Scalpel: Inserting Code into Firmware Images

As critical embedded systems age or their requirements shift, it is imperative that the firmware running these installed systems can be upgraded and extended long into the future. Yet the tremendous variety of embedded system architectures currently in use makes it difficult for a developer to maintain expertise across many devices. GrammaTech proposes SCALPEL, a tool for rewriting embedded firmware using high-level views of the target binary. SCALPEL will enabledevelopers to write patches at a high level of abstraction, while automating the process of implementing the patch on the target architecture. SCALPEL will greatly reduce the patch- development workload by separating concerns: the developer may focus on what the patch must do and where it should be applied, leaving SCALPEL to determine how to implement the patch safely and with minimal disruption. SCALPEL also presents high-level, decompiled views of thefirmware image to the developer, aiding in detection of bugs and enabling patches that reference or modify source-level entities. SCALPEL builds on top of GrammaTech's mature multi-platformstatic analysis tool CodeSurfer for Binaries by presenting a streamlined and user-friendly API that generates safe, low-level rewriting operations to be executed by CodeSurfer's rewriting engine.