 0x00000004 /* parity bit */ 48#define PSL_AF 0x00000010 /* bcd carry bit */ 49#define PSL_Z 0x00000040 /* zero bit */ 50#define PSL_N 0x00000080 /* negative bit */ 51#define PSL_T 0x00000100 /* trace enable bit */ 52#define PSL_I 0x00000200 /* interrupt enable bit */ 53#define PSL_D 0x00000400 /* string instruction direction bit */ 54#define PSL_V 0x00000800 /* overflow bit */ 55#define PSL_IOPL 0x00003000 /* i/o privilege level */ 56#define PSL_NT 0x00004000 /* nested task bit */ 57#define PSL_RF 0x00010000 /* resume flag bit */ 58#define PSL_VM 0x00020000 /* virtual 8086 mode bit */ 59#define PSL_AC 0x00040000 /* alignment checking */ 60#define PSL_VIF 0x00080000 /* virtual interrupt enable */ 61#define PSL_VIP 0x00100000 /* virtual interrupt pending */ 62#define PSL_ID 0x00200000 /* identification bit */ 63 64/* 65 * The i486 manual says that we are not supposed to change reserved flags, 66 * but this is too much trouble since the reserved flags depend on the cpu 67 * and setting them to their historical values works in practice. 68 */ 69#define PSL_RESERVED_DEFAULT 0x00000002 70 71/* 72 * Initial flags for kernel and user mode. The kernel later inherits 73 * PSL_I and some other flags from user mode. 74 */ 75#define PSL_KERNEL PSL_RESERVED_DEFAULT 76#define PSL_USER (PSL_RESERVED_DEFAULT | PSL_I) 77 78/* 79 * Bits that can be changed in user mode on 486's. We allow these bits 80 * to be changed using ptrace(), sigreturn() and procfs. Setting PS_NT 81 * is undesirable but it may as well be allowed since users can inflict 82 * it on the kernel directly. Changes to PSL_AC are silently ignored on 83 * 386's. 84 */ 85#define PSL_USERCHANGE (PSL_C | PSL_PF | PSL_AF | PSL_Z | PSL_N | PSL_T \ 86 | PSL_D | PSL_V | PSL_NT | PSL_AC) 87 88#endif /* !_MACHINE_PSL_H_ */ 89