(BQ) Part 2 book "Software and system development using virtual platforms" has content: Building virtual platforms, a concrete modeling example, simulator extensions, simulator integration, inter architecture bring-up. | CHAPTER Building virtual platforms 6 Essentially, all models are wrong, but some are useful. —George Edward Pelham Box (1987) A virtual platform is a software model of an existing or future hardware system. The model has the ability to run the same software, including operating systems and drivers, as the actual hardware. This chapter introduces the reader to how the parts that make up a virtual platform are developed and how to assemble those parts into a virtual platform and even into a system of many connected virtual platforms. THE PURPOSE OF THE MODEL When creating a model it is important to consider the purpose of that model. What is the problem it is going to solve? To what use cases will it be applied? When it comes to virtual platforms, the problems addressed typically fall into one of four main classes based on the point in time (pre- or post-silicon) the virtual platform is used and if it is targeting hardware or software development use cases. The four main classes, labeled AÀD, are illustrated in Figure . Depending on the class of problems addressed, different tradeoffs need to be considered. As the virtual platform evolves along the time axis, from pre- to post-silicon, the fidelity and completeness of the platform must increase. In pre-silicon use cases it is typically enough to model only a piece of the final system—up to the board level, for example. In post-silicon use cases it is often necessary to view the virtual platform as only a part of a larger system of virtual platforms that are required to support full-system simulation. Thus in the early stages of hardware development, fast development and modifications of the virtual platform are key factors to be able to follow the evolution of the hardware design. However, later on stability, fidelity, flexibility, and the availability of good tools become key factors for the success of the virtual platform. The broader user base later in the development process tends to view the virtual .