Device Configuration Subsystem Overview
Devices are organized hierarchically within the system. This organization requires lower-level device dependence on upper-level devices in child-parent relationships. The system device (sys0) is the highest-level device in the system node, which consists of all physical devices in the system.
Each device is classified into functional classes, functional subclasses and device types (for example, printer class, parallel subclass, 4201 Proprinter type). These classifications are maintained in the device configuration databases with all other device information.
The Device Configuration Subsystem consists of:
| Item | Description |
|---|---|
| High-level Commands | Maintain (add, delete, view, change) configured devices within
the system. These commands manage all of the configuration functions
and are performed by invoking the appropriate device methods for the
device being configured. These commands call device methods and low-level
commands. The system uses the high-level Configuration Manager (cfgmgr) command used to invoke automatic device configurations through system boot phases and the user can invoke the command during system run time. Configuration rules govern the cfgmgr command. |
| Device Methods | Define, configure, change, unconfigure, and undefine devices. The device methods are used to identify or change the device states (operational modes). |
| Database | Maintains data through the ODM (Object Data Manager) by object classes. Predefined Device Objects contain configuration data for all devices that can possibly be used by the system. Customized Device Objects contain data for device instances that are actually in use by the system. |