Trade Study of Scripting Languages for Avionics Systems

Kurzfassung

Developing software for avionics systems presents a multifaceted challenge, both in terms of complexity and cost. One approach to address these challenges while enabling customization and minimizing requalification efforts is through the utilization of the Lua scripting language. Lua empowers a diverse workforce, allowing for potential customization by end-users without necessitating full system re-verification, thereby saving valuable time and resources. Thus, we explore the use of scripting languages, which have different properties than compiled languages typically used for avionics systems. Scripting languages can reduce complexity by increasing the abstraction layer and supporting software development in the production environment, leading to faster iteration times. However, avionics systems have strict requirements for real-time behavior, memory constraints, and safety-critical certification, which scripting languages are not designed to fulfill. In this paper, we discuss the pros and cons of using scripting languages for safety-critical systems. We present a comparison of different off-the-shelf scripting engines, based on the following criteria: real-time performance, memory usage, portability, reliability, and certifiability to be used in safety-critical systems such as avionics systems. The result is a recommendation of the most suitable language to use in the avionics domain based on different criteria. We recommend Lua as the most suitable language for use in the avionics domain, as it has the best fit to the given requirements. We also suggest modifications that would need to be made to the engine and the scripts to make them certifiable with respect to the DO-178C standards and the additional tool qualification supplements. These include changes to the garbage collector, the type system, and the coding rules and verification methods.