... 2nd Edition June 2001 . ... Interrupt-Driven Block Drivers . ... The first, sbull (Simple Block Utility for Loading Localities) implements a block device using system memory -- a RAM-disk driver, essentially. ... The functions for registering and unregistering block devices look similar to those for char devices: #include <linux/fs.h> int register_blkdev(unsigned int major, const char *name, struct block_device_operations *bdops); int unregister_blkdev(unsigned int major, const char *name); . ...