KGDB may be one of the best tools for kernel debugging, besides the famous printk. It allows a developer to connect to the target device from GDB on a host PC. Basic information about KGDB can be found here: http://kgdb.linsyssoft.com. KGDB has two parts: the kgdb core (kernel/kgdb.c) and a few connection interfaces — currently supporting a serial tty device (specified by kgdboc=<serial tty device

