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-rw-r--r--DuetPkg/BootSector/Mbr.S518
1 files changed, 259 insertions, 259 deletions
diff --git a/DuetPkg/BootSector/Mbr.S b/DuetPkg/BootSector/Mbr.S
index 74852681f..a2431e193 100644
--- a/DuetPkg/BootSector/Mbr.S
+++ b/DuetPkg/BootSector/Mbr.S
@@ -1,260 +1,260 @@
-#------------------------------------------------------------------------------
-#*
-#* Copyright 2006 - 2007, Intel Corporation
-#* All rights reserved. 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:
-#*
-#------------------------------------------------------------------------------
-
-.equ BLOCK_SIZE, 0x0200
-.equ BLOCK_MASK, 0x01ff
-.equ BLOCK_SHIFT, 9
-
-# ****************************************************************************
-# Code loaded by BIOS at 0x0000:0x7C00
-# ****************************************************************************
-
-.org 0x0
-
+#------------------------------------------------------------------------------
+#*
+#* Copyright 2006 - 2007, Intel Corporation
+#* All rights reserved. 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:
+#*
+#------------------------------------------------------------------------------
+
+.equ BLOCK_SIZE, 0x0200
+.equ BLOCK_MASK, 0x01ff
+.equ BLOCK_SHIFT, 9
+
+# ****************************************************************************
+# Code loaded by BIOS at 0x0000:0x7C00
+# ****************************************************************************
+
+.org 0x0
+
.global _start
-_start:
-
-# ****************************************************************************
-# Start Print
-# ****************************************************************************
-
- movw $0xb800, %ax
- movw %ax, %es
- movw $0x7c0, %ax
- movw %ax, %ds
- leaw %cs:StartString, %si
- movw $10, %cx
- movw $160, %di
- rep
- movsw
-
-# ****************************************************************************
-# Print over
-# ****************************************************************************
-
-# ****************************************************************************
-# Initialize segment registers and copy code at 0x0000:0x7c00 to 0x0000:0x0600
-# ****************************************************************************
- xorw %ax, %ax # AX = 0x0000
- movw $0x7c00, %bx # BX = 0x7C00
- movw $0x600, %bp # BP = 0x0600
- movw RelocatedStart, %si # SI = Offset(RelocatedStart)
- movw $0x200, %cx # CX = 0x0200
- subw %si, %cx # CS = 0x0200 - Offset(RelocatedStart)
- leaw (%bp,%si,), %di # DI = 0x0600 + Offset(RelocatedStart)
- leaw (%bx,%si,), %si # BX = 0x7C00 + Offset(RelocatedStart)
- movw %ax, %ss # SS = 0x0000
- movw %bx, %sp # SP = 0x7C00
- movw %ax, %es # ES = 0x0000
- movw %ax, %ds # DS = 0x0000
- pushw %ax # PUSH 0x0000
- pushw %di # PUSH 0x0600 + Offset(RelocatedStart)
- cld # Clear the direction flag
- rep
- movsb # Copy 0x0200 bytes from 0x7C00 to 0x0600
- retl # JMP 0x0000:0x0600 + Offset(RelocatedStart)
-
-# ****************************************************************************
-# Code relocated to 0x0000:0x0600
-# ****************************************************************************
-
-RelocatedStart:
-# ****************************************************************************
-# Get Driver Parameters to 0x0000:0x7BFC
-# ****************************************************************************
-
- xorw %ax, %ax # AX = 0
- movw %ax, %ss # SS = 0
- addw $0x1000, %ax
- movw %ax, %ds
-
- movw $0x7c00, %sp # SP = 0x7c00
- movw %sp, %bp # BP = 0x7c00
-
- movb $8, %ah # AH = 8 - Get Drive Parameters Function
- movb %dl, PhysicalDrive(%bp) # BBS defines that BIOS would pass the booting driver number to the loader through DL
- int $0x13 # Get Drive Parameters
- xorw %ax, %ax # AX = 0
- movb %dh, %al # AL = DH
- incb %al # MaxHead = AL + 1
- pushw %ax # 0000:7bfe = MaxHead
- movb %cl, %al # AL = CL
- andb $0x3f, %al # MaxSector = AL & 0x3f
- pushw %ax # 0000:7bfc = MaxSector
-
-# ****************************************************************************
-# Read Target DBR from hard disk to 0x0000:0x7C00
-# ****************************************************************************
-
- xorw %ax, %ax
- movb MbrPartitionIndicator(%bp), %al # AX = MbrPartitionIndex
- cmpb $0xff, %al # 0xFF means do legacy MBR boot
- jnz EfiDbr
-LegacyMbr:
- movl $0x0000600, %eax # Assume LegacyMBR is backuped in Sector 6
- jmp StartReadTo7C00 # EAX = Header/Sector/Tracker/Zero
-
-EfiDbr:
- cmpb $4, %al # MbrPartitionIndex should < 4
- jae BadDbr
- shlw $4, %ax # AX = MBREntrySize * Index
- addw $0x1be, %ax # AX = MBREntryOffset
- movw %ax, %di # 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
- movl %es:8(%bp,%di,), %eax # Start LBA
- movl %eax, %edx
- shrl $16, %edx # DX:AX = Start LBA
- # = Ci * (H * S) + Hi * S + (Si - 1)
-
- # Calculate C/H/S according to LBA
- movw $0x7bfa, %bp
- divw 2(%bp) # AX = Hi + H*Ci
- # DX = Si - 1
- incw %dx # DX = Si
- pushw %dx # 0000:7bfa = Si <----
- xorw %dx, %dx # DX:AX = Hi + H*Ci
- divw 4(%bp) # AX = Ci <----
- # DX = Hi <----
-
-StartReadTo7C00:
-
- movb (%bp), %cl # Si
- movb %al, %ch # Ci[0-7]
- orb %ah, %cl # Ci[8,9]
- movw $0x7c00, %bx # ES:BX = 0000:7C00h
- movb $0x2, %ah # Function 02h
- movb $1, %al # 1 Sector
- movb %dl, %dh # Hi
- movw $0x600, %bp
- movb PhysicalDrive(%bp), %dl # Drive number
- int $0x13
- jc BadDbr
-
-
-
-# ****************************************************************************
-# Transfer control to BootSector - Jump to 0x0000:0x7C00
-# ****************************************************************************
- xorw %ax, %ax
- pushw %ax # PUSH 0x0000 - Segment
- movw $0x7c00, %di
- pushw %di # PUSH 0x7C00 - Offset
- retl # JMP 0x0000:0x7C00
-
-# ****************************************************************************
-# ERROR Condition:
-# ****************************************************************************
-
-BadDbr:
- pushw %ax
- movw $0xb800, %ax
- movw %ax, %es
- movw $0x60, %ax
- movw %ax, %ds
- leaw %cs:ErrorString, %si
- movw $320, %di
- popw %ax
- call A2C
- movb %ah, 16(%si)
- movb %al, 18(%si)
- movw $10, %cx
- rep
- movsw
-Halt:
- jmp Halt
-
-StartString:
-.byte 'M', 0x0c, 'B', 0x0c, 'R', 0x0c, ' ', 0x0c, 'S', 0x0c, 't', 0x0c, 'a', 0x0c, 'r', 0x0c, 't', 0x0c, '!', 0x0c
-ErrorString:
-.byte 'M', 0x0c, 'B', 0x0c, 'R', 0x0c, ' ', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, ':', 0x0c, '?', 0x0c, '?', 0x0c
-
-# ****************************************************************************
-# A2C - convert Ascii code stored in AH to character stored in AX
-# ****************************************************************************
-A2C:
- movb %ah, %al
- shrb $4, %ah
- andb $0xF, %al
- addb '0', %ah
- addb '0', %al
-
- cmpb '9', %ah
- jle A2C_L1
- addb $7, %ah
-A2C_L1:
-
- cmpb '9', %al
- jle A2C_L2
- addb $7, %al
-A2C_L2:
- ret
-
-
-# ****************************************************************************
-# PhysicalDrive - Used to indicate which disk to be boot
-# Can be patched by tool
-# ****************************************************************************
-.org 0x01B6
-PhysicalDrive: .byte 0x80
-
-# ****************************************************************************
-# 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 0x01B7
-MbrPartitionIndicator: .byte 0
-
-# ****************************************************************************
-# Unique MBR signature
-# ****************************************************************************
-.org 0x01B8
- .ascii "DUET"
-
-# ****************************************************************************
-# Unknown
-# ****************************************************************************
-.org 0x01BC
- .word 0
-
-# ****************************************************************************
-# MBR Entry - To be patched
-# ****************************************************************************
-.org 0x01BE
- .long 0,0,0,0
-.org 0x01CE
- .long 0,0,0,0
-.org 0x01DE
- .long 0,0,0,0
-.org 0x01EE
- .long 0,0,0,0
-
-# ****************************************************************************
-# Sector Signature
-# ****************************************************************************
-
-.org 0x01FE
-SectorSignature:
- .word 0xaa55 # Boot Sector Signature
-
-
-
+_start:
+
+# ****************************************************************************
+# Start Print
+# ****************************************************************************
+
+ movw $0xb800, %ax
+ movw %ax, %es
+ movw $0x7c0, %ax
+ movw %ax, %ds
+ leaw %cs:StartString, %si
+ movw $10, %cx
+ movw $160, %di
+ rep
+ movsw
+
+# ****************************************************************************
+# Print over
+# ****************************************************************************
+
+# ****************************************************************************
+# Initialize segment registers and copy code at 0x0000:0x7c00 to 0x0000:0x0600
+# ****************************************************************************
+ xorw %ax, %ax # AX = 0x0000
+ movw $0x7c00, %bx # BX = 0x7C00
+ movw $0x600, %bp # BP = 0x0600
+ movw RelocatedStart, %si # SI = Offset(RelocatedStart)
+ movw $0x200, %cx # CX = 0x0200
+ subw %si, %cx # CS = 0x0200 - Offset(RelocatedStart)
+ leaw (%bp,%si,), %di # DI = 0x0600 + Offset(RelocatedStart)
+ leaw (%bx,%si,), %si # BX = 0x7C00 + Offset(RelocatedStart)
+ movw %ax, %ss # SS = 0x0000
+ movw %bx, %sp # SP = 0x7C00
+ movw %ax, %es # ES = 0x0000
+ movw %ax, %ds # DS = 0x0000
+ pushw %ax # PUSH 0x0000
+ pushw %di # PUSH 0x0600 + Offset(RelocatedStart)
+ cld # Clear the direction flag
+ rep
+ movsb # Copy 0x0200 bytes from 0x7C00 to 0x0600
+ retl # JMP 0x0000:0x0600 + Offset(RelocatedStart)
+
+# ****************************************************************************
+# Code relocated to 0x0000:0x0600
+# ****************************************************************************
+
+RelocatedStart:
+# ****************************************************************************
+# Get Driver Parameters to 0x0000:0x7BFC
+# ****************************************************************************
+
+ xorw %ax, %ax # AX = 0
+ movw %ax, %ss # SS = 0
+ addw $0x1000, %ax
+ movw %ax, %ds
+
+ movw $0x7c00, %sp # SP = 0x7c00
+ movw %sp, %bp # BP = 0x7c00
+
+ movb $8, %ah # AH = 8 - Get Drive Parameters Function
+ movb %dl, PhysicalDrive(%bp) # BBS defines that BIOS would pass the booting driver number to the loader through DL
+ int $0x13 # Get Drive Parameters
+ xorw %ax, %ax # AX = 0
+ movb %dh, %al # AL = DH
+ incb %al # MaxHead = AL + 1
+ pushw %ax # 0000:7bfe = MaxHead
+ movb %cl, %al # AL = CL
+ andb $0x3f, %al # MaxSector = AL & 0x3f
+ pushw %ax # 0000:7bfc = MaxSector
+
+# ****************************************************************************
+# Read Target DBR from hard disk to 0x0000:0x7C00
+# ****************************************************************************
+
+ xorw %ax, %ax
+ movb MbrPartitionIndicator(%bp), %al # AX = MbrPartitionIndex
+ cmpb $0xff, %al # 0xFF means do legacy MBR boot
+ jnz EfiDbr
+LegacyMbr:
+ movl $0x0000600, %eax # Assume LegacyMBR is backuped in Sector 6
+ jmp StartReadTo7C00 # EAX = Header/Sector/Tracker/Zero
+
+EfiDbr:
+ cmpb $4, %al # MbrPartitionIndex should < 4
+ jae BadDbr
+ shlw $4, %ax # AX = MBREntrySize * Index
+ addw $0x1be, %ax # AX = MBREntryOffset
+ movw %ax, %di # 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
+ movl %es:8(%bp,%di,), %eax # Start LBA
+ movl %eax, %edx
+ shrl $16, %edx # DX:AX = Start LBA
+ # = Ci * (H * S) + Hi * S + (Si - 1)
+
+ # Calculate C/H/S according to LBA
+ movw $0x7bfa, %bp
+ divw 2(%bp) # AX = Hi + H*Ci
+ # DX = Si - 1
+ incw %dx # DX = Si
+ pushw %dx # 0000:7bfa = Si <----
+ xorw %dx, %dx # DX:AX = Hi + H*Ci
+ divw 4(%bp) # AX = Ci <----
+ # DX = Hi <----
+
+StartReadTo7C00:
+
+ movb (%bp), %cl # Si
+ movb %al, %ch # Ci[0-7]
+ orb %ah, %cl # Ci[8,9]
+ movw $0x7c00, %bx # ES:BX = 0000:7C00h
+ movb $0x2, %ah # Function 02h
+ movb $1, %al # 1 Sector
+ movb %dl, %dh # Hi
+ movw $0x600, %bp
+ movb PhysicalDrive(%bp), %dl # Drive number
+ int $0x13
+ jc BadDbr
+
+
+
+# ****************************************************************************
+# Transfer control to BootSector - Jump to 0x0000:0x7C00
+# ****************************************************************************
+ xorw %ax, %ax
+ pushw %ax # PUSH 0x0000 - Segment
+ movw $0x7c00, %di
+ pushw %di # PUSH 0x7C00 - Offset
+ retl # JMP 0x0000:0x7C00
+
+# ****************************************************************************
+# ERROR Condition:
+# ****************************************************************************
+
+BadDbr:
+ pushw %ax
+ movw $0xb800, %ax
+ movw %ax, %es
+ movw $0x60, %ax
+ movw %ax, %ds
+ leaw %cs:ErrorString, %si
+ movw $320, %di
+ popw %ax
+ call A2C
+ movb %ah, 16(%si)
+ movb %al, 18(%si)
+ movw $10, %cx
+ rep
+ movsw
+Halt:
+ jmp Halt
+
+StartString:
+.byte 'M', 0x0c, 'B', 0x0c, 'R', 0x0c, ' ', 0x0c, 'S', 0x0c, 't', 0x0c, 'a', 0x0c, 'r', 0x0c, 't', 0x0c, '!', 0x0c
+ErrorString:
+.byte 'M', 0x0c, 'B', 0x0c, 'R', 0x0c, ' ', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, ':', 0x0c, '?', 0x0c, '?', 0x0c
+
+# ****************************************************************************
+# A2C - convert Ascii code stored in AH to character stored in AX
+# ****************************************************************************
+A2C:
+ movb %ah, %al
+ shrb $4, %ah
+ andb $0xF, %al
+ addb '0', %ah
+ addb '0', %al
+
+ cmpb '9', %ah
+ jle A2C_L1
+ addb $7, %ah
+A2C_L1:
+
+ cmpb '9', %al
+ jle A2C_L2
+ addb $7, %al
+A2C_L2:
+ ret
+
+
+# ****************************************************************************
+# PhysicalDrive - Used to indicate which disk to be boot
+# Can be patched by tool
+# ****************************************************************************
+.org 0x01B6
+PhysicalDrive: .byte 0x80
+
+# ****************************************************************************
+# 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 0x01B7
+MbrPartitionIndicator: .byte 0
+
+# ****************************************************************************
+# Unique MBR signature
+# ****************************************************************************
+.org 0x01B8
+ .ascii "DUET"
+
+# ****************************************************************************
+# Unknown
+# ****************************************************************************
+.org 0x01BC
+ .word 0
+
+# ****************************************************************************
+# MBR Entry - To be patched
+# ****************************************************************************
+.org 0x01BE
+ .long 0,0,0,0
+.org 0x01CE
+ .long 0,0,0,0
+.org 0x01DE
+ .long 0,0,0,0
+.org 0x01EE
+ .long 0,0,0,0
+
+# ****************************************************************************
+# Sector Signature
+# ****************************************************************************
+
+.org 0x01FE
+SectorSignature:
+ .word 0xaa55 # Boot Sector Signature
+
+
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-05 16:23:47 +0000