HAL

Download Source:	http://people.freedesktop.org/~david/dist/hal-0.5.8.1.tar.gz

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Introduction to HAL

HAL is a hardware abstraction layer, which is a piece of software that provides a view of the various hardware attached to a system. In addition to this, HAL keeps detailed metadata for each piece of hardware and provides hooks such that system and desktop-level software can react to changes in the hardware configuration in order to maintain system policy.

The most important goal of HAL is to provide plug-and-play facilities for UNIX-like desktops with focus on providing a rich and extensible description of device characteristics and features. One example of the functionality provided by HAL is when you plug in a USB storage device. HAL can automatically create a mount point in /media and mount the device.

Dependencies

As of hal-0.5.8 libvolume_id.so (From Udev) is a required dependency. On multilib systems you must have more then one copy of this library, (32bit,64bit,N32). Please refer to the clfs-svn book for information on configuring a multilib udev. WARNING: Installing a newer or older version of udev then what is currently installed on your system can cause problems booting because of the frequent changes in the rules format. Please use the same version you currently have, or make the appropriate changes/upgrades to your rule set.

Required

• DBUS (With Glib Binding)
• Glib2
• PolicyKit
• Python

Reccomended

• PCI Utilities
• usbutils

Optional

• Parted
• Acpid
• Expat
• libusb
• Doxygen
• DocBook Utils
• intltool
• Gtk-Doc

HalDaemon User/Group

groupadd -g 19 haldaemon &&
useradd -c "HAL Daemon User" -d /dev/null \
        -u 19 -g haldaemon -s /bin/false haldaemon

Configuration Information

If you have Parted installed and you would like to link HAL against libparted pass the following to configure:

--enable-parted

Non-Multilib

Compile the package:

./configure --prefix=/usr --sysconfdir=/etc \
    --libexecdir=/usr/lib/hal --localstatedir=/var &&
make

Install the package

make install &&
install -v -m755 -d /var/run/hald

Command Explanations

--libexecdir=/usr/lib/hal: This parameter forces the installation of libexec files to /usr/lib/hal instead of /usr/libexec.

--localstatedir=/var: This parameter forces the creation of the pid file to /var/run/hald instead of /usr/var/run/hald.

Multilib

32Bit

Compile the package:

export USE_ARCH=32 &&
CC="gcc ${BUILD32}" PKG_CONFIG_PATH="${PKG_CONFIG_PATH32}" \
./configure --prefix=/usr --sysconfdir=/etc \
    --libexecdir=/usr/lib/hal --localstatedir=/var &&
make

Install the package

make install &&
unset USE_ARCH

N32

export USE_ARCH=n32 &&
CC="gcc ${BUILDN32}" PKG_CONFIG_PATH="${PKG_CONFIG_PATHN32}" \
./configure --prefix=/usr --sysconfdir=/etc --libdir=/usr/lib32 \
    --libexecdir=/usr/lib/hal --localstatedir=/var &&
make

Install the package

make install &&
unset USE_ARCH

64Bit

export USE_ARCH=64 &&
CC="gcc ${BUILD64}" PKG_CONFIG_PATH="${PKG_CONFIG_PATH64}" \
./configure --prefix=/usr --sysconfdir=/etc --libdir=/usr/lib64 \
    --libexecdir=/usr/lib/hal --localstatedir=/var &&
make

Install the package

make install &&
unset USE_ARCH &&
install -v -m755 -d /var/run/hald

Configuration

Bootscript

Install the bootscript from the blfs-bootscripts package with the following command:

make install-haldaemon

Contents

Installed Programs:	hal-device, hal-device-manager, hal-find-by-capability, hal-find-by-property, hal-get-property, hal-set-property, hald and lshal
Installed Libraries:	libhal.{so,a} and libhal-storage,{so,a}
Installed Directories:	/etc/hal, /usr/include/hal, /usr/lib/hal, /usr/share/doc/hal-0.5.7, /usr/share/hal and /var/run/hald

Short Descriptions

hal-device	is used to create, remove or show a HAL device.
hal-device-manager	shows a graphical representation of all the devices HAL is aware of. This program requires GNOME-Python. Here is a screenshot of hal-device-manager communicating with the HAL daemon and displaying a tree of device objects. The shown properties in the screenshot are for a device object representing a hard disk.
hal-find-by-capability	prints the Unique Device Identifiers for HAL device objects of a given capability.
hal-find-by-property	prints the Unique Device Identifiers for HAL device objects where a given property assumes a given value.
hal-get-property	retrieves a property from a device.
hal-set-property	attempts to set property for a device. Note that, due to security considerations, it may not be possible to set a property.
hald	is the HAL daemon program.
lshal	shows all devices and their properties. If the --monitor option is given then the device list and all devices are monitored for changes.
libhal.{so,a}	contains the API functions required by the HAL programs.
libhal-storage.{so,a}	contains the API functions required by the HAL storage and volume utility programs.