Hi,
I have been working on a yocto environment. What is missing is a re-arrangement of the Makefiles in the epiphany-libs (
https://github.com/adapteva/epiphany-libs) to be yocto friendly. I might get round to doing that at some point so that you can build epiphany-libs from source. Once done the yocto environment will build a distribution for the prototype board so you can use smart update to update packages, it will also produce an SDK so that you can use yocto eclipse or any IDE to develop epiphany code and then copy this to the board, it will also produce a complete SD card image so that you can boot the board from sd card. Follow the progress of this project at
viewtopic.php?f=9&t=414.
The script at
https://github.com/peteasa/parallella-yoctobuild builds all the compilers and cross compilers you need today. It is also can be configured to use the prebuilt epiphany-sdk with the yocto build. As mentioned the only thing missing now is the build epiphany-libs from source... a relatively simple step if you know yocto!
Peter