diff options
Diffstat (limited to 'DuetPkg/BootSector/Mbr.asm')
| -rw-r--r-- | DuetPkg/BootSector/Mbr.asm | 261 |
1 files changed, 0 insertions, 261 deletions
diff --git a/DuetPkg/BootSector/Mbr.asm b/DuetPkg/BootSector/Mbr.asm deleted file mode 100644 index b105c08901..0000000000 --- a/DuetPkg/BootSector/Mbr.asm +++ /dev/null @@ -1,261 +0,0 @@ -;------------------------------------------------------------------------------
-;*
-;* Copyright (c) 2006 - 2007, Intel Corporation. All rights reserved.<BR>
-;* This program and the accompanying materials
-;* are licensed and made available under the terms and conditions of the BSD License
-;* which accompanies this distribution. The full text of the license may be found at
-;* http://opensource.org/licenses/bsd-license.php
-;*
-;* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
-;* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
-;*
-;* Mbr.asm
-;*
-;* Abstract:
-;*
-;------------------------------------------------------------------------------
-
- .model small
-; .dosseg
- .stack
- .486p
- .code
-
-BLOCK_SIZE EQU 0200h
-BLOCK_MASK EQU 01ffh
-BLOCK_SHIFT EQU 9
-
-; ****************************************************************************
-; Code loaded by BIOS at 0x0000:0x7C00
-; ****************************************************************************
-
- org 0h
-Start:
-
-; ****************************************************************************
-; Start Print
-; ****************************************************************************
-
- mov ax,0b800h
- mov es,ax
- mov ax, 07c0h
- mov ds, ax
- lea si, cs:[StartString]
- mov cx, 10
- mov di, 160
- rep movsw
-
-; ****************************************************************************
-; Print over
-; ****************************************************************************
-
-; ****************************************************************************
-; Initialize segment registers and copy code at 0x0000:0x7c00 to 0x0000:0x0600
-; ****************************************************************************
- xor ax, ax ; AX = 0x0000
- mov bx, 07c00h ; BX = 0x7C00
- mov bp, 0600h ; BP = 0x0600
- mov si, OFFSET RelocatedStart ; SI = Offset(RelocatedStart)
- mov cx, 0200h ; CX = 0x0200
- sub cx, si ; CS = 0x0200 - Offset(RelocatedStart)
- lea di, [bp+si] ; DI = 0x0600 + Offset(RelocatedStart)
- lea si, [bx+si] ; BX = 0x7C00 + Offset(RelocatedStart)
- mov ss, ax ; SS = 0x0000
- mov sp, bx ; SP = 0x7C00
- mov es,ax ; ES = 0x0000
- mov ds,ax ; DS = 0x0000
- push ax ; PUSH 0x0000
- push di ; PUSH 0x0600 + Offset(RelocatedStart)
- cld ; Clear the direction flag
- rep movsb ; Copy 0x0200 bytes from 0x7C00 to 0x0600
- retf ; JMP 0x0000:0x0600 + Offset(RelocatedStart)
-
-; ****************************************************************************
-; Code relocated to 0x0000:0x0600
-; ****************************************************************************
-
-RelocatedStart:
-; ****************************************************************************
-; Get Driver Parameters to 0x0000:0x7BFC
-; ****************************************************************************
-
- xor ax,ax ; AX = 0
- mov ss,ax ; SS = 0
- add ax,1000h
- mov ds,ax
-
- mov sp,07c00h ; SP = 0x7c00
- mov bp,sp ; BP = 0x7c00
-
- mov ah,8 ; AH = 8 - Get Drive Parameters Function
- mov byte ptr [bp+PhysicalDrive],dl ; BBS defines that BIOS would pass the booting driver number to the loader through DL
- int 13h ; Get Drive Parameters
- xor ax,ax ; AX = 0
- mov al,dh ; AL = DH
- inc al ; MaxHead = AL + 1
- push ax ; 0000:7bfe = MaxHead
- mov al,cl ; AL = CL
- and al,03fh ; MaxSector = AL & 0x3f
- push ax ; 0000:7bfc = MaxSector
-
-; ****************************************************************************
-; Read Target DBR from hard disk to 0x0000:0x7C00
-; ****************************************************************************
-
- xor ax, ax
- mov al, byte ptr [bp+MbrPartitionIndicator] ; AX = MbrPartitionIndex
- cmp al, 0ffh ; 0xFF means do legacy MBR boot
- jnz EfiDbr
-LegacyMbr:
- mov eax, 00000600h ; Assume LegacyMBR is backuped in Sector 6
- jmp StartReadTo7C00 ; EAX = Header/Sector/Tracker/Zero
-
-EfiDbr:
- cmp al, 4 ; MbrPartitionIndex should < 4
- jae BadDbr
- shl ax, 4 ; AX = MBREntrySize * Index
- add ax, 1beh ; AX = MBREntryOffset
- mov di, ax ; DI = MBREntryOffset
-
- ; Here we don't use the C/H/S information provided by Partition table
- ; but calculate C/H/S from LBA ourselves
- ; Ci: Cylinder number
- ; Hi: Header number
- ; Si: Sector number
- mov eax, dword ptr es:[bp + di + 8] ; Start LBA
- mov edx, eax
- shr edx, 16 ; DX:AX = Start LBA
- ; = Ci * (H * S) + Hi * S + (Si - 1)
-
- ; Calculate C/H/S according to LBA
- mov bp, 7bfah
- div word ptr [bp+2] ; AX = Hi + H*Ci
- ; DX = Si - 1
- inc dx ; DX = Si
- push dx ; 0000:7bfa = Si <----
- xor dx, dx ; DX:AX = Hi + H*Ci
- div word ptr [bp+4] ; AX = Ci <----
- ; DX = Hi <----
-
-StartReadTo7C00:
-
- mov cl, byte ptr [bp] ; Si
- mov ch, al ; Ci[0-7]
- or cl, ah ; Ci[8,9]
- mov bx, 7c00h ; ES:BX = 0000:7C00h
- mov ah, 2h ; Function 02h
- mov al, 1 ; 1 Sector
- mov dh, dl ; Hi
- mov bp, 0600h
- mov dl, byte ptr [bp + PhysicalDrive] ; Drive number
- int 13h
- jc BadDbr
-
-
-
-; ****************************************************************************
-; Transfer control to BootSector - Jump to 0x0000:0x7C00
-; ****************************************************************************
- xor ax, ax
- push ax ; PUSH 0x0000 - Segment
- mov di, 07c00h
- push di ; PUSH 0x7C00 - Offset
- retf ; JMP 0x0000:0x7C00
-
-; ****************************************************************************
-; ERROR Condition:
-; ****************************************************************************
-
-BadDbr:
- push ax
- mov ax, 0b800h
- mov es, ax
- mov ax, 060h
- mov ds, ax
- lea si, cs:[ErrorString]
- mov di, 320
- pop ax
- call A2C
- mov [si+16], ah
- mov [si+18], al
- mov cx, 10
- rep movsw
-Halt:
- jmp Halt
-
-StartString:
- db 'M', 0ch, 'B', 0ch, 'R', 0ch, ' ', 0ch, 'S', 0ch, 't', 0ch, 'a', 0ch, 'r', 0ch, 't', 0ch, '!', 0ch
-ErrorString:
- db 'M', 0ch, 'B', 0ch, 'R', 0ch, ' ', 0ch, 'E', 0ch, 'r', 0ch, 'r', 0ch, ':', 0ch, '?', 0ch, '?', 0ch
-
-; ****************************************************************************
-; A2C - convert Ascii code stored in AH to character stored in AX
-; ****************************************************************************
-A2C:
- mov al, ah
- shr ah, 4
- and al, 0Fh
- add ah, '0'
- add al, '0'
-
- cmp ah, '9'
- jle @f
- add ah, 7
-@@:
-
- cmp al, '9'
- jle @f
- add al, 7
-@@:
- ret
-
-
-; ****************************************************************************
-; PhysicalDrive - Used to indicate which disk to be boot
-; Can be patched by tool
-; ****************************************************************************
- org 01B6h
-PhysicalDrive db 80h
-
-; ****************************************************************************
-; MbrPartitionIndicator - Used to indicate which MBR partition to be boot
-; Can be patched by tool
-; OxFF means boot to legacy MBR. (LBA OFFSET 6)
-; ****************************************************************************
- org 01B7h
-MbrPartitionIndicator db 0
-
-; ****************************************************************************
-; Unique MBR signature
-; ****************************************************************************
- org 01B8h
- db 'DUET'
-
-; ****************************************************************************
-; Unknown
-; ****************************************************************************
- org 01BCh
- dw 0
-
-; ****************************************************************************
-; MBR Entry - To be patched
-; ****************************************************************************
- org 01BEh
- dd 0, 0, 0, 0
- org 01CEh
- dd 0, 0, 0, 0
- org 01DEh
- dd 0, 0, 0, 0
- org 01EEh
- dd 0, 0, 0, 0
-
-; ****************************************************************************
-; Sector Signature
-; ****************************************************************************
-
- org 01FEh
-SectorSignature:
- dw 0aa55h ; Boot Sector Signature
-
- end
-
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