#------------------------------------------------------------------------------ #* #* 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. #* #* start16.asm #* #* Abstract: #* #------------------------------------------------------------------------------ #.MODEL small .stack: .486p: .code: .equ FAT_DIRECTORY_ENTRY_SIZE, 0x0020 .equ FAT_DIRECTORY_ENTRY_SHIFT, 5 .equ BLOCK_SIZE, 0x0200 .equ BLOCK_MASK, 0x01ff .equ BLOCK_SHIFT, 9 .org 0x00 .global _start _start: Ia32Jump: jmp BootSectorEntryPoint # JMP inst - 3 bytes nop OemId: .ascii "INTEL " # OemId - 8 bytes SectorSize: .word 0 # Sector Size - 16 bits SectorsPerCluster: .byte 0 # Sector Per Cluster - 8 bits ReservedSectors: .word 0 # Reserved Sectors - 16 bits NoFats: .byte 0 # Number of FATs - 8 bits RootEntries: .word 0 # Root Entries - 16 bits Sectors: .word 0 # Number of Sectors - 16 bits Media: .byte 0 # Media - 8 bits - ignored SectorsPerFat: .word 0 # Sectors Per FAT - 16 bits SectorsPerTrack: .word 0 # Sectors Per Track - 16 bits - ignored Heads: .word 0 # Heads - 16 bits - ignored HiddenSectors: .long 0 # Hidden Sectors - 32 bits - ignored LargeSectors: .long 0 # Large Sectors - 32 bits PhysicalDrive: .byte 0 # PhysicalDriveNumber - 8 bits - ignored CurrentHead: .byte 0 # Current Head - 8 bits Signature: .byte 0 # Signature - 8 bits - ignored VolId: .ascii " " # Volume Serial Number- 4 bytes FatLabel: .ascii " " # Label - 11 bytes SystemId: .ascii "FAT16 " # SystemId - 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 %ax # FatOffset = ClusterNumber * 2 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 # Just for passing build. LBAOffsetForBootSector: .long 0x0 # .org 0x01fe # Just for passing build. .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 0x0200 # Just for passing build. 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 stands for '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 loop 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 ############################################################################## .p2align 1 gdtr: .word GDT_END - GDT_BASE - 1 # GDT limit .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 # IDT limit .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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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 # (10001110)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