mirror of
https://github.com/reactos/reactos.git
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[EXT2]
- Use HEX() macro - remove BYTE modifiers - [es:di] -> es:[di] - equ -> = svn path=/trunk/; revision=53930
This commit is contained in:
Timo Kreuzer
parent
41fe9c8d7e
commit
80406e33cf
1 changed files with 87 additions and 87 deletions
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@ -7,15 +7,15 @@
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// [bp-0x0c] Here we will store the size of the disk as the BIOS reports in CHS form
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// [bp-0x10] Here we will store the number of LBA sectors read
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SECTORS_PER_TRACK equ 0x04
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NUMBER_OF_HEADS equ 0x08
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BIOS_CHS_DRIVE_SIZE equ 0x0C
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LBA_SECTORS_READ equ 0x10
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SECTORS_PER_TRACK = HEX(04)
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NUMBER_OF_HEADS = HEX(08)
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BIOS_CHS_DRIVE_SIZE = HEX(0C)
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LBA_SECTORS_READ = HEX(10)
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EXT2_ROOT_INO equ 2
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EXT2_S_IFMT equ 0f0h
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EXT2_S_IFREG equ 080h
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EXT2_ROOT_INO = 2
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EXT2_S_IFMT = HEX(0f0)
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EXT2_S_IFREG = HEX(080)
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org 7c00h
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@ -28,7 +28,7 @@ start:
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jmp short main
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nop
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BootDrive db 0x80
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BootDrive db HEX(80)
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//BootPartition db 0 // Moved to end of boot sector to have a standard format across all boot sectors
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//SectorsPerTrack db 63 // Moved to [bp-SECTORS_PER_TRACK]
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//NumberOfHeads dw 16 // Moved to [bp-NUMBER_OF_HEADS]
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@ -58,26 +58,26 @@ main:
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mov ds,ax // Make DS correct
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mov es,ax // Make ES correct
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mov ss,ax // Make SS correct
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mov bp,7c00h
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mov sp,7b00h // Setup a stack
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mov bp, HEX(7c00)
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mov sp, HEX(7b00) // Setup a stack
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cmp BYTE [BYTE bp+BootDrive],BYTE 0xff // If they have specified a boot drive then use it
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cmp byte ptr [bp+BootDrive], HEX(0ff) // If they have specified a boot drive then use it
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jne GetDriveParameters
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mov [BYTE bp+BootDrive],dl // Save the boot drive
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mov [bp+BootDrive],dl // Save the boot drive
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GetDriveParameters:
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mov ah,08h
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mov dl,[BYTE bp+BootDrive] // Get boot drive in dl
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int 13h // Request drive parameters from the bios
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mov dl,[bp+BootDrive] // Get boot drive in dl
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int HEX(13) // Request drive parameters from the bios
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jnc CalcDriveSize // If the call succeeded then calculate the drive size
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// If we get here then the call to the BIOS failed
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// so just set CHS equal to the maximum addressable
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// size
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mov cx,0ffffh
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mov cx, HEX(0ffff)
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mov dh,cl
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CalcDriveSize:
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@ -86,21 +86,21 @@ CalcDriveSize:
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mov bl,ch // Put the low 8-bits of the cylinder count into BL
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mov bh,cl // Put the high 2-bits in BH
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shr bh,6 // Shift them into position, now BX contains the cylinder count
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and cl,3fh // Mask off cylinder bits from sector count
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and cl, HEX(3f) // Mask off cylinder bits from sector count
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// CL now contains sectors per track and DH contains head count
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movzx eax,dh // Move the heads into EAX
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movzx ebx,bx // Move the cylinders into EBX
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movzx ecx,cl // Move the sectors per track into ECX
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inc eax // Make it one based because the bios returns it zero based
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mov [BYTE bp-NUMBER_OF_HEADS],eax // Save number of heads
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mov [BYTE bp-SECTORS_PER_TRACK],ecx // Save number of sectors per track
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mov [bp-NUMBER_OF_HEADS],eax // Save number of heads
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mov [bp-SECTORS_PER_TRACK],ecx // Save number of sectors per track
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inc ebx // Make the cylinder count one based also
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mul ecx // Multiply heads with the sectors per track, result in edx:eax
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mul ebx // Multiply the cylinders with (heads * sectors) [stored in edx:eax already]
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// We now have the total number of sectors as reported
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// by the bios in eax, so store it in our variable
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mov [BYTE bp-BIOS_CHS_DRIVE_SIZE],eax
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mov [bp-BIOS_CHS_DRIVE_SIZE],eax
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LoadExtraBootCode:
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@ -110,7 +110,7 @@ LoadExtraBootCode:
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xor eax,eax
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inc eax // Read logical sector 1, EAX now = 1
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mov cx,1 // Read one sector
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mov bx,7e00h // Read sector to [0000:7e00h]
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mov bx, HEX(7e00) // Read sector to [0000:7e00h]
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call ReadSectors
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jmp LoadRootDirectory
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@ -124,14 +124,14 @@ LoadExtraBootCode:
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Ext2ReadGroupDesc:
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shl eax,5 // Group = (Group * sizeof(GROUP_DESCRIPTOR) /* 32 */)
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xor edx,edx
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div DWORD [BYTE bp+Ext2GroupDescPerBlock] // Group = (Group / Ext2GroupDescPerBlock)
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add eax,DWORD [BYTE bp+Ext2FirstDataBlock] // Group = Group + Ext2FirstDataBlock + 1
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div dword ptr [bp+Ext2GroupDescPerBlock] // Group = (Group / Ext2GroupDescPerBlock)
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add eax, [bp+Ext2FirstDataBlock] // Group = Group + Ext2FirstDataBlock + 1
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inc eax // EAX now has the group descriptor block number
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// EDX now has the group descriptor offset in the block
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// Adjust the read offset so that the
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// group descriptor is read to 7000:8000
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mov ebx,78000h
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mov ebx, HEX(78000)
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sub ebx,edx
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shr ebx,4
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mov es,bx
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@ -145,7 +145,7 @@ Ext2ReadGroupDesc:
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// Reads ext2 block into [ES:BX]
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// EAX has logical block number to read
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Ext2ReadBlock:
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mov ecx,DWORD [BYTE bp+Ext2BlockSize]
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mov ecx, [bp+Ext2BlockSize]
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mul ecx
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jmp ReadSectors
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@ -156,11 +156,11 @@ Ext2ReadBlock:
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Ext2ReadInode:
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dec eax // Inode = Inode - 1
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xor edx,edx
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div DWORD [BYTE bp+Ext2InodesPerGroup] // Inode = (Inode / Ext2InodesPerGroup)
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div dword ptr [bp+Ext2InodesPerGroup] // Inode = (Inode / Ext2InodesPerGroup)
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mov ebx,eax // EBX now has the inode group number
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mov eax,edx
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xor edx,edx
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div DWORD [BYTE bp+Ext2InodesPerBlock] // Inode = (Inode / Ext2InodesPerBlock)
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div dword ptr [bp+Ext2InodesPerBlock] // Inode = (Inode / Ext2InodesPerBlock)
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shl edx,7 // FIXME: InodeOffset *= 128 (make the array index a byte offset)
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// EAX now has the inode offset block number from inode table
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// EDX now has the inode offset in the block
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@ -174,16 +174,16 @@ Ext2ReadInode:
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// Group descriptor has been read, now
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// grab the inode table block number from it
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push WORD 7000h
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push HEX(7000)
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pop es
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mov di,8008h
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mov di, HEX(8008)
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pop eax // Restore inode offset block number from stack
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add eax,DWORD [es:di] // Add the inode table start block
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add eax, es:[di] // Add the inode table start block
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// Adjust the read offset so that the
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// inode we want is read to 6000:8000
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pop edx // Restore inode offset in the block from stack
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mov ebx,68000h
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mov ebx, HEX(68000)
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sub ebx,edx
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shr ebx,4
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mov es,bx
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@ -197,8 +197,8 @@ Ext2ReadInode:
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// EAX has logical sector number to read
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// CX has number of sectors to read
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ReadSectors:
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add eax,DWORD [BYTE bp+Ext2VolumeStartSector] // Add the start of the volume
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cmp eax,DWORD [BYTE bp-BIOS_CHS_DRIVE_SIZE] // Check if they are reading a sector outside CHS range
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add eax, [bp+Ext2VolumeStartSector] // Add the start of the volume
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cmp eax, [bp-BIOS_CHS_DRIVE_SIZE] // Check if they are reading a sector outside CHS range
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jae ReadSectorsLBA // Yes - go to the LBA routine
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// If at all possible we want to use LBA routines because
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// They are optimized to read more than 1 sector per read
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@ -206,12 +206,12 @@ ReadSectors:
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pushad // Save logical sector number & sector count
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CheckInt13hExtensions: // Now check if this computer supports extended reads
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mov ah,0x41 // AH = 41h
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mov bx,0x55aa // BX = 55AAh
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mov dl,[BYTE bp+BootDrive] // DL = drive (80h-FFh)
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int 13h // IBM/MS INT 13 Extensions - INSTALLATION CHECK
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mov ah, HEX(41) // AH = 41h
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mov bx, HEX(55aa) // BX = 55AAh
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mov dl,[bp+BootDrive] // DL = drive (80h-FFh)
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int HEX(13) // IBM/MS INT 13 Extensions - INSTALLATION CHECK
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jc ReadSectorsCHS // CF set on error (extensions not supported)
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cmp bx,0xaa55 // BX = AA55h if installed
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cmp bx, HEX(0aa55) // BX = AA55h if installed
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jne ReadSectorsCHS
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test cl,1 // CX = API subset support bitmap
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jz ReadSectorsCHS // Bit 0, extended disk access functions (AH=42h-44h,47h,48h) supported
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@ -221,33 +221,33 @@ CheckInt13hExtensions: // Now check if this computer supports extended rea
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ReadSectorsLBA:
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pushad // Save logical sector number & sector count
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cmp cx,byte 64 // Since the LBA calls only support 0x7F sectors at a time we will limit ourselves to 64
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cmp cx, 64 // Since the LBA calls only support 0x7F sectors at a time we will limit ourselves to 64
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jbe ReadSectorsSetupDiskAddressPacket // If we are reading less than 65 sectors then just do the read
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mov cx,64 // Otherwise read only 64 sectors on this loop iteration
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ReadSectorsSetupDiskAddressPacket:
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mov [BYTE bp-LBA_SECTORS_READ],cx
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mov WORD [BYTE bp-LBA_SECTORS_READ+2],0
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o32 push byte 0
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mov [bp-LBA_SECTORS_READ],cx
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mov word ptr [bp-LBA_SECTORS_READ+2],0
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o32 push 0
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push eax // Put 64-bit logical block address on stack
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push es // Put transfer segment on stack
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push bx // Put transfer offset on stack
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push cx // Set transfer count
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push byte 0x10 // Set size of packet to 10h
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push 16 // Set size of packet to 10h
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mov si,sp // Setup disk address packet on stack
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mov dl,[BYTE bp+BootDrive] // Drive number
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mov dl, [bp+BootDrive] // Drive number
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mov ah,42h // Int 13h, AH = 42h - Extended Read
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int 13h // Call BIOS
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jc PrintDiskError // If the read failed then abort
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add sp,byte 0x10 // Remove disk address packet from stack
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add sp, 16 // Remove disk address packet from stack
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popad // Restore sector count & logical sector number
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push bx
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mov ebx,DWORD [BYTE bp-LBA_SECTORS_READ]
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mov ebx,DWORD [bp-LBA_SECTORS_READ]
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add eax,ebx // Increment sector to read
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shl ebx,5
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mov dx,es
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@ -255,7 +255,7 @@ ReadSectorsSetupDiskAddressPacket:
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mov es,dx
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pop bx
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sub cx,[BYTE bp-LBA_SECTORS_READ]
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sub cx,[bp-LBA_SECTORS_READ]
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jnz ReadSectorsLBA // Read next sector
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ret
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@ -270,21 +270,21 @@ ReadSectorsCHS:
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ReadSectorsCHSLoop:
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pushad
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xor edx,edx
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mov ecx,DWORD [BYTE bp-SECTORS_PER_TRACK]
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mov ecx,DWORD [bp-SECTORS_PER_TRACK]
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div ecx // Divide logical by SectorsPerTrack
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inc dl // Sectors numbering starts at 1 not 0
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mov cl,dl // Sector in CL
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mov edx,eax
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shr edx,16
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div WORD [BYTE bp-NUMBER_OF_HEADS] // Divide logical by number of heads
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div WORD [bp-NUMBER_OF_HEADS] // Divide logical by number of heads
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mov dh,dl // Head in DH
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mov dl,[BYTE bp+BootDrive] // Drive number in DL
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mov dl,[bp+BootDrive] // Drive number in DL
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mov ch,al // Cylinder in CX
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ror ah,2 // Low 8 bits of cylinder in CH, high 2 bits
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// in CL shifted to bits 6 & 7
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or cl,ah // Or with sector number
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mov ax,0201h
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int 13h // DISK - READ SECTORS INTO MEMORY
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mov ax, HEX(0201)
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int HEX(13) // DISK - READ SECTORS INTO MEMORY
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// AL = number of sectors to read, CH = track, CL = sector
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// DH = head, DL = drive, ES:BX -> buffer to fill
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// Return: CF set on error, AH = status (see AH=01h), AL = number of sectors read
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@ -296,7 +296,7 @@ ReadSectorsCHSLoop:
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inc eax // Increment Sector to Read
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mov dx,es
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add dx,byte 20h // Increment read buffer for next sector
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add dx, HEX(20) // Increment read buffer for next sector
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mov es,dx
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loop ReadSectorsCHSLoop // Read next sector
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@ -351,7 +351,7 @@ msgAnyKey:
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BootPartition:
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db 0
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dw 0aa55h // BootSector signature
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dw HEX(0aa55) // BootSector signature
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// End of bootsector
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@ -367,14 +367,14 @@ LoadRootDirectory:
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call Ext2ReadInode // Read in the inode
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// Point ES:DI to the inode structure at 6000:8000
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push WORD 6000h
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push WORD HEX(6000)
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pop es
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mov di,8000h
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mov di, HEX(8000)
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push di
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push es // Save these for later
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// Get root directory size from inode structure
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mov eax,DWORD [es:di+4]
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mov eax, [es:di+4]
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push eax
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// Now that the inode has been read in load
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@ -384,7 +384,7 @@ LoadRootDirectory:
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// Since the root directory was loaded to 0000:8000
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// then add 8000h to the root directory's size
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pop eax
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mov edx,8000h // Set EDX to the current offset in the root directory
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mov edx, HEX(8000) // Set EDX to the current offset in the root directory
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add eax,edx // Initially add 8000h to the size of the root directory
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SearchRootDirectory:
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@ -400,17 +400,17 @@ SearchRootDirectory:
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mov es,ax
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mov di,dx
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push di // Save the start of the directory entry
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add di,byte 8 // Add the offset to the filename
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add di, 8 // Add the offset to the filename
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mov si,filename
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mov cl,11
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rep cmpsb // Compare the file names
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repe cmpsb // Compare the file names
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pop di
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pop eax
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pop edx
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jz FoundFile
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// Nope, didn't find it in this entry, keep looking
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movzx ecx,WORD [es:di+4]
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movzx ecx,word ptr [es:di+4]
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add edx,ecx
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// Check to see if we have reached the
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@ -439,11 +439,11 @@ LoadFreeLoader:
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call Ext2ReadEntireFile // Read freeldr.sys to 0000:8000
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mov dl,[BYTE bp+BootDrive]
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mov dh,[BYTE bp+BootPartition]
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mov dl,[bp+BootDrive]
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mov dh,[bp+BootPartition]
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push 0 // push segment (0x0000)
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mov eax, [0x8000 + 0xA8] // load the RVA of the EntryPoint into eax
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add eax, 0x8000 // RVA -> VA
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mov eax, [HEX(8000) + HEX(0A8)] // load the RVA of the EntryPoint into eax
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add eax, HEX(8000) // RVA -> VA
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push ax // push offset
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retf // Transfer control to FreeLoader
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@ -463,17 +463,17 @@ LoadFreeLoader:
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Ext2ReadEntireFile:
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// Reset the load segment
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mov WORD [BYTE bp+Ext2ReadEntireFileLoadSegment],800h
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mov word ptr [bp+Ext2ReadEntireFileLoadSegment], HEX(800)
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// Now we must calculate how
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// many blocks to read in
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// We will do this by rounding the
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// file size up to the next block
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// size and then dividing by the block size
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mov eax,DWORD [BYTE bp+Ext2BlockSizeInBytes] // Get the block size in bytes
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mov eax,DWORD [bp+Ext2BlockSizeInBytes] // Get the block size in bytes
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push eax
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dec eax // Ext2BlockSizeInBytes -= 1
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add eax,DWORD [es:di+4] // Add the file size
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add eax, es:[di+4] // Add the file size
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xor edx,edx
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pop ecx // Divide by the block size in bytes
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div ecx // EAX now contains the number of blocks to load
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@ -486,19 +486,19 @@ Ext2ReadEntireFile:
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Ext2ReadEntireFile2:
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// Save the indirect & double indirect pointers
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mov edx,DWORD [es:di+0x58] // Get indirect pointer
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mov [BYTE bp+Ext2InodeIndirectPointer],edx // Save indirect pointer
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mov edx,DWORD [es:di+0x5c] // Get double indirect pointer
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mov [BYTE bp+Ext2InodeDoubleIndirectPointer],edx // Save double indirect pointer
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mov edx,DWORD [es:di+ HEX(58)] // Get indirect pointer
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mov [bp+Ext2InodeIndirectPointer],edx // Save indirect pointer
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mov edx,DWORD [es:di+ HEX(5c)] // Get double indirect pointer
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mov [bp+Ext2InodeDoubleIndirectPointer],edx // Save double indirect pointer
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// Now copy the direct pointers to 7000:0000
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// so that we can call Ext2ReadDirectBlocks
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push ds // Save DS
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push es
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push WORD 7000h
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push WORD HEX(7000)
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pop es
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pop ds
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mov si,8028h
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mov si, HEX(8028)
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xor di,di // DS:SI = 6000:8028 ES:DI = 7000:0000
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mov cx,24 // Moving 24 words of data
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rep movsw
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@ -521,7 +521,7 @@ Ext2ReadEntireFile2:
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// block and read all it's direct blocks
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push eax // Save the total block count
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mov eax,DWORD [BYTE bp+Ext2InodeIndirectPointer] // Get the indirect block pointer
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push WORD 7000h
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push WORD HEX(7000)
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pop es
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xor bx,bx // Set the load address to 7000:0000
|
||||
call Ext2ReadBlock // Read the block
|
||||
|
|
@ -534,7 +534,7 @@ Ext2ReadEntireFile2:
|
|||
|
||||
// Check to see if we actually have
|
||||
// blocks left to read
|
||||
cmp eax,byte 0
|
||||
cmp eax, 0
|
||||
jz Ext2ReadEntireFileDone
|
||||
|
||||
// Now we have read all the direct blocks from
|
||||
|
|
@ -542,9 +542,9 @@ Ext2ReadEntireFile2:
|
|||
// we have to read the double indirect block
|
||||
// and read all it's indirect blocks
|
||||
// (whew, it's a good thing I don't support triple indirect blocks)
|
||||
mov [BYTE bp+Ext2BlocksLeftToRead],eax // Save the total block count
|
||||
mov eax,DWORD [BYTE bp+Ext2InodeDoubleIndirectPointer] // Get the double indirect block pointer
|
||||
push WORD 7800h
|
||||
mov [bp+Ext2BlocksLeftToRead],eax // Save the total block count
|
||||
mov eax,DWORD [bp+Ext2InodeDoubleIndirectPointer] // Get the double indirect block pointer
|
||||
push WORD HEX(7800)
|
||||
pop es
|
||||
push es // Save an extra copy of this value on the stack
|
||||
xor bx,bx // Set the load address to 7000:8000
|
||||
|
|
@ -559,17 +559,17 @@ Ext2ReadIndirectBlock:
|
|||
push es
|
||||
push di
|
||||
|
||||
push WORD 7000h
|
||||
push WORD HEX(7000)
|
||||
pop es
|
||||
xor bx,bx // Set the load address to 7000:0000
|
||||
call Ext2ReadBlock // Read the indirect block
|
||||
|
||||
// Now we have all the block pointers from the
|
||||
// indirect block in the right location so read them in
|
||||
mov eax,DWORD [BYTE bp+Ext2BlocksLeftToRead] // Restore the total block count
|
||||
mov ecx,DWORD [BYTE bp+Ext2PointersPerBlock] // Get the number of block pointers that one block contains
|
||||
mov eax,DWORD [bp+Ext2BlocksLeftToRead] // Restore the total block count
|
||||
mov ecx,DWORD [bp+Ext2PointersPerBlock] // Get the number of block pointers that one block contains
|
||||
call Ext2ReadDirectBlockList
|
||||
mov [BYTE bp+Ext2BlocksLeftToRead],eax // Save the total block count
|
||||
mov [bp+Ext2BlocksLeftToRead],eax // Save the total block count
|
||||
pop di
|
||||
pop es
|
||||
|
||||
|
|
@ -606,23 +606,23 @@ CallExt2ReadDirectBlocks:
|
|||
// CX contains the number of blocks to read
|
||||
Ext2ReadDirectBlocks:
|
||||
|
||||
push WORD 7000h
|
||||
push WORD HEX(7000)
|
||||
pop es
|
||||
xor di,di // Set ES:DI = 7000:0000
|
||||
|
||||
Ext2ReadDirectBlocksLoop:
|
||||
mov eax,[es:di] // Get direct block pointer from array
|
||||
add di,BYTE 4 // Update DI for next array index
|
||||
add di, 4 // Update DI for next array index
|
||||
|
||||
push cx // Save number of direct blocks left
|
||||
push es // Save array segment
|
||||
push di // Save array offset
|
||||
mov es,[BYTE bp+Ext2ReadEntireFileLoadSegment]
|
||||
mov es,[bp+Ext2ReadEntireFileLoadSegment]
|
||||
xor bx,bx // Setup load address for next read
|
||||
|
||||
call Ext2ReadBlock // Read the block (this updates ES for the next read)
|
||||
|
||||
mov [BYTE bp+Ext2ReadEntireFileLoadSegment],es // Save updated ES
|
||||
mov [bp+Ext2ReadEntireFileLoadSegment],es // Save updated ES
|
||||
|
||||
pop di // Restore the array offset
|
||||
pop es // Restore the array segment
|
||||
|
|
@ -670,4 +670,4 @@ msgLoading:
|
|||
|
||||
times 1022-($-$$) db 0 // Pad to 1022 bytes
|
||||
|
||||
dw 0aa55h // BootSector signature
|
||||
dw HEX(0aa55) // BootSector signature
|
||||
|
|
|
|||
Loading…
Reference in a new issue