Re bitbake :
Both these methods are ok :-
cd $HOME/tuxbox-bb/build
source ./env.source
bitbake -cclean enigma2
bitbake enigma2
. env.source && bitbake -Db ../openembedded/packages/dreambox/dreambox-bootlogo.bb -c clean && bitbake -Db ../openembedded/packages/dreambox/dreambox-bootlogo.bb
The second gives more debug output.
Cheers.