Process Network Models for Embedded System Design Based on the Real-Time BIP Execution Engine

TL;DR

This paper presents a high-level process network modeling approach for embedded real-time systems that guarantees schedulability throughout the design flow, culminating in executable implementations on the BIP runtime environment validated on a spacecraft application.

Contribution

It introduces a process network-based design flow for embedded systems that preserves schedulability properties from high-level models to implementation using BIP.

Findings

Schedulability is guaranteed throughout the design process.

Validated approach on a real spacecraft application.

Supports high-level modeling with automatic property preservation.

Abstract

Existing model-based processes for embedded real-time systems support the analysis of various non-functional properties, most notably schedulability, through model checking, simulation or other means. The analysis results are then used for modifying the system's design, so that the expected properties are satisfied. A rigorous model-based design flow differs in that it aims at a system implementation derived from high-level models by applying a sequence of semantics-preserving transformations. Properties established at any design step are preserved throughout the subsequent steps including the executable implementation. We introduce such a design flow using a process network model of computation for application design at a high level, which combines streaming and reactive control processing with task parallelism. The schedulability of the so-called FPPNs (Fixed Priority Process Networks) is well-studied and various solutions have been presented. This article focuses on the design flow's steps for deriving executable implementations on the BIP (Behavior - Interaction - Priority) runtime environment. FPPNs are designed using the TASTE toolset, a convenient architecture description interface. In this way, the developers do not program explicitly low-level real-time OS services and the schedulability properties are guaranteed throughout the design steps by construction. The approach has been validated on the design of a real spacecraft on-board application that has been scheduled for execution on an industrial multicore platform.