Which OS are you developing a driver for? Many drivers are written in C, but you still need to know the underlying assembly code. At one point, Windows split

Which OS are you developing a driver for? Many drivers are written in C, but you still need to know the underlying assembly code. At one point, Windows split driver development into 2 types. One at the user level and one in the OS. Rumor was this was because of printers. Most of the calls for support at MS (blue screen of death) were caused by printer drivers. By moving them out of the OS and into user space the drivers only crashed their application. I recall there once was a USB driver development kit you could buy. Not sure if it was tied to an OS. But it was a physical device you would plug into a USB port. Cost was like $100-