Tock OT Notes 4/2/2020

Present:

• Brad Campbell (Chair), University of Virginia
• Jon Flatley, Google
• Phil Levis, Stanford
• Silvestrs Timofejevs, lowRISC
• Laura Abbott, Oxide Computer
• Johnathan Van Why, Google

Updates

• Phil: Progress on time HIL updates, working on implementations now.
• Brad: I've been tagging PRs as opentitan-wg in tock/tock, please review when you have a chance.
• Laura: Not much new in libtock-rs. Re-factoring work is on-going.
• Johnathan: Making progress on lightweight libtock-rs core. Still will be a couple weeks until the experiment shows promise or not.

HMAC

• https://github.com/tock/tock/pull/1702
• Phil: questions on the interface, and how much design to do now given this would be a new HIL.
• Also highlights tension between OT and core working groups, since HIL would fall under core, technically.
• Brad: Probably worth making sure the interface is not too hardware specific, as that quickly presents roadblocks for other developers.
• Phil: Alistair's interface mimics the AES interface with a base trait and then other traits with configure functions. Separates out control path, and allows for a shared data path.
• Brad: Alternative in https://github.com/tock/tock/pull/1727
• Gives us an opportunity to compare the approaches.