BIDI_INIT_PORTDRV(8h) initializes a port driver. This command is sent during spooler initialization and when a port driver is first installed. BIDI_INIT_PORTDRV(8h) is called only once per port driver. No other commands are sent to the port driver until this command completes. As a result, a port driver that opens network adapters has the opportunity to do so while processing the BIDI_INIT_PORTDRV(8h) command.

A port driver can spawn threads at this time, if another thread is needed in order to keep the printer connection active.

Note: If the port driver returns an error, the spooler may unload the port driver. No jobs will be sent to this port driver until the BIDI_INIT_PORTDRV(8h) command succeeds.