BITS 16
start:
mov ax, 07C0h ; Set up 4K stack space after this bootloader
add ax, 288 ; (4096 + 512) / 16 bytes per paragraph
mov ss, ax
mov sp, 4096
mov ax, 07C0h ; Set data segment to where we're loaded
mov ds, ax
mov si, text_string ; Put string position into SI
call print_string ; Call our string-printing routine
text_string db 'This is my cool new OS!', 0
print_string: ; Routine: output string in SI to screen
mov ah, 0Eh ; int 10h 'print char' function
.repeat:
loadsb ; Get character from string
cmp al, 0
je .background_colors ; If char is zero, end of string
int 10h ; Otherwise, print it
jmp .repeat
.background_colors:
mov ah,0Bh
mov bh,0
mov bl,02h
int 10h
jmp .cursor_pointer
.cursor_pointer:
mov ah,2h ;set the value to "ah" to move the cursor pointer
mov bh,0 ;select page
mov dh,22 ;set row position of the cursor
mov dl,0 ;set column position of the cursor
int 10h ;tell bios "hey dude now we are done,take action!!!"
jmp .character_write
.character_write:
mov ah,9h
mov al,65 ;ascii value
mov bh,0 ;display page
mov bl,5h ;display attribute
mov cx,10 ;display times
int 10h
jmp .cursor_pointer2
.cursor_pointer2:
mov ah,2h ;set the value to "ah" to move the cursor pointer
mov bh,0 ;select page
mov dh,23 ;set row position of the cursor
mov dl,0 ;set column position of the cursor
int 10h ;tell bios "hey dude now we are done,take action!!!"
jmp .character_read
.character_read:
mov ah,00h ;remeber set the value to "ah" now you are going to read a keyboard input
int 16h ;this interrupt is given to control keystrokes of keyboard
jmp .print_input ;now lets print what we took as input
.print_input:
mov ah,9h ;set the value to "ah" to print one character to std out
mov bh,0 ;set page number
mov bl,5h ;set the color attribute of the font to be print
mov cx,10 ;set the value how many time the character in "al" should be print
int 10h ;tell bios "hey dude now we are done,take action!!!"
jmp .done
.done:
ret
times 510-($-$$) db 0 ; fill up the rest part of the boot secotr with 0 s
dw 0xAA55 ; The standard PC boot signatureI'm writing a simple bootloader to get a key board input. but it gets some errors. i'm using QEMU as my emulator.please help me to find those errors
