osfmk/i386/seg.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990 Carnegie Mellon University
  29  * All Rights Reserved.
  30  *
  31  * Permission to use, copy, modify and distribute this software and its
  32  * documentation is hereby granted, provided that both the copyright
  33  * notice and this permission notice appear in all copies of the
  34  * software, derivative works or modified versions, and any portions
  35  * thereof, and that both notices appear in supporting documentation.
  36  *
  37  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  38  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  39  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  40  *
  41  * Carnegie Mellon requests users of this software to return to
  42  *
  43  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  44  *  School of Computer Science
  45  *  Carnegie Mellon University
  46  *  Pittsburgh PA 15213-3890
  47  *
  48  * any improvements or extensions that they make and grant Carnegie Mellon
  49  * the rights to redistribute these changes.
  50  */
  51 /*
  52  */
  53
  54 #ifndef _I386_SEG_H_
  55 #define _I386_SEG_H_
  56
  57 #include <mach_kdb.h>
  58 #include <stdint.h>
  59 #include <architecture/i386/sel.h>
  60
  61 /*
  62  * i386 segmentation.
  63  */
  64
  65 static inline uint16_t
  66 sel_to_selector(sel_t   sel)
  67 {
  68     union {
  69         sel_t           sel;
  70         uint16_t        selector;
  71     } tconv;
  72
  73     tconv.sel = sel;
  74
  75     return (tconv.selector);
  76 }
  77
  78 static inline sel_t
  79 selector_to_sel(uint16_t selector)
  80 {
  81     union {
  82         uint16_t        selector;
  83         sel_t           sel;
  84     } tconv;
  85
  86     tconv.selector = selector;
  87
  88     return (tconv.sel);
  89 }
  90
  91 #define LDTSZ           15              /* size of the kernel ldt in entries*/
  92
  93 #if     MACH_KDB
  94 #ifdef MACH_BSD
  95 #define GDTSZ           14
  96 #else
  97 #define GDTSZ           11
  98 #endif
  99 #else   /* MACH_KDB */
 100 #ifdef  MACH_BSD
 101 #define GDTSZ           13
 102 #else
 103 #define GDTSZ           10
 104 #endif
 105 #endif  /* MACH_KDB */
 106
 107 /*
 108  * Interrupt table is always 256 entries long.
 109  */
 110 #define IDTSZ           256
 111
 112 #ifndef __ASSEMBLER__
 113
 114 #include <sys/cdefs.h>
 115
 116 /*
 117  * Real segment descriptor.
 118  */
 119 struct real_descriptor {
 120         unsigned int    limit_low:16,   /* limit 0..15 */
 121                         base_low:16,    /* base  0..15 */
 122                         base_med:8,     /* base  16..23 */
 123                         access:8,       /* access byte */
 124                         limit_high:4,   /* limit 16..19 */
 125                         granularity:4,  /* granularity */
 126                         base_high:8;    /* base 24..31 */
 127 };
 128
 129 struct real_gate {
 130         unsigned int    offset_low:16,  /* offset 0..15 */
 131                         selector:16,
 132                         word_count:8,
 133                         access:8,
 134                         offset_high:16; /* offset 16..31 */
 135 };
 136
 137 /*
 138  * We build descriptors and gates in a 'fake' format to let the
 139  * fields be contiguous.  We shuffle them into the real format
 140  * at runtime.
 141  */
 142 struct fake_descriptor {
 143         unsigned int    offset:32;              /* offset */
 144         unsigned int    lim_or_seg:20;          /* limit */
 145                                                 /* or segment, for gate */
 146         unsigned int    size_or_wdct:4;         /* size/granularity */
 147                                                 /* word count, for gate */
 148         unsigned int    access:8;               /* access */
 149 };
 150
 151 /*
 152  * Boot-time data for master (or only) CPU
 153  */
 154 extern struct fake_descriptor   idt[IDTSZ];
 155 extern struct fake_descriptor   gdt[GDTSZ];
 156 extern struct fake_descriptor   ldt[LDTSZ];
 157 extern struct i386_tss          ktss;
 158
 159 __BEGIN_DECLS
 160
 161 #if     MACH_KDB
 162 extern char                     db_stack_store[];
 163 extern char                     db_task_stack_store[];
 164 extern struct i386_tss          dbtss;
 165 extern void                     db_task_start(void);
 166 #endif  /* MACH_KDB */
 167
 168 __END_DECLS
 169
 170 #endif  /*__ASSEMBLER__*/
 171
 172 #define SZ_32           0x4                     /* 32-bit segment */
 173 #define SZ_G            0x8                     /* 4K limit field */
 174
 175 #define ACC_A           0x01                    /* accessed */
 176 #define ACC_TYPE        0x1e                    /* type field: */
 177
 178 #define ACC_TYPE_SYSTEM 0x00                    /* system descriptors: */
 179
 180 #define ACC_LDT         0x02                        /* LDT */
 181 #define ACC_CALL_GATE_16 0x04                       /* 16-bit call gate */
 182 #define ACC_TASK_GATE   0x05                        /* task gate */
 183 #define ACC_TSS         0x09                        /* task segment */
 184 #define ACC_CALL_GATE   0x0c                        /* call gate */
 185 #define ACC_INTR_GATE   0x0e                        /* interrupt gate */
 186 #define ACC_TRAP_GATE   0x0f                        /* trap gate */
 187
 188 #define ACC_TSS_BUSY    0x02                        /* task busy */
 189
 190 #define ACC_TYPE_USER   0x10                    /* user descriptors */
 191
 192 #define ACC_DATA        0x10                        /* data */
 193 #define ACC_DATA_W      0x12                        /* data, writable */
 194 #define ACC_DATA_E      0x14                        /* data, expand-down */
 195 #define ACC_DATA_EW     0x16                        /* data, expand-down,
 196                                                              writable */
 197 #define ACC_CODE        0x18                        /* code */
 198 #define ACC_CODE_R      0x1a                        /* code, readable */
 199 #define ACC_CODE_C      0x1c                        /* code, conforming */
 200 #define ACC_CODE_CR     0x1e                        /* code, conforming,
 201                                                        readable */
 202 #define ACC_PL          0x60                    /* access rights: */
 203 #define ACC_PL_K        0x00                    /* kernel access only */
 204 #define ACC_PL_U        0x60                    /* user access */
 205 #define ACC_P           0x80                    /* segment present */
 206
 207 /*
 208  * Components of a selector
 209  */
 210 #define SEL_LDTS        0x04                    /* local selector */
 211 #define SEL_PL          0x03                    /* privilege level: */
 212 #define SEL_PL_K        0x00                        /* kernel selector */
 213 #define SEL_PL_U        0x03                        /* user selector */
 214
 215 /*
 216  * Convert selector to descriptor table index.
 217  */
 218 #define sel_idx(sel)    (selector_to_sel(sel).index)
 219
 220 #define NULL_SEG        0
 221
 222 /*
 223  * User descriptors for MACH - 32-bit flat address space
 224  */
 225 #define USER_SCALL      0x07            /* system call gate */
 226 #define USER_RPC        0x0f            /* mach rpc call gate */
 227 #define USER_CS         0x17            /* user code segment */
 228 #define USER_DS         0x1f            /* user data segment */
 229 #define USER_CTHREAD    0x27            /* user cthread area */
 230 #define USER_SETTABLE   0x2f            /* start of user settable ldt entries */
 231 #define USLDTSZ         10              /* number of user settable entries */
 232
 233 /*
 234  * Kernel descriptors for MACH - 32-bit flat address space.
 235  */
 236 #define KERNEL_CS       0x08            /* kernel code */
 237 #define KERNEL_DS       0x10            /* kernel data */
 238 #define KERNEL_LDT      0x18            /* master LDT */
 239 #define KERNEL_TSS      0x20            /* master TSS (uniprocessor) */
 240 #ifdef  MACH_BSD
 241 #define BSD_SCALL_SEL   0x28            /* BSD System calls */
 242 #define MK25_SCALL_SEL  0x30            /* MK25 System Calls */
 243 #define MACHDEP_SCALL_SEL 0x38          /* Machdep SYstem calls */
 244 #else
 245 #define USER_LDT        0x28            /* place for per-thread LDT */
 246 #define USER_TSS        0x30            /* place for per-thread TSS
 247                                            that holds IO bitmap */
 248 #define FPE_CS          0x38            /* floating-point emulator code */
 249 #endif
 250 #define USER_FPREGS     0x40            /* user-mode access to saved
 251                                            floating-point registers */
 252 #define CPU_DATA_GS     0x48            /* per-cpu data */
 253
 254 #ifdef  MACH_BSD
 255 #define USER_LDT        0x58
 256 #define USER_TSS        0x60
 257 #define FPE_CS          0x68
 258 #endif
 259
 260 #if     MACH_KDB
 261 #define DEBUG_TSS       0x50            /* debug TSS (uniprocessor) */
 262 #endif
 263
 264 #endif  /* _I386_SEG_H_ */