osfmk/i386/seg.h

   1 /*
   2  * Copyright (c) 2000-2005 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
  56 #include <mach_kdb.h>
  57 #include <stdint.h>
  58 #include <architecture/i386/sel.h>
  59
  60 /*
  61  * i386 segmentation.
  62  */
  63
  64 static inline uint16_t
  65 sel_to_selector(sel_t   sel)
  66 {
  67     union {
  68         sel_t           sel;
  69         uint16_t        selector;
  70     } tconv;
  71
  72     tconv.sel = sel;
  73
  74     return (tconv.selector);
  75 }
  76
  77 static inline sel_t
  78 selector_to_sel(uint16_t selector)
  79 {
  80     union {
  81         uint16_t        selector;
  82         sel_t           sel;
  83     } tconv;
  84
  85     tconv.selector = selector;
  86
  87     return (tconv.sel);
  88 }
  89
  90 #define LDTSZ           15              /* size of the kernel ldt in entries*/
  91
  92 #if     MACH_KDB
  93 #ifdef MACH_BSD
  94 #define GDTSZ           14
  95 #else
  96 #define GDTSZ           11
  97 #endif
  98 #else   /* MACH_KDB */
  99 #ifdef  MACH_BSD
 100 #define GDTSZ           13
 101 #else
 102 #define GDTSZ           10
 103 #endif
 104 #endif  /* MACH_KDB */
 105
 106 /*
 107  * Interrupt table is always 256 entries long.
 108  */
 109 #define IDTSZ           256
 110
 111 #ifndef __ASSEMBLER__
 112
 113 #include <sys/cdefs.h>
 114
 115 /*
 116  * Real segment descriptor.
 117  */
 118 struct real_descriptor {
 119         unsigned int    limit_low:16,   /* limit 0..15 */
 120                         base_low:16,    /* base  0..15 */
 121                         base_med:8,     /* base  16..23 */
 122                         access:8,       /* access byte */
 123                         limit_high:4,   /* limit 16..19 */
 124                         granularity:4,  /* granularity */
 125                         base_high:8;    /* base 24..31 */
 126 };
 127
 128 struct real_gate {
 129         unsigned int    offset_low:16,  /* offset 0..15 */
 130                         selector:16,
 131                         word_count:8,
 132                         access:8,
 133                         offset_high:16; /* offset 16..31 */
 134 };
 135
 136 /*
 137  * We build descriptors and gates in a 'fake' format to let the
 138  * fields be contiguous.  We shuffle them into the real format
 139  * at runtime.
 140  */
 141 struct fake_descriptor {
 142         unsigned int    offset:32;              /* offset */
 143         unsigned int    lim_or_seg:20;          /* limit */
 144                                                 /* or segment, for gate */
 145         unsigned int    size_or_wdct:4;         /* size/granularity */
 146                                                 /* word count, for gate */
 147         unsigned int    access:8;               /* access */
 148 };
 149
 150 /*
 151  * Boot-time data for master (or only) CPU
 152  */
 153 extern struct fake_descriptor   idt[IDTSZ];
 154 extern struct fake_descriptor   gdt[GDTSZ];
 155 extern struct fake_descriptor   ldt[LDTSZ];
 156 extern struct i386_tss          ktss;
 157
 158 __BEGIN_DECLS
 159
 160 #if     MACH_KDB
 161 extern char                     db_stack_store[];
 162 extern char                     db_task_stack_store[];
 163 extern struct i386_tss          dbtss;
 164 extern void                     db_task_start(void);
 165 #endif  /* MACH_KDB */
 166
 167 __END_DECLS
 168
 169 #endif  /*__ASSEMBLER__*/
 170
 171 #define SZ_32           0x4                     /* 32-bit segment */
 172 #define SZ_G            0x8                     /* 4K limit field */
 173
 174 #define ACC_A           0x01                    /* accessed */
 175 #define ACC_TYPE        0x1e                    /* type field: */
 176
 177 #define ACC_TYPE_SYSTEM 0x00                    /* system descriptors: */
 178
 179 #define ACC_LDT         0x02                        /* LDT */
 180 #define ACC_CALL_GATE_16 0x04                       /* 16-bit call gate */
 181 #define ACC_TASK_GATE   0x05                        /* task gate */
 182 #define ACC_TSS         0x09                        /* task segment */
 183 #define ACC_CALL_GATE   0x0c                        /* call gate */
 184 #define ACC_INTR_GATE   0x0e                        /* interrupt gate */
 185 #define ACC_TRAP_GATE   0x0f                        /* trap gate */
 186
 187 #define ACC_TSS_BUSY    0x02                        /* task busy */
 188
 189 #define ACC_TYPE_USER   0x10                    /* user descriptors */
 190
 191 #define ACC_DATA        0x10                        /* data */
 192 #define ACC_DATA_W      0x12                        /* data, writable */
 193 #define ACC_DATA_E      0x14                        /* data, expand-down */
 194 #define ACC_DATA_EW     0x16                        /* data, expand-down,
 195                                                              writable */
 196 #define ACC_CODE        0x18                        /* code */
 197 #define ACC_CODE_R      0x1a                        /* code, readable */
 198 #define ACC_CODE_C      0x1c                        /* code, conforming */
 199 #define ACC_CODE_CR     0x1e                        /* code, conforming,
 200                                                        readable */
 201 #define ACC_PL          0x60                    /* access rights: */
 202 #define ACC_PL_K        0x00                    /* kernel access only */
 203 #define ACC_PL_U        0x60                    /* user access */
 204 #define ACC_P           0x80                    /* segment present */
 205
 206 /*
 207  * Components of a selector
 208  */
 209 #define SEL_LDTS        0x04                    /* local selector */
 210 #define SEL_PL          0x03                    /* privilege level: */
 211 #define SEL_PL_K        0x00                        /* kernel selector */
 212 #define SEL_PL_U        0x03                        /* user selector */
 213
 214 /*
 215  * Convert selector to descriptor table index.
 216  */
 217 #define sel_idx(sel)    (selector_to_sel(sel).index)
 218
 219 #define NULL_SEG        0
 220
 221 /*
 222  * User descriptors for MACH - 32-bit flat address space
 223  */
 224 #define USER_SCALL      0x07            /* system call gate */
 225 #define USER_RPC        0x0f            /* mach rpc call gate */
 226 #define USER_CS         0x17            /* user code segment */
 227 #define USER_DS         0x1f            /* user data segment */
 228 #define USER_CTHREAD    0x27            /* user cthread area */
 229 #define USER_SETTABLE   0x2f            /* start of user settable ldt entries */
 230 #define USLDTSZ         10              /* number of user settable entries */
 231
 232 /*
 233  * Kernel descriptors for MACH - 32-bit flat address space.
 234  */
 235 #define KERNEL_CS       0x08            /* kernel code */
 236 #define KERNEL_DS       0x10            /* kernel data */
 237 #define KERNEL_LDT      0x18            /* master LDT */
 238 #define KERNEL_TSS      0x20            /* master TSS (uniprocessor) */
 239 #ifdef  MACH_BSD
 240 #define BSD_SCALL_SEL   0x28            /* BSD System calls */
 241 #define MK25_SCALL_SEL  0x30            /* MK25 System Calls */
 242 #define MACHDEP_SCALL_SEL 0x38          /* Machdep SYstem calls */
 243 #else
 244 #define USER_LDT        0x28            /* place for per-thread LDT */
 245 #define USER_TSS        0x30            /* place for per-thread TSS
 246                                            that holds IO bitmap */
 247 #define FPE_CS          0x38            /* floating-point emulator code */
 248 #endif
 249 #define USER_FPREGS     0x40            /* user-mode access to saved
 250                                            floating-point registers */
 251 #define CPU_DATA_GS     0x48            /* per-cpu data */
 252
 253 #ifdef  MACH_BSD
 254 #define USER_LDT        0x58
 255 #define USER_TSS        0x60
 256 #define FPE_CS          0x68
 257 #endif
 258
 259 #if     MACH_KDB
 260 #define DEBUG_TSS       0x50            /* debug TSS (uniprocessor) */
 261 #endif
 262
 263 #endif  /* _I386_SEG_H_ */