Guidelines for choosing MACHINE & MACHINE_ARCH?

[Leandro Santi <lesanti%gmail.com@localhost>]

Hello!

I'm looking forward to work a bit on Tom's AVR32 port [1] in order
to build the kernel with build.sh (and eventually merge this code
into the project as discussed with Tom & some of you in Malta quite
a while ago).

A quick look at build.sh shows that one of the first things that
needs to be done is to map the MACHINE name to the CPU architecture
name, i.e. MACHINE_ARCH. I noticed that some ports set
MACHINE=MACHINE_ARCH, but some others don't. Which leads me to the
following: what are the guidelines for choosing these names?

We are currently targeting the only 2 dev boards made by Atmel,
i.e. NGW100 and STK1000, so a-priori I am inclined to set MACHINE
to evbavr32 and MACHINE_ARCH to avr32. Thoughts?

Thanks,
Leandro

[1] https://github.com/Tommmster/netbsd-avr32