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 specificall...