support for Ambiq MCUs

[jerabaul29]

Being curious: is support for the Ambiq MCUs (Apollo3, Apollo4) something that would be reasonably doable with embassy, or would it be far too much work?

[lulf]

'Far too much work' is quite relative to how much time you have, but I will try to summarize what's needed:

• From what I can tell, there are a few peripheral access crates for Ambiq: https://crates.io/search?q=Ambiq . Whether those are in good shape or not, or if it makes more sense to create a new one, I do not know.

• Since Ambiq is cortex-m based (at least from quick googling, I'm not familiar with the MCU), a lot of the basics are covered, your main job would be to implement a few peripherals in an embassy-ambiq HAL

• Once you have a PAC, the next step is to create a hardware abstraction layer (HAL) that usually spans all of the variants, i.e. embassy-ambiq. It may not be a lot of work, depending on which peripherals you need to support or how different it is from existing HALs that you can draw inspiration from.

• I would recommend starting with implementing GPIOs, and perhaps a time driver so that embassy-time etc. works as expected. Critical sections and the executor should already be working on ambiq since they are generic for cortex-m.

• A HAL can be created either within or outside the embassy repo, esp32 for instance is in the esp-rs org. So don't feel like it must be in embassy-rs for it to be embassy compatible.

[jerabaul29]

Ok, thanks for the explanation! :) I will have a look, thought this is probably above my skill and available time. Maybe we keep this open in case I or someone else takes the leap and works on this? :)