[avr-chat] Serial bootloading on ATmega128

[Rick Mann]

In the next couple of weeks I'm going to have to write a bootloader  
for our ATmega128-based autonomous car project. We have a SparkFun  
BlueSMiRF Bluetooth serial link to the car, which shows up as a  
serial port on a Bluetooth-enabled PC (in this case, a Mac). It's  
just as if I had a serial cable connected directly to the '128.

I want to write a bootloader for the ATmega128 and a little command- 
line tool that can open the serial port, talk to the bootloader, and  
report back. I'm an experienced Mac programmer but not terribly  
familiar with the POSIX API for talking to a serial port. I've also  
written basic code for the '128, know how to use the serial port, but  
I've never written a boot loader. I did read the section in the  
datasheet on it, though.

I've looked at the app notes on Atmel's site, and all I can find has  
to do with DES-encrypted firmware loading. I can probably glean a lot  
of what I need from that, and just throw out the crypto parts (we  
don't need crypto support).

However, I figure this has been done more than once, and maybe  
someone's put that code (both firmware and POSIX tool) into the  
public domain. At  the very least, perhaps someone can point out  
pitfalls and make suggestions.

Anything would be welcome. Thanks!

--
Rick