| Vishal Bhoj | 82c8071 | 2015-12-15 21:13:33 +0530 | [diff] [blame] | 1 | #------------------------------------------------------------------------------
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| 2 | #*
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| 3 | #* Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
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| 4 | #* This program and the accompanying materials
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| 5 | #* are licensed and made available under the terms and conditions of the BSD License
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| 6 | #* which accompanies this distribution. The full text of the license may be found at
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| 7 | #* http://opensource.org/licenses/bsd-license.php
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| 8 | #*
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| 9 | #* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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| 10 | #* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| 11 | #*
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| 12 | #* start.S
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| 13 | #*
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| 14 | #* Abstract:
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| 15 | #*
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| 16 | #------------------------------------------------------------------------------
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| 17 |
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| 18 | .stack:
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| 19 | .486p:
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| 20 | .code16
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| 21 |
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| 22 | .equ FAT_DIRECTORY_ENTRY_SIZE, 0x020
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| 23 | .equ FAT_DIRECTORY_ENTRY_SHIFT, 5
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| 24 | .equ BLOCK_SIZE, 0x0200
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| 25 | .equ BLOCK_MASK, 0x01ff
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| 26 | .equ BLOCK_SHIFT, 9
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| 27 |
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| 28 | .org 0x0
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| 29 |
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| 30 | .global _start
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| 31 | _start:
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| 32 |
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| 33 | Ia32Jump:
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| 34 | jmp BootSectorEntryPoint # JMP inst - 3 bytes
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| 35 | nop
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| 36 |
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| 37 | OemId: .ascii "INTEL " # OemId - 8 bytes
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| 38 |
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| 39 | SectorSize: .word 0 # Sector Size - 16 bits
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| 40 | SectorsPerCluster: .byte 0 # Sector Per Cluster - 8 bits
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| 41 | ReservedSectors: .word 0 # Reserved Sectors - 16 bits
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| 42 | NoFats: .byte 0 # Number of FATs - 8 bits
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| 43 | RootEntries: .word 0 # Root Entries - 16 bits
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| 44 | Sectors: .word 0 # Number of Sectors - 16 bits
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| 45 | Media: .byte 0 # Media - 8 bits - ignored
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| 46 | SectorsPerFat: .word 0 # Sectors Per FAT - 16 bits
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| 47 | SectorsPerTrack: .word 0 # Sectors Per Track - 16 bits - ignored
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| 48 | Heads: .word 0 # Heads - 16 bits - ignored
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| 49 | HiddenSectors: .long 0 # Hidden Sectors - 32 bits - ignored
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| 50 | LargeSectors: .long 0 # Large Sectors - 32 bits
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| 51 | PhysicalDrive: .byte 0 # PhysicalDriveNumber - 8 bits - ignored
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| 52 | CurrentHead: .byte 0 # Current Head - 8 bits
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| 53 | Signature: .byte 0 # Signature - 8 bits - ignored
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| 54 | VolId: .ascii " " # Volume Serial Number- 4 bytes
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| 55 | FatLabel: .ascii " " # Label - 11 bytes
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| 56 | SystemId: .ascii "FAT12 " # SystemId - 8 bytes
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| 57 |
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| 58 | BootSectorEntryPoint:
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| 59 | #ASSUME ds:@code
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| 60 | #ASSUME ss:@code
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| 61 | # ds = 1000, es = 2000 + x (size of first cluster >> 4)
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| 62 | # cx = Start Cluster of EfiLdr
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| 63 | # dx = Start Cluster of Efivar.bin
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| 64 |
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| 65 | # Re use the BPB data stored in Boot Sector
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| 66 | movw $0x7c00, %bp
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| 67 |
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| 68 | pushw %cx
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| 69 | # Read Efivar.bin
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| 70 | # 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already
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| 71 | movw $0x1900, %ax
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| 72 | movw %ax, %es
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| 73 | testw %dx, %dx
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| 74 | jnz CheckVarStoreSize
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| 75 |
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| 76 | movb $1, %al
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| 77 | NoVarStore:
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| 78 | pushw %es
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| 79 | # Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl
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| 80 | movb %al, %es:(4)
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| 81 | jmp SaveVolumeId
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| 82 |
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| 83 | CheckVarStoreSize:
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| 84 | movw %dx, %di
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| 85 | cmpl $0x4000, %ds:2(%di)
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| 86 | movb $2, %al
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| 87 | jne NoVarStore
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| 88 |
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| 89 | LoadVarStore:
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| 90 | movb $0, %al
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| 91 | movb %al, %es:(4)
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| 92 | movw (%di), %cx
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| 93 | # ES:DI = 1500:0
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| 94 | xorw %di, %di
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| 95 | pushw %es
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| 96 | movw $0x1500, %ax
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| 97 | movw %ax, %es
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| 98 | call ReadFile
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| 99 | SaveVolumeId:
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| 100 | popw %es
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| 101 | movw VolId(%bp), %ax
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| 102 | movw %ax, %es:(0) # Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId
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| 103 | movw VolId+2(%bp), %ax
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| 104 | movw %ax, %es:(2)
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| 105 |
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| 106 | # Read Efildr
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| 107 | popw %cx
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| 108 | # cx = Start Cluster of Efildr -> BS.com has filled already
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| 109 | # ES:DI = 2000:0, first cluster will be read again
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| 110 | xorw %di, %di # di = 0
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| 111 | movw $0x2000, %ax
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| 112 | movw %ax, %es
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| 113 | call ReadFile
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| 114 | movw %cs, %ax
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| 115 | movw %ax, %cs:JumpSegment
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| 116 |
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| 117 | JumpFarInstruction:
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| 118 | .byte 0xea
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| 119 | JumpOffset:
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| 120 | .word 0x200
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| 121 | JumpSegment:
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| 122 | .word 0x2000
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| 123 |
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| 124 |
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| 125 |
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| 126 | # ****************************************************************************
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| 127 | # ReadFile
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| 128 | #
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| 129 | # Arguments:
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| 130 | # CX = Start Cluster of File
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| 131 | # ES:DI = Buffer to store file content read from disk
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| 132 | #
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| 133 | # Return:
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| 134 | # (ES << 4 + DI) = end of file content Buffer
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| 135 | #
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| 136 | # ****************************************************************************
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| 137 | ReadFile:
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| 138 | # si = NumberOfClusters
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| 139 | # cx = ClusterNumber
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| 140 | # dx = CachedFatSectorNumber
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| 141 | # ds:0000 = CacheFatSectorBuffer
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| 142 | # es:di = Buffer to load file
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| 143 | # bx = NextClusterNumber
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| 144 | pusha
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| 145 | movw $1, %si # NumberOfClusters = 1
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| 146 | pushw %cx # Push Start Cluster onto stack
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| 147 | movw $0xfff, %dx # CachedFatSectorNumber = 0xfff
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| 148 | FatChainLoop:
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| 149 | movw %cx, %ax # ax = ClusterNumber
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| 150 | andw $0xff8, %ax # ax = ax & 0xff8
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| 151 | cmpw $0xff8, %ax # See if this is the last cluster
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| 152 | je FoundLastCluster # Jump if last cluster found
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| 153 | movw %cx, %ax # ax = ClusterNumber
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| 154 | shlw %ax # ax = ClusterNumber * 2
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| 155 | addw %cx, %ax # ax = ClusterNumber * 2 + ClusterNumber = ClusterNumber * 3
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| 156 | shrw %ax # FatOffset = ClusterNumber*3 / 2
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| 157 | pushw %si # Save si
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| 158 | movw %ax, %si # si = FatOffset
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| 159 | shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT
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| 160 | addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET)
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| 161 | andw $BLOCK_MASK,%si # si = FatOffset & BLOCK_MASK
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| 162 | cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber
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| 163 | je SkipFatRead
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| 164 | movw $2, %bx
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| 165 | pushw %es
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| 166 | pushw %ds
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| 167 | popw %es
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| 168 | call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI
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| 169 | popw %es
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| 170 | movw %ax, %dx # CachedFatSectorNumber = FatSectorNumber
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| 171 | SkipFatRead:
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| 172 | movw (%si), %bx # bx = NextClusterNumber
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| 173 | movw %cx, %ax # ax = ClusterNumber
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| 174 | andw $1, %ax # See if this is an odd cluster number
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| 175 | je EvenFatEntry
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| 176 | shrw $4, %bx # NextClusterNumber = NextClusterNumber >> 4
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| 177 | EvenFatEntry:
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| 178 | andw $0xfff, %bx # Strip upper 4 bits of NextClusterNumber
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| 179 | popw %si # Restore si
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| 180 | decw %bx # bx = NextClusterNumber - 1
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| 181 | cmpw %cx, %bx # See if (NextClusterNumber-1)==ClusterNumber
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| 182 | jne ReadClusters
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| 183 | incw %bx # bx = NextClusterNumber
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| 184 | incw %si # NumberOfClusters++
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| 185 | movw %bx, %cx # ClusterNumber = NextClusterNumber
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| 186 | jmp FatChainLoop
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| 187 | ReadClusters:
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| 188 | incw %bx
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| 189 | popw %ax # ax = StartCluster
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| 190 | pushw %bx # StartCluster = NextClusterNumber
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| 191 | movw %bx, %cx # ClusterNumber = NextClusterNumber
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| 192 | subw $2, %ax # ax = StartCluster - 2
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| 193 | xorb %bh, %bh
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| 194 | movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster
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| 195 | mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster
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| 196 | addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster
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| 197 | pushw %ax # save start sector
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| 198 | movw %si, %ax # ax = NumberOfClusters
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| 199 | mulw %bx # ax = NumberOfClusters * SectorsPerCluster
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| 200 | movw %ax, %bx # bx = Number of Sectors
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| 201 | popw %ax # ax = Start Sector
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| 202 | call ReadBlocks
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| 203 | movw $1, %si # NumberOfClusters = 1
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| 204 | jmp FatChainLoop
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| 205 | FoundLastCluster:
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| 206 | popw %cx
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| 207 | popa
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| 208 | ret
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| 209 |
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| 210 |
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| 211 | # ****************************************************************************
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| 212 | # ReadBlocks - Reads a set of blocks from a block device
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| 213 | #
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| 214 | # AX = Start LBA
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| 215 | # BX = Number of Blocks to Read
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| 216 | # ES:DI = Buffer to store sectors read from disk
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| 217 | # ****************************************************************************
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| 218 |
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| 219 | # cx = Blocks
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| 220 | # bx = NumberOfBlocks
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| 221 | # si = StartLBA
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| 222 |
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| 223 | ReadBlocks:
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| 224 | pusha
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| 225 | addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA
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| 226 | addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA
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| 227 | movl %eax, %esi # esi = Start LBA
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| 228 | movw %bx, %cx # cx = Number of blocks to read
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| 229 | ReadCylinderLoop:
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| 230 | movw $0x7bfc, %bp # bp = 0x7bfc
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| 231 | movl %esi, %eax # eax = Start LBA
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| 232 | xorl %edx, %edx # edx = 0
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| 233 | movzwl (%bp), %ebx # bx = MaxSector
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| 234 | divl %ebx # ax = StartLBA / MaxSector
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| 235 | incw %dx # dx = (StartLBA % MaxSector) + 1
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| 236 |
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| 237 | movw (%bp), %bx # bx = MaxSector
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| 238 | subw %dx, %bx # bx = MaxSector - Sector
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| 239 | incw %bx # bx = MaxSector - Sector + 1
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| 240 | cmpw %bx, %cx # Compare (Blocks) to (MaxSector - Sector + 1)
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| 241 | jg LimitTransfer
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| 242 | movw %cx, %bx # bx = Blocks
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| 243 | LimitTransfer:
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| 244 | pushw %ax # save ax
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| 245 | movw %es, %ax # ax = es
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| 246 | shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system
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| 247 | andw $0x7f, %ax # ax = Number of blocks into current seg
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| 248 | addw %bx, %ax # ax = End Block number of transfer
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| 249 | cmpw $0x80, %ax # See if it crosses a 64K boundry
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| 250 | jle NotCrossing64KBoundry # Branch if not crossing 64K boundry
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| 251 | subw $0x80, %ax # ax = Number of blocks past 64K boundry
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| 252 | subw %ax, %bx # Decrease transfer size by block overage
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| 253 | NotCrossing64KBoundry:
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| 254 | popw %ax # restore ax
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| 255 |
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| 256 | pushw %cx
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| 257 | movb %dl, %cl # cl = (StartLBA % MaxSector) + 1 = Sector
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| 258 | xorw %dx, %dx # dx = 0
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| 259 | divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder
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| 260 | # dx = ax % (MaxHead + 1) = Head
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| 261 |
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| 262 | pushw %bx # Save number of blocks to transfer
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| 263 | movb %dl, %dh # dh = Head
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| 264 | movw $0x7c00, %bp # bp = 0x7c00
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| 265 | movb PhysicalDrive(%bp), %dl # dl = Drive Number
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| 266 | movb %al, %ch # ch = Cylinder
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| 267 | movb %bl, %al # al = Blocks
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| 268 | movb $2, %ah # ah = Function 2
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| 269 | movw %di, %bx # es:bx = Buffer address
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| 270 | int $0x13
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| 271 | jc DiskError
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| 272 | popw %bx
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| 273 | popw %cx
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| 274 | movzwl %bx, %ebx
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| 275 | addl %ebx, %esi # StartLBA = StartLBA + NumberOfBlocks
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| 276 | subw %bx, %cx # Blocks = Blocks - NumberOfBlocks
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| 277 | movw %es, %ax
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| 278 | shlw $(BLOCK_SHIFT-4), %bx
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| 279 | addw %bx, %ax
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| 280 | movw %ax, %es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE
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| 281 | cmpw $0, %cx
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| 282 | jne ReadCylinderLoop
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| 283 | popa
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| 284 | ret
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| 285 |
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| 286 | DiskError:
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| 287 | pushw %cs
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| 288 | popw %ds
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| 289 | leaw ErrorString, %si
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| 290 | movw $7, %cx
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| 291 | jmp PrintStringAndHalt
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| 292 |
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| 293 | PrintStringAndHalt:
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| 294 | movw $0xb800, %ax
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| 295 | movw %ax, %es
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| 296 | movw $160, %di
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| 297 | rep
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| 298 | movsw
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| 299 | Halt:
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| 300 | jmp Halt
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| 301 |
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| 302 | ErrorString:
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| 303 | .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!',0x0c
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| 304 |
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| 305 | .org 0x01fa
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| 306 | LBAOffsetForBootSector:
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| 307 | .long 0x0
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| 308 |
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| 309 | .org 0x01fe
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| 310 | .word 0xaa55
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| 311 |
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| 312 | #******************************************************************************
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| 313 | #******************************************************************************
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| 314 | #******************************************************************************
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| 315 |
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| 316 | .equ DELAY_PORT, 0x0ed # Port to use for 1uS delay
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| 317 | .equ KBD_CONTROL_PORT, 0x060 # 8042 control port
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| 318 | .equ KBD_STATUS_PORT, 0x064 # 8042 status port
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| 319 | .equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port
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| 320 | .equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20
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| 321 |
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| 322 | .org 0x200
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| 323 | jmp start
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| 324 | Em64String:
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| 325 | .byte 'E', 0x0c, 'm', 0x0c, '6', 0x0c, '4', 0x0c, 'T', 0x0c, ' ', 0x0c, 'U', 0x0c, 'n', 0x0c, 's', 0x0c, 'u', 0x0c, 'p', 0x0c, 'p', 0x0c, 'o', 0x0c, 'r', 0x0c, 't', 0x0c, 'e', 0x0c, 'd', 0x0c, '!', 0x0c
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| 326 |
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| 327 | start:
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| 328 | movw %cs, %ax
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| 329 | movw %ax, %ds
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| 330 | movw %ax, %es
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| 331 | movw %ax, %ss
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| 332 | movw $MyStack, %sp
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| 333 |
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| 334 | # mov ax,0b800h
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| 335 | # mov es,ax
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| 336 | # mov byte ptr es:[160],'a'
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| 337 | # mov ax,cs
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| 338 | # mov es,ax
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| 339 |
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| 340 | movl $0, %ebx
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| 341 | leal MemoryMap, %edi
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| 342 | MemMapLoop:
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| 343 | movl $0xe820, %eax
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| 344 | movl $20, %ecx
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| 345 | movl $0x534d4150, %edx # SMAP
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| 346 | int $0x15
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| 347 | jc MemMapDone
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| 348 | addl $20, %edi
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| 349 | cmpl $0, %ebx
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| 350 | je MemMapDone
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| 351 | jmp MemMapLoop
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| 352 | MemMapDone:
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| 353 | leal MemoryMap, %eax
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| 354 | subl %eax, %edi # Get the address of the memory map
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| 355 | movl %edi, MemoryMapSize # Save the size of the memory map
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| 356 |
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| 357 | xorl %ebx, %ebx
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| 358 | movw %cs, %bx # BX=segment
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| 359 | shll $4, %ebx # BX="linear" address of segment base
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| 360 | leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt
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| 361 | movl %eax, (gdtr + 2) # Put address of gdt into the gdtr
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| 362 | leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt
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| 363 | movl %eax, (idtr + 2) # Put address of idt into the idtr
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| 364 | leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map
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| 365 |
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| 366 | addl $0x1000, %ebx # Source of EFI32
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| 367 | movl %ebx, JUMP+2
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| 368 | addl $0x1000, %ebx
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| 369 | movl %ebx, %esi # Source of EFILDR32
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| 370 |
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| 371 | # mov ax,0b800h
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| 372 | # mov es,ax
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| 373 | # mov byte ptr es:[162],'b'
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| 374 | # mov ax,cs
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| 375 | # mov es,ax
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| 376 |
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| 377 | #
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| 378 | # Enable A20 Gate
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| 379 | #
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| 380 |
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| 381 | movw $0x2401, %ax # Enable A20 Gate
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| 382 | int $0x15
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| 383 | jnc A20GateEnabled # Jump if it suceeded
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| 384 |
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| 385 | #
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| 386 | # If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually.
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| 387 | #
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| 388 |
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| 389 | call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller
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| 390 | jnz Timeout8042 # Jump if the 8042 timed out
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| 391 | outw %ax, $DELAY_PORT # Delay 1 uS
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| 392 | mov $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port
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| 393 | out %al, $KBD_STATUS_PORT # Send command to the 8042
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| 394 | call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller
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| 395 | jnz Timeout8042 # Jump if the 8042 timed out
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| 396 | mov $ENABLE_A20_CMD, %al # gate address bit 20 on
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| 397 | out %al, $KBD_CONTROL_PORT # Send command to thre 8042
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| 398 | call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller
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| 399 | movw $25, %cx # Delay 25 uS for the command to complete on the 8042
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| 400 | Delay25uS:
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| 401 | outw %ax, $DELAY_PORT # Delay 1 uS
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| 402 | loop Delay25uS
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| 403 | Timeout8042:
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| 404 |
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| 405 |
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| 406 | A20GateEnabled:
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| 407 | movw $0x0008, %bx # Flat data descriptor
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| 408 |
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| 409 | #
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| 410 | # DISABLE INTERRUPTS - Entering Protected Mode
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| 411 | #
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| 412 |
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| 413 | cli
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| 414 |
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| 415 | # mov ax,0b800h
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| 416 | # mov es,ax
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| 417 | # mov byte ptr es:[164],'c'
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| 418 | # mov ax,cs
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| 419 | # mov es,ax
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| 420 |
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| 421 | .byte 0x66
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| 422 | lgdt gdtr
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| 423 | .byte 0x66
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| 424 | lidt idtr
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| 425 |
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| 426 | movl %cr0, %eax
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| 427 | orb $1, %al
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| 428 | movl %eax, %cr0
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| 429 | JUMP:
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| 430 | # jmp far 0010:00020000
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| 431 | .byte 0x66
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| 432 | .byte 0xea
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| 433 | .long 0x00020000
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| 434 | .word 0x0010
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| 435 |
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| 436 | Empty8042InputBuffer:
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| 437 | movw $0, %cx
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| 438 | Empty8042Loop:
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| 439 | outw %ax, $DELAY_PORT # Delay 1us
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| 440 | in $KBD_STATUS_PORT, %al # Read the 8042 Status Port
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| 441 | andb $0x2, %al # Check the Input Buffer Full Flag
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| 442 | loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS
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| 443 | ret
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| 444 |
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| 445 | ##############################################################################
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| 446 | # data
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| 447 | ##############################################################################
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| 448 |
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| 449 | .p2align 1
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| 450 |
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| 451 | gdtr: .long GDT_END - GDT_BASE - 1 # GDT limit
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| 452 | .long 0 # (GDT base gets set above)
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| 453 | ##############################################################################
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| 454 | # global descriptor table (GDT)
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| 455 | ##############################################################################
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| 456 |
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| 457 | .p2align 1
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| 458 |
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| 459 | GDT_BASE:
|
| 460 | # null descriptor
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| 461 | .equ NULL_SEL, .-GDT_BASE
|
| 462 | .word 0 # limit 15:0
|
| 463 | .word 0 # base 15:0
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| 464 | .byte 0 # base 23:16
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| 465 | .byte 0 # type
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| 466 | .byte 0 # limit 19:16, flags
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| 467 | .byte 0 # base 31:24
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| 468 |
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| 469 | # linear data segment descriptor
|
| 470 | .equ LINEAR_SEL, .-GDT_BASE
|
| 471 | .word 0xFFFF # limit 0xFFFFF
|
| 472 | .word 0 # base 0
|
| 473 | .byte 0
|
| 474 | .byte 0x92 # present, ring 0, data, expand-up, writable
|
| 475 | .byte 0xCF # page-granular, 32-bit
|
| 476 | .byte 0
|
| 477 |
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| 478 | # linear code segment descriptor
|
| 479 | .equ LINEAR_CODE_SEL, .-GDT_BASE
|
| 480 | .word 0xFFFF # limit 0xFFFFF
|
| 481 | .word 0 # base 0
|
| 482 | .byte 0
|
| 483 | .byte 0x9A # present, ring 0, data, expand-up, writable
|
| 484 | .byte 0xCF # page-granular, 32-bit
|
| 485 | .byte 0
|
| 486 |
|
| 487 | # system data segment descriptor
|
| 488 | .equ SYS_DATA_SEL, .-GDT_BASE
|
| 489 | .word 0xFFFF # limit 0xFFFFF
|
| 490 | .word 0 # base 0
|
| 491 | .byte 0
|
| 492 | .byte 0x92 # present, ring 0, data, expand-up, writable
|
| 493 | .byte 0xCF # page-granular, 32-bit
|
| 494 | .byte 0
|
| 495 |
|
| 496 | # system code segment descriptor
|
| 497 | .equ SYS_CODE_SEL, .-GDT_BASE
|
| 498 | .word 0xFFFF # limit 0xFFFFF
|
| 499 | .word 0 # base 0
|
| 500 | .byte 0
|
| 501 | .byte 0x9A # present, ring 0, data, expand-up, writable
|
| 502 | .byte 0xCF # page-granular, 32-bit
|
| 503 | .byte 0
|
| 504 |
|
| 505 | # spare segment descriptor
|
| 506 | .equ SPARE3_SEL, .-GDT_BASE
|
| 507 | .word 0 # limit 0xFFFFF
|
| 508 | .word 0 # base 0
|
| 509 | .byte 0
|
| 510 | .byte 0 # present, ring 0, data, expand-up, writable
|
| 511 | .byte 0 # page-granular, 32-bit
|
| 512 | .byte 0
|
| 513 |
|
| 514 | # spare segment descriptor
|
| 515 | .equ SPARE4_SEL, .-GDT_BASE
|
| 516 | .word 0 # limit 0xFFFFF
|
| 517 | .word 0 # base 0
|
| 518 | .byte 0
|
| 519 | .byte 0 # present, ring 0, data, expand-up, writable
|
| 520 | .byte 0 # page-granular, 32-bit
|
| 521 | .byte 0
|
| 522 |
|
| 523 | # spare segment descriptor
|
| 524 | .equ SPARE5_SEL, .-GDT_BASE
|
| 525 | .word 0 # limit 0xFFFFF
|
| 526 | .word 0 # base 0
|
| 527 | .byte 0
|
| 528 | .byte 0 # present, ring 0, data, expand-up, writable
|
| 529 | .byte 0 # page-granular, 32-bit
|
| 530 | .byte 0
|
| 531 |
|
| 532 | GDT_END:
|
| 533 |
|
| 534 | .p2align 1
|
| 535 |
|
| 536 |
|
| 537 |
|
| 538 | idtr: .long IDT_END - IDT_BASE - 1 # IDT limit
|
| 539 | .long 0 # (IDT base gets set above)
|
| 540 | ##############################################################################
|
| 541 | # interrupt descriptor table (IDT)
|
| 542 | #
|
| 543 | # Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ
|
| 544 | # mappings. This implementation only uses the system timer and all other
|
| 545 | # IRQs will remain masked. The descriptors for vectors 33+ are provided
|
| 546 | # for convenience.
|
| 547 | ##############################################################################
|
| 548 |
|
| 549 | #idt_tag db "IDT",0
|
| 550 | .p2align 1
|
| 551 |
|
| 552 | IDT_BASE:
|
| 553 | # divide by zero (INT 0)
|
| 554 | .equ DIV_ZERO_SEL, .-IDT_BASE
|
| 555 | .word 0 # offset 15:0
|
| 556 | .long SYS_CODE_SEL # selector 15:0
|
| 557 | .byte 0 # 0 for interrupt gate
|
| 558 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 559 | .word 0 # offset 31:16
|
| 560 |
|
| 561 | # debug exception (INT 1)
|
| 562 | .equ DEBUG_EXCEPT_SEL, .-IDT_BASE
|
| 563 | .word 0 # offset 15:0
|
| 564 | .long SYS_CODE_SEL # selector 15:0
|
| 565 | .byte 0 # 0 for interrupt gate
|
| 566 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 567 | .word 0 # offset 31:16
|
| 568 |
|
| 569 | # NMI (INT 2)
|
| 570 | .equ NMI_SEL, .-IDT_BASE
|
| 571 | .word 0 # offset 15:0
|
| 572 | .long SYS_CODE_SEL # selector 15:0
|
| 573 | .byte 0 # 0 for interrupt gate
|
| 574 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 575 | .word 0 # offset 31:16
|
| 576 |
|
| 577 | # soft breakpoint (INT 3)
|
| 578 | .equ BREAKPOINT_SEL, .-IDT_BASE
|
| 579 | .word 0 # offset 15:0
|
| 580 | .long SYS_CODE_SEL # selector 15:0
|
| 581 | .byte 0 # 0 for interrupt gate
|
| 582 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 583 | .word 0 # offset 31:16
|
| 584 |
|
| 585 | # overflow (INT 4)
|
| 586 | .equ OVERFLOW_SEL, .-IDT_BASE
|
| 587 | .word 0 # offset 15:0
|
| 588 | .long SYS_CODE_SEL # selector 15:0
|
| 589 | .byte 0 # 0 for interrupt gate
|
| 590 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 591 | .word 0 # offset 31:16
|
| 592 |
|
| 593 | # bounds check (INT 5)
|
| 594 | .equ BOUNDS_CHECK_SEL, .-IDT_BASE
|
| 595 | .word 0 # offset 15:0
|
| 596 | .long SYS_CODE_SEL # selector 15:0
|
| 597 | .byte 0 # 0 for interrupt gate
|
| 598 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 599 | .word 0 # offset 31:16
|
| 600 |
|
| 601 | # invalid opcode (INT 6)
|
| 602 | .equ INVALID_OPCODE_SEL, .-IDT_BASE
|
| 603 | .word 0 # offset 15:0
|
| 604 | .long SYS_CODE_SEL # selector 15:0
|
| 605 | .byte 0 # 0 for interrupt gate
|
| 606 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 607 | .word 0 # offset 31:16
|
| 608 |
|
| 609 | # device not available (INT 7)
|
| 610 | .equ DEV_NOT_AVAIL_SEL, .-IDT_BASE
|
| 611 | .word 0 # offset 15:0
|
| 612 | .long SYS_CODE_SEL # selector 15:0
|
| 613 | .byte 0 # 0 for interrupt gate
|
| 614 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 615 | .word 0 # offset 31:16
|
| 616 |
|
| 617 | # double fault (INT 8)
|
| 618 | .equ DOUBLE_FAULT_SEL, .-IDT_BASE
|
| 619 | .word 0 # offset 15:0
|
| 620 | .long SYS_CODE_SEL # selector 15:0
|
| 621 | .byte 0 # 0 for interrupt gate
|
| 622 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 623 | .word 0 # offset 31:16
|
| 624 |
|
| 625 | # Coprocessor segment overrun - reserved (INT 9)
|
| 626 | .equ RSVD_INTR_SEL1, .-IDT_BASE
|
| 627 | .word 0 # offset 15:0
|
| 628 | .long SYS_CODE_SEL # selector 15:0
|
| 629 | .byte 0 # 0 for interrupt gate
|
| 630 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 631 | .word 0 # offset 31:16
|
| 632 |
|
| 633 | # invalid TSS (INT 0x0a)
|
| 634 | .equ INVALID_TSS_SEL, .-IDT_BASE
|
| 635 | .word 0 # offset 15:0
|
| 636 | .long SYS_CODE_SEL # selector 15:0
|
| 637 | .byte 0 # 0 for interrupt gate
|
| 638 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 639 | .word 0 # offset 31:16
|
| 640 |
|
| 641 | # segment not present (INT 0x0b)
|
| 642 | .equ SEG_NOT_PRESENT_SEL, .-IDT_BASE
|
| 643 | .word 0 # offset 15:0
|
| 644 | .long SYS_CODE_SEL # selector 15:0
|
| 645 | .byte 0 # 0 for interrupt gate
|
| 646 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 647 | .word 0 # offset 31:16
|
| 648 |
|
| 649 | # stack fault (INT 0x0c)
|
| 650 | .equ STACK_FAULT_SEL, .-IDT_BASE
|
| 651 | .word 0 # offset 15:0
|
| 652 | .long SYS_CODE_SEL # selector 15:0
|
| 653 | .byte 0 # 0 for interrupt gate
|
| 654 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 655 | .word 0 # offset 31:16
|
| 656 |
|
| 657 | # general protection (INT 0x0d)
|
| 658 | .equ GP_FAULT_SEL, .-IDT_BASE
|
| 659 | .word 0 # offset 15:0
|
| 660 | .long SYS_CODE_SEL # selector 15:0
|
| 661 | .byte 0 # 0 for interrupt gate
|
| 662 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 663 | .word 0 # offset 31:16
|
| 664 |
|
| 665 | # page fault (INT 0x0e)
|
| 666 | .equ PAGE_FAULT_SEL, .-IDT_BASE
|
| 667 | .word 0 # offset 15:0
|
| 668 | .long SYS_CODE_SEL # selector 15:0
|
| 669 | .byte 0 # 0 for interrupt gate
|
| 670 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 671 | .word 0 # offset 31:16
|
| 672 |
|
| 673 | # Intel reserved - do not use (INT 0x0f)
|
| 674 | .equ RSVD_INTR_SEL2, .-IDT_BASE
|
| 675 | .word 0 # offset 15:0
|
| 676 | .long SYS_CODE_SEL # selector 15:0
|
| 677 | .byte 0 # 0 for interrupt gate
|
| 678 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 679 | .word 0 # offset 31:16
|
| 680 |
|
| 681 | # floating point error (INT 0x10)
|
| 682 | .equ FLT_POINT_ERR_SEL, .-IDT_BASE
|
| 683 | .word 0 # offset 15:0
|
| 684 | .long SYS_CODE_SEL # selector 15:0
|
| 685 | .byte 0 # 0 for interrupt gate
|
| 686 | .byte 0x0e | 0x80 # type = 386 interrupt gate, present
|
| 687 | .word 0 # offset 31:16
|
| 688 |
|
| 689 | # alignment check (INT 0x11)
|
| 690 | .equ ALIGNMENT_CHECK_SEL, .-IDT_BASE
|
| 691 | .word 0 # offset 15:0
|
| 692 | .long SYS_CODE_SEL # selector 15:0
|
| 693 | .byte 0 # 0 for interrupt gate
|
| 694 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 695 | .word 0 # offset 31:16
|
| 696 |
|
| 697 | # machine check (INT 0x12)
|
| 698 | .equ MACHINE_CHECK_SEL, .-IDT_BASE
|
| 699 | .word 0 # offset 15:0
|
| 700 | .long SYS_CODE_SEL # selector 15:0
|
| 701 | .byte 0 # 0 for interrupt gate
|
| 702 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 703 | .word 0 # offset 31:16
|
| 704 |
|
| 705 | # SIMD floating-point exception (INT 0x13)
|
| 706 | .equ SIMD_EXCEPTION_SEL, .-IDT_BASE
|
| 707 | .word 0 # offset 15:0
|
| 708 | .long SYS_CODE_SEL # selector 15:0
|
| 709 | .byte 0 # 0 for interrupt gate
|
| 710 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 711 | .word 0 # offset 31:16
|
| 712 |
|
| 713 | # 85 unspecified descriptors, First 12 of them are reserved, the rest are avail
|
| 714 | .fill 85 * 8, 1, 0 # db (85 * 8) dup(0)
|
| 715 |
|
| 716 | # IRQ 0 (System timer) - (INT 0x68)
|
| 717 | .equ IRQ0_SEL, .-IDT_BASE
|
| 718 | .word 0 # offset 15:0
|
| 719 | .long SYS_CODE_SEL # selector 15:0
|
| 720 | .byte 0 # 0 for interrupt gate
|
| 721 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 722 | .word 0 # offset 31:16
|
| 723 |
|
| 724 | # IRQ 1 (8042 Keyboard controller) - (INT 0x69)
|
| 725 | .equ IRQ1_SEL, .-IDT_BASE
|
| 726 | .word 0 # offset 15:0
|
| 727 | .long SYS_CODE_SEL # selector 15:0
|
| 728 | .byte 0 # 0 for interrupt gate
|
| 729 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 730 | .word 0 # offset 31:16
|
| 731 |
|
| 732 | # Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 0x6a)
|
| 733 | .equ IRQ2_SEL, .-IDT_BASE
|
| 734 | .word 0 # offset 15:0
|
| 735 | .long SYS_CODE_SEL # selector 15:0
|
| 736 | .byte 0 # 0 for interrupt gate
|
| 737 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 738 | .word 0 # offset 31:16
|
| 739 |
|
| 740 | # IRQ 3 (COM 2) - (INT 0x6b)
|
| 741 | .equ IRQ3_SEL, .-IDT_BASE
|
| 742 | .word 0 # offset 15:0
|
| 743 | .long SYS_CODE_SEL # selector 15:0
|
| 744 | .byte 0 # 0 for interrupt gate
|
| 745 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 746 | .word 0 # offset 31:16
|
| 747 |
|
| 748 | # IRQ 4 (COM 1) - (INT 0x6c)
|
| 749 | .equ IRQ4_SEL, .-IDT_BASE
|
| 750 | .word 0 # offset 15:0
|
| 751 | .long SYS_CODE_SEL # selector 15:0
|
| 752 | .byte 0 # 0 for interrupt gate
|
| 753 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 754 | .word 0 # offset 31:16
|
| 755 |
|
| 756 | # IRQ 5 (LPT 2) - (INT 0x6d)
|
| 757 | .equ IRQ5_SEL, .-IDT_BASE
|
| 758 | .word 0 # offset 15:0
|
| 759 | .long SYS_CODE_SEL # selector 15:0
|
| 760 | .byte 0 # 0 for interrupt gate
|
| 761 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 762 | .word 0 # offset 31:16
|
| 763 |
|
| 764 | # IRQ 6 (Floppy controller) - (INT 0x6e)
|
| 765 | .equ IRQ6_SEL, .-IDT_BASE
|
| 766 | .word 0 # offset 15:0
|
| 767 | .long SYS_CODE_SEL # selector 15:0
|
| 768 | .byte 0 # 0 for interrupt gate
|
| 769 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 770 | .word 0 # offset 31:16
|
| 771 |
|
| 772 | # IRQ 7 (LPT 1) - (INT 0x6f)
|
| 773 | .equ IRQ7_SEL, .-IDT_BASE
|
| 774 | .word 0 # offset 15:0
|
| 775 | .long SYS_CODE_SEL # selector 15:0
|
| 776 | .byte 0 # 0 for interrupt gate
|
| 777 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 778 | .word 0 # offset 31:16
|
| 779 |
|
| 780 | # IRQ 8 (RTC Alarm) - (INT 0x70)
|
| 781 | .equ IRQ8_SEL, .-IDT_BASE
|
| 782 | .word 0 # offset 15:0
|
| 783 | .long SYS_CODE_SEL # selector 15:0
|
| 784 | .byte 0 # 0 for interrupt gate
|
| 785 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 786 | .word 0 # offset 31:16
|
| 787 |
|
| 788 | # IRQ 9 - (INT 0x71)
|
| 789 | .equ IRQ9_SEL, .-IDT_BASE
|
| 790 | .word 0 # offset 15:0
|
| 791 | .long SYS_CODE_SEL # selector 15:0
|
| 792 | .byte 0 # 0 for interrupt gate
|
| 793 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 794 | .word 0 # offset 31:16
|
| 795 |
|
| 796 | # IRQ 10 - (INT 0x72)
|
| 797 | .equ IRQ10_SEL, .-IDT_BASE
|
| 798 | .word 0 # offset 15:0
|
| 799 | .long SYS_CODE_SEL # selector 15:0
|
| 800 | .byte 0 # 0 for interrupt gate
|
| 801 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 802 | .word 0 # offset 31:16
|
| 803 |
|
| 804 | # IRQ 11 - (INT 0x73)
|
| 805 | .equ IRQ11_SEL, .-IDT_BASE
|
| 806 | .word 0 # offset 15:0
|
| 807 | .long SYS_CODE_SEL # selector 15:0
|
| 808 | .byte 0 # 0 for interrupt gate
|
| 809 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 810 | .word 0 # offset 31:16
|
| 811 |
|
| 812 | # IRQ 12 (PS/2 mouse) - (INT 0x74)
|
| 813 | .equ IRQ12_SEL, .-IDT_BASE
|
| 814 | .word 0 # offset 15:0
|
| 815 | .long SYS_CODE_SEL # selector 15:0
|
| 816 | .byte 0 # 0 for interrupt gate
|
| 817 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 818 | .word 0 # offset 31:16
|
| 819 |
|
| 820 | # IRQ 13 (Floating point error) - (INT 0x75)
|
| 821 | .equ IRQ13_SEL, .-IDT_BASE
|
| 822 | .word 0 # offset 15:0
|
| 823 | .long SYS_CODE_SEL # selector 15:0
|
| 824 | .byte 0 # 0 for interrupt gate
|
| 825 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 826 | .word 0 # offset 31:16
|
| 827 |
|
| 828 | # IRQ 14 (Secondary IDE) - (INT 0x76)
|
| 829 | .equ IRQ14_SEL, .-IDT_BASE
|
| 830 | .word 0 # offset 15:0
|
| 831 | .long SYS_CODE_SEL # selector 15:0
|
| 832 | .byte 0 # 0 for interrupt gate
|
| 833 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 834 | .word 0 # offset 31:16
|
| 835 |
|
| 836 | # IRQ 15 (Primary IDE) - (INT 0x77)
|
| 837 | .equ IRQ15_SEL, .-IDT_BASE
|
| 838 | .word 0 # offset 15:0
|
| 839 | .long SYS_CODE_SEL # selector 15:0
|
| 840 | .byte 0 # 0 for interrupt gate
|
| 841 | .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present
|
| 842 | .word 0 # offset 31:16
|
| 843 |
|
| 844 | IDT_END:
|
| 845 |
|
| 846 | .p2align 1
|
| 847 |
|
| 848 | MemoryMapSize: .long 0
|
| 849 | MemoryMap: .long 0,0,0,0,0,0,0,0
|
| 850 | .long 0,0,0,0,0,0,0,0
|
| 851 | .long 0,0,0,0,0,0,0,0
|
| 852 | .long 0,0,0,0,0,0,0,0
|
| 853 | .long 0,0,0,0,0,0,0,0
|
| 854 | .long 0,0,0,0,0,0,0,0
|
| 855 | .long 0,0,0,0,0,0,0,0
|
| 856 | .long 0,0,0,0,0,0,0,0
|
| 857 | .long 0,0,0,0,0,0,0,0
|
| 858 | .long 0,0,0,0,0,0,0,0
|
| 859 | .long 0,0,0,0,0,0,0,0
|
| 860 | .long 0,0,0,0,0,0,0,0
|
| 861 | .long 0,0,0,0,0,0,0,0
|
| 862 | .long 0,0,0,0,0,0,0,0
|
| 863 | .long 0,0,0,0,0,0,0,0
|
| 864 | .long 0,0,0,0,0,0,0,0
|
| 865 | .long 0,0,0,0,0,0,0,0
|
| 866 | .long 0,0,0,0,0,0,0,0
|
| 867 | .long 0,0,0,0,0,0,0,0
|
| 868 | .long 0,0,0,0,0,0,0,0
|
| 869 | .long 0,0,0,0,0,0,0,0
|
| 870 | .long 0,0,0,0,0,0,0,0
|
| 871 | .long 0,0,0,0,0,0,0,0
|
| 872 | .long 0,0,0,0,0,0,0,0
|
| 873 | .long 0,0,0,0,0,0,0,0
|
| 874 | .long 0,0,0,0,0,0,0,0
|
| 875 | .long 0,0,0,0,0,0,0,0
|
| 876 | .long 0,0,0,0,0,0,0,0
|
| 877 | .long 0,0,0,0,0,0,0,0
|
| 878 | .long 0,0,0,0,0,0,0,0
|
| 879 |
|
| 880 | .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
|
| 881 | .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
|
| 882 |
|
| 883 | .org 0x0fe0
|
| 884 | MyStack:
|
| 885 | # below is the pieces of the IVT that is used to redirect INT 68h - 6fh
|
| 886 | # back to INT 08h - 0fh when in real mode... It is 'org'ed to a
|
| 887 | # known low address (20f00) so it can be set up by PlMapIrqToVect in
|
| 888 | # 8259.c
|
| 889 |
|
| 890 | int $8
|
| 891 | iret
|
| 892 |
|
| 893 | int $9
|
| 894 | iret
|
| 895 |
|
| 896 | int $10
|
| 897 | iret
|
| 898 |
|
| 899 | int $11
|
| 900 | iret
|
| 901 |
|
| 902 | int $12
|
| 903 | iret
|
| 904 |
|
| 905 | int $13
|
| 906 | iret
|
| 907 |
|
| 908 | int $14
|
| 909 | iret
|
| 910 |
|
| 911 | int $15
|
| 912 | iret
|
| 913 |
|
| 914 |
|
| 915 | .org 0x0ffe
|
| 916 | BlockSignature:
|
| 917 | .word 0xaa55
|
| 918 |
|
| 919 |
|