Licensing?

Didn't know how else to contact you.  What is the license for this software?  Apologies if I've missed something obvious

I'd like to look at adding an extra RTOS - uCos - , and possibly an extra target - the ARM-R5 for the Zynq Ultrascale+, but have to check how we can contribute (example how safe is it looking at GPL projects for references on how the other RTOSes are integrated?)

