Writing Device Drivers

Changes to /devices

All devices in the system are represented by a data structure in the kernel called the device tree. The /devices hierarchy is a representation of this tree in the file system.

In the SunOS 4.1 system,the administrator created special device files using mknod (or an installation script running mknod). Now, device drivers notify the kernel of entries by calling ddi_create_minor_node(9F) once they have determined a particular device exists. drvconfig(1M) actually maintains the file system nodes. This results in names that completely identify the device.