osfmk/i386/seg.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  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52
  53 #ifndef _I386_SEG_H_
  54 #define _I386_SEG_H_
  55 #include <mach_kdb.h>
  56
  57 /*
  58  * i386 segmentation.
  59  */
  60
  61 #ifndef __ASSEMBLER__
  62 /*
  63  * Real segment descriptor.
  64  */
  65 struct real_descriptor {
  66         unsigned int    limit_low:16,   /* limit 0..15 */
  67                         base_low:16,    /* base  0..15 */
  68                         base_med:8,     /* base  16..23 */
  69                         access:8,       /* access byte */
  70                         limit_high:4,   /* limit 16..19 */
  71                         granularity:4,  /* granularity */
  72                         base_high:8;    /* base 24..31 */
  73 };
  74
  75 struct real_gate {
  76         unsigned int    offset_low:16,  /* offset 0..15 */
  77                         selector:16,
  78                         word_count:8,
  79                         access:8,
  80                         offset_high:16; /* offset 16..31 */
  81 };
  82
  83 /*
  84  * We build descriptors and gates in a 'fake' format to let the
  85  * fields be contiguous.  We shuffle them into the real format
  86  * at runtime.
  87  */
  88 struct fake_descriptor {
  89         unsigned int    offset:32;              /* offset */
  90         unsigned int    lim_or_seg:20;          /* limit */
  91                                                 /* or segment, for gate */
  92         unsigned int    size_or_wdct:4;         /* size/granularity */
  93                                                 /* word count, for gate */
  94         unsigned int    access:8;               /* access */
  95 };
  96 #endif  /*__ASSEMBLER__*/
  97
  98 #define SZ_32           0x4                     /* 32-bit segment */
  99 #define SZ_G            0x8                     /* 4K limit field */
 100
 101 #define ACC_A           0x01                    /* accessed */
 102 #define ACC_TYPE        0x1e                    /* type field: */
 103
 104 #define ACC_TYPE_SYSTEM 0x00                    /* system descriptors: */
 105
 106 #define ACC_LDT         0x02                        /* LDT */
 107 #define ACC_CALL_GATE_16 0x04                       /* 16-bit call gate */
 108 #define ACC_TASK_GATE   0x05                        /* task gate */
 109 #define ACC_TSS         0x09                        /* task segment */
 110 #define ACC_CALL_GATE   0x0c                        /* call gate */
 111 #define ACC_INTR_GATE   0x0e                        /* interrupt gate */
 112 #define ACC_TRAP_GATE   0x0f                        /* trap gate */
 113
 114 #define ACC_TSS_BUSY    0x02                        /* task busy */
 115
 116 #define ACC_TYPE_USER   0x10                    /* user descriptors */
 117
 118 #define ACC_DATA        0x10                        /* data */
 119 #define ACC_DATA_W      0x12                        /* data, writable */
 120 #define ACC_DATA_E      0x14                        /* data, expand-down */
 121 #define ACC_DATA_EW     0x16                        /* data, expand-down,
 122                                                              writable */
 123 #define ACC_CODE        0x18                        /* code */
 124 #define ACC_CODE_R      0x1a                        /* code, readable */
 125 #define ACC_CODE_C      0x1c                        /* code, conforming */
 126 #define ACC_CODE_CR     0x1e                        /* code, conforming,
 127                                                        readable */
 128 #define ACC_PL          0x60                    /* access rights: */
 129 #define ACC_PL_K        0x00                    /* kernel access only */
 130 #define ACC_PL_U        0x60                    /* user access */
 131 #define ACC_P           0x80                    /* segment present */
 132
 133 /*
 134  * Components of a selector
 135  */
 136 #define SEL_LDTS        0x04                    /* local selector */
 137 #define SEL_PL          0x03                    /* privilege level: */
 138 #define SEL_PL_K        0x00                        /* kernel selector */
 139 #define SEL_PL_U        0x03                        /* user selector */
 140
 141 /*
 142  * Convert selector to descriptor table index.
 143  */
 144 #define sel_idx(sel)    ((sel)>>3)
 145
 146 /*
 147  * User descriptors for MACH - 32-bit flat address space
 148  */
 149 #define USER_SCALL      0x07            /* system call gate */
 150 #define USER_RPC        0x0f            /* mach rpc call gate */
 151 #define USER_CS         0x17            /* user code segment */
 152 #define USER_DS         0x1f            /* user data segment */
 153
 154 #define LDTSZ           4
 155
 156 /*
 157  * Kernel descriptors for MACH - 32-bit flat address space.
 158  */
 159 #define KERNEL_CS       0x08            /* kernel code */
 160 #define KERNEL_DS       0x10            /* kernel data */
 161 #define KERNEL_LDT      0x18            /* master LDT */
 162 #define KERNEL_TSS      0x20            /* master TSS (uniprocessor) */
 163 #ifdef  MACH_BSD
 164 #define BSD_SCALL_SEL   0x28            /* BSD System calls */
 165 #define MK25_SCALL_SEL  0x30            /* MK25 System Calls */
 166 #define MACHDEP_SCALL_SEL 0x38          /* Machdep SYstem calls */
 167 #else
 168 #define USER_LDT        0x28            /* place for per-thread LDT */
 169 #define USER_TSS        0x30            /* place for per-thread TSS
 170                                            that holds IO bitmap */
 171 #define FPE_CS          0x38            /* floating-point emulator code */
 172 #endif
 173 #define USER_FPREGS     0x40            /* user-mode access to saved
 174                                            floating-point registers */
 175 #define CPU_DATA        0x48            /* per-cpu data */
 176
 177 #ifdef  MACH_BSD
 178 #define USER_LDT        0x58
 179 #define USER_TSS        0x60
 180 #define FPE_CS          0x68
 181 #endif
 182
 183 #if     MACH_KDB
 184 #define DEBUG_TSS       0x50            /* debug TSS (uniprocessor) */
 185
 186 #ifdef MACH_BSD
 187 #define GDTSZ           14
 188 #else
 189 #define GDTSZ           11
 190 #endif
 191 #else
 192
 193 #ifdef  MACH_BSD
 194 #define GDTSZ           13
 195 #else
 196 #define GDTSZ           10
 197 #endif
 198 #endif
 199
 200 /*
 201  * Interrupt table is always 256 entries long.
 202  */
 203 #define IDTSZ           256
 204
 205 #endif  /* _I386_SEG_H_ */