System-on-Chip Information Flow Validation Under Asynchronous Resets

Modern system-on-chip (SoC) designs comprise hundreds of individual IP blocks, each with its custom implementation of reset signals in most cases. The asynchronous nature of these resets while crossing different reset domains makes the SoC prone to various vulnerabilities if not implemented and validated thoroughly. A key aspect in validating system functionality is to ensure the functionality under reset is verified. Traditional simulation-based validation techniques often become a bottleneck in complex SoC designs due to the large control path of these designs. We propose SoC security checker under asynchronous resets (SoCCAR), a SoC validation framework that addresses this problem. SoCCAR leverages control flow graphs (CFGs) of the design to extract the control flow associated with property violations caused by reset domain crossings due to asynchronous resets. SoCCAR efficiently tracks the chain of events leading to the payload without suffering from state space explosion, a common challenge in complex designs. We test the efficacy of SoCCAR in detecting such vulnerabilities by developing multiple SoC benchmarks, each embedded with custom vulnerability originating from reset implementations across different domains. These vulnerabilities reflect practical design complexity and correspond to security violations encountered in practice as a result of multiple asynchronous resets. SoCCAR successfully detected all violations with minimal computation overhead and runtime, making it a viable approach for detecting such violations in complex SoC designs.