Originally Posted by JNT
Thanks for all the answers thus far, but unfortunately I still have some doubts that I would like to clear up. Do I need this "data.tar.gz" each time that I want to run a startup script, or only the first time?
No, you can install a startup script in the upstart folder with all the other "normal" startup scripts. Beware that a broken script can brick your kindle because it can prevent critical startup scripts from running. But you can always debrick with simple debricking, so not as big a problem as when we were first learning about upstart scripts on 5.0.0 and you needed to use the serial port to debrick.