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.TH hal 5 "11 Sep 2006" "SunOS 5.11" "Standards, Environments, and Macros"
.SH NAME
hal \- overview of hardware abstraction layer
.SH DESCRIPTION
.sp
.LP
The Hardware Abstraction Layer (HAL) provides a view of the various hardware
attached to a system. This view is updated dynamically as hardware
configuration changes by means of hotplug or other mechanisms. HAL represents a
piece of hardware as a device object. A device object is identified by a unique
identifer and carries a set of key/value pairs, referred to as device
properties. Some properties are derived from the actual hardware, some are
merged from device information files (\fB\&.fdi\fR files), and some are related
to the actual device configuration.
.sp
.LP
HAL provides an easy-to-use API through D-Bus. D-Bus is an IPC framework that,
among other features, provides a system-wide message-bus that allows
applications to talk to one another. Specifically, D-Bus provides asynchronous
notification such that HAL can notify other peers on the message-bus when
devices are added and removed, as well as when properties on a device are
changing.
.sp
.LP
In the Solaris operating system, HAL is supported by a daemon, \fBhald\fR(1M),
and a set of utilities that enable the adding and removing of devices and the
modification of their properties.
.SH SEE ALSO
.sp
.LP
\fBhald\fR(1M), \fBfdi\fR(4)
.sp
.LP
See the HAL pages, including the HAL specification, under
http://freedesktop.org.