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ToyOS

ToyOS is a simple x86 OS that only accepts numeric values into the input stream and returns them to a standard out console.

STEP 1: Code

mov bp, 0xffff						; set the stack base
mov sp, bp						; set the top of the stack to base

call set_video_mode
call get_char_input

jmp $

set_video_mode:
	mov al, 0x03					; 80x25 8x8 640x200 16 gray
	mov ah 0x00
	int 0x10
	ret

get_char_input:						    
	xor ah, ah                  			; wait for a numeric char
	int 0x16            
	cmp al, 0x30					; compare if numeric 0
	jl get_char_input				; jmp if less than and restart loop
	cmp al, 0x39					; compare if numeric 9
	jg get_char_input				; jmp if greater than and restart loop
	mov ah, 0x0e
	int 0x10
	jmp get_char_input				; re-start internal subroutine

times 0x1fe-($-$$) db 0
dw 0xaa55

STEP 2: Run

sudo apt-get install nasm
sudo apt-get install qemu-system-x86_64
nasm bootsector.asm -f bin -o bootsector.bin
qemu-system-x86_64 bootsector.bin

License

Apache License, Version 2.0