About Openboot :
The firmware in Sun's boot PROM is
called OpenBoot. The main features of openboot are – initial program
loading , & debugging features to assist kernel debugging.
OpenBoot supports plug-in device drivers which are written in language
Forth. This plug in feature allows Sun or any third-party vendors to
develop new boot devices but without making any changes to boot PROM.
Accessing the openboot
console can be accessed by any of the following means . Be careful
not to do this on a live system as you might end up in rebooting the
la suite : http://adminschoice.com/sun-openboot-parameters-and-commands