#include <avr/io.h>

    .section text

    .org 0
    .global init
init:
    rjmp main

    .org 0x020
    .global main
main:
    ; on Arduino, this will light up the on-board LED
    ldi 16, 0xFF
    out _SFR_IO_ADDR(DDRB), 16
    out _SFR_IO_ADDR(PORTB), 16

loop:
    rjmp loop