Buildroot[1] is another good tool for rolling your own rootfs. If you have ever built your own kernel (i.e. ran make menu-config) you will feel right at home using buildroot. And their documentation is fantastic[2].
Buildroot is a lot simpler than Yocto or OpenEmbedded. I found it a lot easier to quickly understand how Buildroot works and get something working with it than I did with Yocto. Of course Buildroot's simplicity means that you give up some nice to have features that you would probably want for more serious projects.
They have specific instructions for getting started with RaspberryPI v1[3].
Going to second buildroot. I played around with yocto/oe and found it overly complicated for what I needed. Buildrot is much easier to grok and modify/add packages.
OpenEmbedded was indeed fairly frustrating to work with when I did a project with it several years ago. I don't remember the details, though. What I do remember is that OE decoupled board-specific configuration from package selection. buildroot does both in a single .config file, so that may make it less suitable for some projects.
Buildroot is a lot simpler than Yocto or OpenEmbedded. I found it a lot easier to quickly understand how Buildroot works and get something working with it than I did with Yocto. Of course Buildroot's simplicity means that you give up some nice to have features that you would probably want for more serious projects.
They have specific instructions for getting started with RaspberryPI v1[3].
[1]: http://buildroot.uclibc.org/ [2]: http://buildroot.uclibc.org/downloads/manual/manual.html [3]: http://git.buildroot.net/buildroot/tree/board/raspberrypi/re...