FMCOMMS2 and FMCOMMS3 are SW- and HDL-wise identical.
See instructions here:
http://wiki.analog.com/resources/eval/user-guides/ad-fmcomms2-ebz/quickstart/microblaze
The kernel and bitstream is all build from our 2014_R2 branches here:
https://github.com/analogdevicesinc/hdl/tree/hdl_2014_r2
https://github.com/analogdevicesinc/linux/tree/2014_R2
-Michael