It’s been a long war… but finally I did it. My development PC with Xubuntu 13.10 is finally correctly configured and now it is cross-compiling Qt5.2.1 for the Pandaboard ES running Ubuntu Core 12.04… just one night of waiting.
The whole procedure for the preparation of the operating system and the subsequent compilation of QT5 will soon be available online on this site and on robot-home.it blog