Some of them are open source: https://github.com/sifive/freedom https://github.com/sifive/freedom So this board has an open source CPU: https://www.sifive.com/

Some of them are open source: https://github.com/sifive/freedom https://github.com/sifive/freedom So this board has an open source CPU: https://www.sifive.com/boards/hifive1-rev-b https://www.sifive.com/boards/hifive1-rev-b This does not: https://www.sifive.com/boards/hifive-unmatched https://www.sifive.com/boards/hifive-unmatched Although, I get the feeling they will open source design on a rolling basis. Pure speculation.