Add support for SWD sequence

[jonathanherbstgrapple]

Process SWD sequence commands to pass them down to the device.

I changed the version to 0.2.0 instead of 0.1.1 because I modified the Swd trait, which would break dependent crates.

Changes:

• Added code to process an swd sequence command and translate to swd trait functions
• Modified the Swd trait to support swd sequence commands
• Added mocking to be able to test the dap protocol without hardware

Testing:

• Unit tests to test some cases of the swd sequence commands.

Related Issues:

• Addresses Support For SWD Sequence #3

[korken89]

Hi Jonathan,

Thank you for implementing this addition, is was really missing!
I'll review during tomorrow. Feel free to hit me up on Matrix if you want to discuss something sync.

[korken89]

Over all this looks good! Is there any implementation using this for reference?

I'm in the process of getting the Rusty Probe upgraded to latest HAL, after that I can try implementing this to make sure it works.

[jonathanherbstgrapple]

It's not tested other than the unit tests.

[jonathanherbstgrapple]

Over all this looks good! Is there any implementation using this for reference?

I'm in the process of getting the Rusty Probe upgraded to latest HAL, after that I can try implementing this to make sure it works.

Let me know if there's anything I can do to help upgrading to the latest hal.

[korken89]

If you have a probe, feel free to give it a try: https://github.com/probe-rs/rusty-probe-firmware/tree/update-rp-hal
I think I have finished the update, but I don't have hardware at home to test on.

I'll need to get my testing setup up and running again. :)

[korken89]

Was this tested based on the new HAL branch?

[korken89]

Can you rebase this on master? Then I'll have it merged and released 👍

[korken89]

I pushed the fixes to https://github.com/probe-rs/dap-rs/tree/Grapple-Systems-add-swd-sequence you can steal my commit :)

[jonathanherbstgrapple]

Can you rebase this on master? Then I'll have it merged and released 👍

I pushed the fixes to https://github.com/probe-rs/dap-rs/tree/Grapple-Systems-add-swd-sequence you can steal my commit :)

Done, your changes look fine to me.

[jonathanherbstgrapple]

Don't merge this, I think it's wrong. I missed the sequence count and the fact you can have multiple sequences.

[korken89]

Alright! Ping me when you want feedback

[jonathanherbstgrapple]

Fixed. I guess the next step is to implement swd sequence reading and writing through the rusty probe firmware and test with something that already does swd sequences correctly.

[jonathanherbstgrapple]

I went ahead and did a bitbanged implementation of this in the rusty probe firmware, you can check it out here:
https://github.com/jonathanherbstgrapple/rusty-probe-firmware/tree/swd-sequence-working

That branch also has a hacked fix for probe-rs/rusty-probe-firmware#26

There's one piece of this I'm still not 100% sure on. If you put two read sequences in the same command I don't know if they get packed together within the same byte or if each one starts on a new byte. I currently have them starting on a new byte, which seems sane to me, but I'll spend some time reading the cmsis dap library to figure out what the right thing to do is.
CMSIS DAP does input responses the way I implemented it.

[korken89]

Thank you for fixing this!

[korken89]

I'll prepare a release of 0.2 so we can use it in rusty-probe-firmware

[korken89]

Released! I'll look into your commits and adding them.

[korken89]

I gave your commits a go, seems to be working fine.

Is there anything you are having issues with?
I only added the changes you made to src/dap.rs.

[korken89]

I cherry-picked your changes, and fixed it up a little: probe-rs/rusty-probe-firmware#29
I think it's ready for merge, feel free to comment on the PR.