Test Driven Development for Device Drivers and Rapid Hardware Prototyping

Technologies like microdrivers have simplified the development of device drivers by providing protection against system crashes and allowing the use of programming tools such as debuggers. However, newer software engineering techniques such as Test Driven Development are still not available for developing device drivers, because of the stateful nature of most devices. Additionally, hardware/software codesing often causes a "chicken-and-egg" problem, because driver testing is not possible without a device and vice versa. In this paper we show how Test Driven Development for PCI device drivers works by extending a virtualization software (KVM/Qemu). We show how a fully functional device emulation can be developed and shipped independently to the driver programmer. Furthermore, we outline how the technique can be harnessed for implementing an entirely software-based PCI tracer.