Software portability gains realized with METAH and Ada95

Abstract

MetaH is an Architecture Description Language (ADL) developed to express and evaluate the software architecture of avionics and flight control systems. It is intended for not only description and analysis, but also for integration of the software components on the specified embedded hardware. This automated composition to specification with glue code generation allows rapid development and evolution of real-time embedded mission and safety critical systems. It also provides very high portability in these complex systems for software application code across various execution environments. This is accomplished by leveraging language and O/S standards, minimizing component dependencies, and by constructing component timing relationships to specification across differing execution platforms.This paper describes MetaH and provides the results of porting a highly time sensitive application across significantly different embedded hardware/software execution environments. We initially developed a reusable MetaH specification for missile architectures, populated it with software components reengineered from a production missile system, and executed it on single and dual i80960MC target configurations. We then retargeted this application to single and dual Pentium target configurations; and to a single PowerPC configuration. We compare the costs of these exercises with estimated costs to do the same tasks using traditional methods.In each of these cases the high portability and supported functionality of Ada95 was a significant enabler. Current trends say that future avionics systems and perhaps other safety critical applications will require space and time partitioning. Should Ada95 and the Ravenscar profile support these capabilities?