Powerbook G4 12" external monitor

[Lastic]

I have searched quite a lot on the topic but haven't found any answer yet.

I've got an Apple Cinema Display DVI hooked up to the Powerbook's mini-DVI
port.

In Ubuntu and OS X the external display works from booting the machine.

However in OpenBSD no console at boot nor does xrandr suggest that I have an external display or a mini-DVI port.

Anybody got a clue ?

[Lastic]

In the meantime I've switched to FreeBSD 10 but had the same issue.

Current solution :

boot the powerbook with the external display attached via DVI then close
the powerbook immediately.

Open Firmware and FreeBSD boot on the external display but once I'm on a text console
after 3 minutes , the machine does a shutdown ( which also happens with no external display when closing the powerbook lid after booting ).

Thus I have to boot with external display attached via DVI, close the powerbook lid, then login and reopen the powerbook lid .

I then can keep working on the external display and no screen on the powerbook.