To get started with the OpenEmbedded framework and the Yocto Project’s
infrastructure, I suggest that you spend some time to try out the Quick
Start with Poky Denzil to cross-compile and get a qemu virtual machine
and image running.
Once, you have seen how bitbake works and learned the basic concepts,
you can move on and go through the .
After that, you should be able to run roscore on the qemu virtual
machine, and can try get this running on your specific board by
developing and using a board support package.