Validation of Embedded Software through Static Analysis of Machine Codes

A code validation tool for RISC microcontrollers, at the level of machine instruction stream is described. This purports to a methodological approach to achieve software debugging and code validation, where the source code might be created in assembly language or a high level language. The appropriateness of instructions as well as its sequence in a program is validated with the help of rules governing the occurrence of illegal instructions and code sequences for executing the CPU and integrated peripheral functions. This is achieved through the static analysis of machine codes by applying the rules formulated. This validation tool can be integrated to the system development environment for the detection of such errors without introducing any software or run time overhead in the resulting code. A prototype based on PIC 16F87X microcontrollers is developed. The algorithm can encompass a wide range of RISC processors, once appropriate rules are available for such processors.