GPL'd RISC-V implementation?

Question

Am I allowed to release a RISC-V implementation (written in VHDL or Verilog) under the GPL-v3? If so, what additional "credit", etc. do I have to give?

The FAQ on the RISC-V site says that the ISA spec is licensed with a BSD license, but the BSD license is specific in talking about licensing source code and binaries, so I don't understand how they are applying it.

Can anyone explain how their licensing works and point me to a link on the website that actually has the license?

Answer 1

You can do whatever you want with your implementation, including keeping it closed source and selling it.

If you're going the open-source route and don't want to use BSD, then I personally recommend you look into the CERN Open Hardware License, and listen to the licensing talk from the 2015 ORCONF conference that took place at CERN. GPL was not written for hardware and may not properly protect you or your work.

The FAQ on the RISC-V site says that the ISA spec is licensed with a BSD license, but the BSD license is specific in talking about licensing source code and binaries, so I don't understand how they are applying it.

That's a great question for a lawyer. Even if the RISC-V Foundation is using the wrong license, their intention is clear - anybody can implement the ISA and do whatever they want with their implementations and the Foundation will not come after you.

Answer 2

I believe the answer is yes. The BSD license refers to the spec (an interface described in a document), not to your implementation.