EXTERNAL_HEADERS/architecture/i386/desc.h

   1 /*
   2  * Copyright (c) 2000-2019 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
  43 typedef 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                                 :1,
  54                         Lflag   :1,
  55                         opsz    :1,
  56 #define DESC_CODE_16B   0
  57 #define DESC_CODE_32B   1
  58                         granular:1;
  59 #define DESC_GRAN_BYTE  0
  60 #define DESC_GRAN_PAGE  1
  61     unsigned char       base24;
  62 } code_desc_t;
  63
  64 /*
  65  * Data segment descriptor.
  66  */
  67
  68 typedef struct data_desc {
  69     unsigned short      limit00;
  70     unsigned short      base00;
  71     unsigned char       base16;
  72     unsigned char       type    :5,
  73 #define DESC_DATA_RONLY 0x10
  74 #define DESC_DATA_WRITE 0x12
  75                         dpl     :2,
  76                         present :1;
  77     unsigned char       limit16 :4,
  78                                 :2,
  79                         stksz   :1,
  80 #define DESC_DATA_16B   0
  81 #define DESC_DATA_32B   1
  82                         granular:1;
  83     unsigned char       base24;
  84 } data_desc_t;
  85
  86 /*
  87  * LDT segment descriptor.
  88  */
  89
  90 typedef struct ldt_desc {
  91     unsigned short      limit00;
  92     unsigned short      base00;
  93     unsigned char       base16;
  94     unsigned char       type    :5,
  95 #define DESC_LDT        0x02
  96                                 :2,
  97                         present :1;
  98     unsigned char       limit16 :4,
  99                                 :3,
 100                         granular:1;
 101     unsigned char       base24;
 102 } ldt_desc_t;
 103
 104 #include <architecture/i386/sel.h>
 105
 106 /*
 107  * Call gate descriptor.
 108  */
 109
 110 typedef struct call_gate {
 111     unsigned short      offset00;
 112     sel_t               seg;
 113     unsigned int        argcnt  :5,
 114                                 :3,
 115                         type    :5,
 116 #define DESC_CALL_GATE  0x0c
 117                         dpl     :2,
 118                         present :1,
 119                         offset16:16;
 120 } call_gate_t;
 121
 122 /*
 123  * Trap gate descriptor.
 124  */
 125
 126 typedef struct trap_gate {
 127     unsigned short      offset00;
 128     sel_t               seg;
 129     unsigned int                :8,
 130                         type    :5,
 131 #define DESC_TRAP_GATE  0x0f
 132                         dpl     :2,
 133                         present :1,
 134                         offset16:16;
 135 } trap_gate_t;
 136
 137
 138 /*
 139  * Interrupt gate descriptor.
 140  */
 141
 142 typedef struct intr_gate {
 143     unsigned short      offset00;
 144     sel_t               seg;
 145     unsigned int                :8,
 146                         type    :5,
 147 #define DESC_INTR_GATE  0x0e
 148                         dpl     :2,
 149                         present :1,
 150                         offset16:16;
 151 } intr_gate_t;