EXTERNAL_HEADERS/architecture/i386/desc.h

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