Have virtual FW emulation for unit-testing devices

[bentiss]

This is a thought that came up with a discussion with @whot today.

Basically, it's hard to work on libratbag because we are never sure that a change we are introducing will not break existing devices that we do not have.

It would be really nice to be able to have reversed engineered firmwares that behave in the way we are expecting them to be.

Writing such thing is possible with uhid for devices that are using hidraw, and we now have a wrapper in python in hid-tools.

I am not saying it will be easy, but there are things that could be easily done:

• on receiving a certain report, we can change the resolution of the mouse, the LED, the profile info
• we can emulate basic relative movement based on a generic interface (like move the virtual mouse 10 cm to the right at speed 1mm/s)
• etc...

I don't think we need to write all part of the firmware, some could be just dumped from a particular device. But at least, we might be able to have regression tests.

[whot]

Just a thought: should this tool be a separate entity if it ends up being generic enough? With libratbag using it to emulate a firmware, but not necessarily containing the actual work? I have no answer for this, just to keep in mind as a potential option.

[FFY00]

I think so, it will be helpful for more that just libratbag.