Things which are relatively standard tend to get good generic support: Ethernet devices will generally be USB/CDC/ECM or RNDIS, for example. That may Just Work (tm) if it has the right descriptors.

The userland approach is much more useful for weird or custom devices. In particular, on Windows you can do one of these user space "drivers" without having to bother with driver signing, and if you use libusb it will be portable too.

(I maintain a small USB DFU based tool for work)

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Neywiny 5 hours ago | parent [-]

DFU - great example. If you have a USB device that has a DFU class that needs a custom driver, can dfu-util and the like hook into these userspace drivers? Or do you also need to maintain the application part?

	▲	pjc50 5 hours ago \| parent \| next [-]
		Dfu-util is one of those "user space drivers", so if you have a nonstandard protocol you'd have to add it directly to dfu-util. There's no intermediate API. It's not easy to set up a fake or "remapped" USB device on most OS as far as I'm aware, if you were trying to write an adapter program that modified USB packets.
	▲	WerWolv 5 hours ago \| parent \| prev [-]
		dfu-util actually also just uses libusb under the hood! Any class or device that doesn't have a driver baked into the OS can be implemented like this. And if you'd need the DFU functionality in a different application, you may be able to just simply link parts of the dfu-util tool into your application