Figure 15–1 shows data structures and routines that define the structure of a character device driver. Device drivers typically include the following elements:
Device-loadable driver section
Device configuration section
Character driver entry points
The shaded device access section in the following figure illustrates character driver entry points.
Associated with each device driver is a dev_ops(9S) structure, which in turn refers to a cb_ops(9S) structure. These structures contain pointers to the driver entry points:
Some of these entry points can be replaced with nodev(9F) or nulldev(9F) as appropriate.