Port DFU code from T1 CLI to update SAMD21 firmware over USB

[kevinmehall]

No description provided.

[kevinmehall]

Firmware side completed with tessel/t2-firmware#44

[johnnyman727]

@kevinmehall should the CLI portion of the code be pretty similar to the original CLI's process?

[kevinmehall]

Yeah, almost all the code will port straight over. The main difference is that enterBootloader is a vendor request 0xBB.

[johnnyman727]

👍 thanks!

And, presumably, this update command should also check the openWrt image and update that if necessary.

[johnnyman727]

It should be 0xBB instead of 0x0042 as found here?

[johnnyman727]

Ah, I think I understand. I need to do a vendor request like so. Is that more accurate?

[kevinmehall]

Correct, a control transfer with bRequest (2nd argument) 0xBB.

[johnnyman727]

Fixed with #231.