mirror of https://github.com/acidanthera/audk.git
925 lines
35 KiB
NASM
925 lines
35 KiB
NASM
;------------------------------------------------------------------------------
|
|
;*
|
|
;* 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
|
|
.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 - 2 bytes
|
|
SectorsPerCluster db 0 ; Sector Per Cluster - 1 byte
|
|
ReservedSectors dw 0 ; Reserved Sectors - 2 bytes
|
|
NoFats db 0 ; Number of FATs - 1 byte
|
|
RootEntries dw 0 ; Root Entries - 2 bytes
|
|
Sectors dw 0 ; Number of Sectors - 2 bytes
|
|
Media db 0 ; Media - 1 byte
|
|
SectorsPerFat16 dw 0 ; Sectors Per FAT for FAT12/FAT16 - 2 byte
|
|
SectorsPerTrack dw 0 ; Sectors Per Track - 2 bytes
|
|
Heads dw 0 ; Heads - 2 bytes
|
|
HiddenSectors dd 0 ; Hidden Sectors - 4 bytes
|
|
LargeSectors dd 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 dd 0 ; Sectors Per FAT for FAT32 - 4 bytes
|
|
ExtFlags dw 0 ; Mirror Flag - 2 bytes
|
|
FSVersion dw 0 ; File System Version - 2 bytes
|
|
RootCluster dd 0 ; 1st Cluster Number of Root Dir - 4 bytes
|
|
FSInfo dw 0 ; Sector Number of FSINFO - 2 bytes
|
|
BkBootSector dw 0 ; Sector Number of Bk BootSector - 2 bytes
|
|
Reserved db 12 dup(0) ; Reserved Field - 12 bytes
|
|
PhysicalDrive db 0 ; Physical Drive Number - 1 byte
|
|
Reserved1 db 0 ; Reserved Field - 1 byte
|
|
Signature db 0 ; Extended Boot Signature - 1 byte
|
|
VolId db " " ; Volume Serial Number - 4 bytes
|
|
FatLabel db " " ; Volume Label - 11 bytes
|
|
FileSystemType db "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
|
|
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,0fff8h ; ax = ax & 0xfff8
|
|
cmp ax,0fff8h ; See if this is the last cluster
|
|
je FoundLastCluster ; Jump if last cluster found
|
|
mov ax,cx ; ax = ClusterNumber
|
|
shl ax,2 ; FatOffset = ClusterNumber * 4
|
|
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
|
|
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:
|
|
mov bx,0008h ; 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
|
|
|
|
db 66h
|
|
lgdt fword ptr [gdtr]
|
|
db 66h
|
|
lidt fword ptr [idtr]
|
|
|
|
mov eax,cr0
|
|
or al,1
|
|
mov cr0,eax
|
|
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
|