A Road to a Formally Verified General-Purpose Operating System

Methods of formal description and verification represent a viable way for achieving fundamentally bug-free software. However, in reality only a small subset of the existing operating systems were ever formally verified, despite the fact that an operating system is a critical part of almost any other software system. This paper points out several key design choices which should make the formal verification of an operating system easier and presents a work-in-progress and initial experiences with formal verification of HelenOS, a state-of-the-art microkernel-based operating system, which, however, was not designed specifically with formal verification in mind, as this is mostly prohibitive due to time and