The software used in this book is entirely open source. The versions used are, in most cases, the latest stable versions available at the time of writing. While I have tried to describe the main features in a manner that are not specific to a particular version, it is inevitable that the examples of commands contain some details that will not work with the later versions. I hope that the descriptions that accompany them are sufficiently informative so that you can apply the same principles to the later versions of the package.

There are two systems involved in creating an embedded system: the host system that is used to cross-compile the software and the target system on which it runs. For the host system, I have used Ubuntu 14.04, but most Linux distributions will work with little modification. In the same way, I had to choose a target system to represent an embedded system. I chose two: the BeagelBone Black and the QEMU CPU emulator, emulating an ARM target. The latter target means that you can try out the examples without having to invest in the hardware for an actual target device. At the same time, it should be possible to apply the examples to a wide range of targets with adaptations for specifics, such as device names and memory layout.

The versions of the main packages for the target are U-Boot 2015.07, Linux 4.1, Yocto Project 1.8 "Fido", and Buildroot 2015.08.