Basic Device Configuration Procedures Overview

At system boot time, cfgmgr) is automatically invoked to configure all devices detected as well as any device whose device information is stored in the Configuration database. At run time, you can configure a specific device by directly invoking (or indirectly invoking through a usability interface layer) high-level device commands.

High-level device commands invoke methods and allow the user to add, delete, show, and change devices and their associated attributes.

When a specific device is defined through its define method, the information from the Predefined database for that type of device is used to create the information describing the specific device instance. This specific device instance information is then stored in the Customized database.

The process of configuring a device is often highly device-specific. The configure method for a kernel device must:

• Load the device's driver into the kernel.
• Pass the device dependent structure (DDS) describing the device instance to the driver. For more information on DDS, see Device Dependent Structure (DDS) Overview.
• Create a special file for the device in the /dev directory. For more information, see Special Files.

Many devices do not have device drivers. For this type of device the configured state is not as meaningful. However, it still has a Configure method that simply marks the device as configured or performs more complex operations to determine if there are any devices attached to it.

The configuration process requires that a device be defined or configured before a device attached to it can be defined or configured. At system boot time, the Configuration Manager first configures the system device. The remaining devices are configured by traversing down the parent-child connections layer by layer. The Configuration Manager then configures any pseudo-devices that need to be configured.