| | 1 | ;------------------------------------------------------------------------------\r |
| | 2 | ; @file\r |
| | 3 | ; Transition from 16 bit real mode into 32 bit flat protected mode\r |
| | 4 | ;\r |
| | 5 | ; Copyright (c) 2008 - 2010, Intel Corporation\r |
| | 6 | ; All rights reserved. This program and the accompanying materials\r |
| | 7 | ; are licensed and made available under the terms and conditions of the BSD License\r |
| | 8 | ; which accompanies this distribution. The full text of the license may be found at\r |
| | 9 | ; http://opensource.org/licenses/bsd-license.php\r |
| | 10 | ;\r |
| | 11 | ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
| | 12 | ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
| | 13 | ;\r |
| | 14 | ;------------------------------------------------------------------------------\r |
| | 15 | \r |
| | 16 | %define SEC_DEFAULT_CR0 0x40000023\r |
| | 17 | %define SEC_DEFAULT_CR4 0x640\r |
| | 18 | \r |
| | 19 | BITS 16\r |
| | 20 | \r |
| | 21 | ;\r |
| | 22 | ; Modified: EAX, EBX\r |
| | 23 | ;\r |
| | 24 | TransitionFromReal16To32BitFlat:\r |
| | 25 | \r |
| | 26 | debugShowPostCode POSTCODE_16BIT_MODE\r |
| | 27 | \r |
| | 28 | cli\r |
| | 29 | \r |
| | 30 | mov bx, 0xf000\r |
| | 31 | mov ds, bx\r |
| | 32 | \r |
| | 33 | mov bx, ADDR16_OF(gdtr)\r |
| | 34 | \r |
| | 35 | o32 lgdt [bx]\r |
| | 36 | \r |
| | 37 | mov eax, SEC_DEFAULT_CR0\r |
| | 38 | mov cr0, eax\r |
| | 39 | \r |
| | 40 | jmp LINEAR_CODE_SEL:dword ADDR_OF(jumpTo32BitAndLandHere)\r |
| | 41 | BITS 32\r |
| | 42 | jumpTo32BitAndLandHere:\r |
| | 43 | \r |
| | 44 | mov eax, SEC_DEFAULT_CR4\r |
| | 45 | mov cr4, eax\r |
| | 46 | \r |
| | 47 | debugShowPostCode POSTCODE_32BIT_MODE\r |
| | 48 | \r |
| | 49 | mov ax, LINEAR_SEL\r |
| | 50 | mov ds, ax\r |
| | 51 | mov es, ax\r |
| | 52 | mov fs, ax\r |
| | 53 | mov gs, ax\r |
| | 54 | mov ss, ax\r |
| | 55 | \r |
| | 56 | OneTimeCallRet TransitionFromReal16To32BitFlat\r |
| | 57 | \r |
| | 58 | ALIGN 2\r |
| | 59 | \r |
| | 60 | gdtr:\r |
| | 61 | dw GDT_END - GDT_BASE - 1 ; GDT limit\r |
| | 62 | dd ADDR_OF(GDT_BASE)\r |
| | 63 | \r |
| | 64 | ALIGN 16\r |
| | 65 | \r |
| | 66 | GDT_BASE:\r |
| | 67 | ; null descriptor\r |
| | 68 | NULL_SEL equ $-GDT_BASE\r |
| | 69 | dw 0 ; limit 15:0\r |
| | 70 | dw 0 ; base 15:0\r |
| | 71 | db 0 ; base 23:16\r |
| | 72 | db 0 ; type\r |
| | 73 | db 0 ; limit 19:16, flags\r |
| | 74 | db 0 ; base 31:24\r |
| | 75 | \r |
| | 76 | ; linear data segment descriptor\r |
| | 77 | LINEAR_SEL equ $-GDT_BASE\r |
| | 78 | dw 0FFFFh ; limit 0xFFFFF\r |
| | 79 | dw 0 ; base 0\r |
| | 80 | db 0\r |
| | 81 | db 093h ; present, ring 0, data, expand-up, writable, accessed\r |
| | 82 | db 0CFh ; page-granular, 32-bit\r |
| | 83 | db 0\r |
| | 84 | \r |
| | 85 | ; linear code segment descriptor\r |
| | 86 | LINEAR_CODE_SEL equ $-GDT_BASE\r |
| | 87 | dw 0FFFFh ; limit 0xFFFFF\r |
| | 88 | dw 0 ; base 0\r |
| | 89 | db 0\r |
| | 90 | db 09Bh ; present, ring 0, data, expand-up, writable, accessed\r |
| | 91 | db 0CFh ; page-granular, 32-bit\r |
| | 92 | db 0\r |
| | 93 | \r |
| | 94 | ; system data segment descriptor\r |
| | 95 | SYS_DATA_SEL equ $-GDT_BASE\r |
| | 96 | dw 0FFFFh ; limit 0xFFFFF\r |
| | 97 | dw 0 ; base 0\r |
| | 98 | db 0\r |
| | 99 | db 093h ; present, ring 0, data, expand-up, writable, accessed\r |
| | 100 | db 0CFh ; page-granular, 32-bit\r |
| | 101 | db 0\r |
| | 102 | \r |
| | 103 | ; system code segment descriptor\r |
| | 104 | SYS_CODE_SEL equ $-GDT_BASE\r |
| | 105 | dw 0FFFFh ; limit 0xFFFFF\r |
| | 106 | dw 0 ; base 0\r |
| | 107 | db 0\r |
| | 108 | db 09Bh ; present, ring 0, data, expand-up, writable, accessed\r |
| | 109 | db 0CFh ; page-granular, 32-bit\r |
| | 110 | db 0\r |
| | 111 | \r |
| | 112 | ; spare segment descriptor\r |
| | 113 | LINEAR_CODE64_SEL equ $-GDT_BASE\r |
| | 114 | DW -1 ; LimitLow\r |
| | 115 | DW 0 ; BaseLow\r |
| | 116 | DB 0 ; BaseMid\r |
| | 117 | DB 9bh\r |
| | 118 | DB 0afh ; LimitHigh (CS.L=1, CS.D=0)\r |
| | 119 | DB 0 ; BaseHigh\r |
| | 120 | \r |
| | 121 | ; spare segment descriptor\r |
| | 122 | SPARE4_SEL equ $-GDT_BASE\r |
| | 123 | dw 0 ; limit 0xFFFFF\r |
| | 124 | dw 0 ; base 0\r |
| | 125 | db 0\r |
| | 126 | db 0 ; present, ring 0, data, expand-up, writable\r |
| | 127 | db 0 ; page-granular, 32-bit\r |
| | 128 | db 0\r |
| | 129 | \r |
| | 130 | ; spare segment descriptor\r |
| | 131 | SPARE5_SEL equ $-GDT_BASE\r |
| | 132 | dw 0 ; limit 0xFFFFF\r |
| | 133 | dw 0 ; base 0\r |
| | 134 | db 0\r |
| | 135 | db 0 ; present, ring 0, data, expand-up, writable\r |
| | 136 | db 0 ; page-granular, 32-bit\r |
| | 137 | db 0\r |
| | 138 | \r |
| | 139 | GDT_END:\r |
| | 140 | \r |
projects / mirror_edk2.git / blame_incremental