Post-silicon Conformance Checking with Virtual Prototypes

Virtual prototypes are increasingly used in device/driver co-development and co-validation to enable early driver development and reduce product time-to-market. However, drivers developed over virtual prototypes often do not work readily on silicon devices, since silicon devices often do not conform to virtual prototypes. Therefore, it is important to detect the inconsistences between silicon devices and virtual prototypes. We present an approach to post-silicon conformance checking of a hardware device with its virtual prototype, i.e., a virtual device. The conformance between the silicon and virtual devices is defined over their interface states. This approach symbolically executes the virtual device with the same driver request sequence to the silicon device, and checks if the interface states of the silicon and virtual devices are consistent. Inconsistencies detected indicate potential errors in either the silicon device or the virtual device. We have evaluated our approach on three network adapters and their virtual devices, and found 15 inconsistencies exposing 15 real bugs in total from the silicon and virtual devices. The results demonstrate that our approach is useful and efficient in facilitating device/driver co-validation at the post-silicon stage.