A method and apparatus for loading and executing program code at a micro-processor are disclosed. In this method, a monitoring procedure is performed to monitor whether the micro-processor receives a loading request corresponding to a target program code. If the loading request is received, the target program code is loaded from an external memory into an internal memory of the micro-processor. The micro-processor is then rebooted to enter a first mode in which the target program code in the internal memory is to be executed.