Maybe you could point me to a place where I can find some additional info. The area I am still guessing about is the various firmware/software elements in a phone. So far I understand that there is a basic program installed: Firmware Main. In addititon to that there is a filesystem, firmware FS. Then there appears to be 1) a loader and 2) customized items like menus etc. To me it's not clear how things fit together. Is there some explanation somewhere?