osfmk/i386/seg.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  */
  58
  59 #ifndef _I386_SEG_H_
  60 #define _I386_SEG_H_
  61
  62 #include <mach_kdb.h>
  63 #include <stdint.h>
  64 #include <architecture/i386/sel.h>
  65
  66 /*
  67  * i386 segmentation.
  68  */
  69
  70 static inline uint16_t
  71 sel_to_selector(sel_t   sel)
  72 {
  73     union {
  74         sel_t           sel;
  75         uint16_t        selector;
  76     } tconv;
  77
  78     tconv.sel = sel;
  79
  80     return (tconv.selector);
  81 }
  82
  83 static inline sel_t
  84 selector_to_sel(uint16_t selector)
  85 {
  86     union {
  87         uint16_t        selector;
  88         sel_t           sel;
  89     } tconv;
  90
  91     tconv.selector = selector;
  92
  93     return (tconv.sel);
  94 }
  95
  96 #define LDTSZ           15              /* size of the kernel ldt in entries*/
  97
  98 #if     MACH_KDB
  99 #ifdef MACH_BSD
 100 #define GDTSZ           14
 101 #else
 102 #define GDTSZ           11
 103 #endif
 104 #else   /* MACH_KDB */
 105 #ifdef  MACH_BSD
 106 #define GDTSZ           13
 107 #else
 108 #define GDTSZ           10
 109 #endif
 110 #endif  /* MACH_KDB */
 111
 112 /*
 113  * Interrupt table is always 256 entries long.
 114  */
 115 #define IDTSZ           256
 116
 117 #ifndef __ASSEMBLER__
 118
 119 #include <sys/cdefs.h>
 120
 121 /*
 122  * Real segment descriptor.
 123  */
 124 struct real_descriptor {
 125         unsigned int    limit_low:16,   /* limit 0..15 */
 126                         base_low:16,    /* base  0..15 */
 127                         base_med:8,     /* base  16..23 */
 128                         access:8,       /* access byte */
 129                         limit_high:4,   /* limit 16..19 */
 130                         granularity:4,  /* granularity */
 131                         base_high:8;    /* base 24..31 */
 132 };
 133
 134 struct real_gate {
 135         unsigned int    offset_low:16,  /* offset 0..15 */
 136                         selector:16,
 137                         word_count:8,
 138                         access:8,
 139                         offset_high:16; /* offset 16..31 */
 140 };
 141
 142 /*
 143  * We build descriptors and gates in a 'fake' format to let the
 144  * fields be contiguous.  We shuffle them into the real format
 145  * at runtime.
 146  */
 147 struct fake_descriptor {
 148         unsigned int    offset:32;              /* offset */
 149         unsigned int    lim_or_seg:20;          /* limit */
 150                                                 /* or segment, for gate */
 151         unsigned int    size_or_wdct:4;         /* size/granularity */
 152                                                 /* word count, for gate */
 153         unsigned int    access:8;               /* access */
 154 };
 155
 156 /*
 157  * Boot-time data for master (or only) CPU
 158  */
 159 extern struct fake_descriptor   idt[IDTSZ];
 160 extern struct fake_descriptor   gdt[GDTSZ];
 161 extern struct fake_descriptor   ldt[LDTSZ];
 162 extern struct i386_tss          ktss;
 163
 164 __BEGIN_DECLS
 165
 166 #if     MACH_KDB
 167 extern char                     db_stack_store[];
 168 extern char                     db_task_stack_store[];
 169 extern struct i386_tss          dbtss;
 170 extern void                     db_task_start(void);
 171 #endif  /* MACH_KDB */
 172
 173 __END_DECLS
 174
 175 #endif  /*__ASSEMBLER__*/
 176
 177 #define SZ_32           0x4                     /* 32-bit segment */
 178 #define SZ_G            0x8                     /* 4K limit field */
 179
 180 #define ACC_A           0x01                    /* accessed */
 181 #define ACC_TYPE        0x1e                    /* type field: */
 182
 183 #define ACC_TYPE_SYSTEM 0x00                    /* system descriptors: */
 184
 185 #define ACC_LDT         0x02                        /* LDT */
 186 #define ACC_CALL_GATE_16 0x04                       /* 16-bit call gate */
 187 #define ACC_TASK_GATE   0x05                        /* task gate */
 188 #define ACC_TSS         0x09                        /* task segment */
 189 #define ACC_CALL_GATE   0x0c                        /* call gate */
 190 #define ACC_INTR_GATE   0x0e                        /* interrupt gate */
 191 #define ACC_TRAP_GATE   0x0f                        /* trap gate */
 192
 193 #define ACC_TSS_BUSY    0x02                        /* task busy */
 194
 195 #define ACC_TYPE_USER   0x10                    /* user descriptors */
 196
 197 #define ACC_DATA        0x10                        /* data */
 198 #define ACC_DATA_W      0x12                        /* data, writable */
 199 #define ACC_DATA_E      0x14                        /* data, expand-down */
 200 #define ACC_DATA_EW     0x16                        /* data, expand-down,
 201                                                              writable */
 202 #define ACC_CODE        0x18                        /* code */
 203 #define ACC_CODE_R      0x1a                        /* code, readable */
 204 #define ACC_CODE_C      0x1c                        /* code, conforming */
 205 #define ACC_CODE_CR     0x1e                        /* code, conforming,
 206                                                        readable */
 207 #define ACC_PL          0x60                    /* access rights: */
 208 #define ACC_PL_K        0x00                    /* kernel access only */
 209 #define ACC_PL_U        0x60                    /* user access */
 210 #define ACC_P           0x80                    /* segment present */
 211
 212 /*
 213  * Components of a selector
 214  */
 215 #define SEL_LDTS        0x04                    /* local selector */
 216 #define SEL_PL          0x03                    /* privilege level: */
 217 #define SEL_PL_K        0x00                        /* kernel selector */
 218 #define SEL_PL_U        0x03                        /* user selector */
 219
 220 /*
 221  * Convert selector to descriptor table index.
 222  */
 223 #define sel_idx(sel)    (selector_to_sel(sel).index)
 224
 225 #define NULL_SEG        0
 226
 227 /*
 228  * User descriptors for MACH - 32-bit flat address space
 229  */
 230 #define USER_SCALL      0x07            /* system call gate */
 231 #define USER_RPC        0x0f            /* mach rpc call gate */
 232 #define USER_CS         0x17            /* user code segment */
 233 #define USER_DS         0x1f            /* user data segment */
 234 #define USER_CTHREAD    0x27            /* user cthread area */
 235 #define USER_SETTABLE   0x2f            /* start of user settable ldt entries */
 236 #define USLDTSZ         10              /* number of user settable entries */
 237
 238 /*
 239  * Kernel descriptors for MACH - 32-bit flat address space.
 240  */
 241 #define KERNEL_CS       0x08            /* kernel code */
 242 #define KERNEL_DS       0x10            /* kernel data */
 243 #define KERNEL_LDT      0x18            /* master LDT */
 244 #define KERNEL_TSS      0x20            /* master TSS (uniprocessor) */
 245 #ifdef  MACH_BSD
 246 #define BSD_SCALL_SEL   0x28            /* BSD System calls */
 247 #define MK25_SCALL_SEL  0x30            /* MK25 System Calls */
 248 #define MACHDEP_SCALL_SEL 0x38          /* Machdep SYstem calls */
 249 #else
 250 #define USER_LDT        0x28            /* place for per-thread LDT */
 251 #define USER_TSS        0x30            /* place for per-thread TSS
 252                                            that holds IO bitmap */
 253 #define FPE_CS          0x38            /* floating-point emulator code */
 254 #endif
 255 #define USER_FPREGS     0x40            /* user-mode access to saved
 256                                            floating-point registers */
 257 #define CPU_DATA_GS     0x48            /* per-cpu data */
 258
 259 #ifdef  MACH_BSD
 260 #define USER_LDT        0x58
 261 #define USER_TSS        0x60
 262 #define FPE_CS          0x68
 263 #endif
 264
 265 #if     MACH_KDB
 266 #define DEBUG_TSS       0x50            /* debug TSS (uniprocessor) */
 267 #endif
 268
 269 #endif  /* _I386_SEG_H_ */