arch/x86/kernel/platform/i86pc/boot/boot_gdt.s

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27
  28
  29         .align 16
  30         .data
  31         /*
  32          * This must remain in sync with the entries in x86/include/sys/gdt.h;
  33          * in particular kmdb uses B64CODE_SEL or B32CODE_SEL in perpetuity for
  34          * its IDT entries (they're copied to the kernel's GDT in init_idt()).
  35          */
  36
  37 global_descriptor_table:
  38         .long   0
  39         .long   0
  40
  41         /* GDT_B32DATA: 32 bit flat data descriptor */
  42         .value  0xFFFF  /* segment limit 0..15 */
  43         .value  0x0000  /* segment base 0..15 */
  44         .byte   0x0     /* segment base 16..23 */
  45         .byte   0x92    /* P = 1, read/write data */
  46         .byte   0xCF    /* G=1, B=1, Limit (16..19)=1111 */
  47         .byte   0x0     /* segment base 24..32 */
  48
  49         /* GDT_B32CODE 32 bit flat code descriptor */
  50         .value  0xFFFF  /* segment limit 0..15 */
  51         .value  0x0000  /* segment base 0..15 */
  52         .byte   0x0     /* segment base 16..23 */
  53         .byte   0x9A    /* P=1, code, exec, readable */
  54         .byte   0xCF    /* G=1, D=1, Limit (16..19)=1111 */
  55         .byte   0x0     /* segment base 24..32 */
  56
  57         /*
  58          * GDT_B16CODE 16 bit code descriptor for doing BIOS calls
  59          */
  60         .value  0xFFFF  /* segment limit 0..15 */
  61         .value  0x0000  /* segment base 0..15 */
  62         .byte   0x0     /* segment base 16..23 */
  63         .byte   0x9A    /* P=1, code, exec, readable */
  64         .byte   0x0F    /* G=0, D=0, Limit (16..19)=1111 */
  65         .byte   0x0     /* segment base 24..32 */
  66
  67         /*
  68          * GDT_B16DATA 16 bit data descriptor for doing BIOS calls
  69          */
  70         .value  0xFFFF  /* segment limit 0..15 */
  71         .value  0x0000  /* segment base 0..15 */
  72         .byte   0x0     /* segment base 16..23 */
  73         .byte   0x92    /* P = 1, read/write data */
  74         .byte   0x4F    /* G=0, D=1, Limit (16..19)=1111 */
  75         .byte   0x0     /* segment base 24..32 */
  76
  77         /* GDT_B64CODE: 64 bit flat code descriptor - only L bit has meaning */
  78         .value  0xFFFF  /* segment limit 0..15 */
  79         .value  0x0000  /* segment base 0..15 */
  80         .byte   0x0     /* segment base 16..23 */
  81         .byte   0x9A    /* P=1, code, exec, readable */
  82         .byte   0xAF    /* G=1, D=0, L=1, Limit (16..19)=1111 */
  83         .byte   0x0     /* segment base 24..32 */
  84
  85         /*
  86          * unused
  87          */
  88         .long   0
  89         .long   0
  90
  91         /*
  92          * GDT_BGSTMP -- an entry for kmdb to use during boot
  93          * the fast reboot code uses this entry for memory copies, too.
  94          */
  95         .value  0x0001  /* segment limit 0..15 */
  96
  97         .globl fake_cpu_gdt_base_0_15
  98 fake_cpu_gdt_base_0_15:
  99
 100         .value  0x0000  /* segment base 0..15 */
 101
 102         .globl fake_cpu_gdt_base_16_23
 103 fake_cpu_gdt_base_16_23:
 104         .byte   0x0     /* segment base 16..23 */
 105         .byte   0x9A    /* P=1, code, exec, readable */
 106         .byte   0xC0    /* G=1, D=1, Limit (16..19)=0000 */
 107
 108         .globl fake_cpu_gdt_base_24_31
 109 fake_cpu_gdt_base_24_31:
 110         .byte   0x0     /* segment base 24..32 */
 111
 112 /       .long   0
 113 /       .long   0
 114
 115 gdt_info:
 116         .value  gdt_info - global_descriptor_table - 1
 117         .long   global_descriptor_table
 118         .long   0               /* needed for 64 bit */
 119
 120 fake_cpu:
 121         .4byte 0
 122         .4byte 0
 123         .4byte 0
 124         .globl fake_cpu_ptr
 125 fake_cpu_ptr:
 126         .4byte 0
 127         .skip 0x6c0, 0
 128