I am experimenting with ATMEGA328P bootloader and I created HEX file with program with infinite loop on the begining and with optiboot code at end of hex file. (code loaded into chip is here: http://relliks.php5.cz/stackexchange/DUMP.bin) Then I disabled BOOTRST fuse and press restart button on arduino uno r3 but the bootloader still blinks with LED on digital port 13.
How is it possible, that bootloader is executed after chip reset and BOOTRST is disabled? My fuse settings is: only SPIEN and BODLEVEL0 is set.
I found that when I disable BODLEVEL0 fuse, the bootloader turns off. BODLEVEL0 is used to set brown-out voltage and shouldn't affect bootloader start, where is the issue?