Browse Prior Art Database

Recursive Configuration and Unconfiguration of a Device

IP.com Disclosure Number: IPCOM000115508D
Original Publication Date: 1995-May-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 102K

Publishing Venue

IBM

Related People

Bo, W: AUTHOR [+2]

Abstract

In the AIX* operating system, almost all the devices are dynamically configured. The dynamic configuration of devices is managed by the device configuration manager. When the configuration manager is run, it configures as many devices as it can. The dynamic configuration of devices results in a tree structure where the nodes are the device objects and the branches are the parent-child relationships between these objects.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Recursive Configuration and Unconfiguration of a Device

      In the AIX* operating system, almost  all the devices are
dynamically configured.  The dynamic configuration of devices  is
managed  by the device  configuration manager.  When the
configuration manager is run, it configures as many devices as it
can.  The dynamic configuration of devices results in a tree
structure where the nodes are the device objects and the branches are
the parent-child relationships between these objects.

      When the device configuration is done by the configuration
manager, it configures all the devices that it discovers.  However,
if a specific device is to be configured, the "mkdev" command can be
run.  Since the parent device needs to be configured before a child
device can be configured, this command first checks if the parent is
configured.  If it is, then the device is configured.  If the parent
device is not in a configured state, this command will fail.

      When the user wishes to unconfigure a device, the "rmdev"
command can be run to unconfigure it.  Since a device cannot be
unconfigured unless its children devices are unconfigured, this
command first checks to make sure that all the children devices are
unconfigured.  If they are, then the device is unconfigured.  If any
one child device is configured, this command fails.

      AIX* version 3.2 operating system currently does not support
the functionality to configure a device when its ancestor devices are
unconfigured, or unconfigure a device when its descendant devices are
configured.

      Disclosed is an algorithm to configure a device regardless of
their ancestor devices' states and unconfigure a device regardless of
its descendant devices' states.

      The device configuration manager starts by running
configuration methods for the system device.  The method will load
the device drivers if needed, and update the device configuration
database.  It also defines the children of that device and returns
the list of child devices to the configuration manager.  The
configuration manager maintains the list of these devices and
subsequently configures them.  It halts when this list is exhausted.
This results in a device configuration tree where the nodes of the
tree are objects in the configuration database representing devices
and branches are parent-child relationships  between device objects.
The Figure indicates the device configuration tree structure.

      The underlying idea of the invention is to traverse the
configuration tree as the device is configured or unconfigured.

      For instance, if a device which is a leaf node (such as Dev9)
...