Talking Tock 15

Cryptography, external libraries and document wrangling

April 3rd 2017 by Amit

This is the fifteenth post in a series tracking the development of Tock, a safe multi-tasking operating system for microcontrollers.

IRC and Mailing List
Hail Pre-sale
Pull Requests

IRC and Mailing List

We’ve arranged with the organizers of RustFest for there to be a few Hails available to check out at RustFest at the end of April.

@JayKickliter chimed in on IRC (formerly at https://bot.tockos.org/tockbot/tock/2017-04-01/?msg=947&page=1) to ask some questions about porting Tock to a new chip and board in an external repository. It sounds like he’s working on a port to another Cortex-M0 with some exciting features. In the process, he’s been compiling a list of questions arising from the documentation, which we very much appreciate him sharing with us.

Hail Pre-sale

Presales for the Hail platform are ongoing but going fast. The current batch is in production and will ship in early May. There are still about 70 Hails remaining in this batch, so get them while their hot, lest you have to wait for the next one. We plan to start supporting other platforms soon, but if you’re interested in playing around with Tock in all it’s glory, Hail will still your best bet since it’s so feature packed. Pre-order one today on our hardware page

Pull Requests

Another successful week of merging all proposed pull requests. We’re not sure if it’s the slightly reduced volume of PRs or just procrastinating from writing papers, but either way it seems to be working!

@niklasad1 and @frenicth added support for encryption/decryption in AES in counter mode on top of the NRF51’s AES in ECB mode. The HIL for symmetric encryption is still in-flux, but good enough to merge for now. Next step will be to implement the same interface for the SAM4L (which has a built in counter-mode AES controller).
@ppannuto Made consistent the signature for the main function in userland while fixing some usability bugs in the process startup code. One important point from the discussion on the PR thread is that we decided to avoid explicitly adding support for various kinds of programming styles (e.g. an Arduino-style interface) since they are easy to build on top of our existing interface. We expect to see a few additional libraries for doing this on top of the core library in the future.
@ppannuto Added a standardized way of including external libraries into userland apps in our build system. He also conformed the core libtock library to this mechanism instead of special casing it. This means it’s virtually as easy to replace libtock with a different userland library as it is to use the one we provide.
@bradjc fixed up some inconsistent tables of contents in our documentation and added a TravisCI check that verifies TOCs in markdown files in case such inconsistencies arise again.