osfmk/i386/gdt.c

   1 /*
   2  * Copyright (c) 2000 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 /* CMU_ENDHIST */
  32 /*
  33  * Mach Operating System
  34  * Copyright (c) 1991,1990 Carnegie Mellon University
  35  * All Rights Reserved.
  36  *
  37  * Permission to use, copy, modify and distribute this software and its
  38  * documentation is hereby granted, provided that both the copyright
  39  * notice and this permission notice appear in all copies of the
  40  * software, derivative works or modified versions, and any portions
  41  * thereof, and that both notices appear in supporting documentation.
  42  *
  43  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  44  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  45  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  46  *
  47  * Carnegie Mellon requests users of this software to return to
  48  *
  49  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  50  *  School of Computer Science
  51  *  Carnegie Mellon University
  52  *  Pittsburgh PA 15213-3890
  53  *
  54  * any improvements or extensions that they make and grant Carnegie Mellon
  55  * the rights to redistribute these changes.
  56  */
  57 /*
  58  */
  59
  60 /*
  61  * Global descriptor table.
  62  */
  63 #include <mach/machine.h>
  64 #include <mach/i386/vm_param.h>
  65 #include <kern/thread.h>
  66 #include <i386/cpu_data.h>
  67 #include <i386/mp_desc.h>
  68
  69 #ifdef  MACH_BSD
  70 extern int      trap_unix_syscall(void), trap_mach25_syscall(void),
  71                 trap_machdep_syscall(void), syscall(void);
  72 #endif
  73
  74 struct fake_descriptor gdt[GDTSZ] = {
  75 /* 0x000 */     { 0, 0, 0, 0 },         /* always NULL */
  76 /* 0x008 */     { 0,
  77                   0xfffff,
  78                   SZ_32|SZ_G,
  79                   ACC_P|ACC_PL_K|ACC_CODE_R
  80                 },                      /* kernel code */
  81 /* 0x010 */     { 0,
  82                   0xfffff,
  83                   SZ_32|SZ_G,
  84                   ACC_P|ACC_PL_K|ACC_DATA_W
  85                 },                      /* kernel data */
  86 /* 0x018 */     { (unsigned int)ldt,
  87                   LDTSZ*sizeof(struct fake_descriptor)-1,
  88                   0,
  89                   ACC_P|ACC_PL_K|ACC_LDT
  90                 },                      /* local descriptor table */
  91 /* 0x020 */     { (unsigned int)&ktss,
  92                   sizeof(struct i386_tss)-1,
  93                   0,
  94                   ACC_P|ACC_PL_K|ACC_TSS
  95                 },                      /* TSS for this processor */
  96 #ifdef  MACH_BSD
  97 /* 0x28 */      { (unsigned int) &trap_unix_syscall,
  98                    KERNEL_CS,
  99                    0,                           /* no parameters */
 100                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 101                 },
 102 /* 0x30 */      { (unsigned int) &trap_mach25_syscall,
 103                    KERNEL_CS,
 104                    0,                           /* no parameters */
 105                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 106                 },
 107 /* 0x38 */      { (unsigned int) &trap_machdep_syscall,
 108                    KERNEL_CS,
 109                    0,                           /* no parameters */
 110                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 111                 },
 112 #else
 113 /* 0x028 */     { 0, 0, 0, 0 },         /* per-thread LDT */
 114 /* 0x030 */     { 0, 0, 0, 0 },         /* per-thread TSS for IO bitmap */
 115 /* 0x038 */     { 0, 0, 0, 0 },
 116 #endif
 117 /* 0x040 */     { 0, 0, 0, 0 },
 118 /* 0x048 */     { (unsigned int)&cpu_data_master,
 119                   sizeof(cpu_data_t)-1,
 120                   SZ_32,
 121                   ACC_P|ACC_PL_K|ACC_DATA_W
 122                 },                      /* per-CPU current thread address */
 123 #if     MACH_KDB
 124 /* 0x050 */     { (unsigned int)&dbtss,
 125                   sizeof(struct i386_tss)-1,
 126                   0,
 127                   ACC_P|ACC_PL_K|ACC_TSS
 128                 }                       /* TSS for this processor */
 129 #endif  /* MACH_KDB */
 130 };