I'm not sure how much of the Java API is supported in the cRIO version, but you may want to look at
Jython, which allows Python programs to be compiled to Java bytecode, and allows you to directly import existing Java classes into your Python code, which means you could use the cRIO's Java API directly.
Disclaimer: I've never tried this, but this came to mind in reading your question and the previous responses as a possible course of action. Would probably be much easier than trying to cross compile the entire Python runtime using WindRiver
Good luck, and let us know of any results.
--Ryan
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FRC 1708, 2009-2012, College mentor; 2013-2014, Mentor
FRC 766, 2015-, Mentor