Power on without pressing power button

Hello -- I recently got my hands on a 2005 Mac Mini G4 and installed
NetBSD 10. I'm have a lot of fun with it.

One issue: I don't know how to have this Mac automatically boot when first
plugged in, or after a power failure.
 
Is there a way to configure this Mac to automatically power on?

Maybe there is a setting in Open Firmware 3 that I can set?

Thanks - Joel