diff options
Diffstat (limited to 'DuetPkg/BootSector/start.asm')
-rw-r--r-- | DuetPkg/BootSector/start.asm | 921 |
1 files changed, 921 insertions, 0 deletions
diff --git a/DuetPkg/BootSector/start.asm b/DuetPkg/BootSector/start.asm new file mode 100644 index 0000000000..e8eb22982d --- /dev/null +++ b/DuetPkg/BootSector/start.asm @@ -0,0 +1,921 @@ +;------------------------------------------------------------------------------
+;*
+;* 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.
+;*
+;* start.asm
+;*
+;* Abstract:
+;*
+;------------------------------------------------------------------------------
+
+ .model small
+ .stack
+ .486p
+ .code
+
+FAT_DIRECTORY_ENTRY_SIZE EQU 020h
+FAT_DIRECTORY_ENTRY_SHIFT EQU 5
+BLOCK_SIZE EQU 0200h
+BLOCK_MASK EQU 01ffh
+BLOCK_SHIFT EQU 9
+
+ org 0h
+Ia32Jump:
+ jmp BootSectorEntryPoint ; JMP inst - 3 bytes
+ nop
+
+OemId db "INTEL " ; OemId - 8 bytes
+
+SectorSize dw 0 ; Sector Size - 16 bits
+SectorsPerCluster db 0 ; Sector Per Cluster - 8 bits
+ReservedSectors dw 0 ; Reserved Sectors - 16 bits
+NoFats db 0 ; Number of FATs - 8 bits
+RootEntries dw 0 ; Root Entries - 16 bits
+Sectors dw 0 ; Number of Sectors - 16 bits
+Media db 0 ; Media - 8 bits - ignored
+SectorsPerFat dw 0 ; Sectors Per FAT - 16 bits
+SectorsPerTrack dw 0 ; Sectors Per Track - 16 bits - ignored
+Heads dw 0 ; Heads - 16 bits - ignored
+HiddenSectors dd 0 ; Hidden Sectors - 32 bits - ignored
+LargeSectors dd 0 ; Large Sectors - 32 bits
+PhysicalDrive db 0 ; PhysicalDriveNumber - 8 bits - ignored
+CurrentHead db 0 ; Current Head - 8 bits
+Signature db 0 ; Signature - 8 bits - ignored
+VolId db " " ; Volume Serial Number- 4 bytes
+FatLabel db " " ; Label - 11 bytes
+SystemId db "FAT12 " ; 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
+ mov bp,07c00h
+
+ push cx
+; Read Efivar.bin
+; 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already
+ mov ax,01900h
+ mov es,ax
+ test dx,dx
+ jnz CheckVarStoreSize
+
+ mov al,1
+NoVarStore:
+ push es
+; Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl
+ mov byte ptr es:[4],al
+ jmp SaveVolumeId
+
+CheckVarStoreSize:
+ mov di,dx
+ cmp dword ptr ds:[di+2], 04000h
+ mov al,2
+ jne NoVarStore
+
+LoadVarStore:
+ mov al,0
+ mov byte ptr es:[4],al
+ mov cx,word ptr[di]
+; ES:DI = 1500:0
+ xor di,di
+ push es
+ mov ax,01500h
+ mov es,ax
+ call ReadFile
+SaveVolumeId:
+ pop es
+ mov ax,word ptr [bp+VolId]
+ mov word ptr es:[0],ax ; Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId
+ mov ax,word ptr [bp+VolId+2]
+ mov word ptr es:[2],ax
+
+; Read Efildr
+ pop cx
+; cx = Start Cluster of Efildr -> BS.com has filled already
+; ES:DI = 2000:0, first cluster will be read again
+ xor di,di ; di = 0
+ mov ax,02000h
+ mov es,ax
+ call ReadFile
+ mov ax,cs
+ mov word ptr cs:[JumpSegment],ax
+
+JumpFarInstruction:
+ db 0eah
+JumpOffset:
+ dw 0200h
+JumpSegment:
+ dw 2000h
+
+
+
+; ****************************************************************************
+; 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
+ mov si,1 ; NumberOfClusters = 1
+ push cx ; Push Start Cluster onto stack
+ mov dx,0fffh ; CachedFatSectorNumber = 0xfff
+FatChainLoop:
+ mov ax,cx ; ax = ClusterNumber
+ and ax,0ff8h ; ax = ax & 0xff8
+ cmp ax,0ff8h ; See if this is the last cluster
+ je FoundLastCluster ; Jump if last cluster found
+ mov ax,cx ; ax = ClusterNumber
+ shl ax,1 ; ax = ClusterNumber * 2
+ add ax,cx ; ax = ClusterNumber * 2 + ClusterNumber = ClusterNumber * 3
+ shr ax,1 ; FatOffset = ClusterNumber*3 / 2
+ push si ; Save si
+ mov si,ax ; si = FatOffset
+ shr ax,BLOCK_SHIFT ; ax = FatOffset >> BLOCK_SHIFT
+ add ax,word ptr [bp+ReservedSectors] ; ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET)
+ and si,BLOCK_MASK ; si = FatOffset & BLOCK_MASK
+ cmp ax,dx ; Compare FatSectorNumber to CachedFatSectorNumber
+ je SkipFatRead
+ mov bx,2
+ push es
+ push ds
+ pop es
+ call ReadBlocks ; Read 2 blocks starting at AX storing at ES:DI
+ pop es
+ mov dx,ax ; CachedFatSectorNumber = FatSectorNumber
+SkipFatRead:
+ mov bx,word ptr [si] ; bx = NextClusterNumber
+ mov ax,cx ; ax = ClusterNumber
+ and ax,1 ; See if this is an odd cluster number
+ je EvenFatEntry
+ shr bx,4 ; NextClusterNumber = NextClusterNumber >> 4
+EvenFatEntry:
+ and bx,0fffh ; Strip upper 4 bits of NextClusterNumber
+ pop si ; Restore si
+ dec bx ; bx = NextClusterNumber - 1
+ cmp bx,cx ; See if (NextClusterNumber-1)==ClusterNumber
+ jne ReadClusters
+ inc bx ; bx = NextClusterNumber
+ inc si ; NumberOfClusters++
+ mov cx,bx ; ClusterNumber = NextClusterNumber
+ jmp FatChainLoop
+ReadClusters:
+ inc bx
+ pop ax ; ax = StartCluster
+ push bx ; StartCluster = NextClusterNumber
+ mov cx,bx ; ClusterNumber = NextClusterNumber
+ sub ax,2 ; ax = StartCluster - 2
+ xor bh,bh
+ mov bl,byte ptr [bp+SectorsPerCluster] ; bx = SectorsPerCluster
+ mul bx ; ax = (StartCluster - 2) * SectorsPerCluster
+ add ax, word ptr [bp] ; ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster
+ push ax ; save start sector
+ mov ax,si ; ax = NumberOfClusters
+ mul bx ; ax = NumberOfClusters * SectorsPerCluster
+ mov bx,ax ; bx = Number of Sectors
+ pop ax ; ax = Start Sector
+ call ReadBlocks
+ mov si,1 ; NumberOfClusters = 1
+ jmp FatChainLoop
+FoundLastCluster:
+ pop 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
+ add eax,dword ptr [bp+LBAOffsetForBootSector] ; Add LBAOffsetForBootSector to Start LBA
+ add eax,dword ptr [bp+HiddenSectors] ; Add HiddenSectors to Start LBA
+ mov esi,eax ; esi = Start LBA
+ mov cx,bx ; cx = Number of blocks to read
+ReadCylinderLoop:
+ mov bp,07bfch ; bp = 0x7bfc
+ mov eax,esi ; eax = Start LBA
+ xor edx,edx ; edx = 0
+ movzx ebx,word ptr [bp] ; bx = MaxSector
+ div ebx ; ax = StartLBA / MaxSector
+ inc dx ; dx = (StartLBA % MaxSector) + 1
+
+ mov bx,word ptr [bp] ; bx = MaxSector
+ sub bx,dx ; bx = MaxSector - Sector
+ inc bx ; bx = MaxSector - Sector + 1
+ cmp cx,bx ; Compare (Blocks) to (MaxSector - Sector + 1)
+ jg LimitTransfer
+ mov bx,cx ; bx = Blocks
+LimitTransfer:
+ push ax ; save ax
+ mov ax,es ; ax = es
+ shr ax,(BLOCK_SHIFT-4) ; ax = Number of blocks into mem system
+ and ax,07fh ; ax = Number of blocks into current seg
+ add ax,bx ; ax = End Block number of transfer
+ cmp ax,080h ; See if it crosses a 64K boundry
+ jle NotCrossing64KBoundry ; Branch if not crossing 64K boundry
+ sub ax,080h ; ax = Number of blocks past 64K boundry
+ sub bx,ax ; Decrease transfer size by block overage
+NotCrossing64KBoundry:
+ pop ax ; restore ax
+
+ push cx
+ mov cl,dl ; cl = (StartLBA % MaxSector) + 1 = Sector
+ xor dx,dx ; dx = 0
+ div word ptr [bp+2] ; ax = ax / (MaxHead + 1) = Cylinder
+ ; dx = ax % (MaxHead + 1) = Head
+
+ push bx ; Save number of blocks to transfer
+ mov dh,dl ; dh = Head
+ mov bp,07c00h ; bp = 0x7c00
+ mov dl,byte ptr [bp+PhysicalDrive] ; dl = Drive Number
+ mov ch,al ; ch = Cylinder
+ mov al,bl ; al = Blocks
+ mov ah,2 ; ah = Function 2
+ mov bx,di ; es:bx = Buffer address
+ int 013h
+ jc DiskError
+ pop bx
+ pop cx
+ movzx ebx,bx
+ add esi,ebx ; StartLBA = StartLBA + NumberOfBlocks
+ sub cx,bx ; Blocks = Blocks - NumberOfBlocks
+ mov ax,es
+ shl bx,(BLOCK_SHIFT-4)
+ add ax,bx
+ mov es,ax ; es:di = es:di + NumberOfBlocks*BLOCK_SIZE
+ cmp cx,0
+ jne ReadCylinderLoop
+ popa
+ ret
+
+DiskError:
+ push cs
+ pop ds
+ lea si, [ErrorString]
+ mov cx, 7
+ jmp PrintStringAndHalt
+
+PrintStringAndHalt:
+ mov ax,0b800h
+ mov es,ax
+ mov di,160
+ rep movsw
+Halt:
+ jmp Halt
+
+ErrorString:
+ db 'S', 0ch, 'E', 0ch, 'r', 0ch, 'r', 0ch, 'o', 0ch, 'r', 0ch, '!', 0ch
+
+ org 01fah
+LBAOffsetForBootSector:
+ dd 0h
+
+ org 01feh
+ dw 0aa55h
+
+;******************************************************************************
+;******************************************************************************
+;******************************************************************************
+
+DELAY_PORT equ 0edh ; Port to use for 1uS delay
+KBD_CONTROL_PORT equ 060h ; 8042 control port
+KBD_STATUS_PORT equ 064h ; 8042 status port
+WRITE_DATA_PORT_CMD equ 0d1h ; 8042 command to write the data port
+ENABLE_A20_CMD equ 0dfh ; 8042 command to enable A20
+
+ org 200h
+ jmp start
+Em64String:
+ db 'E', 0ch, 'm', 0ch, '6', 0ch, '4', 0ch, 'T', 0ch, ' ', 0ch, 'U', 0ch, 'n', 0ch, 's', 0ch, 'u', 0ch, 'p', 0ch, 'p', 0ch, 'o', 0ch, 'r', 0ch, 't', 0ch, 'e', 0ch, 'd', 0ch, '!', 0ch
+
+start:
+ mov ax,cs
+ mov ds,ax
+ mov es,ax
+ mov ss,ax
+ mov sp,MyStack
+
+; mov ax,0b800h
+; mov es,ax
+; mov byte ptr es:[160],'a'
+; mov ax,cs
+; mov es,ax
+
+ mov ebx,0
+ lea edi,MemoryMap
+MemMapLoop:
+ mov eax,0e820h
+ mov ecx,20
+ mov edx,'SMAP'
+ int 15h
+ jc MemMapDone
+ add edi,20
+ cmp ebx,0
+ je MemMapDone
+ jmp MemMapLoop
+MemMapDone:
+ lea eax,MemoryMap
+ sub edi,eax ; Get the address of the memory map
+ mov dword ptr [MemoryMapSize],edi ; Save the size of the memory map
+
+ xor ebx,ebx
+ mov bx,cs ; BX=segment
+ shl ebx,4 ; BX="linear" address of segment base
+ lea eax,[GDT_BASE + ebx] ; EAX=PHYSICAL address of gdt
+ mov dword ptr [gdtr + 2],eax ; Put address of gdt into the gdtr
+ lea eax,[IDT_BASE + ebx] ; EAX=PHYSICAL address of idt
+ mov dword ptr [idtr + 2],eax ; Put address of idt into the idtr
+ lea edx,[MemoryMapSize + ebx] ; Physical base address of the memory map
+
+ add ebx,01000h ; Source of EFI32
+ mov dword ptr [JUMP+2],ebx
+ add ebx,01000h
+ mov esi,ebx ; Source of EFILDR32
+
+; mov ax,0b800h
+; mov es,ax
+; mov byte ptr es:[162],'b'
+; mov ax,cs
+; mov es,ax
+
+;
+; Enable A20 Gate
+;
+
+ mov ax,2401h ; Enable A20 Gate
+ int 15h
+ 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
+ out DELAY_PORT,ax ; Delay 1 uS
+ mov al,WRITE_DATA_PORT_CMD ; 8042 cmd to write output port
+ out KBD_STATUS_PORT,al ; Send command to the 8042
+ call Empty8042InputBuffer ; Empty the Input Buffer on the 8042 controller
+ jnz Timeout8042 ; Jump if the 8042 timed out
+ mov al,ENABLE_A20_CMD ; gate address bit 20 on
+ out KBD_CONTROL_PORT,al ; Send command to thre 8042
+ call Empty8042InputBuffer ; Empty the Input Buffer on the 8042 controller
+ mov cx,25 ; Delay 25 uS for the command to complete on the 8042
+Delay25uS:
+ out DELAY_PORT,ax ; 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
+
+ db 66h
+ lgdt fword ptr [gdtr]
+ db 66h
+ lidt fword ptr [idtr]
+
+ mov eax,cr0
+ or al,1
+ mov cr0,eax
+
+ mov eax,0008h ; Flat data descriptor
+ mov ebp,000400000h ; Destination of EFILDR32
+ mov ebx,000070000h ; Length of copy
+
+JUMP:
+; jmp far 0010:00020000
+ db 066h
+ db 0eah
+ dd 000020000h
+ dw 00010h
+
+Empty8042InputBuffer:
+ mov cx,0
+Empty8042Loop:
+ out DELAY_PORT,ax ; Delay 1us
+ in al,KBD_STATUS_PORT ; Read the 8042 Status Port
+ and al,02h ; Check the Input Buffer Full Flag
+ loopnz Empty8042Loop ; Loop until the input buffer is empty or a timout of 65536 uS
+ ret
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; data
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+ align 02h
+
+gdtr dw GDT_END - GDT_BASE - 1 ; GDT limit
+ dd 0 ; (GDT base gets set above)
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; global descriptor table (GDT)
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+ align 02h
+
+public GDT_BASE
+GDT_BASE:
+; null descriptor
+NULL_SEL equ $-GDT_BASE
+ dw 0 ; limit 15:0
+ dw 0 ; base 15:0
+ db 0 ; base 23:16
+ db 0 ; type
+ db 0 ; limit 19:16, flags
+ db 0 ; base 31:24
+
+; linear data segment descriptor
+LINEAR_SEL equ $-GDT_BASE
+ dw 0FFFFh ; limit 0xFFFFF
+ dw 0 ; base 0
+ db 0
+ db 092h ; present, ring 0, data, expand-up, writable
+ db 0CFh ; page-granular, 32-bit
+ db 0
+
+; linear code segment descriptor
+LINEAR_CODE_SEL equ $-GDT_BASE
+ dw 0FFFFh ; limit 0xFFFFF
+ dw 0 ; base 0
+ db 0
+ db 09Ah ; present, ring 0, data, expand-up, writable
+ db 0CFh ; page-granular, 32-bit
+ db 0
+
+; system data segment descriptor
+SYS_DATA_SEL equ $-GDT_BASE
+ dw 0FFFFh ; limit 0xFFFFF
+ dw 0 ; base 0
+ db 0
+ db 092h ; present, ring 0, data, expand-up, writable
+ db 0CFh ; page-granular, 32-bit
+ db 0
+
+; system code segment descriptor
+SYS_CODE_SEL equ $-GDT_BASE
+ dw 0FFFFh ; limit 0xFFFFF
+ dw 0 ; base 0
+ db 0
+ db 09Ah ; present, ring 0, data, expand-up, writable
+ db 0CFh ; page-granular, 32-bit
+ db 0
+
+; spare segment descriptor
+SPARE3_SEL equ $-GDT_BASE
+ dw 0 ; limit 0xFFFFF
+ dw 0 ; base 0
+ db 0
+ db 0 ; present, ring 0, data, expand-up, writable
+ db 0 ; page-granular, 32-bit
+ db 0
+
+; spare segment descriptor
+SPARE4_SEL equ $-GDT_BASE
+ dw 0 ; limit 0xFFFFF
+ dw 0 ; base 0
+ db 0
+ db 0 ; present, ring 0, data, expand-up, writable
+ db 0 ; page-granular, 32-bit
+ db 0
+
+; spare segment descriptor
+SPARE5_SEL equ $-GDT_BASE
+ dw 0 ; limit 0xFFFFF
+ dw 0 ; base 0
+ db 0
+ db 0 ; present, ring 0, data, expand-up, writable
+ db 0 ; page-granular, 32-bit
+ db 0
+
+GDT_END:
+
+ align 02h
+
+
+
+idtr dw IDT_END - IDT_BASE - 1 ; IDT limit
+ dd 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 02h
+
+public IDT_BASE
+IDT_BASE:
+; divide by zero (INT 0)
+DIV_ZERO_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; debug exception (INT 1)
+DEBUG_EXCEPT_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; NMI (INT 2)
+NMI_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; soft breakpoint (INT 3)
+BREAKPOINT_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; overflow (INT 4)
+OVERFLOW_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; bounds check (INT 5)
+BOUNDS_CHECK_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; invalid opcode (INT 6)
+INVALID_OPCODE_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; device not available (INT 7)
+DEV_NOT_AVAIL_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; double fault (INT 8)
+DOUBLE_FAULT_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; Coprocessor segment overrun - reserved (INT 9)
+RSVD_INTR_SEL1 equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; invalid TSS (INT 0ah)
+INVALID_TSS_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; segment not present (INT 0bh)
+SEG_NOT_PRESENT_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; stack fault (INT 0ch)
+STACK_FAULT_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; general protection (INT 0dh)
+GP_FAULT_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; page fault (INT 0eh)
+PAGE_FAULT_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; Intel reserved - do not use (INT 0fh)
+RSVD_INTR_SEL2 equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; floating point error (INT 10h)
+FLT_POINT_ERR_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; alignment check (INT 11h)
+ALIGNMENT_CHECK_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; machine check (INT 12h)
+MACHINE_CHECK_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; SIMD floating-point exception (INT 13h)
+SIMD_EXCEPTION_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; 85 unspecified descriptors, First 12 of them are reserved, the rest are avail
+ db (85 * 8) dup(0)
+
+; IRQ 0 (System timer) - (INT 68h)
+IRQ0_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 1 (8042 Keyboard controller) - (INT 69h)
+IRQ1_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah)
+IRQ2_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 3 (COM 2) - (INT 6bh)
+IRQ3_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 4 (COM 1) - (INT 6ch)
+IRQ4_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 5 (LPT 2) - (INT 6dh)
+IRQ5_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 6 (Floppy controller) - (INT 6eh)
+IRQ6_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 7 (LPT 1) - (INT 6fh)
+IRQ7_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 8 (RTC Alarm) - (INT 70h)
+IRQ8_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 9 - (INT 71h)
+IRQ9_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 10 - (INT 72h)
+IRQ10_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 11 - (INT 73h)
+IRQ11_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 12 (PS/2 mouse) - (INT 74h)
+IRQ12_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 13 (Floating point error) - (INT 75h)
+IRQ13_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 14 (Secondary IDE) - (INT 76h)
+IRQ14_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+; IRQ 15 (Primary IDE) - (INT 77h)
+IRQ15_SEL equ $-IDT_BASE
+ dw 0 ; offset 15:0
+ dw SYS_CODE_SEL ; selector 15:0
+ db 0 ; 0 for interrupt gate
+ db 0eh OR 80h ; (10001110)type = 386 interrupt gate, present
+ dw 0 ; offset 31:16
+
+IDT_END:
+
+ align 02h
+
+MemoryMapSize dd 0
+MemoryMap dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+ dd 0,0,0,0,0,0,0,0
+
+ dd 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
+ dd 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 0fe0h
+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 0ffeh
+BlockSignature:
+ dw 0aa55h
+
+ end
|