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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1992 NeXT Computer, Inc.
  24  *
  25  * Intel386 Family:     Segment descriptors.
  26  *
  27  * HISTORY
  28  *
  29  * 29 March 1992 ? at NeXT
  30  *      Created.
  31  */
  32
  33 /*
  34  * Code segment descriptor.
  35  */
  36
  37 typedef struct code_desc {
  38     unsigned short      limit00;
  39     unsigned short      base00;
  40     unsigned char       base16;
  41     unsigned char       type    :5,
  42 #define DESC_CODE_EXEC  0x18
  43 #define DESC_CODE_READ  0x1a
  44                         dpl     :2,
  45                         present :1;
  46     unsigned char       limit16 :4,
  47                                 :2,
  48                         opsz    :1,
  49 #define DESC_CODE_16B   0
  50 #define DESC_CODE_32B   1
  51                         granular:1;
  52 #define DESC_GRAN_BYTE  0
  53 #define DESC_GRAN_PAGE  1
  54     unsigned char       base24;
  55 } code_desc_t;
  56
  57 /*
  58  * Data segment descriptor.
  59  */
  60
  61 typedef struct data_desc {
  62     unsigned short      limit00;
  63     unsigned short      base00;
  64     unsigned char       base16;
  65     unsigned char       type    :5,
  66 #define DESC_DATA_RONLY 0x10
  67 #define DESC_DATA_WRITE 0x12
  68                         dpl     :2,
  69                         present :1;
  70     unsigned char       limit16 :4,
  71                                 :2,
  72                         stksz   :1,
  73 #define DESC_DATA_16B   0
  74 #define DESC_DATA_32B   1
  75                         granular:1;
  76     unsigned char       base24;
  77 } data_desc_t;
  78
  79 /*
  80  * LDT segment descriptor.
  81  */
  82
  83 typedef struct ldt_desc {
  84     unsigned short      limit00;
  85     unsigned short      base00;
  86     unsigned char       base16;
  87     unsigned char       type    :5,
  88 #define DESC_LDT        0x02
  89                                 :2,
  90                         present :1;
  91     unsigned char       limit16 :4,
  92                                 :3,
  93                         granular:1;
  94     unsigned char       base24;
  95 } ldt_desc_t;
  96
  97 #include <architecture/i386/sel.h>
  98
  99 /*
 100  * Call gate descriptor.
 101  */
 102
 103 typedef struct call_gate {
 104     unsigned short      offset00;
 105     sel_t               seg;
 106     unsigned int        argcnt  :5,
 107                                 :3,
 108                         type    :5,
 109 #define DESC_CALL_GATE  0x0c
 110                         dpl     :2,
 111                         present :1,
 112                         offset16:16;
 113 } call_gate_t;
 114
 115 /*
 116  * Trap gate descriptor.
 117  */
 118
 119 typedef struct trap_gate {
 120     unsigned short      offset00;
 121     sel_t               seg;
 122     unsigned int                :8,
 123                         type    :5,
 124 #define DESC_TRAP_GATE  0x0f
 125                         dpl     :2,
 126                         present :1,
 127                         offset16:16;
 128 } trap_gate_t;
 129
 130
 131 /*
 132  * Interrupt gate descriptor.
 133  */
 134
 135 typedef struct intr_gate {
 136     unsigned short      offset00;
 137     sel_t               seg;
 138     unsigned int                :8,
 139                         type    :5,
 140 #define DESC_INTR_GATE  0x0e
 141                         dpl     :2,
 142                         present :1,
 143                         offset16:16;
 144 } intr_gate_t;