1/* 2 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23/* 24 * Copyright (c) 1992 NeXT Computer, Inc. 25 * 26 * Intel386 Family: Segment descriptors. 27 * 28 * HISTORY 29 * 30 * 29 March 1992 ? at NeXT 31 * Created. 32 */ 33 34#ifndef _ARCH_I386_DESC_H_ 35#define _ARCH_I386_DESC_H_ 36 37/* 38 * Code segment descriptor. 39 */ 40 41typedef struct code_desc { 42 unsigned short limit00; 43 unsigned short base00; 44 unsigned char base16; 45 unsigned char type :5, 46#define DESC_CODE_EXEC 0x18 47#define DESC_CODE_READ 0x1a 48 dpl :2, 49 present :1; 50 unsigned char limit16 :4, 51 :2, 52 opsz :1, 53#define DESC_CODE_16B 0 54#define DESC_CODE_32B 1 55 granular:1; 56#define DESC_GRAN_BYTE 0 57#define DESC_GRAN_PAGE 1 58 unsigned char base24; 59} code_desc_t; 60 61/* 62 * Data segment descriptor. 63 */ 64 65typedef struct data_desc { 66 unsigned short limit00; 67 unsigned short base00; 68 unsigned char base16; 69 unsigned char type :5, 70#define DESC_DATA_RONLY 0x10 71#define DESC_DATA_WRITE 0x12 72 dpl :2, 73 present :1; 74 unsigned char limit16 :4, 75 :2, 76 stksz :1, 77#define DESC_DATA_16B 0 78#define DESC_DATA_32B 1 79 granular:1; 80 unsigned char base24; 81} data_desc_t; 82 83/* 84 * LDT segment descriptor. 85 */ 86 87typedef struct ldt_desc { 88 unsigned short limit00; 89 unsigned short base00; 90 unsigned char base16; 91 unsigned char type :5, 92#define DESC_LDT 0x02 93 :2, 94 present :1; 95 unsigned char limit16 :4, 96 :3, 97 granular:1; 98 unsigned char base24; 99} ldt_desc_t; 100 101#include <architecture/i386/sel.h> 102 103/* 104 * Call gate descriptor. 105 */ 106 107typedef struct call_gate { 108 unsigned short offset00; 109 sel_t seg; 110 unsigned int argcnt :5, 111 :3, 112 type :5, 113#define DESC_CALL_GATE 0x0c 114 dpl :2, 115 present :1, 116 offset16:16; 117} call_gate_t; 118 119/* 120 * Trap gate descriptor. 121 */ 122 123typedef struct trap_gate { 124 unsigned short offset00; 125 sel_t seg; 126 unsigned int :8, 127 type :5, 128#define DESC_TRAP_GATE 0x0f 129 dpl :2, 130 present :1, 131 offset16:16; 132} trap_gate_t; 133 134 135/* 136 * Interrupt gate descriptor. 137 */ 138 139typedef struct intr_gate { 140 unsigned short offset00; 141 sel_t seg; 142 unsigned int :8, 143 type :5, 144#define DESC_INTR_GATE 0x0e 145 dpl :2, 146 present :1, 147 offset16:16; 148} intr_gate_t; 149 150#endif /* _ARCH_I386_DESC_H_ */ 151