I'd like to program the M4 without having to run the Arduino UI. I found Arturo (https://github.com/scottdarch/Arturo), but the support for the recent Arduino builds is Alpha. I hope to try it out tonight. I'd love to just program it in C, but need some pointers for getting started.
Have a look at this: http://www.udoo.org/docs-neo/Arduino_M4_Processor/Overview.html Quoting, "High Performaces are provided by low level libraries developed by Freescale called MQX. There are low level libraries written ad-hoc on iMX6 M4 core implementing a real-time OS. The high level Arduino headers are "linked" with low level MQX calls." If you manage to get a binary executable from M4 you can try to use the tool to flash this binary on M4. Here's the guide: http://www.udoo.org/docs-neo/Arduino_M4_Processor/Programming.html