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


NAME


hal - overview of hardware abstraction layer

DESCRIPTION


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 identifier 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 (.fdi
files), and some are related to the actual device configuration.


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.


In the Solaris operating system, HAL is supported by a daemon, hald(1M),
and a set of utilities that enable the adding and removing of devices and
the modification of their properties.

SEE ALSO


hald(1M), fdi(4)


See the HAL pages, including the HAL specification, under
http://freedesktop.org.


November 26, 2017 HAL(5)