An Automata-Theoretic Approach to Hardware/Software Co-verification

Abstract

Abstract. In this paper, we present an automata-theoretic approach to Hardware/ Software (HW/SW) co-verification. We designed a co-specification framework describing HW/SW systems; synthesized a hybrid Büchi Automaton Pushdown System model for co-verification, namely Büchi Pushdown System (BPDS), from the co-specification; and built a software tool for deciding reachability of BPDS models. Using our approach, we succeeded in co-verifying the Windows driver and the hardware model of the PIO-24 digital I/O card, finding a previously undiscovered software bug. In addition, our experiments have shown that our co-verification approach performs well in terms of time and memory usages.

Model Checking Büchi Pushdown Systems

“…A BPDS BP, as defined in [1], is the Cartesian product of a BA B and an LPDS P, where the input alphabet of B is the power set of the set of propositions that may hold on a configuration of P; the input alphabet of P is the power set of the set of propositions that may hold on a state of B; and two labeling functions are defined as follows: -L P2B : (G × Γ ) → Σ, associates the head of an LPDS configuration with the set of propositions that hold on it. Given a configuration c ∈ Conf (P), we write L P2B (c) instead of L P2B (head(c)) for simplicity.…”

“…An accepting run of B 2 P is an infinite trace π such that (1) π has infinitely many occurrences of configurations from the set { c | head(c) ∈ F B 2 P }, i.e., the Büchi acceptance condition is satisfied; and (2) both π B and π P are infinite, i.e., the BPDS loop constraint is satisfied.…”

“…(see [11] for proof) Our LTL model checking algorithm for BPDS has two phases. First, computing a special set of repeating heads, R ⊆ Rep(B 2 P), where the repeating paths of the heads satisfy the BPDS loop constraint.…”

“…In previous work, we proposed a Büchi Pushdown System (BPDS) as a formal representation for co-verification [1]: a Büchi Automaton (BA) represents a hardware device model and a Labeled Pushdown System (LPDS) represents a model of the system software; the interactions between hardware and software take place through the synchronization of the BA and LPDS. This is different from a BPDS model used in software verification [2], where BA only monitors the state transitions of the Pushdown System (PDS) (see Related Work).…”

“…This is different from a BPDS model used in software verification [2], where BA only monitors the state transitions of the Pushdown System (PDS) (see Related Work). We also designed an algorithm for checking safety properties of BPDS [1,3]. However, besides the verification of safety properties, the verification of liveness properties is also highly desirable.…”