File size: 5,304 Bytes
94f6f0e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 | org 0x7c00
bits 16
mov [BOOT_DRIVE], dl ;MDP - Save boot drive
%include "Data\decompress.asm" ;Include decompressor part
;The decompressor will jump here if it's done
compressorDone:
;Set video mode
mov ax, 13h
int 10h
;Set source address to uncompresed data
mov bx, daddr
mov ds, bx
mov si, uncompressed
;Get the color table length
mov ah, 0
lodsb
mov bx, 0
mov cx, ax
;Load the color table
setcolor:
mov dx, 0x3C8
mov al, bl
out dx, al
inc bx
mov dx, 0x3C9
lodsb
out dx, al
lodsb
out dx, al
lodsb
out dx, al
loop setcolor
;Set destination address to the video memory
mov bx, 0xA000
mov es, bx
mov di, 0
;Put the pixel data into the video memory
mov cx, 32000
rep movsw
;=====================================================================================================================
Keypress:
mov ah, 86h ;AH = 86
mov cx, 50 ;Set for timeout 50
int 15h ;Wait function
mov ah, 0h ;AH = 0
cmp ah, 0h ;Check same or not same
jne Keypress ;If same continue else abort
xor ah,ah ;AH = 0
int 16h ;Wait for key
cmp ah, 01h ;Scan code 1 = Escape
jne Keypress ;If Escape not pressed get another key
mov ah, 2h
int 16h ;Query keyboard status flags
and al, 0b00001111 ;Mask all the key press flags
cmp al, 0b00001100 ;Check if ONLY Control and Alt are pressed and make sure Left and/or Right Shift are not being pressed
jne Keypress ;If not go back and wait for another keystroke ; Otherwise Control-Alt-Escape has been pressed
;=====================================================================================================================
RestoreMBR:
; Setup segments
xor ax, ax ; AX=0
mov ds, ax ; DS=ES=0 because we use an org of 0x7c00 - Segment<<4+offset = 0x0000<<4+0x7c00 = 0x07c00
mov es, ax
mov ss, ax
mov sp, 0x7c00 ; SS:SP= 0x0000:0x7c00 stack just below bootloader
;Read sector - 2th
mov bx, buffer ;ES: BX must point to the buffer
mov dl, [BOOT_DRIVE] ;Use boot drive passed to bootloader by BIOS in DL
mov dh, 0 ;Head number
mov ch, 0 ;Track number
mov cl, 2 ;Sector number - (2th)
mov al, 1 ;Number of sectors to read
mov ah, 2 ;Read function number
int 13h
;Write sector - 1th
mov bx, buffer ;ES: BX must point to the buffer
mov dl, [BOOT_DRIVE] ;Use boot drive passed to bootloader by BIOS in DL
mov dh, 0 ;Head number
mov ch, 0 ;Track number
mov cl, 1 ;Sector number - (1th)
mov al, 2 ;Number of sectors to write
mov ah, 3 ;Write function number
int 13h
;Read sector for zero filling
mov bx, buffer ;ES: BX must point to the buffer
mov dl, [BOOT_DRIVE] ;Use boot drive passed to bootloader by BIOS in DL
mov dh, 0 ;Head number
mov ch, 0 ;Track number
mov cl, 2 ;Sector number - (2th)
mov al, 1 ;Number of sectors to read
mov ah, 2 ;Read function number
int 13h
mov byte [SECTOR_NUMBER], 3
.loop: ;Fill sectors with zero
mov bx, buffer ;ES: BX must point to the buffer
mov dl, [BOOT_DRIVE] ;Use boot drive passed to bootloader by BIOS in DL
mov cl, [SECTOR_NUMBER] ;Sector number - (1th)
mov al, 1 ;Number of sectors to write
mov ah, 3 ;Write function number
int 13h
inc byte [SECTOR_NUMBER]
cmp byte [SECTOR_NUMBER], 65
jne .loop
RebootPC:
xor ax, ax
mov es, ax
mov bx, 1234
mov [es:0472], bx
cli
mov ds, ax
mov es, ax
mov ss, ax
mov sp, ax
mov ax, 2
push ax
mov ax, 0xf000
push ax
mov ax, 0xfff0
push ax
iret
;=====================================================================================================================
buffer: equ 0x4f00 ;Address for
daddr: equ 0x07e0 ;Base address of the data (compressed and uncompressed)
compressed: equ 0x0000 ;Address offset to load the compressed data
BOOT_DRIVE: dd 0 ;Address where save the boot drive
SECTOR_NUMBER: dd 0 ;Sector number where write
times 510 - ($ - $$) db 0 ;Fill the data with zeros until we reach 510 bytes
dw 0xAA55 ;Add the boot sector signature
db 'ORIGINAL MBR' ;Original MBR
times 1024 - ($ - $$) db 0 ;Fill the data with zeros until we reach 1024 bytes - original sector place
comp: incbin "Image\Custom.bin" ;Include the compressed data (it will go right after the original MBR)
compsize: equ $-comp ;Size of the compressed data
uncompressed: equ compressed+compsize ;Put the uncompressed data right after the compressed data
times 32768 - ($ - $$) db 0 ;Fill the rest of the disk image so it reaches 32768 bytes |