Hi All,
A quick courtesy email to say I'm working on this. The board is a cheap SAMD21 board much like the Arduino Zero without the debug cpu. Website is https://www.sparkfun.com/products/13664
GPIO and SPI are working locally with the enc28j60 ethernet chip, need a more comprehensive test before checkin.
Tracking issue is at https://github.com/RIOT-OS/RIOT/issues/7197
Wiki is at https://github.com/RIOT-OS/RIOT/wiki/Board%3A-SparkFun-SAMD21-Mini
I'm not affiliated with SparkFun, just a hobbyist customer.
Thanks, Tom