mirror of
				https://git.proxmox.com/git/mirror_edk2
				synced 2025-11-04 01:03:23 +00:00 
			
		
		
		
	Signed-off-by: rsun3 Reviewed-by: niruiyu git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12773 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			928 lines
		
	
	
		
			36 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			928 lines
		
	
	
		
			36 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
#------------------------------------------------------------------------------
 | 
						|
#*
 | 
						|
#*   Copyright (c) 2006 - 2011, 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.             
 | 
						|
#*   
 | 
						|
#*    start32.asm
 | 
						|
#*  
 | 
						|
#*   Abstract:
 | 
						|
#*
 | 
						|
#------------------------------------------------------------------------------
 | 
						|
 | 
						|
        #.MODEL small
 | 
						|
        .stack: 
 | 
						|
        .486p: 
 | 
						|
        .code16
 | 
						|
 | 
						|
.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
 | 
						|
 | 
						|
.global _start
 | 
						|
_start:
 | 
						|
 | 
						|
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: 
 | 
						|
        movw    $0x0008, %bx                # Flat data descriptor
 | 
						|
#
 | 
						|
# 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
 | 
						|
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
 | 
						|
##############################################################################
 | 
						|
 | 
						|
        .p2align 1
 | 
						|
 | 
						|
gdtr:    .word GDT_END - GDT_BASE - 1   
 | 
						|
        .long 0                     # (GDT base gets set above)
 | 
						|
##############################################################################
 | 
						|
#   global descriptor table (GDT)
 | 
						|
##############################################################################
 | 
						|
 | 
						|
        .p2align 1
 | 
						|
 | 
						|
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: 
 | 
						|
 | 
						|
        .p2align 1
 | 
						|
 | 
						|
 | 
						|
 | 
						|
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     
 | 
						|
        .p2align 1
 | 
						|
 | 
						|
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: 
 | 
						|
 | 
						|
        .p2align 1
 | 
						|
 | 
						|
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
 | 
						|
 | 
						|
 |