This plugin can flash the firmware on Logitech Unifying dongles, both the Nordic (U0007) device and the Texas Instruments (U0008) version.
This plugin will not work with the different "Nano" dongle (U0010) as it does not use the Unifying protocol.
Some bootloader protocol infomation was taken from the Mousejack project, specifically logitech-usb-restore.py and unifying.py. Other documentation was supplied by Logitech.
Additional constants were taken from the Solaar project.
When a dongle is detected in bootloader mode we detach the hidraw driver from the kernel and use raw control transfers. This ensures that we don't accidentally corrupt the uploading firmware. For application firmware we use hidraw which means the hardware keeps working while probing, and also allows us to detect paired devices.
If you do not have Unifying hardware you can emulate writing firmware using:
unifying-tool write file.hex -v --emulate=bootloader-nordic
This can also be used to produce protocol data to the command line to compare against USB dumps. This plugin should interact with the hardware exactly like the Logitech-provided flashing tool, although only a few devices have been tested.