Narrow the search Use methodical testing procedures, and debugging messages if necessary, to locate the problem area. Low level code can be debugged using KPrintF() serial (or dprintf() parallel) messages. Check the initial values, allocation, use, and freeing of all pointers and structures used in the problem area. Check that all of your system and internal function calls pass correct initialized arguments, and that all possible error returns are checked for and handled. Isolate the problem If errors cannot be found, simplify your code to the smallest possible example that still functions. Often you will find that this smallest example will not have the problem. If so, add back the other features of your code until the problem reappears, then debug that section. Use debugging tools A variety of debugging tools are available to help locate faulty code. Some of these are source level and other debuggers, crash interceptors, vital watchdog and memory invalidation tools like Enforcer and MungWall.