PATH
Once loaded, a driver must be installed in the unit table to become available to Device Manager clients. This process begins with a CFM fragment connection ID and results in a refNum value.
The installing software can specify a desired range of unit numbers in the unit table. For example, pre-version 4.3 SCSI drivers use the range 32 through 38 as a convention to their clients. If the driver cannot be installed within that range, an error is returned. The unit table may grow to accommodate the new driver, however. For the rules of this growth, see the important statement on the InstallDriverFromFragment function page.
When installing a native driver, the caller also passes the RegEntryIDPtr value of the device that the driver is to manage. This pointer (along with the refNum value) is given to the driver as a parameter in the initialization command. The driver may use this pointer to iterate through a device's property list, as an aid to initialization. The native driver should return noErr to indicate a successful initialization command.
These functions, described in the next sections, operate on a loaded driver fragment: