The Ångström Distribution | Embedded power. Minnowboard.org. Embedded Linux Conference 2013 - Building a Custom Embedded Linux Distribution. Experiment with Yocto. I recently had the opportunity to use Yocto. I already practiced quite a lot with OpenEmbedded before. You can see Yocto as a project derived from OpenEmbedded even it is a bit more than that.
In fact, Yocto is made of Poky (a build system based on OpenEmbedded), a few added build tools (swabber, pseudo, etc.), as well as a set of meta data allowing to create embedded distributions for a number of targets. The strength but also the weakness of OpenEmbedded is that it a very flexible build system. It can make production root filesystems, but also a complete distribution with its ready to use package repository, and this for multiple hardware platforms. With Yocto, I was pleased to realize that substantial progress had been made on this side. In a few hours, I managed to develop a minimalistic BSP (Board Support Package) for a given board (in this case a AT91SAM9G20-EK). As you can see, even to support a simple embedded board, there is already a number of concepts to deal with.
CLFS Trac.