figure out firmware flashing protocol

[khusmann]

Right now the only way to flash the radio's firmware is via the HT app.

• This is concerning for the long-term health / use of the radios, because as soon as the HT app goes out of date we lose our ability to update the firmware.
• If we can flash our own firmwares, we get the freedom to downgrade firmware versions, as well as install whatever firmware flavor we want (e.g. potentially install BTech firmware on a N76, etc... it remains to be seen how compatible they are)
• It gets the community one step closer to building / modding their own firmware

I have a number of btsnoop logs of firmware downloads I've created, but haven't yet had a chance to sit down and figure out what's going on. It doesn't look trivial -- there's some checksumming / verifying going on in the process that we'll need to figure out. (I've been focusing on audio support recently)

[Ylianst]

@khusmann Oh wow. Yes, this is super important. Once there is no more firmware updates, there is no way to get these logs anymore. Thank you so much for capturing these!