Certification of Ada real time executives for safety critical applications

Abstract

The certification procedures apply to a full equipment including both hardware and software components. The issue is that the equipment supplier must integrate various components coming from separate sources. In particular, the Ada Run Time System is embedded in the equipment as any other application component. This leads to two major requirements:

• a. the Ada Run Time System must be a glass box

• b. unused run-time services must be eliminated from the embedded components.

The first requirement comes from the civil aviation procedures DO 178A [1] and the second is a consequence of the need to proof the system. This can lead to eliminate some unpredictible or unsafe Ada language features. The criticity of the system consists of three levels: critical, essential and non essential. The report ARINC 613 (from the Airlines Electronic Engineering Committee) surveys the Ada language and provides a list of features not to be used in avionics embedded software at least for the two first levels.