Steps:
1. install all AVR necessary tools (from source or from repository):

* avr-libc -  The C runtime library for the AVR family of microcontrollers for use with the GNU toolset (cross-avr-binutils, cross-avr-gcc, uisp, etc.).
* cross-avr-binutils – Cross-development utilities: ar, as, gasp, gprof, ld, nm, objcopy, objdump, ranlib, size, strings, strip.
* cross-avr-gcc – compiler for AVR microprocessors.
* simulavr – AVR simulator
* gdb-avr – GNU debugger for avr

Note:

for users which are not familiar with gdb command line interface would be good install also ddd (graphic extension for gdb)

2. for compilation we will use Makefile

What is necessary set in Makefile:

* MCU – type of processor

* PROJECTNAME – project name

* PRJSRC – sources

* OPTLEVEL – optimization level (for debugging must be set to 0!!!)

3. Start debugging
start simulavr first:

simulavr

Start GDB server:

make gdbserver

start dddd:

make ddd

If everything is OK you should see a ddd debugger window with your sources loaded and you can start debugging.

Marek