wg VS tock

Inspired by James Munns's call, and as 2023 is coming to an end, I figure it's a good opportunity to reflect and look forward to 2024. It's been a bit over 1.5 years since I embarked on my embedded Rust journey and it's been nothing less than exciting since. So here it goes.

Because you are an embedded guy. There is the https://github.com/rust-embedded/wg working-group. Rust on embedded is really on a got track forward. There are many chips/vendors that are supported both in no std / std rust world, but still there is a lot of niche things where you can actively help to be the first to get it run in Rust.

To specifically answer your question, here:

* <http://www.areweembeddedyet.com/>

It currently redirects to:

* <https://rust-embedded.org>

Which doesn't really contain anything other than a link to <https://github.com/rust-embedded>.

(via <https://github.com/rust-embedded/wg/issues/15>)

Then the Rust Embedded workgroup provides: - Direction on how to using generics and zero-sized types to achieve functional safety - svd2rust, which provides safe abstractions to peripheral access from SVD files and achieves this functional safety - The embedded HAL spec, which makes porting to different vendors/hardware easy - Peripheral access controllers and HALs for various vendors & hardware

The Rust Embedded Devices Working Group curates a list of useful embedded Rust resources, including Peripheral Access Crates (autogenerated from SVD files), embedded-hal Implementation Crates (hand-written libraries implementing the traits (interfaces) specified by the embedded-hal), and Board Support Crates.

You should also look at https://github.com/rust-embedded/wg/issues/41 and https://github.com/rust-lang/rust/pull/55011#issuecomment-429336055.

Here's an interesting discussion, consolidated here. My view is you should use a restricted scope atomic (as best as can be supported) and interact with that through a handler struct. I.e. no global state.

Most of the issues are explained in EWG RFC 419. The TL;DR is that some resources need to implement Send to be usable from interrupts, but they must not be sent across cores.

Hi! This is Daniel from OxidOS Automotive (stating this for disclaimer purposes).

Yes, our OS is based on TockOS, and our CEO (Alex Radovici) is #7 in the contributors list (https://github.com/tock/tock/graphs/contributors), with other colleagues contributing in the past years.

I'm definitely not the best person to answer this, but honestly it's not bad. Here's an example of a moderately complex peripheral, the cortex-m MPU, and how one rust OS handles it:

https://github.com/tock/tock/blob/3a0527d586702b8ae8cb242391...

Reads and writes turn into volatile reads, so everything works out under the hood. You get the benefits of everything having good names, declared sizes, and proper typing on your register accesses. You can extend that to bit accesses as well.

Rust still has a few areas it isn't competitive in, like your hyper limited or obscure chips (e.g. 8051s, XAP), mature tooling around formal methods, and a certification story for safety critical code. People are working on these latter two issues (e.g. ferrocene) and supposedly very close to public delivery, but you know how slow the industry is to adopt new things even then.

There's Tock (https://www.tockos.org/), which is written in Rust (with sprinkles of assembly).

Yeah, and I like I mentioned in the earlier comment, omitting the frame pointer reduces code size by 10% on RISC-V targets, which is huge when dealing with embedded flash: https://github.com/tock/tock/pull/1660

Tock is an excellent embedded OS written in Rust and has some good industrial support. I think Tock gets a lot of stuff right and I highly recommend some of the talks the developers gave on it.

Unfortunately, it increases the code size by 10%. I was looking into this just last week, and can confirm that it's still a problem on the latest version of Rust nightly: https://github.com/tock/tock/pull/1660

I wish we could have frame pointers, because they would make working in embedded land so much easier and more reliable, but a 10% increase in code size just isn't worth it.

TockOS was the first rust RTOS I found. Coincidentally, it has had support for the esp32c3 for over a year now.