Hal daemon what is

Connect and share knowledge within a single location that is structured and easy to search. Very close. OpenSUSE The functionality it provides is being served up by udev now.

So, I guess it depends on what version of opensuse you're running. Sign up to join this community. The best answers are voted up and rise to the top.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Can the HAL daemon be safely disabled for servers? Ask Question. Asked 10 years, 9 months ago. SCSI devices are represented by device objects where info. For device objects representing USB devices the property info. Note that the corresponding USB interfaces are represented by separate device objects as children.

Device objects that represent USB interfaces, ie. Devices on the VirtIO bus are represented by device objects where info. Virtual devices of the VMBus, which is part of the Hyper-V technologies which is a hypervisor based virtualization solution included in the Windows Server , are represented by device objects where info. Device objects representing virtual devices under the Xen Virtual Machine Monitor, such as frontend network or block devices, will have info. The section describe functional properties of device objects, that is, properties that are merged onto device objects representing addressable hardware.

In most circumstances such properties stem from a kernel level driver attached to the device represented by the device object, however, as HAL can merge properties from anywhere, they may have been merged from device information files or callouts. Device objects with the capability alsa represent all the streams available through ALSA on a soundcard.

Device objects with the capability battery represent all the devices having some battery in many cases - rechargeable inside. Device objects with the capability biometric represent a biometric device e. Device objects with the capabilities biometric. Device objects with the capability button represent the devices capable of providing a state to the system. Device objects with the capability camera represent digital still cameras that can be attached to a computer to exchange files.

This does not include card readers for memory cards used for cameras. This capability can't, in general, be reliably probed from the hardware so the information needs to be merged from either device information files or callouts. Therefore this capability should be merged on the appropriate device object that represents the addressable piece of hardware that is the digital still camera; for USB devices this would be the device object representing the appropriate USB interface.

The following properties are available:. This namespace is concerned with human input devices such as keyboards, mice, pointing devices and game controllers. If a device object has the capability input then the following properties are available.

Device objects with the capability input. The input device have keys that can be pressed. The input device is a switch, e. Note: normally those devices have also the leds capability. Device objects with the capability killswitch represent switches to turn a radio on and off. The following methods exist on the interface org. Device objects with the capability sensor represent light sensors in the system. This namespace is used to describe networking devices and their capabilities.

Such device objects will have the capability net and they will export the properties below. This namespace only describe the generic aspect of networking devices; specific networking technologies such as IEEE Ethernet networking devices is described in this namespace for device objects with the capability net. Note that device objects can only have the net. Wireless ethernet networking devices is described in this namespace for device objects with the capability net.

Control devices for Wireless ethernet networking devices are described in this namespace for device objects with the capability net. Warning: You should know what you do if you touch this devices.

They are not always stable and can cause kernel crashes on linux. Bluetooth ethernet networking devices is described in this namespace for device objects with the capability net. Bridge ethernet networking devices is described in this namespace for device objects with the capability net.

IrDA Infrared Data Association Networking devices are described in this namespace for device objects with the capability net. Loopback networking devices are described in this namespace for device objects with the capability net. Device objects with the capability obex represent devices that have implemented OBject EXchange protocol for communication.

Typically such devices are mobile phones and the protocol is used to transfer files, synchronize data and manage mobile phone configuration. Device objects with the capability oss represent all the streams available through OSS on a soundcard. The following properties are available. They can also playback audio. Sometimes they can also record audio. Therefore this capability should be merged on the appropriate device object that represents the addressable piece of hardware that is the portable music player; for USB devices this would be the device object representing the appropriate USB interface.

Device objects with the capability printer represent printers. Device objects with the capability processor represent CPU's in the system. Device objects with the capability scanner represent image scanners. This capability should be merged on the appropriate device object that represents the addressable piece of hardware that is the digital still camera; for USB devices this would be the device object representing the appropriate USB interface.

This namespace is used to describe storage devices and their capabilities. Such device objects will have the capability storage and they will export the properties below. Note that device objects can only have the storage capability if they already got capability block and the property block.

One significant between the storage and block namespace is that the properties exported in the storage represents constant vital product information, whereas the properties in the block namespace represent variable system-dependent information. This namespace is used to describe optical storage drives and their capabilities. Such device objects will have the capability storage. Note that device objects can only have the storage.

By and large, all the same properties under the storage name space applies except that storage. In addition, the following properties are available. This namespace is found on the toplevel "Computer" device, and represents information about the system and the currently running kernel.

Device objects with the capability tape represent tape devices. Device objects with the capability video4linux represent Video4Linux devices. The video4linux device has audio inputs or outputs. The video4linux device has some sort of tuner or modulator to receive or emit RF-modulated video signals. This namespace is for device objects that represent storage devices with a filesystem that can be mounted. Such device objects will have the capability volume and they will export the properties below.

Note that device objects can only have the volume capability if they already have the capability block and the property block. This namespace is for device objects that represent optical discs, e. Such device objects will also have the capability volume.

The section represents properties that are deprecated and should be no longer used. Introspectable interface. For example, a command like. For brevity, the org. Hal prefix have been stripped from the exceptions listed in the following sections. Also note that other exceptions than the ones listed may be thrown; for example the org. InterfaceLocked exception may be thrown regardless of how the interface is implemented depending on if some other process is holding a lock on the device cf.

Chapter 4, Locking ; if PolicyKit support is enabled, the org. PermissionDeniedByPolicy exception may be thrown the two first words in the exception detail is resp. Every hal device object e. It provides generic functionality. The following methods are available:. Determines whether a given process on the system message bus is authorized according to PolicyKit on a specific device for a specific PolicyKit privilege. Unprivileged callers e.

This can be used ahead of time to see if a given call will succeed or if it requires privilege elevation TODO: clarify this once PolicyKit can auth over D-Bus. Returns the textual representation of a PolKitResult value on success. Error exception. This interface provides a mechanism for discovering when an ACL is added or removed for a device file. The following signals are available:. This interface provides a mechanism to configure CPU frequency scaling. This interface provides a mechanism for both querying whether a radio is on as well as turning it on and off.

This interface provides a mechanism to get information from a light sensor. This interface provides a mechanism to interact with a storage device. This interface provides a mechanism to interact with a storage device that uses removable media. This interface provides a mechanism to affect system-wide power management. Implementors of power management daemons should make sure that their software respects the locking guidelines described in Chapter 6, D-Bus interfaces.

This interface provides a mechanism to interact with a volume that has a mountable file system. If a volume originates from a storage device and all volumes do , it also is checked whether the caller is locked out of the org. Storage interface of the originating storage device. As a corollary, it is sufficient to just either a lock the storage device; or b globally lock the org. Storage interface if one wants to lock out callers from mounting volumes from either a specific drive or all drives.

This interface provides a mechanism to interact with a volume that is encrypted at the block layer. Storage interface for the storage device that the volume originates from. It's primarily used to discover devices. This interface is provided by singleton addons to allow the Manager to request handling of new devices and removal of old ones. This differs from other HAL interface definitions in that it is provided by addon processes, rather than the HAL daemon itself.

Called by the HAL Manager when a device is added that has this singleton listed in info. An addon implementing this function should start handling the device before returning, and keep track that is is handling this udi.

The implementer of this function should keep track of which devices it is still handling and exit when no longer handling any devices. HAL 0. Table of Contents 1. Locking Overview Guidelines 5. Device Properties org. D-Bus interfaces org. Device interface org. AccessControl interface org. CPUFreq interface org. DockStation interface org.

KeyboardBacklight interface org. KillSwitch interface org. Leds interface org. LaptopPanel interface org. LightSensor interface org. Storage interface org. Removable interface org. SystemPowerManagement interface org. Volume interface org. Crypto interface org. WakeOnLan interface org. Manager interface org. Chapter 1.

Architecture of HAL. HAL daemon A system-wide service that maintains a database of device objects. Callouts Callouts are programs that run when device objects are added and removed in the HAL daemon.

Addons An addon can be characterized as a daemon whose life cycle is tied to a device object in HAL. Device Information Files A set of files that matches properties on device objects and merges additional information.

Device Objects. Device Capabilities. Chapter 2. Device Information Files. Search Paths. HAL now runs the preprobe callouts. Chapter 3. Access Control. Device Files.

Device Files policies. D-Bus Interfaces. Chapter 4. Table of Contents Overview Guidelines. Power Management Typically, a desktop session includes a session-wide power management daemon that enforces the policy of the users choice, e.

Chapter 5. Device Properties. Table of Contents org. Hal namespace. Key type Values Mandatory Description org. General Properties. Key type Values Mandatory Description info. The lock is only advisory. A localized text suitable for UI display info.

The base D-BUS service of the process holding the lock. Yes, if info. Key type Values Mandatory Description linux. This can differ from info. Normaly only for HAL internal use. The device isn't removed before the last callout has finished. Can only be set on the root computer device object. Singleton Addons. Method calls. Device interface. Each entry is a white-space separated list for that particular method.

The signature should only cover incoming arguments; each method is defined as returning an integer. The return code of the program will be passed as the integer result to the D-Bus caller. If a program wants to return an error, it just needs to write two lines to stderr; the first line is the exception name to throw and the second line is the exception detail. Subsystem-Specific Properties. Key type Values Mandatory Description block.

In this case the volume capability will be set and thus, properties, in the volume namespace are available. For the child, that is when block. Key type Values Mandatory Description ccw. Key type Values Mandatory Description ccwgroup. Not valid in layer2 mode and for ethernet devices. Not valid in layer2 mode. Key type Values Mandatory Description drm.

Key type Values Mandatory Description ibmebus. Key type Values Mandatory Description ide. Key type Values Mandatory Description ieee Key type Values Mandatory Description iucv. Key type Values Mandatory Description leds.

Key type Values Mandatory Description modem. Implies V. Key type Values Mandatory Description mmc. Key type Values Mandatory Description pci. Key type Values Mandatory Description platform. Key type Values Mandatory Description pnp.

Only available if: HAL was compiled with support for pnp. Contains the prefered irq of the device. Key type Values Mandatory Description scsi. Key type Values Mandatory Description sdio.

Key type Values Mandatory Description serial. For USB serial devices it's the port number of the serial device itself. For other serial devices, where is no device port info available, it's based on the number in serial.

Key type Values Mandatory Description ssb. Note that the serial number is broken on some USB devices. Key type Values Mandatory Description usb. Key type Values Mandatory Description vio. Key type Values Mandatory Description virtio.

Key type Values Mandatory Description vmbus. Key type Values Mandatory Description xen. Functional Properties. Key type Values Mandatory Description alsa. Key type Values Mandatory Description battery. This property is defined for the development simplicity - battery indicators can use it to find the proper iconic representation. Most of the time this is an external device.

In many cases, this property is omitted - which indicates that the charge properties are measured in some unknown units. The units should never be mAh as this is not a measurement of charge. Measured in "battery. This is an estimate and may be imprecise. This key is not present for invalid data. This is useful if an application does not want to process the raw values and do all the extra checks on the result.

Introduced mostly for the daemons' coding simplicity. This key is needed as the hardware often does not specify the description text for a battery, and so we have to calculate it from the output of battery.

Key type Values Mandatory Description biometric. These drivers can export information in biometric. Can also be used by libraries or programs providing extra device information to indicate the presence of this information in the appropriate sub-namespace. Key type Values Mandatory Description button. Key type Values Mandatory Description camera. Application Developers should descent down the device object tree to find the device object of capability storage in order to access the device.

Key type Values Mandatory Description input. The keycode name is not case sensitive. You can append as many input. Key type Values Mandatory Description killswitch.

If this key is set true, then any power manager software should not attempt to set any new values on brightness keypress, as it may cause the panel to flash uncontrollably. No This method adjusts the brightness on an laptop screen. The values are returned as hardware values rather than percentages as we cannot easily to floating point rounding in shell code and therefore use the raw values to prevent integer rounding errors.

No This method gets the hardware brightness of the laptop screen, which we may need to do fairly regually on hardware that changes the values in hardware without a software event.

Key type Values Mandatory Description net. Is hardware dependant net. True if the ethernet adaptor is connected to a another transceiver. NOTE: property not implemented yet. Displayable Name for network connection net. Universal Unique Identifier for network connection. Key type Values Mandatory Description obex. Standardized OBEX file transfer is supported and possibly proprietary extensions. Key type Values Mandatory Description oss. Key type Values Mandatory Description pda.

USB or a serial device. HP iPAQ hotsync interface e. This may not mean the machine is able to suspend successfully. This may not mean the machine is able to hibernate successfully. Arbitrary values for newer or obscure protocols are allowed but entities providing this information should try to ensure that they are not duplicating protocols under a different name. If the driver is providing information only, this should be set to information.

If empty, it means that the device is not capable of recording. If the device does not have a limit, do not set this property. Paths are relative to the mount point of the device. If there is one or more entry in this property, the first one is where files will be written to by applications.

Do not enter a folder and a parent of that folder. If the device places files in its root directory, then do not set this property. Leave blank if none. Leave blank if playlist files are not supported. Thank you very much. Try closing all X sessions and, from the console force dbus to re-update by running: pacman -Sf dbus I had this problem on all my machines running arch - we should both check the package news more often! Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

I will try to recompile hal maybe linking with the new dbus shared library fixes it. Maybe this changed some pemissions? I've found e.

I got e. Pages: 1.