Towards an executable semantics of automobile RTOS standard and its application to conformance verification

TL;DR

This paper develops a formal, executable semantics for automobile RTOS standards using the $ extbf{K}$ framework, enabling precise conformance verification of kernels and applications, addressing ambiguities in natural language specifications.

Contribution

It introduces a rewriting-based formal semantics for the OSEK/VDX RTOS standard, facilitating unambiguous verification of conformance and identifying ambiguities in the original standard.

Findings

Formal semantics of OSEK/VDX using $ extbf{K}$ framework

Detection of ambiguities in the standard

Application of semantics to verify conformance

Abstract

The automobile Real-Time Operating System (RTOS) is hard to design and implement due to its real time features and increasing complexity. Some automobile RTOS standards are released aiming at unifying the software architecture of vehicle systems. Most of the standards are presented informally in natural languages, which may lead to not only ambiguities in specifications but also difficulties in conformance verification. This paper proposes a rewriting-based approach for formalising the automobile RTOS standard. Taking the OSEK/VDX standard as an example, an executional formal semantics of the automobile RTOS kernel, which focuses on the real time features, is defined using $\mathbb{K}$, a rewriting-based framework. We also report some ambiguous definitions of the OSEK/VDX standard, which we find in the process of formalisation. The $\mathbb{K}$ semantics of the OSEK/VDX standard is applied to conformance verification, which is used to check the conformance of not only the automobile operating system kernel but the applications.