System tracing is a helpful method for engineersand users to know exactly what happens in an operating system,especially in real-time operating systems (RTOS), because forreal-time system, it is normally more difficult to know theperformance of hardware and software than for desktopcomputers. Although this kind of tracing tools already exist forsome commercial RTOS, it is fairly hard to see those tools forsmall or open source RTOS. Moreover, because the structure andimplementation of different RTOS varies, it is rare to find aframework that can easily be ported to those platforms. In thisthesis, a solution is presented to this general tracing problem ondifferent platforms. By using the portable framework, it ispossible to implement tracing component into a real timeoperating system by some simple reconfigurations. This platformportability feature is accomplished by separating the specificplatform logic from the logic of the tracing part. Finally, adeployment of this framwork onto a small open source real-timeoperating system—AtomThreads, running on an AVRATmega1650 – is used as a demonstration of this framework.