https://www.theregister.co.uk/2019/11/05/google_opentitan/

The OpenTitan project – an open-source design for a Root of Trust (RoT) SoC (System on a Chip) based on RISC-V and managed by a team in Cambridge, UK – was teased by Google along with several partners today.

Hardware RoT is a means of verifying the firmware and system software in a computing device has not been tampered with, enabling features such as secure boot. Hardware RoT can also verify updates and prevent a system from being rolled back to an earlier version with known vulnerabilities. It is the lowest-level security piece in a trustworthy system.