osfmk/i386/seg.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * @OSF_COPYRIGHT@
  32  */
  33 /*
  34  * Mach Operating System
  35  * Copyright (c) 1991,1990 Carnegie Mellon University
  36  * All Rights Reserved.
  37  *
  38  * Permission to use, copy, modify and distribute this software and its
  39  * documentation is hereby granted, provided that both the copyright
  40  * notice and this permission notice appear in all copies of the
  41  * software, derivative works or modified versions, and any portions
  42  * thereof, and that both notices appear in supporting documentation.
  43  *
  44  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  45  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  46  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  47  *
  48  * Carnegie Mellon requests users of this software to return to
  49  *
  50  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  51  *  School of Computer Science
  52  *  Carnegie Mellon University
  53  *  Pittsburgh PA 15213-3890
  54  *
  55  * any improvements or extensions that they make and grant Carnegie Mellon
  56  * the rights to redistribute these changes.
  57  */
  58 /*
  59  */
  60
  61 #ifndef _I386_SEG_H_
  62 #define _I386_SEG_H_
  63
  64 #include <mach_kdb.h>
  65 #include <stdint.h>
  66 #include <architecture/i386/sel.h>
  67
  68 /*
  69  * i386 segmentation.
  70  */
  71
  72 static inline uint16_t
  73 sel_to_selector(sel_t   sel)
  74 {
  75     union {
  76         sel_t           sel;
  77         uint16_t        selector;
  78     } tconv;
  79
  80     tconv.sel = sel;
  81
  82     return (tconv.selector);
  83 }
  84
  85 static inline sel_t
  86 selector_to_sel(uint16_t selector)
  87 {
  88     union {
  89         uint16_t        selector;
  90         sel_t           sel;
  91     } tconv;
  92
  93     tconv.selector = selector;
  94
  95     return (tconv.sel);
  96 }
  97
  98 #define LDTSZ           15              /* size of the kernel ldt in entries*/
  99
 100 #if     MACH_KDB
 101 #ifdef MACH_BSD
 102 #define GDTSZ           14
 103 #else
 104 #define GDTSZ           11
 105 #endif
 106 #else   /* MACH_KDB */
 107 #ifdef  MACH_BSD
 108 #define GDTSZ           13
 109 #else
 110 #define GDTSZ           10
 111 #endif
 112 #endif  /* MACH_KDB */
 113
 114 /*
 115  * Interrupt table is always 256 entries long.
 116  */
 117 #define IDTSZ           256
 118
 119 #ifndef __ASSEMBLER__
 120
 121 #include <sys/cdefs.h>
 122
 123 /*
 124  * Real segment descriptor.
 125  */
 126 struct real_descriptor {
 127         unsigned int    limit_low:16,   /* limit 0..15 */
 128                         base_low:16,    /* base  0..15 */
 129                         base_med:8,     /* base  16..23 */
 130                         access:8,       /* access byte */
 131                         limit_high:4,   /* limit 16..19 */
 132                         granularity:4,  /* granularity */
 133                         base_high:8;    /* base 24..31 */
 134 };
 135
 136 struct real_gate {
 137         unsigned int    offset_low:16,  /* offset 0..15 */
 138                         selector:16,
 139                         word_count:8,
 140                         access:8,
 141                         offset_high:16; /* offset 16..31 */
 142 };
 143
 144 /*
 145  * We build descriptors and gates in a 'fake' format to let the
 146  * fields be contiguous.  We shuffle them into the real format
 147  * at runtime.
 148  */
 149 struct fake_descriptor {
 150         unsigned int    offset:32;              /* offset */
 151         unsigned int    lim_or_seg:20;          /* limit */
 152                                                 /* or segment, for gate */
 153         unsigned int    size_or_wdct:4;         /* size/granularity */
 154                                                 /* word count, for gate */
 155         unsigned int    access:8;               /* access */
 156 };
 157
 158 /*
 159  * Boot-time data for master (or only) CPU
 160  */
 161 extern struct fake_descriptor   idt[IDTSZ];
 162 extern struct fake_descriptor   gdt[GDTSZ];
 163 extern struct fake_descriptor   ldt[LDTSZ];
 164 extern struct i386_tss          ktss;
 165
 166 __BEGIN_DECLS
 167
 168 #if     MACH_KDB
 169 extern char                     db_stack_store[];
 170 extern char                     db_task_stack_store[];
 171 extern struct i386_tss          dbtss;
 172 extern void                     db_task_start(void);
 173 #endif  /* MACH_KDB */
 174
 175 __END_DECLS
 176
 177 #endif  /*__ASSEMBLER__*/
 178
 179 #define SZ_32           0x4                     /* 32-bit segment */
 180 #define SZ_G            0x8                     /* 4K limit field */
 181
 182 #define ACC_A           0x01                    /* accessed */
 183 #define ACC_TYPE        0x1e                    /* type field: */
 184
 185 #define ACC_TYPE_SYSTEM 0x00                    /* system descriptors: */
 186
 187 #define ACC_LDT         0x02                        /* LDT */
 188 #define ACC_CALL_GATE_16 0x04                       /* 16-bit call gate */
 189 #define ACC_TASK_GATE   0x05                        /* task gate */
 190 #define ACC_TSS         0x09                        /* task segment */
 191 #define ACC_CALL_GATE   0x0c                        /* call gate */
 192 #define ACC_INTR_GATE   0x0e                        /* interrupt gate */
 193 #define ACC_TRAP_GATE   0x0f                        /* trap gate */
 194
 195 #define ACC_TSS_BUSY    0x02                        /* task busy */
 196
 197 #define ACC_TYPE_USER   0x10                    /* user descriptors */
 198
 199 #define ACC_DATA        0x10                        /* data */
 200 #define ACC_DATA_W      0x12                        /* data, writable */
 201 #define ACC_DATA_E      0x14                        /* data, expand-down */
 202 #define ACC_DATA_EW     0x16                        /* data, expand-down,
 203                                                              writable */
 204 #define ACC_CODE        0x18                        /* code */
 205 #define ACC_CODE_R      0x1a                        /* code, readable */
 206 #define ACC_CODE_C      0x1c                        /* code, conforming */
 207 #define ACC_CODE_CR     0x1e                        /* code, conforming,
 208                                                        readable */
 209 #define ACC_PL          0x60                    /* access rights: */
 210 #define ACC_PL_K        0x00                    /* kernel access only */
 211 #define ACC_PL_U        0x60                    /* user access */
 212 #define ACC_P           0x80                    /* segment present */
 213
 214 /*
 215  * Components of a selector
 216  */
 217 #define SEL_LDTS        0x04                    /* local selector */
 218 #define SEL_PL          0x03                    /* privilege level: */
 219 #define SEL_PL_K        0x00                        /* kernel selector */
 220 #define SEL_PL_U        0x03                        /* user selector */
 221
 222 /*
 223  * Convert selector to descriptor table index.
 224  */
 225 #define sel_idx(sel)    (selector_to_sel(sel).index)
 226
 227 #define NULL_SEG        0
 228
 229 /*
 230  * User descriptors for MACH - 32-bit flat address space
 231  */
 232 #define USER_SCALL      0x07            /* system call gate */
 233 #define USER_RPC        0x0f            /* mach rpc call gate */
 234 #define USER_CS         0x17            /* user code segment */
 235 #define USER_DS         0x1f            /* user data segment */
 236 #define USER_CTHREAD    0x27            /* user cthread area */
 237 #define USER_SETTABLE   0x2f            /* start of user settable ldt entries */
 238 #define USLDTSZ         10              /* number of user settable entries */
 239
 240 /*
 241  * Kernel descriptors for MACH - 32-bit flat address space.
 242  */
 243 #define KERNEL_CS       0x08            /* kernel code */
 244 #define KERNEL_DS       0x10            /* kernel data */
 245 #define KERNEL_LDT      0x18            /* master LDT */
 246 #define KERNEL_TSS      0x20            /* master TSS (uniprocessor) */
 247 #ifdef  MACH_BSD
 248 #define BSD_SCALL_SEL   0x28            /* BSD System calls */
 249 #define MK25_SCALL_SEL  0x30            /* MK25 System Calls */
 250 #define MACHDEP_SCALL_SEL 0x38          /* Machdep SYstem calls */
 251 #else
 252 #define USER_LDT        0x28            /* place for per-thread LDT */
 253 #define USER_TSS        0x30            /* place for per-thread TSS
 254                                            that holds IO bitmap */
 255 #define FPE_CS          0x38            /* floating-point emulator code */
 256 #endif
 257 #define USER_FPREGS     0x40            /* user-mode access to saved
 258                                            floating-point registers */
 259 #define CPU_DATA_GS     0x48            /* per-cpu data */
 260
 261 #ifdef  MACH_BSD
 262 #define USER_LDT        0x58
 263 #define USER_TSS        0x60
 264 #define FPE_CS          0x68
 265 #endif
 266
 267 #if     MACH_KDB
 268 #define DEBUG_TSS       0x50            /* debug TSS (uniprocessor) */
 269 #endif
 270
 271 #endif  /* _I386_SEG_H_ */