OpenBoot 3.x Command Reference Manual

Plug-in Device Drivers

A plug-in device driver is usually loaded from a plug-in device such as an SBus card. The plug-in device driver can be used to boot the operating system from that device or to display text on the device before the operating system has activated its own drivers. This feature enables the input and output devices supported by a particular system to evolve without changing the system PROM.