osfmk/i386/gdt.c

   1 /*
   2  * Copyright (c) 2000 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 /* CMU_ENDHIST */
  34 /*
  35  * Mach Operating System
  36  * Copyright (c) 1991,1990 Carnegie Mellon University
  37  * All Rights Reserved.
  38  *
  39  * Permission to use, copy, modify and distribute this software and its
  40  * documentation is hereby granted, provided that both the copyright
  41  * notice and this permission notice appear in all copies of the
  42  * software, derivative works or modified versions, and any portions
  43  * thereof, and that both notices appear in supporting documentation.
  44  *
  45  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  46  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  47  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  48  *
  49  * Carnegie Mellon requests users of this software to return to
  50  *
  51  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  52  *  School of Computer Science
  53  *  Carnegie Mellon University
  54  *  Pittsburgh PA 15213-3890
  55  *
  56  * any improvements or extensions that they make and grant Carnegie Mellon
  57  * the rights to redistribute these changes.
  58  */
  59 /*
  60  */
  61
  62 /*
  63  * Global descriptor table.
  64  */
  65 #include <mach/machine.h>
  66 #include <mach/i386/vm_param.h>
  67 #include <kern/thread.h>
  68 #include <i386/cpu_data.h>
  69 #include <i386/mp_desc.h>
  70
  71 #ifdef  MACH_BSD
  72 extern int      trap_unix_syscall(void), trap_mach25_syscall(void),
  73                 trap_machdep_syscall(void), syscall(void);
  74 #endif
  75
  76 struct fake_descriptor gdt[GDTSZ] = {
  77 /* 0x000 */     { 0, 0, 0, 0 },         /* always NULL */
  78 /* 0x008 */     { 0,
  79                   0xfffff,
  80                   SZ_32|SZ_G,
  81                   ACC_P|ACC_PL_K|ACC_CODE_R
  82                 },                      /* kernel code */
  83 /* 0x010 */     { 0,
  84                   0xfffff,
  85                   SZ_32|SZ_G,
  86                   ACC_P|ACC_PL_K|ACC_DATA_W
  87                 },                      /* kernel data */
  88 /* 0x018 */     { (unsigned int)ldt,
  89                   LDTSZ*sizeof(struct fake_descriptor)-1,
  90                   0,
  91                   ACC_P|ACC_PL_K|ACC_LDT
  92                 },                      /* local descriptor table */
  93 /* 0x020 */     { (unsigned int)&ktss,
  94                   sizeof(struct i386_tss)-1,
  95                   0,
  96                   ACC_P|ACC_PL_K|ACC_TSS
  97                 },                      /* TSS for this processor */
  98 #ifdef  MACH_BSD
  99 /* 0x28 */      { (unsigned int) &trap_unix_syscall,
 100                    KERNEL_CS,
 101                    0,                           /* no parameters */
 102                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 103                 },
 104 /* 0x30 */      { (unsigned int) &trap_mach25_syscall,
 105                    KERNEL_CS,
 106                    0,                           /* no parameters */
 107                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 108                 },
 109 /* 0x38 */      { (unsigned int) &trap_machdep_syscall,
 110                    KERNEL_CS,
 111                    0,                           /* no parameters */
 112                    ACC_P|ACC_PL_U|ACC_CALL_GATE
 113                 },
 114 #else
 115 /* 0x028 */     { 0, 0, 0, 0 },         /* per-thread LDT */
 116 /* 0x030 */     { 0, 0, 0, 0 },         /* per-thread TSS for IO bitmap */
 117 /* 0x038 */     { 0, 0, 0, 0 },
 118 #endif
 119 /* 0x040 */     { 0, 0, 0, 0 },
 120 /* 0x048 */     { (unsigned int)&cpu_data_master,
 121                   sizeof(cpu_data_t)-1,
 122                   SZ_32,
 123                   ACC_P|ACC_PL_K|ACC_DATA_W
 124                 },                      /* per-CPU current thread address */
 125 #if     MACH_KDB
 126 /* 0x050 */     { (unsigned int)&dbtss,
 127                   sizeof(struct i386_tss)-1,
 128                   0,
 129                   ACC_P|ACC_PL_K|ACC_TSS
 130                 }                       /* TSS for this processor */
 131 #endif  /* MACH_KDB */
 132 };