Well, I'm dumb. Of course the firmware has to be embedded in the BIOS or the chip itself, because most machines with Realtek NICs support network booting. Firmw

Well, I'm dumb. Of course the firmware has to be embedded in the BIOS or the chip itself, because most machines with Realtek NICs support network booting. Firmware loading in OS drivers probably only delivers updates. So there is firmware, it can be updated by the OS, we don't know exactly what's inside. Though at least the firmware isn't designed to update the OS as in those Soviet Russia jokes.