Add support for rock3b platform

[JDuchniewicz]

No description provided.

[omeh-a]

Looks pretty good, just a few minor comments re: timer mostly.

[JDuchniewicz]

The builds will be failing until new version of sdf_gen is released because of adding a parameter to Serial class au-ts/microkit_sdf_gen#27

[JDuchniewicz]

Currently it is broken after 768 seconds due to an overflow in ticks calculation

[midnightveil]

You should also add this to ci/matrix.py so that CI builds these examples.

[JDuchniewicz]

Still waiting for a new release of https://github.com/au-ts/microkit_sdf_gen to happen before the CI will be passing. Are we okay with that @Ivan-Velickovic?

[Ivan-Velickovic]

Still waiting for a new release of https://github.com/au-ts/microkit_sdf_gen to happen before the CI will be passing. Are we okay with that @Ivan-Velickovic?

Need to merge some other things for sdfgen, will make a release by the end of the week hopefully.

[JDuchniewicz]

@midnightveil this depends on seL4/microkit#356 so it won't build right now.

[Ivan-Velickovic]

I started doing the rebase but would be better if the commits were squashed instead.

Something like:

1. add DTS
2. add X driver
3. add Rock3B support to X example

and so on.

[Ivan-Velickovic]

I'll make a separate PR that updates Microkit so then this should just be able to rebase on main and then we can finally merge.