Hello, I am very new to Arduino boards, IDE, and the AVR chips. I've just recently acquired a UNO board (R3) and I am diving into the details of how it works. I haven't seen the following written anywhere but I have preliminarily deduced the following about the R3 UNO board as it comes new: - it has the optiboot bootloader - the optiboot bootloader does not support all of the avrdude functions - in particular the fuse queries - the BOOTRST option must be set to direct the RESET to 0x7E00 (3F00) location. I deduce this because the 0x0000 RESET vector location in flash gets re-written every time a use the IDE to store a new program.
I don't think I can definitively [u]know[/u] the above without having a separate programmer to read the MCU flash, etc with avrdude (e.g) since the stock bootloader does not support the query of the fuses.
Do I have all this correct? Sorry if this is all answered somewhere else. I'm overwhelmed with search results at the moment.