Re: https://firmwaresecurity.com/2018/11/12/keystone-open-source-secure-hardware-enclave/

There is a new document on their site, with more info on this project.

https://keystone-enclave.org/2018/12/13/what-is-keystone.html

Keystone is an open-source project for building trusted execution environments (TEE) with secure hardware enclaves, based on the RISC-V architecture. Our goal is to build a secure and trustworthy open-source secure hardware enclave, accessible to everyone in industry and academia.

https://keystone-enclave.org/