Model-driven reverse engineering focuses on automatically discovering models from different kinds of available information on existing software systems. Although the source code of an application is often used as a basic input, this information may take various forms such as: design "models", bug reports, or any kind of documentation in general. All this metadata may have been either built manually or generated (semi)automatically during the whole software life cycle, from the specification and development phase to the effective running of the system. This paper proposes an automated and extensible MDE approach to build a usable cartography of a given platform from available metadata by combining several MDE techniques. As a running example, the approach has been applied to the TopCased MDE platform for Embedded & Real-Time Systems.