In general, the configuration file for a driver defines all of the properties that the driver needs. Entries in the driver configuration file specify possible device instances that the driver can probe for existence. Driver global properties can be set in the driver's configuration file. See the driver.conf(4) man page for more information.
Driver configuration files are required for devices that are not self-identifying.
Driver configuration files are optional for self-identifying devices (SID). For self-identifying devices, the configuration file can be used to add properties into SID nodes.
The following properties are examples of properties that are not set in the driver configuration file:
Drivers that use the SBus peripheral bus generally get property information from the SBus card. In cases where additional properties are needed, the driver configuration file can contain properties that are defined by sbus(4).
The properties of a PCI bus can generally be derived from the PCI configuration space. In cases where private driver properties are needed, the driver configuration file can contain properties that are defined by pci(4).
Drivers on the ISA bus can use additional properties that are defined by isa(4).