## Physical Device Driver Reference

[prev][next][parent][TOC]

### Physical View Management

The Resource Manager maintains a physical view of the system (hardware topology) that is utilized by all RM-aware components.

The physical view is shown in a tree structure. Each node within the tree structure represents a device or adapter. Associated with each adapter or device node are resource and driver structures.

The Resource Manager automatically creates adapter and device nodes representing basic system resources, such as the CPU and system buses during its initialization. In addition, devices managed directly by the OS/ 2 kernel, such as the Interrupt Controller (PIC) and DMA Channels, are also automatically defined. In the following diagram, the X_Bus represents the system bus where many of the integrated components reside, such as the DMA control and the real-time clock. The following is a physical view of the Resource Manager.

As device drivers initialize, additional adapter and device nodes are created by the device drivers issuing Resource Manager service calls.

Each node has associated resources owned by the underlying device or adapter and the software driver responsible for managing the adapter or device. The following diagram illustrates the process.