As the title says: i want to make an own script that's called on every boot (and shutdown), just like mount-sd.sh.

Why not modify mount-sd.sh?

• it's called too late during boot
• it will be overwritten by system updates

i was using it, see here: http://talk.maemo.org/showthread.php?t=92449, but since the update to 1.0.4 this does not work very well anymore, since there were a lot of changes: https://github.com/nemomobile/sd-utils/commits/master

How do i make my own script, called before the "ambiance-stuff" is executed?

edit: must be executed as root