Chronos: A timing analyzer for embedded software

Abstract

Estimating the Worst Case Execution Time (WCET) of real-time embedded software is an important problem. WCET is defined as the upper bound b on the execution time of a program P on a processor X such that for any input the execution time of P on X is guaranteed to not exceed b. Such WCET estimates are crucial for schedulability analysis of real-time systems. In this paper, we present Chronos, a static analysis tool for generating WCET estimates of C programs. It performs detailed micro-architectural modeling to capture the timing effects of the underlying processor platform. Consequently, we can provide safe but tight WCET estimate of a given C program running on a complex modern processor. Chronos is an open-source distribution specifically suited to the needs of the research community. We support processor models captured by the popular SimpleScalar architectural simulator rather than targeting specific commercial processors. This makes the Chronos flexible, extensible and easily accessible to the researcher. © 2007 Elsevier B.V. All rights reserved.