In the previous chapters, we learned how to obtain the source code, how the build system works, and how to build our first custom Android system for the emulator. The only things we know about real hardware are that Android is primarily used on smartphones and tablets and that we can certify our hardware according to the Android Compatibility Definition Document (CDD), with all its constraints and rules. The truth is that Android CDD aims to provide guidelines to bring to the market devices that are compliant with Google Mobile Services requirements. This is crucial information because it gives us the freedom to choose different hardware if our goal is not to develop a smartphone or a tablet for the main consumer market.

In the last two years, the amount of devices not being a smartphone or a tablet, but being able to run Android has increased enormously. There is a whole new ecosystem of te so-called development boards that can run Android or Ubuntu Linux, for instance...