osfmk/i386/gdt.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 /* CMU_ENDHIST */
  29 /*
  30  * Mach Operating System
  31  * Copyright (c) 1991,1990 Carnegie Mellon University
  32  * All Rights Reserved.
  33  *
  34  * Permission to use, copy, modify and distribute this software and its
  35  * documentation is hereby granted, provided that both the copyright
  36  * notice and this permission notice appear in all copies of the
  37  * software, derivative works or modified versions, and any portions
  38  * thereof, and that both notices appear in supporting documentation.
  39  *
  40  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  41  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  42  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  43  *
  44  * Carnegie Mellon requests users of this software to return to
  45  *
  46  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  47  *  School of Computer Science
  48  *  Carnegie Mellon University
  49  *  Pittsburgh PA 15213-3890
  50  *
  51  * any improvements or extensions that they make and grant Carnegie Mellon
  52  * the rights to redistribute these changes.
  53  */
  54 /*
  55  */
  56
  57 /*
  58  * Global descriptor table.
  59  */
  60 #include <i386/thread.h>
  61 #include <i386/seg.h>
  62 #include <mach/i386/vm_param.h>
  63 #include <kern/thread.h>
  64 #include <mach_kdb.h>
  65
  66 #ifdef  MACH_BSD
  67 extern int      trap_unix_syscall(void), trap_mach25_syscall(void),
  68                 trap_machdep_syscall(void), syscall(void);
  69 #endif
  70
  71 struct fake_descriptor gdt[GDTSZ] = {
  72 /* 0x000 */     { 0, 0, 0, 0 },         /* always NULL */
  73 /* 0x008 */     { LINEAR_KERNEL_ADDRESS + VM_MIN_ADDRESS,
  74                   (VM_MAX_KERNEL_ADDRESS-1-VM_MIN_KERNEL_ADDRESS)>>12,
  75                   SZ_32|SZ_G,
  76                   ACC_P|ACC_PL_K|ACC_CODE_R
  77                 },                      /* kernel code */
  78 /* 0x010 */     { LINEAR_KERNEL_ADDRESS + VM_MIN_ADDRESS,
  79                   (VM_MAX_KERNEL_ADDRESS-1-VM_MIN_KERNEL_ADDRESS)>>12,
  80                   SZ_32|SZ_G,
  81                   ACC_P|ACC_PL_K|ACC_DATA_W
  82                 },                      /* kernel data */
  83 /* 0x018 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)ldt,
  84                   LDTSZ*sizeof(struct fake_descriptor)-1,
  85                   0,
  86                   ACC_P|ACC_PL_K|ACC_LDT
  87                 },                      /* local descriptor table */
  88 /* 0x020 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)&ktss,
  89                   sizeof(struct i386_tss)-1,
  90                   0,
  91                   ACC_P|ACC_PL_K|ACC_TSS
  92                 },                      /* TSS for this processor */
  93 #ifdef  MACH_BSD
  94 /* 0x28 */      { (unsigned int) &trap_unix_syscall,
  95                    KERNEL_CS,
  96                    0,                           /* no parameters */
  97                    ACC_P|ACC_PL_U|ACC_CALL_GATE
  98                 },
  99 /* 0x30 */      { (unsigned int) &trap_mach25_syscall,
 100                    KERNEL_CS,
 101                    0,                           /* no parameters */
 102                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 103                 },
 104 /* 0x38 */      { (unsigned int) &trap_machdep_syscall,
 105                    KERNEL_CS,
 106                    0,                           /* no parameters */
 107                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 108                 },
 109 #else
 110 /* 0x028 */     { 0, 0, 0, 0 },         /* per-thread LDT */
 111 /* 0x030 */     { 0, 0, 0, 0 },         /* per-thread TSS for IO bitmap */
 112 /* 0x038 */     { 0, 0, 0, 0 },
 113 #endif
 114 /* 0x040 */     { 0, 0, 0, 0 },
 115 /* 0x048 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)&cpu_data[0],
 116                   sizeof(cpu_data)-1,
 117                   SZ_32,
 118                   ACC_P|ACC_PL_K|ACC_DATA_W
 119                 },                      /* per-CPU current thread address */
 120 #if     MACH_KDB
 121 /* 0x050 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)&dbtss,
 122                   sizeof(struct i386_tss)-1,
 123                   0,
 124                   ACC_P|ACC_PL_K|ACC_TSS
 125                 }                       /* TSS for this processor */
 126 #endif  /* MACH_KDB */
 127 };