How Can I Keep My Linux Kernel Module Loaded After Reboot?

It's important to note that different Linux distributions have varying init systems and service management, which means that relying on userspace could require different scripts for each. I'm also on the lookout for a kernel-side solution that wouldn't entail a complete kernel rebuild just to get this little driver working. Does anyone have insights into that?

If you really want to avoid any userspace scripts to load your module (for whatever reason), then you'll need to compile your module as a built-in driver. That way, it gets loaded with the kernel itself. How flexible is the USB_DEVICE_ADD function? If this is a concern, you could explore building your module into an initramfs to see if that will let it load before the xhci driver kicks in.

It sounds like your module isn't actually getting unloaded. When the system powers off, the kernel stops running, which means anything loaded with `insmod` will indeed disappear after a reboot. On the other hand, other modules load automatically at boot thanks to utilities like udev that handle plug-and-play devices. For your module, to ensure it loads automatically, you might want to create a configuration file in `/etc/modules-load.d/` and place your module in a location where `modprobe` can find it.