I had trouble getting setup.sh to run with the options shown in the document (I ended up leaving them off the command, AKA no shared downloads dir across different yocto builds)
setup needs to be run before bitbake can be run (you need to run setup.sh and 'source poky/oe-init-build-env' in order to run bitbake).
FYI: I posted an Edison Image with video/audio kernel drivers/utils here: http://viking-helmet.herokuapp.com/projects/files/toFlashv4.zip (if you want to play around with something while your yocto build is compiling)