Not necessarily. There are a number of ways to interact with hardware from userspace: uio[1], libusb[2], spidev[3] and etc. [1] http://lwn.net/Articles/232575

Not necessarily. There are a number of ways to interact with hardware from userspace: uio[1], libusb[2], spidev[3] and etc. [1] http://lwn.net/Articles/232575 http://lwn.net/Articles/232575 [2] http://libusb.org http://libusb.org [3] http://www.kernel.org/doc/Documentation/spi/spidev http://www.kernel.org/doc/Documentation/spi/spidev