Once the building environment is up and running, we will have to get all the needed Yocto sources. To do so, we should keep in mind which is the target system where our new system should run. In fact, even if the Yocto OS supports different architectures from several CPU vendors, it’s quite common that each vendor has forked its tree to support its products. This is not typically a problem since whatever we are going to present in this book is generic and (maybe the last 5% of) the customizations can be easily adapted for each development kit we have to work on.