use GDB with Atmel AVR debuggers

 AVaRICE is a program which interfaces the GNU Debugger with the AVR JTAG ICE,
 and other debuggers, available from Atmel. It connects to gdb via a TCP socket
 and communicates via gdb's "serial debug protocol".
 .
 This protocol allows gdb to send commands like "set/remove breakpoint" and
 "read/write memory". AVaRICE translates this commands into the Atmel protocol
 used to control the JTAG ICE (or other) debugger.
 .
 Because the GDB-AVaRICE connection is via a TCP socket, the two programs do
 not need to run on the same machine.
 .
 The currently supported debuggers are:
 .
  * JTAG ICE mkI
  * JTAG ICE mkII
  * AVR Dragon