In order to ensure that the Kestrel SoC can be legally implemented in silicon, Raptor requires a CLA to be on file for any contributors submitting changes to the Kestrel RTL. This CLA is primarily used to ensure that the rights granted under copyright via the GPL are extended to other rights, for example patent and mask rights, which otherwise would prevent the use of Kestrel RTL/HDL outside of FPGA targets.
We have adopted an OpenBMC CLA (see doc/kestrel-icla.pdf) in furtherance of this goal.