#include <avr/io.h>


outpin = PB5

.section .text
.global main



main:  
   sbi _SFR_IO_ADDR(DDRB), outpin  ; LED_BUILTIN output
   
1: ; main loop
   sbi _SFR_IO_ADDR(PINB), outpin ; LED_BUILTIN toggle 2,6666MHz
   rjmp 1b ; main loop
   
   ldi r24, 0x00 ; dummy return value low
   ldi r25, 0x00 ; dummy return value high
   ret