16-bit memory support (RCM40x0)

[spth]

Currently, trying to use an RCM4050 (which has 16-bit flash and RAM), OpenRabbit hangs:

philipp@notebook6:~/OpenRabbit$ src/openrabbitfu --verbose --verbose --run --serialout examples/hello/hello-RCM4110.ihx /dev/ttyUSB3
Reset Rabbit.
Sending initial loader.
set baudrate to 2400
Sending 266 initial loader triplets.
set baudrate to 57600
Secondary loader format detected as Dynamic C 9

We don't even get to read the processor type, so we don't even get as far as we do on an RCM5700. I guess getting this to work fully will require multiple steps. Finding a way to read out the processor type should be the first one.

[tomlogic]

Consider looking at the Dynamic C 10 documentation on how it performs a cold boot of Rabbit 4000/5000/6000 processors. Hopefully you can integrate those methods with how you're handling the Rabbit 2000/3000 processors.

It includes steps for detecting internal memory on /CS3 (Rabbit 5000 or 6000) and then a precoldload.bin to detect whether the Rabbit 4000 is using 8-bit or 16-bit memory.

The directory with that README file includes source to all of the loaders so you can see how they work.