diff options
| author | gikidy <gikidy@6f19259b-4bc3-4df7-8a09-765794883524> | 2009-02-20 08:22:04 +0000 |
|---|---|---|
| committer | gikidy <gikidy@6f19259b-4bc3-4df7-8a09-765794883524> | 2009-02-20 08:22:04 +0000 |
| commit | ccec4c39691f3e2bc3108ef82f744b278b59fda3 (patch) | |
| tree | 1821798327a6f14124568495857ed96ff3e2721c /DuetPkg/BootSector | |
| parent | 01f1138afeda57f67d783c0e29aafeb7ce6edda6 (diff) | |
| download | edk2-platforms-ccec4c39691f3e2bc3108ef82f744b278b59fda3.tar.xz | |
Port Intel .asm to GAS S
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7557 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'DuetPkg/BootSector')
| -rw-r--r-- | DuetPkg/BootSector/efi32.S | 581 | ||||
| -rw-r--r-- | DuetPkg/BootSector/start.S | 12 | ||||
| -rw-r--r-- | DuetPkg/BootSector/start32.S | 928 |
3 files changed, 1517 insertions, 4 deletions
diff --git a/DuetPkg/BootSector/efi32.S b/DuetPkg/BootSector/efi32.S new file mode 100644 index 0000000000..421271c516 --- /dev/null +++ b/DuetPkg/BootSector/efi32.S @@ -0,0 +1,581 @@ +#------------------------------------------------------------------------------
+#*
+#* Copyright 2006, 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.
+#*
+#* efi32.asm
+#*
+#* Abstract:
+#*
+#------------------------------------------------------------------------------
+
+##############################################################################
+# Now in 32-bit protected mode.
+##############################################################################
+
+ .486:
+ #.MODEL flat
+ .stack:
+ .code:
+ .org 0x21000
+
+.equ DEFAULT_HANDLER_SIZE, INT1 - INT0
+
+.macro jmpCommonIdtEntry
+ # jmp commonIdtEntry - this must be hand coded to keep the assembler from
+ # using a 8 bit reletive jump when the entries are
+ # within 255 bytes of the common entry. This must
+ # be done to maintain the consistency of the size
+ # of entry points...
+ .byte 0xe9 # jmp 16 bit relative
+ .long commonIdtEntry - . - 4 # A problem
+.endm
+
+Start:
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %fs
+ movw %ax, %gs
+ movw %ax, %ss
+ movl $0x001ffff0, %esp
+
+ call ClearScreen
+
+ # Populate IDT with meaningful offsets for exception handlers...
+ sidt Idtr
+
+ movl Halt, %eax
+ movl %eax, %ebx # use bx to copy 15..0 to descriptors
+ shrl $16, %eax # use ax to copy 31..16 to descriptors
+ movl $0x78, %ecx # 78h IDT entries to initialize with unique entry points (exceptions)
+ movl (Idtr + 2), %esi
+ movl (%esi), %edi
+
+LOOP_1: # loop through all IDT entries exception handlers and initialize to default handler
+ movw %bx, (%edi) # write bits 15..0 of offset
+ movw $0x20, 2(%edi) # SYS_CODE_SEL from GDT
+ movw $(0x0e00 | 0x8000), 4(%edi) # type = 386 interrupt gate, present
+ movw %ax, 6(%edi) # write bits 31..16 of offset
+ addl $8, %edi # move up to next descriptor
+ addw DEFAULT_HANDLER_SIZE, %bx # move to next entry point
+ loopl LOOP_1 # loop back through again until all descriptors are initialized
+
+ ## at this point edi contains the offset of the descriptor for INT 20
+ ## and bx contains the low 16 bits of the offset of the default handler
+ ## so initialize all the rest of the descriptors with these two values...
+# mov ecx, 101 ; there are 100 descriptors left (INT 20 (14h) - INT 119 (77h)
+#@@: ; loop through all IDT entries exception handlers and initialize to default handler
+# mov word ptr [edi], bx ; write bits 15..0 of offset
+# mov word ptr [edi+2], 20h ; SYS_CODE_SEL from GDT
+# mov word ptr [edi+4], 0e00h OR 8000h ; type = 386 interrupt gate, present
+# mov word ptr [edi+6], ax ; write bits 31..16 of offset
+# add edi, 8 ; move up to next descriptor
+# loop @b ; loop back through again until all descriptors are initialized
+
+
+## DUMP location of IDT and several of the descriptors
+# mov ecx, 8
+# mov eax, [offset Idtr + 2]
+# mov eax, [eax]
+# mov edi, 0b8000h
+# call PrintDword
+# mov esi, eax
+# mov edi, 0b80a0h
+# jmp OuterLoop
+
+##
+## just for fun, let's do a software interrupt to see if we correctly land in the exception handler...
+# mov eax, 011111111h
+# mov ebx, 022222222h
+# mov ecx, 033333333h
+# mov edx, 044444444h
+# mov ebp, 055555555h
+# mov esi, 066666666h
+# mov edi, 077777777h
+# push 011111111h
+# push 022222222h
+# push 033333333h
+# int 119
+
+
+ movl $0x22000, %esi # esi = 22000
+ movl 0x14(%esi), %eax # eax = [22014]
+ addl %eax, %esi # esi = 22000 + [22014] = Base of EFILDR.C
+ movl 0x3c(%esi), %ebp # ebp = [22000 + [22014] + 3c] = NT Image Header for EFILDR.C
+ addl %esi, %ebp
+ movl 0x34(%ebp), %edi # edi = [[22000 + [22014] + 3c] + 30] = ImageBase
+ movl 0x28(%ebp), %eax # eax = [[22000 + [22014] + 3c] + 24] = EntryPoint
+ addl %edi, %eax # eax = ImageBase + EntryPoint
+ movl %eax, EfiLdrOffset # Modify far jump instruction for correct entry point
+
+ movw 6(%ebp), %bx # bx = Number of sections
+ xorl %eax, %eax
+ movw 0x14(%ebp), %ax # ax = Optional Header Size
+ addl %eax, %ebp
+ addl $0x18, %ebp # ebp = Start of 1st Section
+
+SectionLoop:
+ pushl %esi # Save Base of EFILDR.C
+ pushl %edi # Save ImageBase
+ addl 0x14(%ebp), %esi # esi = Base of EFILDR.C + PointerToRawData
+ addl 0x0c(%ebp), %edi # edi = ImageBase + VirtualAddress
+ movl 0x10(%ebp), %ecx # ecs = SizeOfRawData
+
+ cld
+ shrl $2, %ecx
+ rep
+ movsl
+
+ popl %edi # Restore ImageBase
+ popl %esi # Restore Base of EFILDR.C
+
+ addw $0x28, %bp # ebp = ebp + 028h = Pointer to next section record
+ decw %bx
+ cmpw $0, %bx
+ jne SectionLoop
+
+ movzwl Idtr, %eax # get size of IDT
+ incl %eax
+ addl Idtr + 2, %eax # add to base of IDT to get location of memory map...
+ pushl %eax # push memory map location on stack for call to EFILDR...
+
+ pushl %eax # push return address (useless, just for stack balance)
+ .byte 0xb8
+EfiLdrOffset:
+ .long 0x00401000 # Offset of EFILDR
+# mov eax, 401000h
+ pushl %eax
+ ret
+
+# db "**** DEFAULT IDT ENTRY ***",0
+ .align 0x2
+Halt:
+INT0:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x0
+ jmpCommonIdtEntry
+# db 0e9h ; jmp 16 bit reletive
+# dd commonIdtEntry - $ - 4 ; offset to jump to
+
+INT1:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x1
+ jmpCommonIdtEntry
+
+INT2:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x2
+ jmpCommonIdtEntry
+
+INT3:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x3
+ jmpCommonIdtEntry
+
+INT4:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x4
+ jmpCommonIdtEntry
+
+INT5:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x5
+ jmpCommonIdtEntry
+
+INT6:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x6
+ jmpCommonIdtEntry
+
+INT7:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x7
+ jmpCommonIdtEntry
+
+INT8:
+# Double fault causes an error code to be pushed so no phony push necessary
+ nop
+ nop
+ pushl $0x8
+ jmpCommonIdtEntry
+
+INT9:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $0x9
+ jmpCommonIdtEntry
+
+INT10:
+# Invalid TSS causes an error code to be pushed so no phony push necessary
+ nop
+ nop
+ pushl $10
+ jmpCommonIdtEntry
+
+INT11:
+# Segment Not Present causes an error code to be pushed so no phony push necessary
+ nop
+ nop
+ pushl $11
+ jmpCommonIdtEntry
+
+INT12:
+# Stack fault causes an error code to be pushed so no phony push necessary
+ nop
+ nop
+ pushl $12
+ jmpCommonIdtEntry
+
+INT13:
+# GP fault causes an error code to be pushed so no phony push necessary
+ nop
+ nop
+ pushl $13
+ jmpCommonIdtEntry
+
+INT14:
+# Page fault causes an error code to be pushed so no phony push necessary
+ nop
+ nop
+ pushl $14
+ jmpCommonIdtEntry
+
+INT15:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $15
+ jmpCommonIdtEntry
+
+INT16:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $16
+ jmpCommonIdtEntry
+
+INT17:
+# Alignment check causes an error code to be pushed so no phony push necessary
+ nop
+ nop
+ pushl $17
+ jmpCommonIdtEntry
+
+INT18:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $18
+ jmpCommonIdtEntry
+
+INT19:
+ pushl $0x0 # push error code place holder on the stack
+ pushl $19
+ jmpCommonIdtEntry
+
+INTUnknown:
+.rept (0x78 - 20)
+ pushl $0x0 # push error code place holder on the stack
+# push $0xxx # push vector number
+ .byte 0x6a
+ .long ( . - INTUnknown - 3 ) / 9 + 20 # vector number
+ jmpCommonIdtEntry
+.endr
+
+commonIdtEntry:
+ pushal
+ movl %esp, %ebp
+##
+## At this point the stack looks like this:
+##
+## eflags
+## Calling CS
+## Calling EIP
+## Error code or 0
+## Int num or 0ffh for unknown int num
+## eax
+## ecx
+## edx
+## ebx
+## esp
+## ebp
+## esi
+## edi <------- ESP, EBP
+##
+
+ call ClearScreen
+ movl String1, %esi
+ call PrintString
+ movl 32(%ebp), %eax ## move Int number into EAX
+ cmpl $19, %eax
+ ja PrintDefaultString
+PrintExceptionString:
+ shll $2, %eax ## multiply by 4 to get offset from StringTable to actual string address
+ addl StringTable, %eax
+ movl (%eax), %esi
+ jmp PrintTheString
+PrintDefaultString:
+ movl IntUnknownString, %esi
+ # patch Int number
+ movl %eax, %edx
+ call A2C
+ movb %al, 1(%esi)
+ movl %edx, %eax
+ shrl $4, %eax
+ call A2C
+ movb %al, (%esi)
+PrintTheString:
+ call PrintString
+ movl String2, %esi
+ call PrintString
+ movl 44(%ebp), %eax # CS
+ call PrintDword
+ movb ':', %al
+ movb %al, (%edi)
+ addl $2, %edi
+ movl 40(%ebp), %eax # EIP
+ call PrintDword
+ movl String3, %esi
+ call PrintString
+
+ movl $0xb8140, %edi
+
+ movl StringEax, %esi # eax
+ call PrintString
+ movl 28(%ebp), %eax
+ call PrintDword
+
+ movl StringEbx, %esi # ebx
+ call PrintString
+ movl 16(%ebp), %eax
+ call PrintDword
+
+ movl StringEcx, %esi # ecx
+ call PrintString
+ movl 24(%ebp), %eax
+ call PrintDword
+
+ movl StringEdx, %esi # edx
+ call PrintString
+ movl 20(%ebp), %eax
+ call PrintDword
+
+ movl StringEcode, %esi # error code
+ call PrintString
+ movl 36(%ebp), %eax
+ call PrintDword
+
+ movl $0xb81e0, %edi
+
+ movl StringEsp, %esi # esp
+ call PrintString
+ movl 12(%ebp), %eax
+ call PrintDword
+
+ movl StringEbp, %esi # ebp
+ call PrintString
+ movl 8(%ebp), %eax
+ call PrintDword
+
+ movl StringEsi, %esi # esi
+ call PrintString
+ movl 4(%ebp), %eax
+ call PrintDword
+
+ movl StringEdi, %esi # edi
+ call PrintString
+ movl (%ebp), %eax
+ call PrintDword
+
+ movl StringEflags, %esi # eflags
+ call PrintString
+ movl 48(%ebp), %eax
+ call PrintDword
+
+ movl $0xb8320, %edi
+
+ movl %ebp, %esi
+ addl $52, %esi
+ movl $8, %ecx
+
+
+OuterLoop:
+ pushl %ecx
+ movl $8, %ecx
+ movl %edi, %edx
+
+InnerLoop:
+ movl (%esi), %eax
+ call PrintDword
+ addl $4, %esi
+ movb ' ', %al
+ movb %al, (%edi)
+ addl $2, %edi
+ loop InnerLoop
+
+ popl %ecx
+ addl $0xa0, %edx
+ movl %edx, %edi
+ loop OuterLoop
+
+
+ movl $0xb8960, %edi
+
+ movl 40(%ebp), %eax # EIP
+ subl $32*4, %eax
+ movl %eax, %esi # esi = eip - 32 DWORD linear (total 64 DWORD)
+
+ movl $8, %ecx
+
+OuterLoop1:
+ pushl %ecx
+ movl $8, %ecx
+ movl %edi, %edx
+
+InnerLoop1:
+ movl (%esi), %eax
+ call PrintDword
+ addl $4, %esi
+ movb ' ', %al
+ movb %al, (%edi)
+ addl $2, %edi
+ loop InnerLoop1
+
+ popl %ecx
+ addl $0xa0, %edx
+ movl %edx, %edi
+ loop OuterLoop1
+
+
+
+# wbinvd ; this intruction does not support in early than 486 arch
+LN_C1:
+ jmp LN_C1
+#
+# return
+#
+ movl %ebp, %esp
+ popal
+ addl $8, %esp # error code and INT number
+
+ iretl
+
+
+PrintString:
+ pushl %eax
+LN_C2:
+ movb (%esi), %al
+ cmpb $0, %al
+ je LN_C3
+ movb %al, (%edi)
+ incl %esi
+ addl $2, %edi
+ jmp LN_C2
+LN_C3:
+ popl %eax
+ ret
+
+## EAX contains dword to print
+## EDI contains memory location (screen location) to print it to
+PrintDword:
+ pushl %ecx
+ pushl %ebx
+ pushl %eax
+
+ movl $8, %ecx
+looptop:
+ roll $4, %eax
+ movb %al, %bl
+ andb $0xf, %bl
+ addb '0', %bl
+ cmpb '9', %bl
+ jle LN_C4
+ addb $7, %bl
+LN_C4:
+ movb %bl, (%edi)
+ addl $2, %edi
+ loop looptop
+ #wbinvd
+
+ popl %eax
+ popl %ebx
+ popl %ecx
+ ret
+
+ClearScreen:
+ pushl %eax
+ pushl %ecx
+
+ movb ' ', %al
+ movb $0xc, %ah
+ movl $0xb8000, %edi
+ movl $80*24, %ecx
+LN_C5:
+ movw %ax, (%edi)
+ addl $2, %edi
+ loop LN_C5
+ movl $0xb8000, %edi
+
+ popl %ecx
+ popl %eax
+
+ ret
+
+A2C:
+ andb $0xf, %al
+ addb '0', %al
+ cmpb '9', %al
+ jle LN_C6
+ addb $7, %al
+LN_C6:
+ ret
+
+String1: .asciz "*** INT "
+
+Int0String: .asciz "00h Divide by 0 -"
+Int1String: .asciz "01h Debug exception -"
+Int2String: .asciz "02h NMI -"
+Int3String: .asciz "03h Breakpoint -"
+Int4String: .asciz "04h Overflow -"
+Int5String: .asciz "05h Bound -"
+Int6String: .asciz "06h Invalid opcode -"
+Int7String: .asciz "07h Device not available -"
+Int8String: .asciz "08h Double fault -"
+Int9String: .asciz "09h Coprocessor seg overrun (reserved) -"
+Int10String: .asciz "0Ah Invalid TSS -"
+Int11String: .asciz "0Bh Segment not present -"
+Int12String: .asciz "0Ch Stack fault -"
+Int13String: .asciz "0Dh General protection fault -"
+Int14String: .asciz "0Eh Page fault -"
+Int15String: .asciz "0Fh (Intel reserved) -"
+Int16String: .asciz "10h Floating point error -"
+Int17String: .asciz "11h Alignment check -"
+Int18String: .asciz "12h Machine check -"
+Int19String: .asciz "13h SIMD Floating-Point Exception -"
+IntUnknownString: .asciz "??h Unknown interrupt -"
+
+StringTable: .long Int0String, Int1String, Int2String, Int3String, \
+ Int4String, Int5String, Int6String, Int7String, \
+ Int8String, Int9String, Int10String, Int11String, \
+ Int12String, Int13String, Int14String, Int15String,\
+ Int16String, Int17String, Int18String, Int19String
+
+String2: .asciz " HALT!! *** ("
+String3: .asciz ")"
+StringEax: .asciz "EAX="
+StringEbx: .asciz "EBX="
+StringEcx: .asciz "ECX="
+StringEdx: .asciz "EDX="
+StringEcode: .asciz "ECODE="
+StringEsp: .asciz "ESP="
+StringEbp: .asciz "EBP="
+StringEsi: .asciz "ESI="
+StringEdi: .asciz "EDI="
+StringEflags: .asciz "EFLAGS="
+
+Idtr: .float 0
+
+ .org 0x21ffe
+BlockSignature:
+ .word 0xaa55
+
+
diff --git a/DuetPkg/BootSector/start.S b/DuetPkg/BootSector/start.S index 9d06654108..d558652a9a 100644 --- a/DuetPkg/BootSector/start.S +++ b/DuetPkg/BootSector/start.S @@ -15,6 +15,10 @@ #*
#------------------------------------------------------------------------------
+
+
+
+
.equ FAT_DIRECTORY_ENTRY_SIZE, 0x020
.equ FAT_DIRECTORY_ENTRY_SHIFT, 5
@@ -149,9 +153,9 @@ FatChainLoop: shrw %ax # FatOffset = ClusterNumber*3 / 2
pushw %si # Save si
movw %ax, %si # si = FatOffset
- shrw %ax # ax = FatOffset >> BLOCK_SHIFT
+ shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT
addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET)
- andw BLOCK_MASK,%si # si = FatOffset & BLOCK_MASK
+ andw $BLOCK_MASK,%si # si = FatOffset & BLOCK_MASK
cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber
je SkipFatRead
movw $2, %bx
@@ -279,7 +283,7 @@ NotCrossing64KBoundry: DiskError:
pushw %cs
popw %ds
- leaw %cs:ErrorString, %si
+ leaw ErrorString, %si
movw $7, %cx
jmp PrintStringAndHalt
@@ -295,7 +299,7 @@ Halt: ErrorString:
.byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!',0x0c
- #.org 0x0242 # For Code size overflow, Modified this just for pass build
+ .org 0x0241 # For Code size overflow, Modified this just for pass build
LBAOffsetForBootSector:
.long 0x0
diff --git a/DuetPkg/BootSector/start32.S b/DuetPkg/BootSector/start32.S new file mode 100644 index 0000000000..3ddebfc862 --- /dev/null +++ b/DuetPkg/BootSector/start32.S @@ -0,0 +1,928 @@ +#------------------------------------------------------------------------------
+#*
+#* 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.
+#*
+#* start32.asm
+#*
+#* Abstract:
+#*
+#------------------------------------------------------------------------------
+
+ #.MODEL small
+ .stack:
+ .486p:
+ .code:
+
+.equ FAT_DIRECTORY_ENTRY_SIZE, 0x020
+.equ FAT_DIRECTORY_ENTRY_SHIFT, 5
+.equ BLOCK_SIZE, 0x0200
+.equ BLOCK_MASK, 0x01ff
+.equ BLOCK_SHIFT, 9
+
+ .org 0x0
+Ia32Jump:
+ jmp BootSectorEntryPoint # JMP inst - 3 bytes
+ nop
+
+OemId: .ascii "INTEL " # OemId - 8 bytes
+SectorSize: .word 0 # Sector Size - 2 bytes
+SectorsPerCluster: .byte 0 # Sector Per Cluster - 1 byte
+ReservedSectors: .word 0 # Reserved Sectors - 2 bytes
+NoFats: .byte 0 # Number of FATs - 1 byte
+RootEntries: .word 0 # Root Entries - 2 bytes
+Sectors: .word 0 # Number of Sectors - 2 bytes
+Media: .byte 0 # Media - 1 byte
+SectorsPerFat16: .word 0 # Sectors Per FAT for FAT12/FAT16 - 2 byte
+SectorsPerTrack: .word 0 # Sectors Per Track - 2 bytes
+Heads: .word 0 # Heads - 2 bytes
+HiddenSectors: .long 0 # Hidden Sectors - 4 bytes
+LargeSectors: .long 0 # Large Sectors - 4 bytes
+
+#******************************************************************************
+#
+#The structure for FAT32 starting at offset 36 of the boot sector. (At this point,
+#the BPB/boot sector for FAT12 and FAT16 differs from the BPB/boot sector for FAT32.)
+#
+#******************************************************************************
+
+SectorsPerFat32: .long 0 # Sectors Per FAT for FAT32 - 4 bytes
+ExtFlags: .word 0 # Mirror Flag - 2 bytes
+FSVersion: .word 0 # File System Version - 2 bytes
+RootCluster: .long 0 # 1st Cluster Number of Root Dir - 4 bytes
+FSInfo: .word 0 # Sector Number of FSINFO - 2 bytes
+BkBootSector: .word 0 # Sector Number of Bk BootSector - 2 bytes
+Reserved: .fill 12,1,0 # Reserved Field - 12 bytes
+PhysicalDrive: .byte 0 # Physical Drive Number - 1 byte
+Reserved1: .byte 0 # Reserved Field - 1 byte
+Signature: .byte 0 # Extended Boot Signature - 1 byte
+VolId: .ascii " " # Volume Serial Number - 4 bytes
+FatLabel: .ascii " " # Volume Label - 11 bytes
+FileSystemType: .ascii "FAT32 " # File System Type - 8 bytes
+
+BootSectorEntryPoint:
+ #ASSUME ds:@code
+ #ASSUME ss:@code
+ # ds = 1000, es = 2000 + x (size of first cluster >> 4)
+ # cx = Start Cluster of EfiLdr
+ # dx = Start Cluster of Efivar.bin
+
+# Re use the BPB data stored in Boot Sector
+ movw $0x7c00, %bp
+
+
+ pushw %cx
+# Read Efivar.bin
+# 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already
+ movw $0x1900, %ax
+ movw %ax, %es
+ testw %dx, %dx
+ jnz CheckVarStoreSize
+
+ movb $1, %al
+NoVarStore:
+ pushw %es
+# Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl
+ movb %al, %es:($4)
+ jmp SaveVolumeId
+
+CheckVarStoreSize:
+ movw %dx, %di
+ cmpl $0x4000, %ds:2(%di)
+ movb $2, %al
+ jne NoVarStore
+
+LoadVarStore:
+ movb $0, %al
+ movb %al, %es:($4)
+ movw (%di), %cx
+# ES:DI = 1500:0
+ xorw %di, %di
+ pushw %es
+ movw $0x1500, %ax
+ movw %ax, %es
+ call ReadFile
+SaveVolumeId:
+ popw %es
+ movw VolId(%bp), %ax
+ movw %ax, %es:($0) # Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId
+ movw VolId+2(%bp), %ax
+ movw %ax, %es:($2)
+
+# Read Efildr
+ popw %cx
+# cx = Start Cluster of Efildr -> BS.com has filled already
+# ES:DI = 2000:0, first cluster will be read again
+ xorw %di, %di # di = 0
+ movw $0x2000, %ax
+ movw %ax, %es
+ call ReadFile
+ movw %cs, %ax
+ movw %ax, %cs:JumpSegment
+JumpFarInstruction:
+ .byte 0xea
+JumpOffset:
+ .word 0x200
+JumpSegment:
+ .word 0x2000
+
+
+
+
+# ****************************************************************************
+# ReadFile
+#
+# Arguments:
+# CX = Start Cluster of File
+# ES:DI = Buffer to store file content read from disk
+#
+# Return:
+# (ES << 4 + DI) = end of file content Buffer
+#
+# ****************************************************************************
+ReadFile:
+# si = NumberOfClusters
+# cx = ClusterNumber
+# dx = CachedFatSectorNumber
+# ds:0000 = CacheFatSectorBuffer
+# es:di = Buffer to load file
+# bx = NextClusterNumber
+ pusha
+ movw $1, %si # NumberOfClusters = 1
+ pushw %cx # Push Start Cluster onto stack
+ movw $0xfff, %dx # CachedFatSectorNumber = 0xfff
+FatChainLoop:
+ movw %cx, %ax # ax = ClusterNumber
+ andw $0xfff8, %ax # ax = ax & 0xfff8
+ cmpw $0xfff8, %ax # See if this is the last cluster
+ je FoundLastCluster # Jump if last cluster found
+ movw %cx, %ax # ax = ClusterNumber
+ shlw $2, %ax # FatOffset = ClusterNumber * 4
+ pushw %si # Save si
+ movw %ax, %si # si = FatOffset
+ shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT
+ addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET)
+ andw $BLOCK_MASK, %si # si = FatOffset & BLOCK_MASK
+ cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber
+ je SkipFatRead
+ movw $2, %bx
+ pushw %es
+ pushw %ds
+ popw %es
+ call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI
+ popw %es
+ movw %ax, %dx # CachedFatSectorNumber = FatSectorNumber
+SkipFatRead:
+ movw (%si), %bx # bx = NextClusterNumber
+ movw %cx, %ax # ax = ClusterNumber
+ popw %si # Restore si
+ decw %bx # bx = NextClusterNumber - 1
+ cmpw %cx, %bx # See if (NextClusterNumber-1)==ClusterNumber
+ jne ReadClusters
+ incw %bx # bx = NextClusterNumber
+ incw %si # NumberOfClusters++
+ movw %bx, %cx # ClusterNumber = NextClusterNumber
+ jmp FatChainLoop
+ReadClusters:
+ incw %bx
+ popw %ax # ax = StartCluster
+ pushw %bx # StartCluster = NextClusterNumber
+ movw %bx, %cx # ClusterNumber = NextClusterNumber
+ subw $2, %ax # ax = StartCluster - 2
+ xorb %bh, %bh
+ movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster
+ mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster
+ addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster
+ pushw %ax # save start sector
+ movw %si, %ax # ax = NumberOfClusters
+ mulw %bx # ax = NumberOfClusters * SectorsPerCluster
+ movw %ax, %bx # bx = Number of Sectors
+ popw %ax # ax = Start Sector
+ call ReadBlocks
+ movw $1, %si # NumberOfClusters = 1
+ jmp FatChainLoop
+FoundLastCluster:
+ popw %cx
+ popa
+ ret
+
+
+# ****************************************************************************
+# ReadBlocks - Reads a set of blocks from a block device
+#
+# AX = Start LBA
+# BX = Number of Blocks to Read
+# ES:DI = Buffer to store sectors read from disk
+# ****************************************************************************
+
+# cx = Blocks
+# bx = NumberOfBlocks
+# si = StartLBA
+
+ReadBlocks:
+ pusha
+ addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA
+ addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA
+ movl %eax, %esi # esi = Start LBA
+ movw %bx, %cx # cx = Number of blocks to read
+ReadCylinderLoop:
+ movw $0x7bfc, %bp # bp = 0x7bfc
+ movl %esi, %eax # eax = Start LBA
+ xorl %edx, %edx # edx = 0
+ movzwl (%bp), %ebx # bx = MaxSector
+ divl %ebx # ax = StartLBA / MaxSector
+ incw %dx # dx = (StartLBA % MaxSector) + 1
+
+ movw (%bp), %bx # bx = MaxSector
+ subw %dx, %bx # bx = MaxSector - Sector
+ incw %bx # bx = MaxSector - Sector + 1
+ cmpw %bx, %cx # Compare (Blocks) to (MaxSector - Sector + 1)
+ jg LimitTransfer
+ movw %cx, %bx # bx = Blocks
+LimitTransfer:
+ pushw %ax # save ax
+ movw %es, %ax # ax = es
+ shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system
+ andw $0x7f, %ax # ax = Number of blocks into current seg
+ addw %bx, %ax # ax = End Block number of transfer
+ cmpw $0x80, %ax # See if it crosses a 64K boundry
+ jle NotCrossing64KBoundry # Branch if not crossing 64K boundry
+ subw $0x80, %ax # ax = Number of blocks past 64K boundry
+ subw %ax, %bx # Decrease transfer size by block overage
+NotCrossing64KBoundry:
+ popw %ax # restore ax
+
+ pushw %cx
+ movb %dl, %cl # cl = (StartLBA % MaxSector) + 1 = Sector
+ xorw %dx, %dx # dx = 0
+ divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder
+ # dx = ax % (MaxHead + 1) = Head
+
+ pushw %bx # Save number of blocks to transfer
+ movb %dl, %dh # dh = Head
+ movw $0x7c00, %bp # bp = 0x7c00
+ movb PhysicalDrive(%bp), %dl # dl = Drive Number
+ movb %al, %ch # ch = Cylinder
+ movb %bl, %al # al = Blocks
+ movb $2, %ah # ah = Function 2
+ movw %di, %bx # es:bx = Buffer address
+ int $0x13
+ jc DiskError
+ popw %bx
+ popw %cx
+ movzwl %bx, %ebx
+ addl %ebx, %esi # StartLBA = StartLBA + NumberOfBlocks
+ subw %bx, %cx # Blocks = Blocks - NumberOfBlocks
+ movw %es, %ax
+ shlw $(BLOCK_SHIFT-4), %bx
+ addw %bx, %ax
+ movw %ax, %es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE
+ cmpw $0, %cx
+ jne ReadCylinderLoop
+ popa
+ ret
+
+DiskError:
+ pushw %cs
+ popw %ds
+ leaw ErrorString, %si
+ movw $7, %cx
+ jmp PrintStringAndHalt
+
+PrintStringAndHalt:
+ movw $0xb800, %ax
+ movw %ax, %es
+ movw $160, %di
+ rep
+ movsw
+Halt:
+ jmp Halt
+
+ErrorString:
+ .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!', 0x0c
+
+ .org 0x01fa # Will cause build break
+LBAOffsetForBootSector:
+ .long 0x0
+
+ .org 0x01fe # Will cause build break
+ .word 0xaa55
+
+#******************************************************************************
+#******************************************************************************
+#******************************************************************************
+
+.equ DELAY_PORT, 0x0ed # Port to use for 1uS delay
+.equ KBD_CONTROL_PORT, 0x060 # 8042 control port
+.equ KBD_STATUS_PORT, 0x064 # 8042 status port
+.equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port
+.equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20
+
+.org 0x200 # Will cause build break
+ jmp start
+Em64String:
+ .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
+
+start:
+ movw %cs, %ax
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %ss
+ movw $MyStack, %sp
+
+# mov ax,0b800h
+# mov es,ax
+# mov byte ptr es:[160],'a'
+# mov ax,cs
+# mov es,ax
+
+ movl $0, %ebx
+ leal MemoryMap, %edi
+MemMapLoop:
+ movl $0xe820, %eax
+ movl $20, %ecx
+ movl $0x534d4150, %edx # 0x534d4150 = 'SMAP'
+ int $0x15
+ jc MemMapDone
+ addl $20, %edi
+ cmpl $0, %ebx
+ je MemMapDone
+ jmp MemMapLoop
+MemMapDone:
+ leal MemoryMap, %eax
+ subl %eax, %edi # Get the address of the memory map
+ movl %edi, MemoryMapSize # Save the size of the memory map
+
+ xorl %ebx, %ebx
+ movw %cs, %bx # BX=segment
+ shll $4, %ebx # BX="linear" address of segment base
+ leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt
+ movl %eax, gdtr + 2 # Put address of gdt into the gdtr
+ leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt
+ movl %eax, idtr + 2 # Put address of idt into the idtr
+ leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map
+
+ addl $0x1000, %ebx # Source of EFI32
+ movl %ebx, JUMP+2
+ addl $0x1000, %ebx
+ movl %ebx, %esi # Source of EFILDR32
+
+# mov ax,0b800h
+# mov es,ax
+# mov byte ptr es:[162],'b'
+# mov ax,cs
+# mov es,ax
+
+#
+# Enable A20 Gate
+#
+
+ movw $0x2401, %ax # Enable A20 Gate
+ int $0x15
+ jnc A20GateEnabled # Jump if it suceeded
+
+#
+# If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually.
+#
+
+ call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller
+ jnz Timeout8042 # Jump if the 8042 timed out
+ outw %ax, $DELAY_PORT # Delay 1 uS
+ movb $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port
+ outb %al, $KBD_STATUS_PORT # Send command to the 8042
+ call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller
+ jnz Timeout8042 # Jump if the 8042 timed out
+ movb $ENABLE_A20_CMD, %al # gate address bit 20 on
+ outb %al, $KBD_CONTROL_PORT # Send command to thre 8042
+ call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller
+ movw $25, %cx # Delay 25 uS for the command to complete on the 8042
+Delay25uS:
+ outw %ax, $DELAY_PORT # Delay 1 uS
+ loopl Delay25uS
+Timeout8042:
+
+
+A20GateEnabled:
+
+#
+# DISABLE INTERRUPTS - Entering Protected Mode
+#
+
+ cli
+
+# mov ax,0b800h
+# mov es,ax
+# mov byte ptr es:[164],'c'
+# mov ax,cs
+# mov es,ax
+
+ .byte 0x66
+ lgdt gdtr
+ .byte 0x66
+ lidt idtr
+
+ movl %cr0, %eax
+ orb $1, %al
+ movl %eax, %cr0
+
+ movl $0x008, %eax # Flat data descriptor
+ movl $0x00400000, %ebp # Destination of EFILDR32
+ movl $0x00070000, %ebx # Length of copy
+
+JUMP:
+# jmp far 0010:00020000
+ .byte 0x66
+ .byte 0xea
+ .long 0x00020000
+ .word 0x0010
+
+Empty8042InputBuffer:
+ movw $0, %cx
+Empty8042Loop:
+ outw %ax, $DELAY_PORT # Delay 1us
+ inb $KBD_STATUS_PORT, %al # Read the 8042 Status Port
+ andb $0x2, %al # Check the Input Buffer Full Flag
+ loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS
+ ret
+
+##############################################################################
+# data
+##############################################################################
+
+ .align 0x2
+
+gdtr: .word GDT_END - GDT_BASE - 1
+ .long 0 # (GDT base gets set above)
+##############################################################################
+# global descriptor table (GDT)
+##############################################################################
+
+ .align 0x2
+
+GDT_BASE:
+# null descriptor
+.equ NULL_SEL, .-GDT_BASE
+ .word 0 # limit 15:0
+ .word 0 # base 15:0
+ .byte 0 # base 23:16
+ .byte 0 # type
+ .byte 0 # limit 19:16, flags
+ .byte 0 # base 31:24
+
+# linear data segment descriptor
+.equ LINEAR_SEL, .-GDT_BASE
+ .word 0xFFFF # limit 0xFFFFF
+ .word 0 # base 0
+ .byte 0
+ .byte 0x92 # present, ring 0, data, expand-up, writable
+ .byte 0xCF # page-granular, 32-bit
+ .byte 0
+
+# linear code segment descriptor
+.equ LINEAR_CODE_SEL, .-GDT_BASE
+ .word 0xFFFF # limit 0xFFFFF
+ .word 0 # base 0
+ .byte 0
+ .byte 0x9A # present, ring 0, data, expand-up, writable
+ .byte 0xCF # page-granular, 32-bit
+ .byte 0
+
+# system data segment descriptor
+.equ SYS_DATA_SEL, .-GDT_BASE
+ .word 0xFFFF # limit 0xFFFFF
+ .word 0 # base 0
+ .byte 0
+ .byte 0x92 # present, ring 0, data, expand-up, writable
+ .byte 0xCF # page-granular, 32-bit
+ .byte 0
+
+# system code segment descriptor
+.equ SYS_CODE_SEL, .-GDT_BASE
+ .word 0xFFFF # limit 0xFFFFF
+ .word 0 # base 0
+ .byte 0
+ .byte 0x9A # present, ring 0, data, expand-up, writable
+ .byte 0xCF # page-granular, 32-bit
+ .byte 0
+
+# spare segment descriptor
+.equ SPARE3_SEL, .-GDT_BASE
+ .word 0 # limit 0xFFFFF
+ .word 0 # base 0
+ .byte 0
+ .byte 0 # present, ring 0, data, expand-up, writable
+ .byte 0 # page-granular, 32-bit
+ .byte 0
+
+# spare segment descriptor
+.equ SPARE4_SEL, .-GDT_BASE
+ .word 0 # limit 0xFFFFF
+ .word 0 # base 0
+ .byte 0
+ .byte 0 # present, ring 0, data, expand-up, writable
+ .byte 0 # page-granular, 32-bit
+ .byte 0
+
+# spare segment descriptor
+.equ SPARE5_SEL, .-GDT_BASE
+ .word 0 # limit 0xFFFFF
+ .word 0 # base 0
+ .byte 0
+ .byte 0 # present, ring 0, data, expand-up, writable
+ .byte 0 # page-granular, 32-bit
+ .byte 0
+
+GDT_END:
+
+ .align 0x2
+
+
+
+idtr: .word IDT_END - IDT_BASE - 1
+ .long 0 # (IDT base gets set above)
+##############################################################################
+# interrupt descriptor table (IDT)
+#
+# Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ
+# mappings. This implementation only uses the system timer and all other
+# IRQs will remain masked. The descriptors for vectors 33+ are provided
+# for convenience.
+##############################################################################
+
+#idt_tag db "IDT",0
+ .align 0x2
+
+IDT_BASE:
+# divide by zero (INT 0)
+.equ DIV_ZERO_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# debug exception (INT 1)
+.equ DEBUG_EXCEPT_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# NMI (INT 2)
+.equ NMI_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# soft breakpoint (INT 3)
+.equ BREAKPOINT_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# overflow (INT 4)
+.equ OVERFLOW_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# bounds check (INT 5)
+.equ BOUNDS_CHECK_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# invalid opcode (INT 6)
+.equ INVALID_OPCODE_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# device not available (INT 7)
+.equ DEV_NOT_AVAIL_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# double fault (INT 8)
+.equ DOUBLE_FAULT_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# Coprocessor segment overrun - reserved (INT 9)
+.equ RSVD_INTR_SEL1, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# invalid TSS (INT 0ah)
+.equ INVALID_TSS_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# segment not present (INT 0bh)
+.equ SEG_NOT_PRESENT_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# stack fault (INT 0ch)
+.equ STACK_FAULT_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# general protection (INT 0dh)
+.equ GP_FAULT_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# page fault (INT 0eh)
+.equ PAGE_FAULT_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# Intel reserved - do not use (INT 0fh)
+.equ RSVD_INTR_SEL2, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# floating point error (INT 10h)
+.equ FLT_POINT_ERR_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# alignment check (INT 11h)
+.equ ALIGNMENT_CHECK_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# machine check (INT 12h)
+.equ MACHINE_CHECK_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# SIMD floating-point exception (INT 13h)
+.equ SIMD_EXCEPTION_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# 85 unspecified descriptors, First 12 of them are reserved, the rest are avail
+ .fill 85 * 8, 1, 0
+
+# IRQ 0 (System timer) - (INT 68h)
+.equ IRQ0_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 1 (8042 Keyboard controller) - (INT 69h)
+.equ IRQ1_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah)
+.equ IRQ2_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 3 (COM 2) - (INT 6bh)
+.equ IRQ3_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 4 (COM 1) - (INT 6ch)
+.equ IRQ4_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 5 (LPT 2) - (INT 6dh)
+.equ IRQ5_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 6 (Floppy controller) - (INT 6eh)
+.equ IRQ6_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 7 (LPT 1) - (INT 6fh)
+.equ IRQ7_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 8 (RTC Alarm) - (INT 70h)
+.equ IRQ8_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 9 - (INT 71h)
+.equ IRQ9_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 10 - (INT 72h)
+.equ IRQ10_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 11 - (INT 73h)
+.equ IRQ11_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 12 (PS/2 mouse) - (INT 74h)
+.equ IRQ12_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 13 (Floating point error) - (INT 75h)
+.equ IRQ13_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 14 (Secondary IDE) - (INT 76h)
+.equ IRQ14_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+# IRQ 15 (Primary IDE) - (INT 77h)
+.equ IRQ15_SEL, .-IDT_BASE
+ .word 0 # offset 15:0
+ .word SYS_CODE_SEL # selector 15:0
+ .byte 0 # 0 for interrupt gate
+ .byte 0x0e | 0x80 # type = 386 interrupt gate, present
+ .word 0 # offset 31:16
+
+IDT_END:
+
+ .align 0x2
+
+MemoryMapSize: .long 0
+MemoryMap: .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+ .long 0,0,0,0,0,0,0,0
+
+ .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
+ .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
+
+ .org 0x0fe0
+MyStack:
+ # below is the pieces of the IVT that is used to redirect INT 68h - 6fh
+ # back to INT 08h - 0fh when in real mode... It is 'org'ed to a
+ # known low address (20f00) so it can be set up by PlMapIrqToVect in
+ # 8259.c
+
+ int $8
+ iret
+
+ int $9
+ iret
+
+ int $10
+ iret
+
+ int $11
+ iret
+
+ int $12
+ iret
+
+ int $13
+ iret
+
+ int $14
+ iret
+
+ int $15
+ iret
+
+
+ .org 0x0ffe
+BlockSignature:
+ .word 0xaa55
+
+
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