EXTERNAL_HEADERS/architecture/i386/desc.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1992 NeXT Computer, Inc.
  27  *
  28  * Intel386 Family:     Segment descriptors.
  29  *
  30  * HISTORY
  31  *
  32  * 29 March 1992 ? at NeXT
  33  *      Created.
  34  */
  35
  36 /*
  37  * Code segment descriptor.
  38  */
  39
  40 typedef struct code_desc {
  41     unsigned short      limit00;
  42     unsigned short      base00;
  43     unsigned char       base16;
  44     unsigned char       type    :5,
  45 #define DESC_CODE_EXEC  0x18
  46 #define DESC_CODE_READ  0x1a
  47                         dpl     :2,
  48                         present :1;
  49     unsigned char       limit16 :4,
  50                                 :2,
  51                         opsz    :1,
  52 #define DESC_CODE_16B   0
  53 #define DESC_CODE_32B   1
  54                         granular:1;
  55 #define DESC_GRAN_BYTE  0
  56 #define DESC_GRAN_PAGE  1
  57     unsigned char       base24;
  58 } code_desc_t;
  59
  60 /*
  61  * Data segment descriptor.
  62  */
  63
  64 typedef struct data_desc {
  65     unsigned short      limit00;
  66     unsigned short      base00;
  67     unsigned char       base16;
  68     unsigned char       type    :5,
  69 #define DESC_DATA_RONLY 0x10
  70 #define DESC_DATA_WRITE 0x12
  71                         dpl     :2,
  72                         present :1;
  73     unsigned char       limit16 :4,
  74                                 :2,
  75                         stksz   :1,
  76 #define DESC_DATA_16B   0
  77 #define DESC_DATA_32B   1
  78                         granular:1;
  79     unsigned char       base24;
  80 } data_desc_t;
  81
  82 /*
  83  * LDT segment descriptor.
  84  */
  85
  86 typedef struct ldt_desc {
  87     unsigned short      limit00;
  88     unsigned short      base00;
  89     unsigned char       base16;
  90     unsigned char       type    :5,
  91 #define DESC_LDT        0x02
  92                                 :2,
  93                         present :1;
  94     unsigned char       limit16 :4,
  95                                 :3,
  96                         granular:1;
  97     unsigned char       base24;
  98 } ldt_desc_t;
  99
 100 #include <architecture/i386/sel.h>
 101
 102 /*
 103  * Call gate descriptor.
 104  */
 105
 106 typedef struct call_gate {
 107     unsigned short      offset00;
 108     sel_t               seg;
 109     unsigned int        argcnt  :5,
 110                                 :3,
 111                         type    :5,
 112 #define DESC_CALL_GATE  0x0c
 113                         dpl     :2,
 114                         present :1,
 115                         offset16:16;
 116 } call_gate_t;
 117
 118 /*
 119  * Trap gate descriptor.
 120  */
 121
 122 typedef struct trap_gate {
 123     unsigned short      offset00;
 124     sel_t               seg;
 125     unsigned int                :8,
 126                         type    :5,
 127 #define DESC_TRAP_GATE  0x0f
 128                         dpl     :2,
 129                         present :1,
 130                         offset16:16;
 131 } trap_gate_t;
 132
 133
 134 /*
 135  * Interrupt gate descriptor.
 136  */
 137
 138 typedef struct intr_gate {
 139     unsigned short      offset00;
 140     sel_t               seg;
 141     unsigned int                :8,
 142                         type    :5,
 143 #define DESC_INTR_GATE  0x0e
 144                         dpl     :2,
 145                         present :1,
 146                         offset16:16;
 147 } intr_gate_t;