1/* 2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_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. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* 29 * Copyright (c) 1992 NeXT Computer, Inc. 30 * 31 * Intel386 Family: Segment descriptors. 32 * 33 * HISTORY 34 * 35 * 29 March 1992 ? at NeXT 36 * Created. 37 */ 38 39/* 40 * Code segment descriptor. 41 */ 42 43typedef struct code_desc { 44 unsigned short limit00; 45 unsigned short base00; 46 unsigned char base16; 47 unsigned char type :5, 48#define DESC_CODE_EXEC 0x18 49#define DESC_CODE_READ 0x1a 50 dpl :2, 51 present :1; 52 unsigned char limit16 :4, 53 :2, 54 opsz :1, 55#define DESC_CODE_16B 0 56#define DESC_CODE_32B 1 57 granular:1; 58#define DESC_GRAN_BYTE 0 59#define DESC_GRAN_PAGE 1 60 unsigned char base24; 61} code_desc_t; 62 63/* 64 * Data segment descriptor. 65 */ 66 67typedef struct data_desc { 68 unsigned short limit00; 69 unsigned short base00; 70 unsigned char base16; 71 unsigned char type :5, 72#define DESC_DATA_RONLY 0x10 73#define DESC_DATA_WRITE 0x12 74 dpl :2, 75 present :1; 76 unsigned char limit16 :4, 77 :2, 78 stksz :1, 79#define DESC_DATA_16B 0 80#define DESC_DATA_32B 1 81 granular:1; 82 unsigned char base24; 83} data_desc_t; 84 85/* 86 * LDT segment descriptor. 87 */ 88 89typedef struct ldt_desc { 90 unsigned short limit00; 91 unsigned short base00; 92 unsigned char base16; 93 unsigned char type :5, 94#define DESC_LDT 0x02 95 :2, 96 present :1; 97 unsigned char limit16 :4, 98 :3, 99 granular:1; 100 unsigned char base24; 101} ldt_desc_t; 102 103#include <architecture/i386/sel.h> 104 105/* 106 * Call gate descriptor. 107 */ 108 109typedef struct call_gate { 110 unsigned short offset00; 111 sel_t seg; 112 unsigned int argcnt :5, 113 :3, 114 type :5, 115#define DESC_CALL_GATE 0x0c 116 dpl :2, 117 present :1, 118 offset16:16; 119} call_gate_t; 120 121/* 122 * Trap gate descriptor. 123 */ 124 125typedef struct trap_gate { 126 unsigned short offset00; 127 sel_t seg; 128 unsigned int :8, 129 type :5, 130#define DESC_TRAP_GATE 0x0f 131 dpl :2, 132 present :1, 133 offset16:16; 134} trap_gate_t; 135 136 137/* 138 * Interrupt gate descriptor. 139 */ 140 141typedef struct intr_gate { 142 unsigned short offset00; 143 sel_t seg; 144 unsigned int :8, 145 type :5, 146#define DESC_INTR_GATE 0x0e 147 dpl :2, 148 present :1, 149 offset16:16; 150} intr_gate_t; 151