Extended quasi-static scheduling for formal synthesis and code generation of embedded software

With the computerization of most daily-life amenities such as home appliances, the software in a real-time embedded system now accounts for as much as 70% of a system design. On one hand, this increase in software has made embedded systems more accessible and easy to use, while on the other hand, it has also necessitated further research on how complex embedded software can be designed automatically and correctly. Enhancing recent advances in this research, we propose an Extended Quasi-Static Scheduling (EQSS) method for formally synthesizing and automatically generating code for embedded software, using the Complex-Choice Petri Nets (CCPN) model. Our method improves on previous work in three ways: (1) by removing model restrictions to cover a much wider range of applications, (2) by proposing an extended algorithm to schedule the more unrestricted model, and (3) by implementing a code generator that can produce multi-threaded embedded software programs. The requirements of an embedded software are specified by a set of CCPN, which is scheduled using EQSS such that the schedules satisfy limited embedded memory requirements and task precedence constraints. Finally, a POSIX-based multi-threaded embedded software program is generated in the C programming language. Through an example, we illustrate the feasibility and advantages of the proposed EQSS method.