jump to bootloader from main app

main.c

#include <avr/io.h>
#include <util/delay.h>
#include <avr/wdt.h>

typedef void (*do_reboot_t)(void);
const do_reboot_t do_reboot = (do_reboot_t)((FLASHEND-1023)>>1);

int main (void)
{
    DDRB = 0xFF;
    for (int i=0; i < 15; i++) {
        // toggle PORTB pins
        PORTB ^= 0xFF;
        // wait one second
        _delay_ms(300);
    }


    //MCUSR=0;
    do_reboot();
    //MCUSR = 0;
    //wdt_reset();
    //wdt_enable(WDTO_1S);

    return 0;
}