Clarification of SiFive license contents and the licensed technology

From My understanding and please correct me if I am wrong, since rocket chip is under BSD and freedom and freedom-e-sdk are both under apache 2.0, then modification and commercial use are allowed. freedom is kind of the environment to build the E300 Platform which is based on E31 Coreplex using a customized configuration on top of rocket chip chisel implementation. Since, again it is under apache 2.0, then modification and commercial use are allowed. However SiFive is selling a license for E31 Coreplex IP. I am not sure what I missed, but what does the license, offered by SiFive for purchase, contain more than what’s available and open in freedom which is under apache 2.0 ?

Besides, in the link it is claimed that there will be no roaylties applied on the commercial products sold using Coreplex IP, But in the license agreement preview under section 4.3 it was mentioned that if royalties are due a royalty report will be submitted to SiFive. Does that mean that under some conditions there will be royalties due ? if so what are they ?

If you use Rocket Chip, which is currently located at, then that is under Apache 2.0 as per the license agreement located at the same location. You are correct that Apache allows for modification and commercial use. Rocket Chip is an open-source project, to which SiFive contributes to, which means it is constantly changing and evolving as well.

The E31 Coreplex IP is a commercial product offered by SiFive for license. The E31 Coreplex is a fully verified Verilog instantiation with guaranteed power, performance, area. It also comes with an integration guide, constraints file (SDC), and a test simulation environment, as well as commercial support. Many customers looking to tapeout a commercial chip have asked us for a commercial license that comes with the additional support, integration guide, and test environments.

On the contracts, the royalty clause is inserted into the agreement as a boilerplate, so that the agreement does not need to be re-written. The standard agreement specifies a royalty rate is 0%.

Thank you for the clarification. However, In addition to Rocket Chip, both freedom and freedom-e-sdk located at and are under Apache 2.0. So technically I can modify and use the output of these directories in a commercial tapeout freely with no charge. Since both of these directories contain the verilog and test environment of E31 Coreplex IP, I understood from what you wrote that I can use it only under a contract and a license agreement with SiFive. Since, both previous statements seem contradictory, could you please clarify this part.

Anything you get from the github locations you mention above is under the Apache license.

The E31 Coreplex is a separate deliverable that is made directly to our end licensees via the SiFive dev website after a license agreement is signed. It will be obvious what that deliverable is because it will come directly from SiFive (not github) and will only be available after an agreement is signed.

Thank you for the clarification.

It seems like the E31 Coreplex offered by SiFive, after an agreement is signed, is different either in content or form from the E31 Coreplex that is generated in

Is it possible to know what does commercial support comprise ?