It seems like operations that communicate with userspace are really discouraged. And I am not arguing with that. Although it doesn't mean that they cannot be accomplished. A driver loads configuration that could be stored only on HDD. When MS Windows XP boots up it remembers that I have turned Bluetooth off so it is not powered on, unlike even the latest Linux (Fedora 14 at the moment of writing) – such functionality in many drivers was not implemented. When developer uses procfs or character devices there should be another software or script in boot sequence that is actually sending information from a file to particular device. After some time looking over the internet I have managed to write such module that reads a file.