osfmk/i386/gdt.c

   1 /*
   2  * Copyright (c) 2000 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 /* CMU_ENDHIST */
  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 /*
  55  * Global descriptor table.
  56  */
  57 #include <i386/thread.h>
  58 #include <i386/seg.h>
  59 #include <mach/i386/vm_param.h>
  60 #include <kern/thread.h>
  61 #include <mach_kdb.h>
  62
  63 #ifdef  MACH_BSD
  64 extern int      trap_unix_syscall(void), trap_mach25_syscall(void),
  65                 trap_machdep_syscall(void), syscall(void);
  66 #endif
  67
  68 struct fake_descriptor gdt[GDTSZ] = {
  69 /* 0x000 */     { 0, 0, 0, 0 },         /* always NULL */
  70 /* 0x008 */     { LINEAR_KERNEL_ADDRESS + VM_MIN_ADDRESS,
  71                   (VM_MAX_KERNEL_ADDRESS-1-VM_MIN_KERNEL_ADDRESS)>>12,
  72                   SZ_32|SZ_G,
  73                   ACC_P|ACC_PL_K|ACC_CODE_R
  74                 },                      /* kernel code */
  75 /* 0x010 */     { LINEAR_KERNEL_ADDRESS + VM_MIN_ADDRESS,
  76                   (VM_MAX_KERNEL_ADDRESS-1-VM_MIN_KERNEL_ADDRESS)>>12,
  77                   SZ_32|SZ_G,
  78                   ACC_P|ACC_PL_K|ACC_DATA_W
  79                 },                      /* kernel data */
  80 /* 0x018 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)ldt,
  81                   LDTSZ*sizeof(struct fake_descriptor)-1,
  82                   0,
  83                   ACC_P|ACC_PL_K|ACC_LDT
  84                 },                      /* local descriptor table */
  85 /* 0x020 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)&ktss,
  86                   sizeof(struct i386_tss)-1,
  87                   0,
  88                   ACC_P|ACC_PL_K|ACC_TSS
  89                 },                      /* TSS for this processor */
  90 #ifdef  MACH_BSD
  91 /* 0x28 */      { (unsigned int) &trap_unix_syscall,
  92                    KERNEL_CS,
  93                    0,                           /* no parameters */
  94                    ACC_P|ACC_PL_U|ACC_CALL_GATE
  95                 },
  96 /* 0x30 */      { (unsigned int) &trap_mach25_syscall,
  97                    KERNEL_CS,
  98                    0,                           /* no parameters */
  99                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 100                 },
 101 /* 0x38 */      { (unsigned int) &trap_machdep_syscall,
 102                    KERNEL_CS,
 103                    0,                           /* no parameters */
 104                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 105                 },
 106 #else
 107 /* 0x028 */     { 0, 0, 0, 0 },         /* per-thread LDT */
 108 /* 0x030 */     { 0, 0, 0, 0 },         /* per-thread TSS for IO bitmap */
 109 /* 0x038 */     { 0, 0, 0, 0 },
 110 #endif
 111 /* 0x040 */     { 0, 0, 0, 0 },
 112 /* 0x048 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)&cpu_data[0],
 113                   sizeof(cpu_data)-1,
 114                   SZ_32,
 115                   ACC_P|ACC_PL_K|ACC_DATA_W
 116                 },                      /* per-CPU current thread address */
 117 #if     MACH_KDB
 118 /* 0x050 */     { LINEAR_KERNEL_ADDRESS + (unsigned int)&dbtss,
 119                   sizeof(struct i386_tss)-1,
 120                   0,
 121                   ACC_P|ACC_PL_K|ACC_TSS
 122                 }                       /* TSS for this processor */
 123 #endif  /* MACH_KDB */
 124 };