i think it worked. When it rebooted, the phone had a commandline with tux on top left and it said loading kernel image or similar.
So, all i need to do now is find a suitable OS to try boot?
I have been thinking about it.
And this is my conclusion:
To use the OmniaHD version of Symbian would be the closest, hardware-wise. It has same hardware, and all OSs based on Symbian support a regular keyboard and arrows. The only thing i see missing is something to act as a menu-key.
But thats just a thought...
Important is: it works like a charm, at least the first part.