monkey123:
Thanks for the help! So to clarify, I'd need to FIRST load the firmware onto the 8U2. I would then have USB functionality, correct?
Yes, you would then have created a USB virtual serial port communications link to and from the PC.Can I then use the 8U2 over USB to load the bootloader AND software onto the 2560?
No, the bootloader for the 2560 needs to be installed via a ICSP hardware programmer, which can be another arduino board loaded with the arduino as ICP sketch. The 8U2 chip is not a ICSP programmer, it's just a USB serial converter chip. So whatever you used to install the firmware into the 8U2 chip is what you would use to burn the bootloader into the 2560 chip.What file do I need for the 8U2 firmware and how would I load it with the hardware programmer? I have the Atmel FLIP software if that helps.
I've never owned a arduino board with a 8U2 chip so I'm not the one to give you specific steps to take. However the first step is identifying and obtaining the ICSP programmer you are going to use to load the firmware and later the bootloader for the 2560 chip.
Lefty