osfmk/i386/seg.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  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * Mach Operating System
  30  * Copyright (c) 1991,1990 Carnegie Mellon University
  31  * All Rights Reserved.
  32  *
  33  * Permission to use, copy, modify and distribute this software and its
  34  * documentation is hereby granted, provided that both the copyright
  35  * notice and this permission notice appear in all copies of the
  36  * software, derivative works or modified versions, and any portions
  37  * thereof, and that both notices appear in supporting documentation.
  38  *
  39  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  40  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  41  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  42  *
  43  * Carnegie Mellon requests users of this software to return to
  44  *
  45  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  46  *  School of Computer Science
  47  *  Carnegie Mellon University
  48  *  Pittsburgh PA 15213-3890
  49  *
  50  * any improvements or extensions that they make and grant Carnegie Mellon
  51  * the rights to redistribute these changes.
  52  */
  53 /*
  54  */
  55
  56 #ifndef _I386_SEG_H_
  57 #define _I386_SEG_H_
  58 #include <mach_kdb.h>
  59
  60 /*
  61  * i386 segmentation.
  62  */
  63
  64 #ifndef __ASSEMBLER__
  65 /*
  66  * Real segment descriptor.
  67  */
  68 struct real_descriptor {
  69         unsigned int    limit_low:16,   /* limit 0..15 */
  70                         base_low:16,    /* base  0..15 */
  71                         base_med:8,     /* base  16..23 */
  72                         access:8,       /* access byte */
  73                         limit_high:4,   /* limit 16..19 */
  74                         granularity:4,  /* granularity */
  75                         base_high:8;    /* base 24..31 */
  76 };
  77
  78 struct real_gate {
  79         unsigned int    offset_low:16,  /* offset 0..15 */
  80                         selector:16,
  81                         word_count:8,
  82                         access:8,
  83                         offset_high:16; /* offset 16..31 */
  84 };
  85
  86 /*
  87  * We build descriptors and gates in a 'fake' format to let the
  88  * fields be contiguous.  We shuffle them into the real format
  89  * at runtime.
  90  */
  91 struct fake_descriptor {
  92         unsigned int    offset:32;              /* offset */
  93         unsigned int    lim_or_seg:20;          /* limit */
  94                                                 /* or segment, for gate */
  95         unsigned int    size_or_wdct:4;         /* size/granularity */
  96                                                 /* word count, for gate */
  97         unsigned int    access:8;               /* access */
  98 };
  99 #endif  /*__ASSEMBLER__*/
 100
 101 #define SZ_32           0x4                     /* 32-bit segment */
 102 #define SZ_G            0x8                     /* 4K limit field */
 103
 104 #define ACC_A           0x01                    /* accessed */
 105 #define ACC_TYPE        0x1e                    /* type field: */
 106
 107 #define ACC_TYPE_SYSTEM 0x00                    /* system descriptors: */
 108
 109 #define ACC_LDT         0x02                        /* LDT */
 110 #define ACC_CALL_GATE_16 0x04                       /* 16-bit call gate */
 111 #define ACC_TASK_GATE   0x05                        /* task gate */
 112 #define ACC_TSS         0x09                        /* task segment */
 113 #define ACC_CALL_GATE   0x0c                        /* call gate */
 114 #define ACC_INTR_GATE   0x0e                        /* interrupt gate */
 115 #define ACC_TRAP_GATE   0x0f                        /* trap gate */
 116
 117 #define ACC_TSS_BUSY    0x02                        /* task busy */
 118
 119 #define ACC_TYPE_USER   0x10                    /* user descriptors */
 120
 121 #define ACC_DATA        0x10                        /* data */
 122 #define ACC_DATA_W      0x12                        /* data, writable */
 123 #define ACC_DATA_E      0x14                        /* data, expand-down */
 124 #define ACC_DATA_EW     0x16                        /* data, expand-down,
 125                                                              writable */
 126 #define ACC_CODE        0x18                        /* code */
 127 #define ACC_CODE_R      0x1a                        /* code, readable */
 128 #define ACC_CODE_C      0x1c                        /* code, conforming */
 129 #define ACC_CODE_CR     0x1e                        /* code, conforming,
 130                                                        readable */
 131 #define ACC_PL          0x60                    /* access rights: */
 132 #define ACC_PL_K        0x00                    /* kernel access only */
 133 #define ACC_PL_U        0x60                    /* user access */
 134 #define ACC_P           0x80                    /* segment present */
 135
 136 /*
 137  * Components of a selector
 138  */
 139 #define SEL_LDTS        0x04                    /* local selector */
 140 #define SEL_PL          0x03                    /* privilege level: */
 141 #define SEL_PL_K        0x00                        /* kernel selector */
 142 #define SEL_PL_U        0x03                        /* user selector */
 143
 144 /*
 145  * Convert selector to descriptor table index.
 146  */
 147 #define sel_idx(sel)    ((sel)>>3)
 148
 149 /*
 150  * User descriptors for MACH - 32-bit flat address space
 151  */
 152 #define USER_SCALL      0x07            /* system call gate */
 153 #define USER_RPC        0x0f            /* mach rpc call gate */
 154 #define USER_CS         0x17            /* user code segment */
 155 #define USER_DS         0x1f            /* user data segment */
 156
 157 #define LDTSZ           4
 158
 159 /*
 160  * Kernel descriptors for MACH - 32-bit flat address space.
 161  */
 162 #define KERNEL_CS       0x08            /* kernel code */
 163 #define KERNEL_DS       0x10            /* kernel data */
 164 #define KERNEL_LDT      0x18            /* master LDT */
 165 #define KERNEL_TSS      0x20            /* master TSS (uniprocessor) */
 166 #ifdef  MACH_BSD
 167 #define BSD_SCALL_SEL   0x28            /* BSD System calls */
 168 #define MK25_SCALL_SEL  0x30            /* MK25 System Calls */
 169 #define MACHDEP_SCALL_SEL 0x38          /* Machdep SYstem calls */
 170 #else
 171 #define USER_LDT        0x28            /* place for per-thread LDT */
 172 #define USER_TSS        0x30            /* place for per-thread TSS
 173                                            that holds IO bitmap */
 174 #define FPE_CS          0x38            /* floating-point emulator code */
 175 #endif
 176 #define USER_FPREGS     0x40            /* user-mode access to saved
 177                                            floating-point registers */
 178 #define CPU_DATA        0x48            /* per-cpu data */
 179
 180 #ifdef  MACH_BSD
 181 #define USER_LDT        0x58
 182 #define USER_TSS        0x60
 183 #define FPE_CS          0x68
 184 #endif
 185
 186 #if     MACH_KDB
 187 #define DEBUG_TSS       0x50            /* debug TSS (uniprocessor) */
 188
 189 #ifdef MACH_BSD
 190 #define GDTSZ           14
 191 #else
 192 #define GDTSZ           11
 193 #endif
 194 #else
 195
 196 #ifdef  MACH_BSD
 197 #define GDTSZ           13
 198 #else
 199 #define GDTSZ           10
 200 #endif
 201 #endif
 202
 203 /*
 204  * Interrupt table is always 256 entries long.
 205  */
 206 #define IDTSZ           256
 207
 208 #endif  /* _I386_SEG_H_ */