BLESS: Formal specification and verification of behaviors for embedded systems with software

Abstract

Recent experience in the avionics sector has demonstrated the benefits of using rigorous system architectural models, such as those supported by the standard Architectural and Analysis Definition Language (AADL), to ensure that multi-organization composition and integration tasks are successful. Despite its ability to capture interface signatures and system properties, such as scheduling periods and communication latencies as model attributes, AADL lacks a formal interface specification language, a formal semantics for component behavioral descriptions, and tools for reasoning about the compliance of behaviors to interface contracts. In this paper we introduce the Behavioral Language for Embedded Systems with Software (BLESS) - a behavioral interface specification language and proof environment for AADL. BLESS enables engineers to specify contracts on AADL components that capture both functional and timing properties. BLESS provides a formal semantics for AADL behavioral descriptions and automatic generation of verification conditions that, when proven by the BLESS proof tool, establish that behavioral descriptions conform to AADL contracts. We report on the application of BLESS to a collection of embedded system examples, including definition of multiple modes of a pacemaker. © 2013 Springer-Verlag.