PSEUDO(5) Standards, Environments, and Macros PSEUDO(5)


pseudo - configuration files for pseudo device drivers


Pseudo devices are devices that are implemented entirely in software.
Drivers for pseudo devices must provide driver configuration files to
inform the system of each pseudo device that should be created.

Configuration files for pseudo device drivers must identify the parent
driver explicitly as pseudo, and must create an integer property called
instance which is unique to this entry in the configuration file.

Each entry in the configuration file creates a prototype devinfo node.
Each node is assigned an instance number which is determined by the value
of the instance property. This property is only applicable to children of
the pseudo parent, and is required since pseudo devices have no hardware
address from which to determine the instance number. See driver.conf(5)
for further details of configuration file syntax.


Example 1: A sample configuration file.

Here is a configuration file called ramdisk.conf for a pseudo device
driver that implements a RAM disk. This file creates two nodes called
"ramdisk". The first entry creates ramdisk node instance 0, and the
second creates ramdisk node, instance 1, with the additional disk-size
property set to 512.

# Copyright (c) 1993, by Sun Microsystems, Inc.
#ident "@(#)ramdisk.conf 1.3 93/06/04 SMI"
name="ramdisk" parent="pseudo" instance=0;
name="ramdisk" parent="pseudo" instance=1 disk-size=512;


driver.conf(5), ddi_prop_op(9F)

Writing Device Drivers

June 15, 1993 PSEUDO(5)