Table of Contents
This document concerns the specification of HAL 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 provide hooks such that system- and desktop-level software can react to changes in the hardware configuration in order to maintain system policy.
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 paris referred to as device properties. Some properties are derived from the actual hardware, some are merged from device information files and some are related to the actual device configuration. This document specifies the set of device properties and gives them well-defined meaning. This enable system and desktop level components to distinguish between the different device objects and discover and configure devices based on these properties.
HAL provides an easy-to-use API through D-Bus which is an IPC framework that, among other things, 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.
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. HAL has no other major dependencies apart from D-Bus which, given sufficient infrastructure, allows it to be implemented on many UNIX-like systems. The major focus, initially, is systems running the Linux 2.6 series kernels.
Havoc Pennington's article ''Making Hardware Just Work'' motivated this work. The specification and software would not exist without all the useful ideas, suggestions, comments and patches from the Free Desktop and HAL mailing lists.
All trademarks mentioned belong to their respective owners.
The HAL consists of a number of components as outlined in the diagram below. Note that this diagram is high-level and doesn't capture all implementation details.
Details on each component
HAL daemon
A system-wide service that maintains a database of device objects. The daemon is responsible for merging information from device information files and managing the life cycle of device objects. The service is implemented as a daemon and uses helpers to query devices for specific information.
Applications
These are applications consuming services from HAL; this includes desktop-wide session daemons for maintaining policy such as power and disk/volume management.
Callouts
Callouts are programs that run when device objects are
added and removed in the HAL daemon. This is useful for
3rd party software to merge additional information onto
the device object before it is announced on
D-Bus. Callouts are specified on a per-device basis with
the info.callouts.add
and
info.callouts.remove
. See
the section called “
info namespace
” for details.
Methods
It is possible to specify that a given HAL device object
implements a specific D-Bus interface,
e.g. org.freedesktop.Hal.Device.Frob
with a set of
methods Foo
, Bar
and Baz
and have programs run when
applications call into this interface. This is defined in
the info.interfaces
property, consult
the section called “
info namespace
” for details.
Addons
An addon can be characterized as a
daemon whose life cycle is tied to a device object in
HAL. And addon can also claim a
specific interface on the device object to provide
services to applications for configuring / using the
device without having to spawn a new program for every
method call. HAL provides a facility to launch/destroy one
or more addons per device object using
the info.addons
property. See
the section called “
info namespace
” for details.
Device Information Files
A set of files that matches properties on device objects and merges additional information. These files are used, for among other things, to specify what callouts, methods and addons to associate with a device object. For example, for drives using removable media, HAL includes an add-on daemon which sole purpose is to continously poll the drive to detect media change.
The D-Bus system message bus is used to provide a ''network API'' to applications. As D-Bus is designed to be language independent, potentially many languages / runtime systems will be able to easily access the services offered by HAL.
It is important to precisely define the term HAL device object. It's actually a bit blurry to define in general, it includes what most UNIX-like systems consider first class objects when it comes to hardware. In particular, a device object should represent the smallest unit of addressable hardware. This means there can be a one-to-many relationship between a physical device and the device objects exported by HAL. Specifically, a multi-function printer, which appear to users as a single device may show up as several device objects; e.g. one HAL device object for each of the printing, scanning, fax and storage interfaces. Conversely, some devices may be implemented such that the HAL device object represent several functional interfaces. HAL is not concerned with this duality of either one-to-many or many-to-one relationships between device objects and the actual iron constituting what users normally understand as a single piece of hardware; a device object represents the smallest addressable unit.
Device objects in HAL are organised on a by-connection basis, e.g. for a given device object X it is possible to find the device object Y where X is attached to Y. This gives structure to the device database of HAL; it is possible to map the devices out in a tree. Further, software emulation devices exported by the operating system kernel, such as SCSI emulation for USB Storage Devices, are also considered device objects in HAL. This implies that operating system kernel specific bits leak into the device object database. However applications using HAL will not notice this, such device objects are not referenced anywhere in the device objects that users are interested in; they are merely used as glue to build the device tree.
In addition to provide information about what kind of hardware a
device object represents (such as a PCI or USB device) and how
to address it, HAL merges information about the functional
interfaces the operating system kernel provides in order to use
the device; in most cases this is represented on the device
object as a string property with the name of the special device
file in
/dev
. In addition to the special device file,
a number of other useful properties are merged. This means that
both hardware and functional properties are on the same device
object, which may prove to be useful for an application
programmer. For example, an application might query HAL for the
device object that exports the special device file
/dev/input/mouse2
and learn that this is
provide by an USB mouse from a certain manufacturer by
checking the properties that export the USB vendor and product
identifiers. See the section called “Device Capabilities”
and
Chapter 5, Device Properties
for details.
Finally, HAL provides one or more D-Bus interfaces for applications to configure and/or use the device. These interfaces are discussed in Chapter 6, D-Bus interfaces.
Summarizing, a device object is comprised by
UDI
This is the the Unique Device Identifer, that is unique for a device object - that is, no other device object can have the same UDI at the same time. The UDI is computed using bus-specific information and is meant to be unique across device insertions and independent of the physical port or slot the device may be plugged into.
Properties
Each device object got a set of properties which are key/value pairs. The key is an ASCII string while the value can be one of several types, see below. Properties are arranged into name spaces using ''.'' as a separator.
string
- UTF8 string
strlist
- ordered list with UTF8 strings
int
- 32-bit signed integer
uint64
- 64-bit unsigned integer
bool
- truth value
double
- IEEE754 double precision
floating point number
Interfaces
Applications can configure and/or use a device using D-Bus interfaces. Typically, there's a one-to-one relationship between capabilities/namespaces and interfaces.
Properties of a device object carry all the important information about a device object. For organisational reasons properties are also namespaced using ''.'' as a separator.
It can be useful to classify properties into four groups
Metadata - Information about how the devices are connected with respect to each other (parent/child relationships), what kind of device it is, what functionality it provides etc.
Facts - vendor ID, product ID, disk serial numbers, number of buttons on a mouse, formats accepted by a mp3 player and so on.
Usage specific information - Network link status, special device file name, filesystem mount location etc.
Policy - How the device is to be used be users; usually defined by the system administrator.
The first category is determined by HAL, the second category includes information merged from either querying the hardware itself or from device information files. The third category is intercepted by monitoring the hardware and finally the last is merged from files under control of the system administrator. This document is concerned with precisely defining several properties; see Chapter 5, Device Properties and onwards for more information. As a complement to device properties, HAL also provides conditions on HAL device objects. Conditions are used to relay events that are happening on devices which are not easily expressed in properties. This includes events such as ''processor is overheating'' or ''block device unmounted''.
There is a special hal device object referred to as the ''root
computer device object''. This device object represent the
entire system as a whole and all other devices are either
directly or indirectly childs of this device object. It has
the
UDI /org/freedesktop/Hal/devices/computer
.
The fundamental idea about HAL is that all ''interesting'' information about hardware that a desktop application needs, can be obtained by querying HAL.
Mainstream hardware isn't very good at reporting what it really is, it only reports, at best, how to interact with it. This is a problem; many devices, such as MP3 players or digital still cameras, appear to the operating system as plain USB Mass Storage devices when the device in fact is a lot more than just that. The core of the problem is that without external metadata, the operating system and desktop environment will present it to the user as just e.g. a mass storage device.
As HAL is concerned with merging of external metadata, through
e.g. device information files, there needs to be some scheme on
how to record what the device actually is. This is achieved by
two textual properties, info.category
and
info.capabilities
. The former describes
what the device is (as a single
alphanumeric keyword) and the latter describes
what the device does (as a number of
alphanumeric keywords separated by whitespace). The keywords
available for use is defined in this document; we'll refer to
them in following simply as capabilities.
HAL itself, assigns capabilities on device detection time by inspecting the device class (if available, it depends on the bus type) and looking at information from the operating system and the hardware itself.
User mode drivers such as libgphoto2
and sane
provides device information to
merge information about devices they can drive. As such,
device objects represent an USB interface gain additional
properties such as ''scanner'' or ''camera''.
Having a capability also means that part of the property namespace, prefixed with the capability name, will be populated with more specific information about the capability. Indeed, some properties may even be required such that applications and device libraries have something to expect. For instance, the capability for being a MP3 player may require properties defining what audio formats the device support (e.g. Ogg and MP3), whether it support recording of audio, and how to interact with the device. For example, the latter may specify ''USB Storage Device'' or ''proprietary protocol, use libfooplayer''.
Finally, capabilities have an inheritance scheme, e.g. if a device
has a capability foo.bar
, it must also have
the capability foo
.
Table of Contents
Device information files (.fdi
files is a
shorthand) are used to merge arbitrary properties onto device
objects. The way device information files works is that once all
device properties are merged onto a device object it is tried
against the set of installed device information files. Device
information files are used for both merging facts and policy
settings about devices.
Each device information file got a number of
<match key="some_property"
[string|int|bool|..]="required_value" >
directives
that is tested against the properties of the device object. If
all the match directives passes then the device information can
include <[merge|append|prepend|addset] key="some_property"
type="[string|int|bool|..]">
directives to
respectively merge new properties or append to existing
properties on the device object. It's important to emphasize
that any previously property stemming from device detection can
be overridden by a device information file.
The <match>
,
<merge>
, <append>
,
<prepend>
and <addset>
directives always
requires the key
attribute which must be
either a property name on the device object in question or a
path to a property on another device object. The latter case is
expressed either through direct specification of the UDI, such
as
/org/freedesktop/Hal/devices/computer:foo.bar
or indirect references such as
@info.parent:baz
where the latter means that
the device object specified by the UDI in the string property
info.parent
should be used to query the
property baz
. It is also possible to use
multiple indirections, e.g. for a volume on a USB memory stick
the indirection @block.storage_device:@storage.originating_device:usb.vendor_id
will reference the usb.vendor_id
property
on the device object representing the USB interface.
When the property to match have been determined a number of
attributes can be used within the <match>
tag:
string
- match a string property; for example
<match key="foo.bar" string="baz">
will match only if 'foo.bar' is a string property assuming the value 'baz'.
string_outof
- work like string
but
the match is done against a list of strings separated by ';'.
For example:
<match key="system.hardware.product" string_outof="Satellite A30;Portable PC">
In this example the line matches if system.hardware.product
is exactly 'Satellite A30' or 'Portable PC'.
int
- match an integer property
int_outof
- work like int
but
the match is done against a list of integer separated by ';'.
For example:
<match key="usb.product_id" int_outof="0x1007;0x1008;0x1009">
In this example the line matches if usb.product_id
is 0x1007, 0x1008 or 0x1009.
uint64
- match property with the 64-bit unsigned type
bool
- match a boolean property
double
- match a property of type double
exists
- used as
<match key="foo.bar" exists="true">
. Can be used with
'true' and 'false' respectively to match when a property exists and it doesn't.
empty
- can only be used on string or strlist properties
with 'true' and 'false'.
The semantics for 'true' is to match only when the string is non-empty.
is_ascii
- matches only when a string property
contain only ASCII characters. Can be used with 'true' or 'false'.
is_absolute_path
- matches only when a string
property represents an absolute path (the path doesn't have to exist).
Can be used with 'true' or 'false'.
sibling_contains
- can only be used with string and
strlist (string list).
For a string key this matches when a sibling item contains the
(sub-)string in the same property. For a string list, this is if a string
matches an item in the list.
contains
- can only be used with string and
strlist (string list).
For a string key this matches when the property contains the given
(sub-)string. For a string list this match if the given string match
a item of the list.
contains_ncase
- like contains
but the property and the given key are converted to lowercase before check.
contains_not
- can only be used with strlist (string list)
and string properties.
For a string list this match if the given string not match any of the
item of the list (or the property is not set for the device). For a string
this match of the property not contains the (sub-)string. You can use this
attribute to construct if/else blocks together with e.g. contains
.
contains_outof
- like contains
but can be
used only with strings and the match is done against a list of (sub-)strings
separated by ';'.
For example:
<match key="system.hardware.product" contains_outof="D600;D610;C540">
In this example the line matches if system.hardware.product
contains D600, D610 or C540.
prefix
- can only be used with string properties.
Matches if property begins with the key.
prefix_ncase
- like prefix
but the
property and the given key are converted to lowercase before the check.
prefix_outof
- like prefix
but the
match is done against a list of prefixes separated by ';'.
For example:
<match key="system.hardware.product" prefix_outof="1860;2366;2371">
In this example the line matches if system.hardware.product
starts with 1860, 2366 or 2371.
suffix
- can only be used with string properties.
Matches if property ends with the key.
suffix_ncase
- like suffix
but the
property and the given key are converted to lowercase before the check.
compare_lt
- can be used on int, uint64, double
and string properties to compare with a constant.
Matches when the given property is less than the given constant
using the default ordering.
compare_le
- like compare_lt
but matches when less than or equal.
compare_gt
- like compare_lt
but matches when greater than.
compare_ge
- like compare_lt
but matches when greater than or equal.
compare_ne
- like compare_lt
but matches when not equal.
The <merge>
, <append>
,
<prepend>
and <addset>
directives all require
the type
attribute which specifies what to
merge. The following values are supported
string
- The value is copied to the property. For example
<merge key="foo.bar" type="string">baz</merge>
will merge the value 'baz' into the property 'foo.bar'.
strlist
- For <merge>
the value is
copied to the property and the current property will be overwritten. For
<append>
and <prepend>
the value is
append or prepend to the list as new
item. For <addset>
the strlist
is treated as a set and the value is appended if, and only
if, the value doesn't exist already. Usage of
<copy_property>
overwrite the complete list with the
value of the given property to copy from.
bool
- Can merge the values 'true' or 'false'
int
- Merges an integer
uint64
- Merges an unsigned 64-bit integer
double
- Merges a double precision floating point number
copy_property
- Copies the value of a given
property - supports paths with direct and indirect UDI's. For example
<merge key="foo.bar" type="copy_property">@info.parent:baz.bat</merge>
will merge the value of the property baz.bat
on the device object with the UDI from
the property info.parent
into the property foo.bar
on
the device object being processed.
The <remove>
, directive require only a key and can be used with all keys.
For strlist
there is additionally a special syntax to remove a item from the
string list. For example to remove item 'bla' from property 'foo.bar':
<remove key="foo.bar" type="strlist">bla</remove>
Device Information files are read from two directories
/usr/share/hal/fdi
- for files provided by packages
/etc/hal/fdi
- for files provided by the system administrator / user
in exactly that order. This means that the files provided by the
system administrator will be processed last such that they can
overwrite / change properties caused by the device information
files provided by packages.
The following directory structure is used in /usr/share/hal/fdi
information
- device information files used to merge device information
10freedesktop
- included with the hal package
20thirdparty
- from a 3rd party, not included in hal package
policy
- device information files to merge policy properties such as addons or callouts.
10osvendor
- included with the hal package
20thirdparty
- from a 3rd party, not included in hal package
preprobe
- device information files read before probing devices
10osvendor
- included with the hal package
20thirdparty
- from a 3rd party, not included in hal package
As evident, third party packages should drop device information files in
/usr/share/hal/fdi/information/20thirdparty
/usr/share/hal/fdi/policy/20thirdparty
/usr/share/hal/fdi/preprobe/20thirdparty
The /etc/hal/fdi
tree uses this layout
information
- device information files used to merge device information
policy
- device information files to merge policy properties such as addons or callouts.
preprobe
- device information files to read before probing devices
All device information files are matched for every hal device object in the following order.
When a device is discovered, the preprobe
device information files (e.g. all files
from /usr/share/hal/fdi/preprobe
and /etc/hal/fdi/preprobe
) are
processed.
Typically, this class of device information files is used to
tell HAL to leave the device alone by setting the bool
property info.ignore
to TRUE. It can also
be used to run programs, preprobe callouts, prior to normal
device investigation.
HAL now runs the preprobe callouts.
HAL now probes/investigates the device.
All the information
device information
files (e.g. all files
from /usr/share/hal/fdi/information
and /etc/hal/fdi/information
) are
processed.
These device information files are typically used to associate extra information with a device object.
All the policy
policy information
files (e.g. all files
from /usr/share/hal/fdi/policy
and /etc/hal/fdi/policy
) are
processed.
These device information files are typically used to associate callouts and addons with a device object.
HAL now runs the callouts, starts addons, and then finally announces the device on the system message bus.
Table of Contents
Access to hardware by unprivileged users is traditionally granted in two ways either by granting access to the special device file or allowing access through another process, using IPC acting on behalf of the user. HAL follows the latter model and uses the system-wide message bus (D-Bus) as the IPC mechanism. In addition, HAL has support for modifying the ACL's (access control lists) on a device file to grant/revoke access to users based on several criteria.
If HAL is built with --enable-acl-management
(requires both --enable-console-kit
and --enable-policy-kit
) then ACL's on device
objects with the capability access_control
are automatically managed according to the properties defined in
the section called “
access_control namespace
”. In addition,
for this configuration, HAL ships with a device information file
(normally installed in
/usr/share/hal/fdi/policy/10osvendor/20-acl-management.fdi
)
that merges this capability on device objects that are normally
accessed by unprivileged users through the device file. This
includes e.g. sound cards, webcams and other devices but
excludes drives and volumes as the latter two are normally
accessed by a user through mounting them into the file system.
HAL uses PolicyKit to decide what users should have access
according to PolicyKit configuration; see the PolicyKit
privilege definition
file /usr/share/PolicyKit/policy/org.freedesktop.hal.device-access.policy
on a system with HAL installed for the default access suggested
by the HAL package and/or OS vendor.
In addition, 3rd party packages can supply device information
files to specify (via
the access_control.grant_user
and access_control.grant_group
properties)
that a given user or group should always have access to a device
file. This is useful for system-wide software (such as AV
streaming management) that runs as an unprivileged system
user. This interface is supposed to be stable so 3rd party
packages can depend on it.
This is a list of the device file policies/rules delivered with
the HAL package to manage ACL's as defined via
access_control.type
and the current default Policykit
policies for inactive and active users.
Type | Description | allow_inactive | allow_active |
---|---|---|---|
audio-player
| Directly access audio players. | no | yes |
camera
| Directly access digital cameras. | no | yes |
cdrom
| Directly access optical drives. | yes | yes |
dvb
| Directly access DVB devices. | no | yes |
fingerprint-reader
| Directly access to fingerprint reader devices. | no | yes |
floppy
| Directly access Floppy devices. | yes | yes |
ieee1394-avc
| Directly access Firewire AVC devices. | no | yes |
ieee1394-iidc
| Directly access Firewire IIDC devices. | no | yes |
joystick
| Directly access Joystick devices. | yes | yes |
modem
| Directly access serial modem devices. | auth_admin_keep_always | auth_admin_keep_always |
mouse
| Directly access Mouse (input) devices | yes | yes |
obex
| Directly access OBEX devices. | no | yes |
pda
| Directly access PDA devices. | no | yes |
ppdev
| Directly access parallel port devices. | auth_admin_keep_always | auth_admin_keep_always |
printer
| Directly access printer devices. | no | yes |
removable-block
| Directly access removable block devices. | no | no |
scanner
| Directly access scanners. | no | yes |
sound
| Directly access sound devices. | no | yes |
video
| Directly access Video devices. | yes | yes |
video4linux
| Directly access video capture devices. | no | yes |
If HAL is built without ConsoleKit support
(e.g. without --enable-console-kit
) access to
the various D-Bus interfaces that provides mechanisms is only
protected by the D-Bus security configuration files
(e.g. using at_console
to restrict to console
user on Red Hat systems) and, in certain cases, restricted to
the super user.
If ConsoleKit support is enabled, access to D-Bus interfaces is
currently hardcoded to only allow active users at the system
console. If PolicyKit support is enabled, the PolicyKit library
will be in charge of determining access; see the PolicyKit
privilege definition files
in /etc/PolicyKit/privileges
on a system with
HAL installed for the default access suggested by the HAL
package and/or OS vendor.
Table of Contents
As HAL is a mechanism that enables programs in a desktop session to enforce the policy of the users choice, unexpected things can happen. For example, if the user is in the middle of partitioning a disk drive, it is desirable to keep the desktop from mounting partitions that have not yet been prepared with a suitable file system. In fact, in such a situation data loss may be the result if a volume have an old file system signature indicating it's mountable and, simultenously, another tool is writing to the raw block device. The mechanism that automounters use, HAL, provides locking primitives to avoid this.
Further, for multi-user systems, several desktop sessions may run on a system each on their own display. Suppose that one session becomes idle and the power management daemon in that session decides to suspend the system according to user preferences in the idle session. The result is that users at other seats will see the system suspend and this is not desirable. The power management daemons in all sessions need to cooperate to ensure that the system only suspends when e.g. all sessions are idle or not at all. The mechanism that each power management daemon uses, HAL, provides locking primitives that can be used to achieve this.
HAL provides a mechanism to lock a specific D-Bus interface either for a specific device or for all the devices the caller have access to.
The former is achieved by using
the AcquireInterfaceLock()
and ReleaseInterfaceLock()
methods on
the org.freedesktop.Hal.Device
interface that
every device object implements (see
the section called “org.freedesktop.Hal.Device interface”). By using this API, a caller
can prevent any other caller from invoking methods on the given
interface for the given device object - other callers will
simply see
the org.freedesktop.Hal.Device.InterfaceLocked
exception if they attempt to invoke a method on the given
interface on the given device. The locker can specify whether
the lock is exclusive meaning if multiple
clients clients can hold the lock or if only one client can hold
the lock at one time. If a client don't have access to the
interface of the device, attempts to lock will fail with
a org.freedesktop.Hal.PermissionDenied
exception. If a client loses access to a device (say, if his
session is switched away from using fast user switching) while
holding a lock, he will lose the lock; this can be tracked by
listening to the InterfaceLockReleased
signal.
All local clients, whether they are active or not, can always lock interfaces on the root computer device object (this doesn't mean that they are privileged to use the interfaces though) - the rationale is that this device object represents shared infrastructure, e.g. power management, and even inactive sessions needs to participate in managing this.
If another client already holds a lock exclusively, attempts
from other clients to acquire the lock will fail with
the org.freedesktop.Hal.Device.InterfaceAlreadyLocked
exception even if they have access to the device.
In addition, a client may opt to lock all devices that he got
access to by using
the AcquireGlobalInterfaceLock()
and ReleaseGlobalInterfaceLock()
methods on
the org.freedesktop.Hal.Manager
interface on
the /org/freedesktop/Hal/Manager
object (see
the section called “org.freedesktop.Hal.Manager interface”). Global interface locks can
also be obtained exclusively if the caller so desires. Unlike
per-device interface locking, it is not checked at locking time
whether the locker have access to a given device; instead
checking is done when callers attempt to access the
interface.
The algorithm used for determining if a caller is locked out is shown below. A caller A is locked out of an interface IFACE on a device object DEVICE if, and only if,
Another caller B is holding a lock on the interface IFACE on DEVICE and A don't have either a global lock on IFACE or a lock on IFACE on DEVICE; or
Another caller B is holding the global lock on the interface IFACE and B has access to DEVICE and and A don't have either a global lock on IFACE or a lock on IFACE on DEVICE.
In other words, a caller A can grab a global lock, but that doesn't mean A can lock other clients out of devices that A doesn't have access to. Specifically a caller is never locked out if he has locked an interface either globally or on the device in question. However, if two clients have a lock on a device, then both can access it. To ensure that everyone is locked out, a caller needs to use an exclusive lock.
Note that certain interfaces will also check whether other locks are being held on other device objects. This is specified on a per-interface basis in Chapter 6, D-Bus interfaces.
If a process holding locks disconnects from the system bus, the locks being held by that process will be released.
Locking is only useful if applications requiring exclusive access actually use the locking primitives to cooperate with other applications. Here is a list of guidelines.
Disk Management / Partitioning
In order to prevent HAL-based automounters from mounting
partitions that are being prepared, applications that access
block devices directly (and pokes the kernel to reload the
partitioning table) should lock out automounters by either
a) obtaining
the org.freedesktop.Hal.Device.Storage
lock on each drive being processed; or b) obtaintaing the
global
org.freedesktop.Hal.Device.Storage
lock. This includes programs like fdisk, gparted, parted and
operating system installers. See also
the section called “org.freedesktop.Hal.Device.Volume interface” and
the hal-lock
(1) program and manual page.
Power Management
Typically, a desktop session includes a session-wide power management daemon that enforces the policy of the users choice, e.g. whether the system should suspend to ram on lid close, whether to hibernate the system after the user being idle for 30 minutes and so on. In a multi-user setup (both fast user switching and multi-seat), this can break in various interesting ways unless the power management daemons cooperate. Also, there may be software running at the system level who will want to inhibit a desktop session power management daemon from suspending / shutting down.
System-level software that do not wish to be interrupted
by the effect of someone calling into the
org.freedesktop.Hal.Device.SystemPowerManagement
interface MUST hold the
org.freedesktop.Hal.Device.SystemPowerManagement
lock non-exclusively on the root computer device
object. For example, the YUM software updater should
hold the lock when doing an RPM transaction.
In addition, any power management session daemon instance
... MUST hold the org.freedesktop.Hal.Device.SystemPowerManagement
lock
non-exclusively on the root computer device object
unless it is prepared to call into this interface
itself. This typically means that the PM daemon instance
simply acquires the lock on start up and releases it
just before it calls into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface. In other words, the PM daemon instance needs
to hold the lock exactly when it doesn't want other PM
daemon instances to call into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface.
This means that if the user have configured the PM
daemon instance to go to sleep after 30 minutes of
inactivity, the lock should be released then.
... MUST not hold the lock when the session is inactive
(fast user switching) UNLESS an application in the
session have explicitly called Inhibit() on
the org.freedesktop.PowerManagement
D-Bus session bus interface of the PM daemon.
... MUST check that no other process is holding the lock (using the IsLockedByOthers
method on the standard org.freedesktop.Hal.Device
interface)
before calling into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface. If another process is holding the lock, it
means that either 1) another session is not prepared to
call into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface; OR 2) some system-level software is holding
the lock. The PM daemon instance MUST respect this by
not calling into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface itself.
However, any Power management daemon instance
... MAY prompt the user, if applicable, to ask if she
still wants to perform the requested action (e.g. call
into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface) despite the fact that another process
(possibly from another user) is indicating that it does
not want the system to e.g. suspend. Only if the user
agrees, the power management instance should call into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface. Typically, it's only useful to prompt the
user with such questions if the request to call into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface originates from user input, e.g. either a
hotkey, the user clicking a suspend button in the UI or
an application invoking the Suspend()
method on the
org.freedesktop.PowerManagement
D-Bus
session interface of the PM daemon.
... MAY ignore that other processes are holding the lock
and call into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface anyway, but ONLY if if the request to call
into
the org.freedesktop.Hal.Device.SystemPowerManagement
interface originated from e.g. lid close, critically low
battery or other similar conditions.
... MAY still call SetPowerSave()
on
the org.freedesktop.Hal.Device.SystemPowerManagement
interface even if other processes are holding the lock.
Table of Contents
Properties are arranged in a namespaces using ''.'' as a separator and are key/value pairs. The value may assume different types; currently int32, double, bool, UTF8 strings and UTF8 string lists are supported. The key of a property is always an ASCII string without any whitespace. When a property changes, HAL will emit a D-Bus signal that applications can catch.
The section represents properties that aren't tied to either physical or functional characteristics of what the device object represents.
The info
namespace contain properties that
can be considered metadata about device objects. These
properties are always available.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
info.subsystem (string)
| example: pci, usb, ide_host, ide, block, usbif, scsi_host, scsi | Yes | Describes what subsystem the device is connected to |
info.udi (string)
| example: /org/freedesktop/Hal/devices/pci_10ec_8139 | Yes | The HAL unique device id |
info.capabilities (strlist)
| example: 'block, storage, storage.cdrom' | No | A string list of capabilities describing what the devices does |
info.category (string)
| example: storage.cdrom | No | The prominent capability describing what the device is |
info.product (string)
| examples: ''SleekKeyboard'', ''MouseMan 2003'', ''Volume'', ''LS-120 SLIM3 00 UHD Floppy'' | No | The name of the device; should not be used in any UI; use subsystem / capability specific properties instead. |
info.vendor (string)
| examples: Logitch, Mustek | No | The name of the vendor of the device; should not be used in any UI; use subsystem / capability specific properties instead. |
info.parent (string)
| example: /org/freedesktop/Hal/devices/computer | Yes, for all non-root device objects | The UDI of the device object that this device object is connected to. |
info.locked (bool)
| No |
If this property is available and set
to TRUE it means that a process
is using the device that the hal device object in
question represents and no other process should attempt
to use or configure the device. The lock is only
advisory.
| |
info.locked.reason (string)
| example: ''The optical drive is currently being used to record a CD-RW disc.'' |
Only available if info.locked is set
to TRUE .
| A localized text suitable for UI display |
info.locked.dbus_service (string)
| example: :1.278 |
Only available if info.locked is set
to TRUE .
| The base D-BUS service of the process holding the lock. |
info.is_recalled (bool)
| No | This is set if the hardware may be recalled and should be checked for any potential problem. | |
info.recall.vendor (string)
| Dell, Sony, HP, Panasonic, etc. | Yes, if info.is_recalled is TRUE | The vendor responsible for the hardware recall. |
info.recall.website_url (string)
| Yes, if info.is_recalled is TRUE | Users should check this website for more details and if their hardware may affected by any possible fault. |
The linux
namespace contain properties that
can be considered metadata about device objects in Linux systems. These
properties are available only on Linux systems.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
linux.subsystem (string)
| pci, usb, ide_host, ide, block, usb, usbif, scsi_host, scsi | Yes | Describes what Linux subsystem the device is connected to. This can
differ from info.subsystem |
linux.sysfs_path (string)
| for example: /sys/class/sound/seq | No | Path to the devuce in the sysfs. Could also be *.linux.sysfs_path
depending on the subsystem in some cases.
|
linux.device_file (string)
| for example: /dev/snd/pcmC0D1c or /dev/input/event6 | No | Path to the corresponding device file in /dev/ on linux system. |
info.linux.driver (string)
| for example: pcspkr, vesafb, serial8250 | No | Name of the driver/module corresponding to the device and/or subsystem. |
linux.hotplug_type (int)
| Yes | The type of hotplug event in a linux system. | |
linux.acpi_type (int)
| No (except for ACPI devices) | The type of ACPI device. Normaly only for HAL internal use. | |
linux.apm_type (int)
| No (except for APM devices) | The type of APM device. Normaly only for HAL internal use. | |
linux.pmu_type (int)
| No (except for PMU devices) | The type of PMU device. Normaly only for HAL internal use. |
Callouts are programs invoked when the device object are added
and removed. As such, callouts can be used to maintain
system-wide policy (that may be specific to the particular OS)
such as changing permissions on device nodes, updating the
systemwide
/etc/fstab
file or configuring the networking
subsystem.
There are three different classes of callouts. A callout involves sequentially invoking all executable programs in the string list in listed order.
All callouts are searched for and execute in a minimal
environment. In addition, the UDI of the device object is
exported in the environment
variable UDI
. All properties of the device
object are exported in the environment prefixed
with HAL_PROP_
. If a device is added or
removed is exported in the environment
variable HALD_ACTION
. The search path for the callout includes the
following paths:
$libexecdir
(typically /usr/libexec
(e.g. Red Hat) or /usr/lib/hal
(e.g. Debian))
$libdir/hal/scripts
(typically /usr/lib/hal/scripts
or
/usr/lib64/hal/scripts
)
$bindir/
(typically /usr/bin
)
including $PATH the HAL daemon was started with during system
initialization. Depending on the distribution, this typically
includes /sbin
,
/usr/sbin
,
/bin
,
/usr/sbin
. If the program to run is not
found in any of these paths, the it will
not run even if the given path is absolute. To be
portable across operating systems, third party packages
providing callouts must therefore only
use $libdir/hal/scripts
.
If ConsoleKit support is enabled, the variables
CK_NUM_SEATS
(number of seats),
CK_NUM_SESSIONS
(number of sessions),
CK_SEATS
(tab sep. list of seat-id's),
CK_SEAT_seat-id
(tab sep. list of session-id's for a seat),
CK_SEAT_NUM_SESSIONS_seat-id
(number of sessions on a seat),
CK_SESSION_SEAT_session-id
(the seat that a session belongs to) and
CK_SESSION_IS_ACTIVE_session-id
(whether a given session is active) and
CK_SESSION_UID_session-id
(the user of the session) and
CK_SESSION_IS_LOCAL_session-id
(whether a session is local),
CK_SESSION_HOSTNAME_session-id
(host name of session's display if it's not local),
will be exported as well. Example:
CK_NUM_SEATS=1 CK_NUM_SESSIONS=2 CK_SEATS=Seat1 CK_SEAT_Seat1=Session1 Session3 CK_SEAT_NUM_SESSIONS_Seat1=2 CK_SESSION_IS_ACTIVE_Session1=true CK_SESSION_IS_ACTIVE_Session3=false CK_SESSION_IS_LOCAL_Session1=true CK_SESSION_IS_LOCAL_Session3=true CK_SESSION_SEAT_Session1=Seat1 CK_SESSION_SEAT_Session3=Seat1 CK_SESSION_UID_Session1=500 CK_SESSION_UID_Session3=501
Note that all ConsoleKit object paths given are just base
names; the real D-Bus object path can be reconstructed by
appending /org/freedesktop/ConsoleKit/
prepended to the given identifer.
The HAL daemon is not suspended while callouts are executing. Thus, callouts can communicate with the HAL daemon using the D-BUS network API. Hence, one application of callouts is to merge or modify properties on a device object.
To reduce round trips and increase privacy, callouts can (and
should) communicate with the HAL daemon using a peer to peer
D-Bus connection specified by
the HALD_DIRECT_ADDR
environment
variable. There is convience API in libhal to do this.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
info.callouts.add (string list)
| No |
A string list with the programs which should be
executed (with HALD_ACTION=add )
when the device is added to the GDL (global device
list) but just before it is announced through the
D-BUS network API.
| |
info.callouts.remove (string list)
| No |
A string list with the programs that should be
executed (with HALD_ACTION=remove )
when the device is removed from the GDL (global device
list). The device isn't removed before the last
callout has finished.
| |
info.callouts.preprobe (string list)
| No |
A string list with the programs that should be
executed
(with HALD_ACTION=preprobe ) before
the device is probed (e.g. investigated) and can be
used to avoid causing unnecessary I/O.
| |
info.callouts.session_add (string list)
| No |
A string list with all programs that should be
executed
(with HALD_ACTION=session_add ) when
a session is added. Can only be set on the root
computer device object. The environment also contains
the variables
HALD_SESSION_ADD_SESSION_ID ,
HALD_SESSION_ADD_SESSION_UID and
HALD_SESSION_ADD_SESSION_IS_ACTIVE
to identify the session. This is only used when HAL is
built with ConsoleKit support.
| |
info.callouts.session_remove (string list)
| No |
A string list with all programs which should be
executed
(with HALD_ACTION=session_remove )
when a session is removed. Can only be set on the root
computer device object. The environment also contains
the variables
HALD_SESSION_REMOVE_SESSION_ID ,
HALD_SESSION_REMOVE_SESSION_UID and
HALD_SESSION_REMOVE_SESSION_IS_ACTIVE
to identify the session. This is only used when HAL is
built with ConsoleKit support.
|
Addons are programs that run for the life time of the device
object. They are searched for and execute in the same
environment as callouts
(e.g. with HAL_PROP_*
set in the
environment to represent the device properties) and are
launched just before the device is announced on D-Bus (but
just after the last add callouts have finished). When the
device object goes away, HAL will send
a SIGTERM
to the process.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
info.addons (strlist)
| No |
List of programs to run when device is added. Each
program will need to call
the AddonIsReady() method in order
for the device to show up on D-Bus.
|
Singleton Addons are programs that are started by HAL to
handle a set of devices. They are identified by the command line
used to start them. They MUST implement the
org.freedesktop.Hal.SingletonAddon
interface. on the path
/org/freedesktop/Hal/Singleton
path on
the direct connection to the HAL daemon.
When a device is added with an info.addons.singleton
string list key, the elements of that key are used as the command line
to start the singleton if the singleton is not already running.
Once the singleton has called SingletonAddonIsReady
on
org.freedesktop.Hal.Manager
interface, it will receive
DeviceAdded
calls on its
org.freedesktop.Hal.SingletonAddon
interface for all devices that have
its commandline in info.addons.singletona
.
If a device is added and the singleton specified in
info.addons.singleton
is already running, the
singleton will recieve DeviceAdded
on its
org.freedesktop.Hal.SingletonAddon
interface for that new device.
When a device is removed that is being handled by a singleton, the
singleton will recieve DeviceRemoved
on
org.freedesktop.Hal.SingletonAddon
.
When it is no longer handling any more devices it should exit cleanly.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
info.addons.singleton (strlist)
| No | A list of commandlines for singleton addons which should service this device. |
Method calls on a specific interface on a device object can be
implemented by the HAL daemon running a program. Note that
this is not the only way to implement support for method
calls; if you expect a lot of method calls it is preferable to
implement an addon and use
the ClaimInterface()
API since it reduces
the overhead of spawning a process and it can handle both
complex incoming and return types as well. See the section called “org.freedesktop.Hal.Device interface” for
details on claiming interfaces via an addon..
Note that method calls implemented via running a program are limited to the return type being an a signed 32-bit integer (this will change in a future release). The incoming parameters are limited to only basic types and arrays of strings. The parameters are passed via stdin using a textual representation. As such, there is a lot of overhead with handling method calls by spawning programs and as such it should only be used for situtations where the nature of the method call is that it will not be frequently used.
As with addons, method calls are searched for and execute in
the same minimal environment as callouts
(e.g. with HAL_PROP_*
set in the
environment to represent the device properties) and in
addition the environment variables
HAL_METHOD_INVOKED_BY_UID
(the uid of the caller)
and
HAL_METHOD_INVOKED_BY_SYSTEMBUS_CONNECTION_NAME
(the unique system bus connection name of the caller) are
set. Additionally, if HAL is built with ConsoleKit support,
HAL_METHOD_INVOKED_BY_PID
and
HAL_METHOD_INVOKED_BY_SELINUX_CONTEXT
(but
only if the running system have SELinux enabled) will be
set. If HAL itself, or a HAL addon, is invoking a method, then
these variables will not be present. Here's an example
HAL_METHOD_INVOKED_BY_UID=500 HAL_METHOD_INVOKED_BY_PID=22553 HAL_METHOD_INVOKED_BY_SELINUX_CONTEXT=user_u:system_r:unconfined_t HAL_METHOD_INVOKED_BY_SYSTEMBUS_CONNECTION_NAME=:1.138
In addition, with ConsoleKit
support, HAL_METHOD_INVOKED_BY_SESSION
will
be set to (the basename) of the ConsoleKit session object path
but only if the caller is in a session. The method handler can
then use the previously
mentioned CK_SESSION_*
to learn everything
about the context of the caller.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
info.interfaces (strlist)
| No |
A list of D-Bus interfaces that the device object
supports apart from the
standard org.freedesktop.Hal.Device
interface.
| |
<iface>.method_names (strlist)
| example: 'Foo', 'Bar', 'Baz' | No | If a D-Bus interface is implemented by executing a program for every method, this property contains an ordered list of the method names. |
<iface>.method_argnames (strlist)
| example: 'foo_arg1 foo_arg2', '', 'baz_arg1' | No | This property contains the names of the arguments for each method. Each entry is a white-space separated list for that particular method. |
<iface>.method_signatures (strlist)
| example: 'si', '', 'as' | No | This property contains the D-Bus signature for each method. The signature should only cover incoming arguments; each method is defined as returning an integer. |
<iface>.method_execpaths (strlist)
| example: 'foo-binary', 'bar-binary', 'baz-binary' | No | This property contains the name of the program to execute when this method is called. 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. |
Items in the <iface>.*
clearly must
correspond with each other. The whole mechanism is best
explained by an example:
info.interfaces = {'org.freedesktop.Hal.Device.Volume'} org.freedesktop.Hal.Device.Volume.method_argnames = {'mount_point fstype extra_options', 'extra_options', 'extra_options'} org.freedesktop.Hal.Device.Volume.method_execpaths = {'hal-storage-mount', 'hal-storage-unmount', 'hal-storage-eject'} org.freedesktop.Hal.Device.Volume.method_names = {'Mount', 'Unmount', 'Eject'} org.freedesktop.Hal.Device.Volume.method_signatures = {'ssas', 'as', 'as'}
which, for example, shows that the Mount()
method on the
interface org.freedesktop.Hal.Device.Volume
takes three arguments: mount_point
(a
string), fstype
(a string)
and extra_options
(an array of strings).
In this section properties for device objects that represent
addressable hardware is described. Availability of
these depends on the value of the info.subsystem
property. These properties are not of particular interest to
application developers, instead they are useful for libraries
and userspace drivers that needs to interact with the device
given a UDI. Knowledge of various subsystem-specific
technologies is assumed for this section to be useful.
Device objects representing Asynchronous Connection-oriented Links.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
bluetooth_acl.address (uint64) | Yes | Address of the device at the other end of the connection. | |
bluetooth_acl.originating_device (string) | Yes | The UDI of the Bluetooth HCI (of
capability bluetooth_hci ) that the
connection is made through.
|
Device objects representing a Bluetooth Host Controller Interface.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
bluetooth_hci.address (uint64) | Yes | Address of the host controller interface. | |
bluetooth_hci.originating_device (string) | Yes | The UDI of the physical device (e.g. an USB interface) that provides the HCI hardware. |
Device objects representing Synchronous Connection-Oriented links.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
bluetooth_sco.address (uint64) | Yes | Address of the device at the other end of the connection. | |
bluetooth_sco.originating_device (string) | Yes | The UDI of the Bluetooth HCI (of
capability bluetooth_hci ) that the
connection is made through.
|
Device objects representing addressable block devices, such as
drives and partitions, will have info.subsystem
set to block
and will export a number of
properties in the block
namespace.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
block.device (string)
| example: /dev/sda | Yes | Special device file to interact with the block device |
block.major (int)
| example: 8 | Yes | Major number of special file to interact with the device |
block.minor (int)
| example: 1 | Yes | Minor number of special file to interact with the device |
block.is_volume (bool)
| Yes | True only when the block device is a volume that can
be mounted into the file system. In this case the
volume capability will be set and
thus, properties, in the volume
namespace are available.
| |
block.no_partitions (bool)
| Yes | For toplevel block devices, this is TRUE only
when no known partition tables have been found on the
media (In this case, if the storage device contain a
file system it will be accessible using the same
special device file as the one for this device object
and the device object representing the filesystem will
appear as a separate device object as a child). For
the child, that is
when block.is_volume is true, this
property is TRUE exactly when it was created for a
storage device with
the storage.no_partitions_hint set
to TRUE.
| |
block.have_scanned (bool)
| Yes | An internal property used by HAL to specify whether a top level block device have already been scanned for filesystems. |
Device objects that represent s390 ccw devices (when info.subsystem
is set to ccw
) are represented by the
properties below.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccw.devtype (string)
| example: 1732/01 | Yes | Device type/model or n/a |
ccw.cutype (string)
| example: 1731/01 | Yes | Control unit type/model |
ccw.cmb_enable (int)
| example: 1 | Yes | If channel measurements are enabled |
ccw.availability (string)
| example: good | Yes | Can be one of 'good', 'boxed', 'no path', or 'no device' |
ccw.online (int)
| example: 1 | Yes | Online status |
ccw.bus_id (string)
| example: 0.0.f588 | Yes | The device's bus id in sysfs |
ccw.subchannel.pim (int)
| example: 0x80 | No | path installed mask |
ccw.subchannel.pam (int)
| example: 0x80 | No | path available mask |
ccw.subchannel.pom (int)
| example: 0xff | No | path operational mask |
ccw.subchannel.chpid0..7 (int)
| example: 0x40 | No | channel path ids |
The following properties describe ccw
devices where
linux.driver
is either dasd-eckd
or dasd-fba
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccw.dasd.use_diag (int)
| example: 0 | Yes | If the device driver shall use diagnose calls to access the device |
ccw.dasd.readonly (int)
| example: 0 | Yes | If the device can only be accessed readonly |
ccw.dasd.discipline (string)
| example: ECKD | No | The dasd discipline used to access the device |
The following properties describe ccw
devices where
linux.driver
is zfcp
. They are
only present when ccw.online = 1
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccw.zfcp.in_recovery (int)
| example: 0 | Yes | Shows whether the adapter is currently in recovery |
ccw.zfcp.failed (int)
| example: 0 | Yes | Shows whether the adapter is in failed state |
The following properties describe ccw
devices where
linux.driver
is of the form tape_3xxx
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccw.tape.state (string)
| example: IN_USE | Yes | The current status of the tape |
ccw.tape.operation (string)
| example: REW | Yes | A three-letter mnemonic of the current tape operation |
ccw.tape.medium_state (string)
| example: no medium | No |
If ccw.online = 1 , shows whether a tape
is loaded
|
ccw.tape.blocksize (int)
| example: 512 | No |
If ccw.online = 1 , shows the blocksize
used for reads and writes to the tape
|
The following properties describe ccw
devices where
linux.driver
is 3270
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccw.3270.model (int)
| example: 3 | Yes | The model of the device, determining rows and columns |
ccw.3270.rows (int)
| example: 32 | Yes | The number of rows |
ccw.3270.columns (int)
| example: 80 | Yes | The number of columns |
Device objects that represent groups of ccw
devices
(when info.subsystem
is set to ccwgroup
have the properties specified below.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccwgroup.online (int)
| example: 1 | Yes | Online status |
ccwgroup.bus_id (string)
| example: 0.0.f588 | Yes | The device's bus id in sysfs |
The following properties describe ccwgroup
devices
where linux.driver
is qeth
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccwgroup.qeth.large_send (string)
| example: TSO | No | Whether large send is provided. Can be "no", "EDDP" (software) or "TSO" (hardware). |
ccwgroup.qeth.card_type (string)
| example: OSD_1000 | Yes | Type of the card |
ccwgroup.qeth.checksumming (string)
| example: sw checksumming | No | The method used to checksum incoming packets |
ccwgroup.qeth.canonical_macaddr (int)
| example: 0 | No | Specifies the token ring macaddress format. Not valid in layer2 mode and for ethernet devices. |
ccwgroup.qeth.broadcast_mode (string)
| example: broadcast_allrings | No | The scope of token ring broadcasts. Not valid in layer2 mode and for ethernet devices. |
ccwgroup.qeth.fake_broadcast (int)
| example: 0 | No | Whether to fake broadcast capability. Not valid in layer2 mode. |
ccwgroup.qeth.fake_ll (int)
| example: 0 | No | Whether to add a faked link level header to packets. Not valid in layer2 mode. |
ccwgroup.qeth.layer2 (int)
| example: 0 | No | Whether the card operates in layer 2 mode |
ccwgroup.qeth.portname (string)
| example: OSAPORT | No | The port name which has been specified for the card |
ccwgroup.qeth.portno (int)
| example: 0 | No | The relative port number on the card |
ccwgroup.qeth.buffer_count (int)
| example: 16 | Yes | Number of inbound buffers used |
ccwgroup.qeth.add_hhlen (int)
| example: 0 | No | How much additional space is provided in the hardware header in skbs in front of packets |
ccwgroup.qeth.priority_queueing
(string)
| example: always queue 2 | No | Which priority queueing algorithm is to be used |
ccwgroup.qeth.route4 (string)
| example: no | No | Whether the card has a routing functionality for ipv4. Not valid in layer2 mode. |
ccwgroup.qeth.route6 (string)
| example: no | No | Whether the card has a routing functionality for ipv6. Not valid in layer2 mode. |
ccwgroup.qeth.state (string)
| example: UP (LAN ONLINE) | Yes | The device's current state |
The following properties describe ccwgroup
devices
where linux.driver
is ctc
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccwgroup.ctc.protocol (int)
| example: 0 | Yes | The protocol/method used by the connection |
ccwgroup.ctc.type (string)
| example: CTC/A | Yes | The device/connection type |
ccwgroup.ctc.buffer (int)
| example: 32768 | No | The maximum buffer size of the connection |
The following properties describe ccwgroup
devices
where linux.driver
is lcs
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccwgroup.lcs.portnumber (int)
| example: 0 | Yes | The port on the card that is used |
ccwgroup.lcs.type (string)
| example: OSA LCS card | Yes | The type of the card |
ccwgroup.lcs.lancmd_timeout (int)
| example: 5 | Yes | The timeout value for LAN commands in seconds |
The following properties describe ccwgroup
devices
where linux.driver
is claw
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ccwgroup.claw.api_type (string)
| Yes | Determines the packing algorithm for outgoing pakets (matching the remote peer) | |
IP | Using the IP protocol | ||
PACKED | Using an enhanced packing algorithm | ||
TCPIP | Using the TCP/IP protocol | ||
ccwgroup.claw.adapter_name (string)
| example: RS1 | Yes | The host name of the remote communication peer. |
ccwgroup.claw.host_name (string)
| example: LNX1 | Yes | The host name of the local adapter. |
ccwgroup.claw.read_buffer (int)
| example: 4 | Yes | The number of read buffers allocated |
ccwgroup.claw.write_buffer (int)
| example: 5 | Yes | The number of write buffers allocated |
The drm
namespace is present for Direct Rendering Manager device objects.
They represent a Direct Rendering Interface.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
drm.dri_library (string) | Yes | Name of the dri (Direct Rendering Interface) library (e.g. i915). | |
drm.version (string) | Yes | The drm version (of the kernel module/diver). |
ATA and IDE drives are represented by device objects where
info.subsystem
equals ide
. The
following properties are available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ide.host (int)
| Yes | Corresponds
to ide_host.host_number of
the ide_host device that is the
parent of this device object
| |
ide.channel (int)
| Yes | Identifies the IDE channel of the host interface |
The ide_host
namespace is present for
device objects where info.subsystem
is set
to ide_host
. Such device objects represent
IDE and ATA host adaptors for harddisks and optical drives as
found in the majority of computer systems.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ide_host.number (int)
| Yes | A unique number identifying the IDE host adaptor | |
ide_host.linux.sysfs_path (string)
| example: /sys/devices/pci0000:00/0000:00:07.1/ide0 | Yes (only on Linux) |
Equals linux.sysfs_path
|
Device objects with info.subsystem
set to
ieee1394
represent IEEE 1394 devices. The
following properties are available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ieee1394.specifier_id (int)
| Yes | TODO |
Device objects with info.subsystem
set to
ieee1394_host
represent IEEE 1394 host
adaptors. The following properties are available for such
device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ieee1394_host.is_busmgr (bool)
| Yes | TODO | |
ieee1394_host.is_irn (bool)
| Yes | TODO | |
ieee1394_host.is_root (bool)
| Yes | TODO | |
ieee1394_host.node_count (int)
| Yes | TODO | |
ieee1394_host.nodes_active (int)
| Yes | TODO |
Device objects with info.subsystem
set to
ieee1394_node
represent IEEE 1394 nodes on
a IEEE 1394 bus. The following properties are available for
such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ieee1394_node.capabilities (int)
| Yes | TODO | |
ieee1394_node.guid (int)
| Yes | TODO | |
ieee1394_node.nodeid (int)
| Yes | TODO | |
ieee1394_node.vendor (int)
| Yes | TODO | |
ieee1394_node.vendor_id (int)
| Yes | TODO |
Device objects with info.subsystem
set to iucv
are using the "Intra-User Comminication Vehicle" and are
described by the following properties.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
iucv.bus_id (string)
| example: netiucv0 | Yes | The device's bus id in sysfs |
The following properties describe iucv
devices
where linux.driver
is netiucv
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
iucv.netiucv.user (string)
| example: linux12 | Yes | The guest name of the connection's target |
iucv.netiucv.buffer (int)
| example: 32768 | Yes | The maximum buffer size of the connection |
Device objects with info.subsystem
set to leds
are LED (light-emitting diode) devices.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
leds.device_name (string)
| example: iwl-phy0, tpacpi | Yes | The name of the related led device |
leds.colour (string)
| example: green, orange | No | The colour of the LED |
leds.function (string)
| example: radio, power, standby, batt | Yes | The function of the LED. |
Serial device objectes that are known to be modems should also gain the
modem
capability in their
info.capabilities
list. Modem device objects must
also be serial device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
modem.command_sets (string)
| example: GSM-07.07, GSM-07.05 | Yes | This property defines the command sets the modem device supports. |
IS-707-A | Yes | This modem supports the IS-707-A standard AT commands (commonly used by CDMA cellular devices). Implies V.250 support. | |
GSM-07.07 | Yes | This modem supports the GSM-07.07 standard AT commands (commonly used by GSM-based cellular devices). Implies V.250 support. | |
GSM-07.05 | Yes | This modem supports the GSM-07.05 standard AT commands (commonly used by GSM-based cellular devices). Implies V.250 support. | |
ITU-V.250 | Yes | This modem supports the ITU V.250 standard AT commands (also known as Hayes-compatible). |
Device objects with the capability memstick
represent
a Sony MemoryStick device. No namespace specific properties.
Device objects with info.subsystem
set to
memstick_host
represent Sony MemoryStick
host adaptors. The following properties are available for such
device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
memstick_host.host (int)
| Yes | A unique number identifying the Sony MemoryStick host adaptor |
Device objects with info.subsystem
set to
mmc
represent MultiMediaCard or Secure
Digital cards. The following properties are available for
such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
mmc.cid (string)
| example: 0150415330303842413a1a8083003a9d | Yes | Card Identification Data register (unique for every card in existence) |
mmc.csd (string)
| example: 005d013213598067b6d9cfff1640002d | Yes | Card Specific Data register |
mmc.scr (string)
| example: 00a5000000410000 | Only for SD cards | SD Card Register |
mmc.rca (int)
| example: 8083 | Yes | Card bus address |
mmc.oem (string)
| Yes | Card OEM distributor | |
mmc.date (string)
| example: 10/2003 | Yes | Manufacturing date |
mmc.serial (int)
| example: 0x3a1a8083 | Yes | Card serial number |
mmc.hwrev (int)
| example: 4 | Yes | Hardware revision |
mmc.fwrev (int)
| example: 1 | Yes | Firmware revision |
mmc.type (string)
| example: SDIO | No | Card type |
Device objects with info.subsystem
set to
mmc_host
represent MultiMediaCard or
Secure Digital host adaptors. The following properties
are available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
mmc_host.host (int)
| Yes | A unique number identifying the MMC/SD host adaptor | |
mmc_host.slot_name (string)
| example: internal, external | No | A unique string identifying the slot name |
This namespace contains properties for device objects representing
functions on devices on a PCI bus. These properties are available
exactly when info.subsystem
equals pci
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
pci.device_class (int)
| example: 3 | Yes | Device Class |
pci.device_subclass (int)
| example: 0 | Yes | PCI Device Sub Class |
pci.device_protocol (int)
| example: 0 | Yes | Device Protocol |
pci.product_id (int)
| example: 0x4c4d | Yes | Product ID |
pci.vendor_id (int)
| example: 0x1002 | Yes | Vendor ID |
pci.subsys_product_id (int)
| example: 0x009e | Yes | Subsystem product id |
pci.subsys_vendor_id (int)
| example: 0x1028 | Yes | Subsystem vendor id |
pci.linux.sysfs_path (string)
| example: /sys/devices/pci0000:00/0000:00:01/0000:01:00.0 | Yes (only on Linux) |
Equals linux.sysfs_path
|
pci.product (string)
| Rage Mobility P/M AGP 2x | No | Name of the product per the PCI database |
pci.vendor (string)
| ATI Technologies Inc | No | Name of the vendor per the PCI database |
pci.subsys_product (string)
| Inspiron 7500 | No | Name of the subsystem product per the PCI database |
pci.subsys_vendor (string)
| Dell Computer Corporation | No | Name of the subsystem vendor per the PCI database |
(FIXME: Some key PCI information (bus, slot, port, function etc.) is missing here)
Devices that are built into the platform or present on busses that
cannot be properly enumerated (e.g. ISA) are represented by device
objects where info.subsystem
equals
platform
. These kind of devices are commonly,
somewhat incorrectly, called legacy devices.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
platform.id (string)
| example: serial | Yes | Device identification |
Device objects that represent Plug and Play (PnP) devices (e.g. System Board or PS/2 Port for PS/2-style Mice). For these devices info.subsystem is set to 'pnp'.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
pnp.id (string)
| example: PNP0a03 or SMCf010 | Yes | This property contains the PnP ID of the device. |
pnp.description (string)
| example: 'ECP printer port' | No | Description from the pnp.ids file. Only available if: HAL was compiled with support for pnp.ids, if the file is available and if the ID was part of the file. |
pnp.serial.irq (int)
| example: 5 | No | Only available if the PnP device is a serial device (as e.g. serial Wacom Tablet devices). Contains the prefered irq of the device. |
pnp.serial.port (string)
| example: 0x200 | No | Only available if the PnP device is a serial device (as e.g. serial Wacom Tablet devices). contains info about the prefered serial port of the device. |
pnp.serial.baud_base (int)
| example: 38400 | No | Only available if the PnP device is a serial device (as e.g. serial Wacom Tablet devices). Contains info about the needed baud_base to setup the device correctly. |
Devices on the PlayStation 3 system bus are represented by device
objects where info.subsystem
equals
ps3_system_bus
. The following properties are
available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ps3_system_bus.id (string)
| example: serial | Yes | Device identification |
SCSI devices are represented by device objects where
info.subsystem
equals scsi
.
The following properties are available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
scsi.host (int)
| Yes |
Corresponds to scsi_host.host
of the scsi_host device that is the
parent of this device object
| |
scsi.bus (int)
| Yes | SCSI channel number | |
scsi.target (int)
| Yes | SCSI identifier number | |
scsi.lun (int)
| Yes | SCSI Logical Unit Number | |
scsi.type (string)
| Example: disk | Yes | SCSI device type |
cdrom | This is a SCSI cdrom device. | ||
comm | This is a SCSI communication device. | ||
disk | This is a SCSI disk device. | ||
medium_changer | This is a SCSI media changer (e.g. for CD/Tape). | ||
printer | This is a SCSI printer. | ||
processor | This is a SCSI processor device. | ||
raid | This is a SCSI raid device. | ||
scanner | This is a SCSI scanner. | ||
tape | This is a SCSI tape device. | ||
unknown | The type of this SCSI device is unknwon. |
The scsi_host
namespace is present for
device objects where info.subsystem
is set
to scsi_host
. Such device objects represent
SCSI host adaptors for SCSI devices as found in some computer
systems.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
scsi_host.host (int)
| Yes | A unique number identifying the SCSI host adaptor |
Device objects with info.subsystem
set to
sdio
represent MultiMediaCard or Secure
Digital cards with SDIO interface. The following properties
are available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
sdio.rca (int)
| example: 8083 | Yes | Card bus address |
sdio.card_id (int)
| example: 1 | Yes | SDIO Class for the interface |
sdio.class_id (int)
| example: 0x03 | Yes | SDIO Class for the interface |
sdio.product_id (int)
| example: 0x046a | Yes | Product ID |
sdio.vendor_id (int)
| example: 0x039d | Yes | Vendor ID |
sdio.product (string)
| SQN1130 WiMAX Network Card | No | Name of the product per the SDIO database |
sdio.vendor (string)
| Sequans Communications | No | Name of the vendor per the SDIO database |
Device objects that represent serial devices (e.g. /dev/ttyS* or /dev/ttyUSB*).
Key (type) | Values | Mandatory | Description |
---|---|---|---|
serial.originating_device (string)
|
example: /org/freedesktop/Hal/devices/pnp_PNP0501
| Yes | UDI of the device the serial device is bound to. |
serial.device (string)
| example: /dev/ttyS0 | Yes | The device node to access the OSS device. |
serial.port (int)
| example: 0 | Yes |
The port number of the device. 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.device .
|
serial.type (string)
| example: platform, usb, unknown | Yes | This property defines the type of the serial device. |
For device objects representing USB devices the property
info.subsystem
will be usb_device
,
and the following properties will be available. Note that the
corresponding USB interfaces are represented by separate
device objects as children.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
usb_device.bus_number (int)
| example: 1 | Yes | The USB bus the device is attached to |
usb_device.configuration_value (int)
| example: 1 | Yes | The current configuration the USB device is in; starting from 1 |
usb_device.configuration (int)
| example: Bulk transfer configuration | No | Human-readable description of the current configuration the USB device is in |
usb_device.num_configurations (int)
| example: 1 | Yes | Number of configurations this USB device can assume |
usb_device.device_class (int)
| example: 0 | Yes | USB Device Class |
usb_device.device_subclass (int)
| example: 0 | Yes | USB Device Sub Class |
usb_device.device_protocol (int)
| example: 0 | Yes | USB Device Protocol |
usb_device.is_self_powered (bool)
| example: false | Yes | The device, in the current configuration, is self powered |
usb_device.can_wake_up (bool)
| example: true | Yes | The device, in the current configuration, can wake up |
usb_device.max_power (int)
| example: 98 | Yes | Max power drain of device, in mA |
usb_device.num_interfaces (int)
| example: 1 | Yes | Number of USB Interfaces in the current configuration |
usb_device.num_ports (int)
| example: 0 | Yes | Number of ports on a hub. Zero for non-hubs |
usb_device.port_number (int)
| example: 1 | Yes | The port number on the parent hub that the device is attached to, starting from 1 |
usb_device.speed (double)
| examples: 1.5, 12.0, 480.0 | Yes | Speed of device, in Mbit/s |
usb_device.version (double)
| examples: 1.0, 1.1, 2.0 | Yes | USB version of device |
usb_device.level_number (int)
| example: 2 | Yes | Depth in USB tree, where the virtual root hub is at depth 0 |
usb_device.linux.device_number (string)
| example: 19 | Yes (only on Linux) | USB Device Number as assigned by the Linux kernel |
usb_device.linux.parent_number (string)
| example: 19 | Yes (only on Linux) | Device number of parent device as assigned by the Linux kernel |
usb_device.linux.sysfs_path (string)
| example: /sys/devices/pci0000:00/0000:00:07.2/usb1/1-1/1-1.1 | Yes (only on Linux) |
Equals linux.sysfs_path
|
usb_device.product_id (int)
| example: 0x3005 | Yes | USB Product ID |
usb_device.vendor_id (int)
| example: 0x04b3 | Yes | USB Vendor ID |
usb_device.device_revision_bcd (int)
| example: 0x0100 | Yes | Device Revision Number encoded in BCD with two decimals |
usb_device.serial (string)
| No | A string uniquely identifying the instance of the device; ie. it will be different for two devices of the same type. Note that the serial number is broken on some USB devices. | |
usb_device.product (string)
| example: IBM USB HUB KEYBOARD | No | Name of the product per the USB ID Database |
usb_device.vendor (string)
| example: IBM Corp. | No | Name of the vendor per the USB ID Database |
Device objects that represent USB interfaces, ie. when
info.subsystem
assumes usb
,
are represented by the properties below. In addition all
the usb_device.*
properties from the parent
USB device is available in this namespace but only with
the usb
prefix instead of
usb_device
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
usb.interface.class (int)
| example: 0x03 | Yes | USB Class for the interface |
usb.interface.subclass (int)
| example: 0x01 | Yes | USB Sub Class for this interface |
usb.interface.protocol (int)
| example: 0x01 | Yes | USB Protocol for the interface |
usb.interface.description (int)
| example: SyncML interface | No | Human-readable description for the interface provided by the device |
usb.interface.number (int)
| example: 1 | Yes | Number of this interface, starting from zero |
usb.linux.sysfs_path (string)
| example: /sys/devices/pci0000:00/0000:00:07.2/usb1/1-1/1-1.1/1-1.1:1.0 | Yes (only on Linux) |
Equals linux.sysfs_path
|
Devices on the IBM pSeries/iSeries 'vio' bus are represented
by device objects where info.subsystem
equals vio
. The following properties are
available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
vio.id (string)
| example: 1,10,3d | Yes | Device identification |
vio.type (string)
| example: viodasd, v-scsi, l-lan | Yes | Device type. |
Devices on the VirtIO bus are represented by device
objects where info.subsystem
equals
virtio
. The following properties are
available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
virtio.id (string)
| example: serial | Yes | Device identification |
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 2008, are represented by device objects where
info.subsystem
equals vmbus
.
The following properties are available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
vmbus.bus_id (string)
| example: vmbus_0_0, vmbus_0_1 | Yes | ID of the bus. |
vmbus.bus_number (int)
| Yes | The VMBus the device is attached to. | |
vmbus.device_id (string)
| example: {5558a04b-62a7-48f5-ae07f1d51ae62faa} | Yes | ID of the device. |
vmbus.device_number (int)
| Yes | The number of the device on a bus. | |
vmbus.class_id (string)
| example: {f8615163-df3e-46c5-913ff2d2f965ed0e} | Yes | Class identifier of the device. |
Device objects representing virtual devices under the Xen
Virtual Machine Monitor, such as frontend network or block
devices, will have info.subsystem
set to
block
and will export a number of
properties in then xen
namespace.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
xen.bus_id (string) | example: vif-0 | Yes | The XenBus ID of the device |
xen.path (string) | example: device/vif/0 | Yes | The XenBus path of the device |
xen.type (string) | example: vif | Yes | The type of Xen device |
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 ac_adapter
represent all the devices capable of powering the system from AC power
Key (type) | Values | Mandatory | Description |
---|---|---|---|
ac_adapter.present (bool)
| Yes | The state of the adapter, i.e. whether it is providing power to the unit from mains power. |
Device objects with the capability alsa
represent all the streams available through ALSA on a soundcard.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
alsa.card (int)
| Yes | Card number in system as registered by ALSA. | |
alsa.card_id (string)
|
Examples: I82801DBICH4 , MP3
| No | Textual description of the card. |
alsa.device (int)
| Yes | Device number assigned by ALSA for a current card. | |
alsa.device_file (string)
| Yes | The device node to access the ALSA device. | |
alsa.device_id (string)
|
Examples: Intel 82801DB-ICH4 MIC2 ADC
| No | Textual description of the specific device for a card |
alsa.pcm_class (string)
| No | The PCM class of the device. | |
generic | A standard PCM sound device (SND_PCM_CLASS_GENERIC). | ||
multi | A multichannel device PCM sound device (SND_PCM_CLASS_MULTI) which e.g. contains a generic and a modem device. | ||
digitizer | A PCM digitizer device (SND_PCM_CLASS_DIGITIZER). | ||
modem | A PCM modem device (SND_PCM_CLASS_MODEM). | ||
unknown | The value is 'unknown' if the kernel provide no information about the PCM device class of the device (e.g. the file pcm_class is missing). | ||
none | The value is 'none' if this there is no PCM class for this device. | ||
alsa.originating_device (string)
| Yes | UDI of the device the ALSA device is bound to. | |
alsa.type (string)
| Yes | The type of the stream. | |
control
| Stream is control device. | ||
capture
| Stream is capture device. | ||
midi
| Stream is MIDI device. | ||
playback
| Stream is playback device. | ||
unknown
| The type of the device is unknown. | ||
hw_specific
| This is a hardware specific device (as e.g. from snd_fm801 for Fortemedia FM801 PCI Audio). The driver can use it freely for purposes that are not covered by standard ALSA API. | ||
timer
| Stream is the global ALSA timer device. This means, the device is for all ALSA devices/cards. | ||
sequencer
| Stream is the global ALSA sequencer device. This means, the device is for all ALSA devices/cards. | ||
unknown
| Stream is unknown device. |
Device objects with the capability battery
represent all the devices having some battery (in many cases -
rechargeable) inside.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
battery.present (bool)
| Yes | This is present as some smart batteries can have acpi/pmu entries, and be physically missing. | |
battery.type (string)
| Yes | This property defines the type of the device holding the battery. This property is defined for the development simplicity - battery indicators can use it to find the proper iconic representation. | |
pda
| The device containing the battery is a personal digital assistant, e.g. a device that looks like a handheld computer to do specific tasks such as keeping notes or containing a personal database | ||
ups
| A battery powered power supply that is guaranteed to provide power to a computer in the event of interruptions in the incoming electrical power. Most of the time this is an external device. | ||
primary
| The battery is a primary power source for the system - an example are laptop batteries. | ||
mouse
| The device containing the battery is a mouse. | ||
keyboard
| The device containing the battery is a keyboard. | ||
keyboard_mouse
| The device containing the battery is a combined mouse and keyboard. | ||
camera
| The device containing the battery is a camera. | ||
usb
| The device containing the battery is a generic usb device. | ||
unknown
| The device containing the battery is not covered by other types. | ||
battery.charge_level.unit (string)
| Examples:
mWh ,
percent
| No | The physical unit used by the charge level properties (maximum and current). 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. |
battery.charge_level.design (int)
| Yes |
The maximum level of charge the device was designed for.
Measured in "battery.charge_level.unit"
units.
| |
battery.charge_level.last_full (int)
| Yes |
The maximum level of charge the device could hold the last
time it was full.
Measured in "battery.charge_level.unit"
units.
| |
battery.charge_level.current (int)
| Yes |
The current level of charge which the device can is holding.
Measured in "battery.charge_level.unit"
units.
| |
battery.charge_level.rate (int)
| No |
The discharge/charge rate measured
in "battery.charge_level.unit"
units per second.
| |
battery.charge_level.warning (int)
| No |
Once the charge level of the battery drops below this value its
state changes to 'warning'.
Measured in "battery.charge_level.unit"
units.
| |
battery.charge_level.low (int)
| No |
Once the charge level of the battery drops below this value its
state changes to 'low'.
Measured in "battery.charge_level.unit"
units.
| |
battery.charge_level.granularity_1 (int)
| No |
Granularity value one of the battery measured
in "battery.charge_level.unit"
units .
| |
battery.charge_level.granularity_2 (int)
| No |
Granularity value two of the battery measured
in "battery.charge_level.unit"
units.
| |
battery.reporting.unit (string)
| Examples:
mWh ,
mAh ,
percent
| No | The physical unit used by the charge level properties (maximum and current) as reported by the hardware. In many cases, this property is omitted - which indicates that the charge properties are measured in some unknown units. |
battery.reporting.design (int)
| Yes |
The maximum level of charge the device was designed for,
as reported by the hardware.
Measured in "battery.reporting.unit"
units.
| |
battery.reporting.last_full (int)
| No |
The maximum level of charge the device could hold the last
time it was full, as reported by the hardware.
Measured in "battery.reporting.unit"
units.
| |
battery.reporting.current (int)
| No |
The current level of charge which the device is holding,
as reported by the hardware.
Measured in "battery.reporting.unit"
units.
| |
battery.reporting.rate (int)
| No |
The discharge/charge rate as reported by the hardware measured
in "battery.reporting.unit"
units per second.
| |
battery.reporting.warning (int)
| No |
Once the hardware charge level of the battery drops below
this value its state changes to 'warning'.
Measured in "battery.reporting.unit"
units.
| |
battery.reporting.low (int)
| No |
Once the hardware charge level of the battery drops below
this value its state changes to 'low'.
Measured in "battery.reporting.unit"
units.
| |
battery.reporting.granularity_1 (int)
| No |
Hardware granularity value one of the battery measured
in "battery.reporting.unit"
units .
| |
battery.reporting.granularity_2 (int)
| No |
Hardware granularity value two of the battery measured
in "battery.reporting.unit"
units.
| |
battery.charge_level.capacity_state (string)
|
Examples: ok , critical
| No | The capacity state of the battery. |
battery.voltage.unit (string)
|
Examples: mV
| No | The physical measurement unit used by the voltage properties (design and current). |
battery.voltage.design (int)
| Yes |
The voltage level for which the battery is designed for.
Measured in "battery.voltage.unit"
units.
| |
battery.voltage.current (int)
| Yes |
The voltage level currently emitted by the battery.
Measured in "battery.voltage.unit"
units.
| |
battery.alarm.unit (string)
|
Examples: mWh , mAh
| No | The physical measurement unit used by the alarm property. |
battery.alarm.design (int)
| No |
Once the charge level of the battery drops below this value
its state changes to 'alarm'.
Measured in "battery.alarm.unit"
units.
| |
battery.remaining_time (int)
| No | Remaining time, in seconds, that the battery can provide power (if discharging) or the time until charged (if charging). This is an estimate and may be imprecise. This key is not present for invalid data. | |
battery.remaining_time.calculate_per_time (bool)
| No |
If this property is true the
battery.remaining_time becomes guessed from
battery.charge_level.current and time.
| |
battery.charge_level.percentage (int)
| No | Charge, normalised to percent. This is useful if an application does not want to process the raw values and do all the extra checks on the result. This key is not present for invalid data. | |
battery.is_rechargeable (bool)
| No | True if the battery unit is rechargeable, false if its is one-time (disposable after one usage). | |
battery.rechargeable.is_charging (bool)
|
Only if battery.is_rechargeable is TRUE
| TRUE if, and only if, the battery is charging. | |
battery.rechargeable.is_discharging (bool)
|
Only if battery.is_rechargeable is TRUE
| TRUE if, and only if, the battery is discharging. | |
battery.command_interface (string)
| No | The abstract name allowing daemons and/or user-level apps to distinguish some groups of devices having similar programming interface. Introduced mostly for the daemons' coding simplicity. | |
battery.vendor (string)
| No | Vendor of the battery. | |
battery.model (string)
| No | Make of the battery. | |
battery.reporting.technology (string)
| example: LION | No | The technology of the battery as reported by the hardware. |
battery.technology (string)
| lead-acid, lithium-ion, lithium-polymer, nickel-metal-hydride, unknown | No |
The technology of the battery processed to a few standard types.
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.reporting.technology .
|
battery.serial (string)
| No | A string uniquely identifying the instance of the battery; it will be different for two (otherwise) identical batteries. | |
battery.quirk.do_not_poll (bool)
| No | True if HAL should not poll the battery, False or not available at all if HAL should show the default behavior. |
Device objects with the capability biometric
represent
a biometric device (e.g. fingerprint reader) . No namespace specific
properties.
Device objects with the capabilities biometric.fingerprint_reader
and biometric
represent a biometric fingerprint reader.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
biometric.fingerprint_reader.access_method (strlist)
| example: libfprint | No |
Indicates installed device driver libraries that can handle this device.
These drivers can export information in
biometric.fingerprint_reader.[access_method] sub-namespaces.
Can also be used by libraries or programs providing extra device information
to indicate the presence of this information in the appropriate sub-namespace.
|
Device objects with the capability button
represent the devices capable of providing a state to the system.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
button.type (string)
| No | The type of button | |
lid | The switch on a laptop that senses whether the lid is open or closed | ||
power | The main power button on the computer. | ||
sleep | The sleep button on a computer capable of putting the computer into a suspend state | ||
button.has_state (bool)
| no | True if the button maintains state, e.g. can toggled on/off | |
button.state.value (bool)
|
Only when button.has_state is
TRUE
| State of the button, TRUE if it is enabled |
Device objects with this capability may emit the following events.
Condition Name | Parameters | Example | Description |
---|---|---|---|
ButtonPressed
|
button.type (string)
| sleep | Emitted when a button is pressed |
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:
Key (type) | Values | Mandatory | Description |
---|---|---|---|
camera.access_method (string)
| Yes | This property defines how the device is accessed | |
storage |
The device is accessed as a Mass Storage device
through a kernel driver. Application Developers
should descent down the device object tree to find the
device object of capability
storage in order to access the
device.
| ||
user | The device is accessed from userspace through a userspace driver. | ||
camera.libgphoto2.support (bool)
| No | If true, the device is supported by a userspace driver from the libgphoto2 project. |
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
Key (type) | Values | Mandatory | Description |
---|---|---|---|
input.device (string)
| Yes | Special device file for recieving input events | |
input.x11_driver (string)
| e.g. "evdev" | No | X11 input driver to use |
Device objects with the capability input.keymap
provide facilities to remap keyboard buttons.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
input.keymap.data (strlist)
| e.g. "e017:brightnessup" | No |
The scancode is represented in hex and the keycode name as
as string. The keycode name is not case sensitive.
On Linux, the keycode name should be the same constant as
present in /usr/include/linux/input.h with the 'KEY_'
prefix removed, e.g. 'KEY_SLEEP' -> 'sleep'.
You can append as many input.keymap.data
values as there are keys to remap.
|
The input device have keys that can be pressed. No namespace specific properties.
The input device is a switch, e.g. it has buttons with state. No namespace specific properties.
Device objects with the capability input.keys
can provide information about their physical layout.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
input.xkb.rules (string)
| e.g. "base" | Yes | XKB rules file to use; 'base' is standard, but 'xorg' or 'xfree86' may be needed for backwards compatibility with very old versions of XKB data. |
input.xkb.model (string)
| e.g. "logicdp" | Yes | Physical keyboard model (e.g. Logitech Cordless Freedom Pro), as given to XKB. |
input.xkb.layout (string)
| e.g. "us" | Yes | Keyboard layout (as engraved on the keys). |
input.xkb.variant (string)
| e.g. "nodeadkeys" | No | Variant of the XKB layout (if any) to use. |
input.xkb.options (strlist)
| e.g. "ctrl:nocaps" | No | Options to be provided to XKB. |
Device objects with the capability killswitch
represent switches to turn a radio on and off. See also the section called “org.freedesktop.Hal.Device.KillSwitch interface”.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
killswitch.type (string)
| Yes | Type of the kill switch | |
wlan | Kill switch is for turning Wireless LAN (WLAN) networking on/off | ||
bluetooth | Kill switch is for turning Bluetooth on/off | ||
wwan | Kill switch is for turning Wireless WAN (WWAN) networking on/off | ||
killswitch.state (int)
| No | Current state of the killswitch (as reported by the kernel) | |
0 | Radio output is blocked | ||
1 | Radio output is allowed/enabled | ||
2 | Radio output is (hard) blocked, non-overrideable via SetPower() | ||
killswitch.name (string)
| No | Name of the kill switch (as reported by the kernel). | |
killswitch.access_method (string)
| Yes | How HAL should program the switch |
Device objects with the capability laptop_panel
represent devices capable of changing the brightness of the display.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
laptop_panel.num_levels (int)
| Yes | The brightness levels supported by the adaptor. | |
laptop_panel.access_method (string)
| Yes | The access method to use in scripts, e.g. pmu, toshiba, ibm, sony. | |
laptop_panel.brightness_in_hardware (bool)
| No | On some laptops, the brightness control is all done in hardware but the hardware also synthesizes keypresses when the brightness is changed. 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. |
The following methods exist on the interface
org.freedesktop.Hal.Device.LaptopPanel
.
Method (parameter types) | Parameters | Mandatory | Description |
---|---|---|---|
SetBrightness (integer)
|
The hardware brightness state, which should be between 0 and
laptop_panel.num_levels - 1.
| 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. |
integer GetBrightness (void)
|
Returns the hardware brightness state, which should be
between 0 and laptop_panel.num_levels - 1.
| 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. |
Device objects with the capability sensor
represent light sensors in the system.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
light_sensor.sensor_locations (strlist)
| Yes | The locations of the sensors | |
light_sensor.num_sensors (int)
| Yes | Number of physical sensors | |
light_sensor.num_levels (int)
| Yes | The number of levels of the sensors |
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 802.3, IEEE 802.11 and Bluetooth have separate
namespaces.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
net.address (string)
| Yes | Hardware address as a string. Is hardware dependant | |
net.arp_proto_hw_id (string)
| Yes | ARP protocol hardware identifier | |
net.interface (string)
| Yes | Name of the interface; may change if an interface is renamed | |
net.interface_up (bool)
| No | Whether the interface is up | |
net.linux.ifindex (string)
| Yes (only on Linux) | Index of the interface | |
net.originating_device (string)
| Yes | UDI of the device the network device is bound to. | |
net.media (string)
| example: Ethernet | Yes | Textual description of the networking media |
Ethernet networking devices is described in this namespace
for device objects with the capability
net.80203
.
Note that device
objects can only have the net.80203
capability
if they already have the capability net
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
net.80203.link (bool)
|
Only if the net.80203 capability is set
and net.interface_up is
TRUE .
| True if the ethernet adaptor is connected to a another transceiver. NOTE: property not implemented yet. | |
net.80203.rate (uint64)
| example: 100000000 |
Only if the net.80203 capability is set
and net.80203.link is
TRUE .
| Bandwidth of connection, in bits/s. NOTE: property not implemented yet. |
net.80203.mac_address (uint64)
| example: 0x0010605d8ef4 |
Only if the net.80203 is set
| 48-bit address |
Wireless ethernet networking devices is described in this namespace
for device objects with the capability
net.80211
.
Note that device
objects can only have the net.80211
capability
if they already have the capability net
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
net.80211.mac_address (uint64)
| example: 0x0010605d8ef4 |
Only if the net.80211 capability is set
| 48-bit address |
Control devices for Wireless ethernet networking devices are described in
this namespace for device objects with the capability
net.80211control
.
Note that device objects can only have the net.80211control
capability if they already have 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.bluetooth
.
Note that device
objects can only have the net.bluetooth
capability
if they already have the capability net
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
net.bluetooth.mac_address (uint64)
| example: 0x0010605d8ef4 |
Only if the net.bluetooth capability is set
| 48-bit address |
net.bluetooth.name (string)
| example: Network Access Point Service |
Only if the net.bluetooth capability is set and Bluez is being used.
| Displayable Name for network connection |
net.bluetooth.uuid (string)
| example: 00001116-0000-1000-8000-00805f9b34fb |
Only if the net.bluetooth capability is set and Bluez is being used.
| Universal Unique Identifier for network connection |
Bridge ethernet networking devices is described in this namespace
for device objects with the capability
net.bridge
.
Note that device
objects can only have the net.bridge
capability
if they already have the capability net
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
net.bridge.mac_address (uint64)
| example: 0x0010605d8ef4 |
Only if the net.bridge capability is set
| 48-bit address |
IrDA (Infrared Data Association) Networking devices are described in
this namespace for device objects with the capability
net.irda
.
Note that device objects can only have the net.irda
capability if they already have the capability net
.
Loopback networking devices are described in this namespace
for device objects with the capability net.loopback
.
Note that device objects can only have the net.loopback
capability
if they already have the capability net
.
No namespace specific properties.
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. No namespace specific properties.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
obex.type (sting)
| example: pcsuite, syncml | No | |
pcsuite | No | Device is meant to be used with Nokia PC Suite application. Standardized OBEX file transfer is supported and possibly proprietary extensions. | |
syncml | No | Device supports SyncML over OBEX protocol. | |
syncml-sync | No | Device supports SyncML over OBEX protocol for data synchronization. | |
syncml-dm | No | Device supports SyncML over OBEX protocol for data management. |
Devices on the virtual 'of_platform' bus are represented
by device objects where info.subsystem
equals of_platform
. The following
properties are available for such device objects.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
of_platform.id (string)
| example: f0003000.ethernet | Yes | Device identification |
Device objects with the capability oss
represent all the streams available through OSS on a soundcard.
OSS devices could be emulated by ALSA.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
oss.card (int)
| Yes | Card number in system as registered by OSS (and/or ALSA). | |
oss.card_id (string)
|
Examples: I82801DBICH4 , MP3
| No | Textual description of the card. |
oss.device (int)
| Yes | Device number assigned by OSS/ALSA for a current card. | |
oss.device_file (string)
| Yes | The device node to access the OSS device. | |
oss.device_id (string)
|
Examples: Intel 82801DB-ICH4 MIC2 ADC
| No | Textual description of the specific device for a card |
oss.originating_device (string)
| Yes | UDI of the device the OSS device is bound to. | |
oss.type (string)
| Yes | The type of the stream. | |
mixer
| Stream is control/mixer device. | ||
pcm
| Stream is PCM device. | ||
midi
| Stream is MIDI device. | ||
sequencer
| Stream is a global OSS sequencer device. This means, the device is for all OSS devices/cards. | ||
unknown
| Stream is unknown device. |
Device objects with the capability pcmcia_socket
represent bridge devices (the actual bus of the device may differ)
that PCMCIA cards can be attached to. The following properties are
available.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
pcmcia_socket.number (int)
| Yes | PCMCIA socket number, starting from zero |
Device objects with the capability pda
represent Personal Digital Assistant (PDA) devices.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
pda.platform (string)
| e.g. palm or pocketpc | Yes | The type of the PDA platform |
pda.palm.hotsync_interface (string)
| Yes | Path to the Palm hotsync interface e.g. a linux device file (e.g. USB) or a serial device. | |
pda.pocketpc.hotsync_interface (string)
| Yes | Path to the Pocket PC (e.g. HP iPAQ) hotsync interface e.g. a linux device file (e.g. USB) or a serial device. |
Keys with the prefix power_management
provide information about power management supported by
the system.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
power_management.type (string)
| Examples:
apm ,
acpi ,
pmu
| Yes | The power management subsystem used on the computer. |
power_management.can_suspend (bool)
| Yes | If suspend support is compiled into the kernel. NB. This may not mean the machine is able to suspend successfully. | |
power_management.can_suspend_hybrid (bool)
| Yes | If the system is capable of hybrid suspend. | |
power_management.can_hibernate (bool)
| Yes | If hibernation support is compiled into the kernel. NB. This may not mean the machine is able to hibernate successfully. | |
power_management.is_powersave_set (bool)
| Yes | Is the last value passed to the SetPowerSave method. | |
power_management.quirk.s3_bios (bool)
| No | Use the S3_BIOS kernel command for suspend. | |
power_management.quirk.s3_mode (bool)
| No | Use the S3_MODE kernel command for suspend. | |
power_management.quirk.dpms_suspend (bool)
| No | Suspend the video card via DPMS on suspend. | |
power_management.quirk.vga_mode_3 (bool)
| No | Reset the VGA text mode to mode 3 on resume. | |
power_management.quirk.dpms_on (bool)
| No | Reactivate the screen with DPMS on resume. | |
power_management.quirk.vbe_post (bool)
| No | Run the VGA BIOS Power On Self Test (POST) on resume. | |
power_management.quirk.vbestate_restore (bool)
| No | Save the VGA BIOS state before suspend, and restore it on resume. | |
power_management.quirk.vbemode_restore (bool)
| No | Save the VGA BIOS mode before suspend, and restore it on resume. | |
power_management.quirk.pci_save (bool)
| No | saving the PCI config space of the graphic card before suspend, restoring it after | |
power_management.quirk.radeon_off (bool)
| No | Turn off the Radeon DAC off before suspend. | |
power_management.quirk.reset_brightness (bool)
| No | Reset the brightness state after resume. | |
power_management.quirk.no_fb (bool)
| No | True if the machine can only suspend when not using framebuffer. | |
power_management.quirk.none (bool)
| No | No quirks are necessary for suspend or resume. |
Device objects with the capability
portable_audio_player
represent portable
audio players that can be attached to a computer to exchange
files. They can also playback audio. Sometimes they can also
record audio. 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 portable music player; for USB devices this would be
the device object representing the appropriate USB
interface. The following properties are available:
Key (type) | Values | Mandatory | Description |
---|---|---|---|
portable_audio_player.access_method.protocols (strlist)
| example: storage ipod mtp pde iriver karma | Yes |
Indicates transfer protocols that this device can speak.
storage indicates USB Mass Storage (UMS) is an access
protocol. ipod indicates UMS plus an iTunes-style database.
mtp indicates a device using Microsoft's Media Transfer Protocol.
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.
|
portable_audio_player.access_method.drivers (strlist)
| example: libgpod, libmtp, libnjb, libifp, libkarma | No |
Indicates installed device driver libraries that can
handle this device. These drivers can export information
in portable_audio_player.[drivername] sub-namespaces.
Can also be used by libraries or programs providing extra device information
to indicate the presence of this information in the appropriate sub-namespace.
|
portable_audio_player.[drivername].protocol (strlist)
| example: mtp | If portable_audio_player.drivers is set |
This entry is required for drivers listed in
portable_audio_player.access_method.drivers . Indicates which
protocol in portable_audio_player.access_method.protocols
a particular driver will use. If the driver is providing information only, this
should be set to information .
|
portable_audio_player.output_formats (strlist)
| example: audio/mpeg audio/x-ms-wma | Yes | A string list of MIME-types representing the kind of audio formats that the device can play back. |
portable_audio_player.input_formats (strlist)
| example: audio/x-wav | Yes | A string list of MIME-types representing the kind of audio formats that the device can record. If empty, it means that the device is not capable of recording. |
portable_audio_player.folder_depth (int)
| example: 1 (If the device only supports one sub-folder) | No | If portable_audio_player.access_method.protocols contains "storage", this tells applications exactly how deep of directory hierarchies files should be placed in. If all files are put in a sub-folder (with the audio_folders property), only the depth within that sub-folder should be entered here. If the device does not have a limit, do not set this property. |
portable_audio_player.audio_folders (strlist)
| example: music/ voice/ linein/ | No | If portable_audio_player.access_method.protocols contains "storage", this may contain a string list of folders in which music can be found. 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. |
portable_audio_player.playlist_format (strlist)
| example: audio/x-mpegurl audio/x-somethingelse | No | A string list of the MIME-type of the playlist formats accepted by this device. Leave blank if none. |
portable_audio_player.playlist_path (string)
| examples: playlists/%File or Playlist.m3u | No | Set to the path to which playlists should be written. Leave blank if playlist files are not supported. If the device supports a single playlist with a specific name/path, set this to the path relative to the mount point that it should be saved to. If it supports multiple playlists, use the %File variable as needed. Applications are responsible for substituting %File with the desired playlist file name, noting that it's use in this string is optional. |
portable_audio_player.storage_device (string)
| examples: a udi | No | Set to the udi of the portable_audio_player device if portable_audio_player.access_method.protocols contains storage for a USB Mass Storage (UMS) music player. Mandatory for storage. |
Device objects with the capability printer
represent printers. The following properties are available.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
printer.device (string)
| Yes | Special device file to interact with the printer device. | |
printer.vendor (string)
| Yes | Name of the device vendor | |
printer.product (string)
| Yes | Name of the product. | |
printer.serial (string)
| Yes | A string uniquely identifying the instance of the device; ie. it will be different for two devices of the same type. Note that the serial number is broken on some USB devices. | |
printer.description (string)
| No | Description for the device. | |
printer.commandset (strlist)
| No | List of supported commands / printer languages. |
Device objects with the capability processor
represent CPU's in the system.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
processor.number (int)
| Yes | The internal processor number in the system, starting from zero | |
processor.can_throttle (bool)
| No | Whether the processor supports throttling to decrease it's own clock speed | |
processor.maximum_speed (long)
| example: 2200 | No | The maximum speed of the processor in units of MHz |
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. The following
properties are available:
Key (type) | Values | Mandatory | Description |
---|---|---|---|
scanner.access_method (string)
| Yes | This property defines how the device is accessed | |
proprietary | The device is accessed from userspace through a userspace driver such as SANE. | ||
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.is_volume
set to FALSE.
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.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
storage.bus (string)
| Yes | Interface the storage device is attached to | |
cciss | HP Smart Array CCISS interface | ||
ccw | IBM s390/s390x ccw interface | ||
ide | IDE or ATA interface | ||
ieee1394 | IEEE 1394 interface | ||
linux_raid | Linux MD (multi disk) RAID device | ||
memstick | Sony MemoryStick device/interface | ||
mmc | MultiMediaCard (MMC) interface | ||
pci | PCI interface | ||
pcmcia | PCMCIA interface | ||
platform | Legacy device that is part of the platform | ||
sata | SATA interface | ||
scsi | SCSI interface | ||
usb | USB interface | ||
vio | IBM pSeries/iSeries Vio interface | ||
storage.drive_type (string)
| Yes | The type of the drive. Note that it may not be possible to probe for some of these properties so in some cases memory card readers may appear as harddisks. Device information files can be used to override this value. | |
disk | The device is a harddisk | ||
cdrom |
The device is an optical drive. The device object will also have the capability storage.cdrom in this case.
| ||
floppy | The device is a floppy disk drive | ||
tape | The device is a tape drive | ||
compact_flash | The device is a card reader for Compact Flash memory cards | ||
memory_stick | The device is a card reader for MemoryStick memory cards | ||
smart_media | The device is a card reader for SmartMedia memory cards | ||
sd_mmc | The device is a card reader for SecureDigital/MultiMediaCard memory cards | ||
storage.removable (bool)
| Yes | Media can be removed from the storage device | |
storage.removable.media_available (bool)
| Yes | true, if and only if, media have been detected in storage device | |
storage.removable.media_size (uint64)
| Yes | Size of media in storage device. Available only if media have been detected in storage device. | |
storage.removable.support_async_notification (bool)
| Yes | Whether the drive reports asynchronous notification for media change. | |
storage.partitioning_scheme (string)
| Only when media is inserted and is partitioned | The partitioning scheme of the media. | |
mbr | Master Boot Record partitioning scheme used in most PC's | ||
gpt | GUID Partitioning Table as defined by UEFI | ||
apm | Apple Partition Map, used in non-Intel Apple computers | ||
storage.size (uint64)
| No | size in bytes of the storage device - only meaningful if storage.removable is FALSE | |
storage.requires_eject (bool)
| Yes | The eject ioctl is required to properly eject the media | |
storage.hotpluggable (bool)
| Yes | The storage device can be removed while the system is running | |
storage.media_check_enabled (bool)
| Yes | If this property is set to FALSE then HAL will not continuosly poll for media changes. | |
storage.automount_enabled_hint (bool)
| Yes | This property is a hint to desktop file managers that they shouldn't automount volumes of the storage device when they appear. | |
storage.no_partitions_hint (bool)
| Yes |
This property is a hint to programs that maintain the
/etc/fstab file to signal, when
TRUE, that the storage drive (such as floppy or
optical drives) is used for media with no partition
table so an entry can be added ahead of media
insertion time. Note that this is only a hint; media
may be inserted that has partition tables that the
kernel may respect. Conversely, when this is FALSE
media without partition tables may be inserted (an
example is a Compact Flash card; this media is normally
formatted with a PC style partition table and a single
FAT partition. However, it may be formatted with just
a single FAT partition and no partition table).
| |
storage.originating_device (string)
| Yes | This contains the UDI of the device object representing the device or blank if there is no such device. | |
storage.model (string)
| Yes | The name of the drive | |
storage.vendor (string)
| Yes | The vendor of the drive | |
storage.serial (string)
| No | The serial number of the drive | |
storage.firmware_revision (string)
| No | The revision of the firmware of the drive | |
storage.icon.drive (string)
| No |
Name of icon to use for displaying the drive. The name
must comply with freedesktop.org icon-theme specification
and must not be an absolute path.
This property exists such that e.g. OEM's can install
icons in /usr/share/icons/hicolor
a device information file matching their device.
| |
storage.icon.volume (string)
| No |
Name of icon to use for displaying volumes from the drive.
The name must comply with freedesktop.org icon-theme
specification and must not be an absolute path.
This property exists such that e.g. OEM's can install
icons in /usr/share/icons/hicolor
a device information file matching their device.
|
This namespace is used to describe optical storage drives
and their capabilities.Such device objects will have the
capability storage.cdrom
and
they will export the properties below. Note that device
objects can only have the storage.cdrom
capability
if they already got the capability storage
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
storage.cdrom.cdr (bool)
| Yes | TRUE when the optical drive can write CD-R discs | |
storage.cdrom.cdrw (bool)
| Yes | TRUE when the optical drive can blank and write to CD-RW discs | |
storage.cdrom.dvd (bool)
| Yes | TRUE when the optical drive can read DVD-ROM discs | |
storage.cdrom.dvdr (bool)
| Yes | TRUE when the optical drive can write to DVD-R discs | |
storage.cdrom.dvdrw (bool)
| Yes | TRUE when the optical drive can blank and write to DVD-RW discs | |
storage.cdrom.dvdrdl (bool)
| Yes | TRUE when the optical drive can write to DVD-R Dual-Layer discs | |
storage.cdrom.dvdram (bool)
| Yes | TRUE when the optical drive can write to DVD-RAM discs | |
storage.cdrom.dvdplusr (bool)
| Yes | TRUE when the optical drive can write to DVD+R discs | |
storage.cdrom.dvdplusrw (bool)
| Yes | TRUE when the optical drive can blank and write to DVD+RW discs | |
storage.cdrom.dvdplusrwdl (bool)
| Yes | TRUE when the optical drive can blank and write to DVD+RW Dual-Layer discs | |
storage.cdrom.dvdplusrdl (bool)
| Yes | TRUE when the optical drive can write to DVD+R Dual-Layer discs | |
storage.cdrom.bd (bool)
| Yes | TRUE when the optical drive can read Blu-ray ROM discs | |
storage.cdrom.bdr (bool)
| Yes | TRUE when the optical drive can write to Blu-ray Recordable discs | |
storage.cdrom.bdre (bool)
| Yes | TRUE when the optical drive can write to Blu-ray Rewritable discs | |
storage.cdrom.hddvd (bool)
| Yes | TRUE when the optical drive can read Read-only HD DVD discs | |
storage.cdrom.hddvdr (bool)
| Yes | TRUE when the optical drive can write to Write-once HD DVD discs | |
storage.cdrom.hddvdrw (bool)
| Yes | TRUE when the optical drive can write to Rewritable HD DVD discs | |
storage.cdrom.mrw (bool)
| Yes | TRUE when the optical drive can read MRW (Mount Rainier Rewrite) discs | |
storage.cdrom.mrw_w (bool)
| Yes | TRUE when the optical drive can write MRW (Mount Rainier Rewrite) discs | |
storage.cdrom.mo (bool)
| No | TRUE when the optical drive is a MO (Magneto Optical) device. | |
storage.cdrom.support_multisession (bool)
| Yes | TRUE if the drive can read multisession discs | |
storage.cdrom.support_media_changed (bool)
| Yes | TRUE if the drive can generate media changed events | |
storage.cdrom.read_speed (int)
| Yes | The maximum reading speed, in kb/s | |
storage.cdrom.write_speed (int)
| Yes | The maximum writing speed, in kb/s | |
storage.cdrom.write_speeds (strlist)
| No | By the device supported write speeds in kb/s |
This namespace is used to describe logical Software RAID
devices under Linux using the md
driver. By
and large, all the same properties under
the storage
name space applies except
that storage.serial
is set to the UUID of
the RAID set, storage.firmware_version
is
set to the version of the md
driver and the
value of storage.hotpluggable
is taken from
the enclosing drive of the first RAID component
encountered. In addition, the following properties are
available.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
storage.linux_raid.level (string)
| Yes | the RAID level of the device as reported by the kernel (linear, raid0, raid1, raid4, raid5, raid6, raid10) | |
storage.linux_raid.sysfs_path (string)
| Yes | sysfs path of device, e.g. /sys/block/md0 | |
storage.linux_raid.num_components (int)
| Yes | Number of components in the RAID array | |
storage.linux_raid.num_components_active (int)
| Yes |
Number of active components in the RAID array. If less
than storage.linux_raid.num_components
it means that the RAID array is running in degraded
mode.
| |
storage.linux_raid.components (strlist)
| Yes | UDI's of the volumes constituting the array. | |
storage.linux_raid.is_syncing (bool)
| Yes | TRUE if, and only if, the array is currently syncing | |
storage.linux_raid.sync.action (string)
| only if .is_syncing is TRUE | The syncing mechanism as reported by the kernel (idle, resync, check, repair, recover) | |
storage.linux_raid.sync.progress (double)
| only if .is_syncing is TRUE | Number between 0 and 1 representing progress of the sync operation. This is updated regulary when syncing is happening. | |
storage.linux_raid.sync.speed (uint64)
| only if .is_syncing is TRUE | Speed of the sync operation, in kB/s. This is updated regulary when syncing is happening. |
This namespace is found on the toplevel "Computer" device, and represents information about the system and the currently running kernel.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
system.kernel.name (string)
| example: Linux | No |
The name of the kernel, usually the equivalent of
uname -s .
|
system.kernel.version (string)
| example: 2.6.5-7.104-default | No |
The version of the currently running kernel. Usually
the equivalent of uname -r .
|
system.kernel.version.major (int)
| example: 2 | No | The major version number of the running kernel. |
system.kernel.version.minor (int)
| example: 6 | No | The minor version number of the running kernel. |
system.kernel.version.micro (int)
| example: 28 | No | The micro version number of the running kernel. |
system.kernel.machine (string)
| example: i686 | No |
The "machine hardware name" of the currently running kernel.
Usually the equivalent of uname -m .
|
system.formfactor (string)
| example: laptop, desktop, server, unknown | Yes |
The formfactor of the system. Usually the equivalent of
system.chassis.type or set from information
about ACPI/APM/PMU properties.
|
system.hardware.vendor (string)
| No | The name of the manufacturer of the machine. | |
system.hardware.product (string)
| No | The product name of the machine. | |
system.hardware.version (string)
| No | The version of the machine. | |
system.hardware.serial (string)
| No | The serial number of the machine. | |
system.hardware.uuid (string)
| No | The unique ID of the machine. | |
system.hardware.primary_video.vendor (int)
| No | The PCI vendor ID of the primary graphics card in the system. | |
system.hardware.primary_video.product (int)
| No | The PCI device ID of the primary graphics card in the system. | |
system.firmware.vendor (string)
| No | The firmware vendor. | |
system.firmware.version (string)
| No | The firmware version. | |
system.firmware.release_date (string)
| No | The release date of the firmware. | |
system.chassis.manufacturer (string)
| No | The manufacturer of the chassis. | |
system.chassis.type (string)
| No | The chassis type of the machine. | |
system.board.vendor (string)
| No | The name of the manufacturer of the base board. | |
system.board.product (string)
| No | The product name of the base board. | |
system.board.version (string)
| No | The version of the base board. | |
system.board.serial (string)
| No | The serial number of the base board. |
Device objects with the capability tape
represent tape devices.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
tape.major (int)
| example: 254 | Yes | The device's major number |
tape.minor (int)
| example: 0 | Yes | The device's minor number |
Device objects with the capability video4linux
represent Video4Linux devices.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
video4linux.device (string)
| Example: /dev/video0 | Yes | The device node to access the Video4Linux device. |
video4linux.version (string)
| Example: 2 | Yes | The highest Video4Linux API version supported by the device. |
The video4linux device has audio inputs or outputs. No namespace specific properties.
The video4linux device is a radio device. No namespace specific properties.
The video4linux device has some sort of tuner or modulator to receive or emit RF-modulated video signals. No namespace specific properties.
The video4linux device can capture video. No namespace specific properties.
The video4linux device can output video. No namespace specific properties.
The video4linux device can overlay video. No namespace specific properties.
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.is_volume
set to TRUE.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
volume.ignore (bool)
| Yes | This is a hint to software higher in the stack that this volume should be ignored. If TRUE, the volume should be invisible in the UI and mount wrappers should refuse to mount it on behalf on an unprivileged user. This is useful for hiding e.g. firmware partitions (e.g. bootstrap on Mac's) and OS reinstall partitions on e.g. OEM systems. | |
volume.is_mounted (bool)
| Yes | This property is TRUE if and only if the volume is mounted | |
volume.is_mounted_read_only (bool)
| Yes | This property is TRUE if and only if the volume is mounted and the volume's file-system is read-only. | |
volume.mount_point (string)
| example: /media/compact_flash1 | Yes (is blank only when volume.is_mounted is FALSE) | A fully qualified path to the mount point of the volume |
volume.fsusage (string)
| example: filesystem | Yes | This property specifies the expected usage of the volume |
filesystem | The volume is a mountable filesystem | ||
partitiontable | The volume contains a partitiontable. | ||
raid | The volume is a member of a raid set and not mountable | ||
other | The volume is not mountable like a swap partition | ||
unused | The volume is marked a unused or free | ||
volume.fstype (string)
| examples: ext3, vfat | Yes (is blank if the type is unknown) | The specific type of either the file system or what the volume is used for, cf. volume.fsusage |
volume.mount.valid_options (string list)
| examples: ro, sync, noexec |
Yes, if the org.freedesktop.Hal.Device.Volume interface is
defined.
| List of the allowed (valid) mount options for the defined fstype. |
volume.unmount.valid_options (string list)
| examples: lazy |
No (only available if the org.freedesktop.Hal.Device.Volume
interface is defined)
| List of the allowed (valid) unmount options for the defined fstype. |
volume.fstype.alternative (string list)
| examples: ntfs-3g, ntfs-fuse | No (only if there is a alternative mount handler) | The allowed (and installed) alternative mount handler/filesystem(s). |
volume.fstype.alternative.preferred (string)
| examples: ntfs-3g | No |
The preferred alternative mount handler/filesystem. Allows e.g. a distributor
do define a preferred of the alternative handlers.
If not set, the default filesystem (defined by volume.fstype )
should be used (or let the fstype parameter of Mount() empty),
otherwise it must be the name of one of the alternative handlers, as in
volume.fstype.alternative .
|
volume.mount.[alternative].valid_options (string list)
| examples: locale=, uid= |
Yes, if volume.fstype.alternative is set and if the
org.freedesktop.Hal.Device.Volume interface is defined.
|
List of the allowed (valid) mount options for the defined alternative filesystem
handler. Replace [alternative] in the property string with the
name of the alternative filesystem handler. For e.g. ntfs-3g the property would be:
volume.mount.ntfs-3g.valid_options .
NOTE: To mount the volume with the alternative handler/filesystem you have
to pass the correct (alternative) fstype parameter to the Mount() method
of the org.freedesktop.Hal.Device.Volume interface
|
volume.unmount.[alternative].valid_options (string list)
| examples: lazy |
No, only available if volume.fstype.alternative is set and
if the org.freedesktop.Hal.Device.Volume interface is defined.
|
List of the allowed (valid) unmount options for the defined alternative filesystem
handler. Replace [alternative] in the property string with the
name of the alternative filesystem handler. For e.g. ntfs-3g the property would be:
volume.unmount.ntfs-3g.valid_options
|
volume.fsversion (string)
| example: FAT32 | Version number or subtype of the filesystem | |
volume.label (string)
| example: 'Fedora Core 1.90' | Yes (is blank if no label is found) | The label of the volume |
volume.uuid (string)
| example: 4060-6C11 | Yes (is blank if no UUID is found) | The Universal Unique Identifer for the volume |
volume.is_disc (bool)
| Yes | If the volume stems from an optical disc, this
property is true and the device object will also have
the capability volume.disc
| |
volume.block_size (string)
| No | The block size of the volume | |
volume.num_blocks (string)
| No | Number of blocks on the volume | |
volume.size (uint64)
| No | Size of the volume in bytes | |
volume.is_partition (bool)
| Yes |
If the volume stems from a partition on e.g. a hard
disk, this property is set to TRUE .
| |
volume.linux.is_device_mapper (bool)
| Yes, but only on Linux |
If the volume stems from the Linux Device Mapper this property is set to TRUE .
| |
volume.partition.number (int)
|
If, and only if, volume.is_partition
is set to TRUE .
| The number of the partition. | |
volume.partition.label (string)
|
If, and only if, volume.is_partition
is set to TRUE .
|
Label of partition. Only available for "apm" and "gpt"
partition tables. Note that this is not the same as the
file system label defined in volume.label .
| |
volume.partition.uuid (string)
|
If, and only if, volume.is_partition
is set to TRUE .
| The UUID or GUID of the partition table entry. Only available for "gpt" partition tables. | |
volume.partition.scheme (string)
|
If, and only if, volume.is_partition
is set to TRUE .
|
The scheme of the partition table this entry is part of.
Note that this is not necessarily the same as
storage.partitioning_scheme as
some partition tables can embed other partition tables.
| |
mbr | Master Boot Record | ||
embr | Extended Master Boot Record | ||
gpt | GUID Partition Table as defined by EFI | ||
apm | Apple Partition Map | ||
volume.partition.type (string)
|
If, and only if, volume.is_partition
is set to TRUE .
|
The type of the partition table entry. Depends on
volume.partition.scheme .
| |
mbr and embr entries | The hexadecimal encoding of the 8-bit partition type, see http://www.win.tue.nl/~aeb/partitions/partition_types-1.html for a list. For example the Linux partition type is represented as the string "0x83". | ||
gpt entries | The GUID encoded as a string. See http://en.wikipedia.org/wiki/GUID_Partition_Table for a list of well-known GUID's. | ||
apm entries | Defined in http://developer.apple.com/documentation/mac/Devices/Devices-126.html. Also note that for FAT file systems, it appears that "DOS_FAT_32", "DOS_FAT_16" and "DOS_FAT_12" are also recognized under Mac OS X (I've tested this too) cf. http://lists.apple.com/archives/Darwin-drivers/2003/May/msg00021.html | ||
volume.partition.flags (strlist)
|
If, and only if, volume.is_partition
is set to TRUE .
| Flags conveying specific information about the partition entry. Dependent on the partitioning scheme. | |
mbr and embr entries | Only one flag, "boot", is defined. This is used by some BIOS'es and boot loaders to populate a boot menu. It means that a partition is bootable. | ||
gpt entries | Only the flag "required" is recognized. This corresponds to bit 0 of the attibutes (at offset 48), meaning "Required for the platform to function. The system cannot function normally if this partition is removed. This partition should be considered as part of the hardware of the system, and if it is removed the system may not boot. It may contain diagnostics, recovery tools, or other code or data that is critical to the functioning of a system independent of any OS." | ||
apm entries | The following flags are recognized: "allocated" if the partition is already allocated; and "in_use" if the partition is in use; may be cleared after a system reset; and "boot" if partition contains valid boot information; and "allow_read" if partition allows reading; and "allow_write"; if partition allows writing; and "boot_code_is_pic"; if boot code is position independent | ||
volume.partition.media_size (uint64)
| example: 500107862016 |
If, and only if, volume.is_partition
is set to TRUE .
| If available, size of the current media or the fixed disk in the storage device. |
volume.partition.start (uint64)
| example: 32256 |
If, and only if, volume.is_partition
is set to TRUE .
| If available, the offset where the partition starts on the media or the fixed disk in the storage device. |
Device objects with this capability may emit the following device conditions
Condition Name | Parameters | Example | Description |
---|---|---|---|
VolumeMount
|
block.device (string),
volume.mount_point (string)
|
/dev/sda1 ,
/media/compact_flash
| Emitted when a volume is mounted |
VolumeUnmount
|
block.device (string),
volume.mount_point (string)
|
/dev/sda1 ,
/media/compact_flash
| Emitted when a volume is unmounted |
VolumeUnmountForced
|
block.device (string),
volume.mount_point (string)
|
/dev/sda1 ,
/media/compact_flash
| Emitted when a volume is forcibly unmounted because the media backing the volume was removed. |
This namespace is for device objects that represent optical
discs, e.g. device objects with the capability
volume.disc
. Such device objects will
also have the capability volume
.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
volume.disc.has_audio (bool)
| Yes | Is true only if the disc contains audio | |
volume.disc.has_data (bool)
| Yes | Is true only if the disc contains data | |
volume.disc.is_vcd (bool)
| Yes | Is true only if the disc is a Video CD | |
volume.disc.is_svcd (bool)
| Yes | Is true only if the disc is a Super Video CD | |
volume.disc.is_videodvd (bool)
| Yes | Is true only if the disc is a Video DVD | |
volume.disc.is_appendable (bool)
| Yes | Is true only if it's possible to write additional data | |
volume.disc.is_blank (bool)
| Yes | Is true only if the disc is blank | |
volume.disc.is_rewritable (bool)
| Yes | Is true only if the disc is rewritable | |
volume.disc.capacity (uint64)
| No | Capacity of disc, in bytes | |
volume.disc.type (string)
| Yes | This property specifies the physical type of the disc | |
cd_rom | CD-ROM disc | ||
cd_r | CD-R disc | ||
cd_rw | CD-RW disc | ||
dvd_rom | DVD-ROM disc | ||
dvd_ram | DVD-RAM disc | ||
dvd_r | DVD-R disc | ||
dvd_rw | DVD-RW disc | ||
dvd_r_dl | DVD-R dual layer disc | ||
dvd_plus_r | DVD+R disc | ||
dvd_plus_r_dl | DVD+R dual layer disc | ||
dvd_plus_rw | DVD+RW disc | ||
dvd_plus_rw_dl | DVD+RW dual layer disc | ||
bd_rom | BD-ROM disc | ||
bd_r | BD-R disc | ||
bd_re | BD-RE disc | ||
hddvd_rom | HD DVD-ROM disc | ||
hddvd_r | HD DVD-R disc | ||
hddvd_rw | HD DVD-Rewritable disc | ||
unknown | Unknown type or lack of support from drive to determine the type |
Device objects with the
capability access_control
represent devices
where access to a special device file can be granted/revoked
to unprivileged users.
Key (type) | Values | Mandatory | Description |
---|---|---|---|
access_control.file (string)
| Example: /dev/snd/pcmC0D1p | Yes | Path to the special device file that access can be granted to. |
access_control.type (string)
| Example: cdrom | Yes |
Type of access - only makes sense when PolicyKit
support is enabled; it's used by PolicyKit to compute
what privilege to check for by
prepending org.freedesktop.hal.device-access. to the
value.
|
access_control.grant_user (strlist)
| Example: "gdm, flumotion" | No | List of UNIX user names to always grant access to the device. This is useful for 3rd party system-wide packages that need access to a device to function properly. |
access_control.grant_group (strlist)
| Example: "pvr_software, staff" | No | List of UNIX group names to always grant access to the device. This is useful for 3rd party system-wide packages that need access to a device to function properly. |
See also the section called “org.freedesktop.Hal.Device.AccessControl interface”.
Table of Contents
All of the HAL D-Bus interfaces are introspectable using the
standard D-Bus introspection methods (e.g. they all implement
the org.freedesktop.DBus.Introspectable
interface). For example, a command like
$ dbus-send --system --print-reply --dest=org.freedesktop.Hal \ /org/freedesktop/Hal/devices/computer \ org.freedesktop.DBus.Introspectable.Introspect
will print out the introspection XML for what interfaces
(ie. methods and signals) the given hal device object
supports. For brevity, the org.freedesktop.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.freedesktop.Hal.Device.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.freedesktop.Hal.Device.PermissionDeniedByPolicy
exception may be thrown (the two first words in the exception
detail is resp. a) the privilege the caller didn't have; b) the
textual result code from PolicyKit specifying if the caller can
obtain the privilege) if the caller is not privileged and so on.
Every hal device object (e.g. objects where the object path is
prefixed with /org/freedesktop/Hal/devices/
)
implements this interface. It provides generic
functionality. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetProperty | Variant | String key | NoSuchProperty | Get property. |
GetPropertyString | String | String key | NoSuchProperty, TypeMismatch | Get property. |
GetPropertyStringList | String[] | String key | NoSuchProperty, TypeMismatch | Get property. |
GetPropertyInteger | Int | String key | NoSuchProperty, TypeMismatch | Get property. |
GetPropertyUInt64 | UInt64 | String key | NoSuchProperty, TypeMismatch | Get property. |
GetPropertyBoolean | Bool | String key | NoSuchProperty, TypeMismatch | Get property. |
GetPropertyDouble | Double | String key | NoSuchProperty, TypeMismatch | Get property. |
SetProperty | Variant | String key | PermissionDenied | Set property. |
SetPropertyString | String | String key | PermissionDenied, TypeMismatch | Set property. |
SetPropertyStringList | String[] | String key | PermissionDenied, TypeMismatch | Set property. |
SetPropertyInteger | Int | String key | PermissionDenied, TypeMismatch | Set property. |
SetPropertyUInt64 | UInt64 | String key | PermissionDenied, TypeMismatch | Set property. |
SetPropertyBoolean | Bool | String key | PermissionDenied, TypeMismatch | Set property. |
SetPropertyDouble | Double | String key | PermissionDenied, TypeMismatch | Set property. |
RemoveProperty | String key | NoSuchProperty, PermissionDenied | Remove a property. | |
GetPropertyType | Int | String key | NoSuchProperty | Get the type of a property. Returns the D-Bus type as an integer. |
PropertyExists | Bool | String key | Determine if a property exists. | |
AddCapability | String capability | PermissionDenied | Adds a capability to a device. | |
QueryCapability | Bool | String capability | Determine if a device have a capability. | |
Lock | Bool | String reason | DeviceAlreadyLocked | Acquires an advisory lock on the device. Returns TRUE if the lock was acquired. |
Unlock | Bool | DeviceNotLocked | Releases an advisory lock on the device. Returns TRUE if the lock was released. | |
AcquireInterfaceLock | String interface_name, Bool exclusive | PermissionDenied, Device.InterfaceAlreadyLocked | Acquires a lock on an interface for a specific device. See Chapter 4, Locking for details. | |
ReleaseInterfaceLock | String interface_name | PermissionDenied, Device.InterfaceNotLocked | Releases a lock on an interface for a specific device. See Chapter 4, Locking for details. | |
IsCallerLockedOut | Bool | String interface_name, String caller_unique_name | PermissionDenied | Determines whether a given process on the system message bus is locked out from an interface on a specific device. Only HAL helpers are privileged to use this method. See Chapter 4, Locking for details. |
IsCallerPrivileged | String | String privilege, String caller_unique_name | PermissionDenied, Error |
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.g. with a non-zero
uid) can only ask
about Returns the textual representation of a PolKitResult value on success.
If HAL is not built with PolicyKit support, this
method always throws
the |
IsLockedByOthers | Bool | String interface_name | Determines whether a determines other processes than the caller holds a lock on the given device. See Chapter 4, Locking for details. | |
StringListAppend | String key, String value | PermissionDenied, TypeMismatch | Appends an item to a string list. | |
StringListPrepend | String key, String value | PermissionDenied, TypeMismatch | Prepends an item to a string list. | |
StringListRemove | String key, String value | PermissionDenied, TypeMismatch | Removes an item from a string list. | |
EmitCondition | Bool | String name, String details | PermissionDenied | Emit a condition on a device object. |
Rescan | Bool | PermissionDenied | Force an updates of the properties of a device object by rereading data that is not monitored for changes. | |
Reprobe | Bool | PermissionDenied | Cause a synthetic remove and subsequent add of the given device object including all children beneath it. Will generate at least one pair of DeviceRemoved() and DeviceAdded() signals on the Manager interface. | |
ClaimInterface | Bool | String name, String introspection_xml | PermissionDenied | An addon can use this method for making the HAL daemon route all D-Bus calls on the given interface to the addon via the peer to peer D-Bus connection between the addon and the HAL daemon. |
AddonIsReady | Bool | PermissionDenied | An addon needs to call this method when it's ready for the device to be announced on D-Bus. The rationale for this method is to allow an addon to modify the device object and claim interfaces before the device is announced on D-Bus. |
The following signals are emitted:
Signal | Parameters | Description |
---|---|---|
PropertyModified | Int num_changes, Array of struct {String property_name, Bool removed, Bool added} | One or more properties on the device object have changed. |
Condition | String name, String details | A generic mechanism used to specify a device condition that cannot be expressed in device properties. (NOTE: newly written code should use dedicated signals on a dedicated interface.). |
InterfaceLockAcquired | String lock_name, String lock_owner, Int num_holders | Sent when a process acquires an interface lock on the device. |
InterfaceLockReleased | String lock_name, String lock_owner, Int num_holders | Sent when a process releases an interface lock on the device. |
This interface provides a mechanism for discovering when an ACL is added or removed for a device file. The following signals are available:
Method | Parameters | Description |
---|---|---|
ACLAdded | UInt unix_user_id |
Emitted when an ACL have been added for a UNIX user on a
device object with the access_control
capability.
|
ACLRemoved | UInt unix_user_id |
Emitted when an ACL have been removed for a UNIX user on
a device object with
the access_control capability.
|
This interface does not export any methods.
This interface provides a mechanism to configure CPU frequency scaling. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetCPUFreqAvailableGovernors | String[] | Retrieves a list of available CPU scaling governors. | ||
GetCPUFreqGovernor | String | Get currently selected CPU Frequency governor. | ||
SetCPUFreqGovernor | Void | String governor | CPUFreq.UnknownGovernor | Selects a CPU frequency scaling governor for all CPUFreq interfaces the kernel provides. If the userspace governor is set, this interface also contains a proper scaling mechanism. |
SetCPUFreqPerformance | Void | Int (1 to 100) | CPUFreq.NoSuitableGovernor | Sets the performance of the dynamic scaling mechanism. This method summarizes and abstracts all the different settings which can be taken for dynamic frequency adjustments, like at which load to switch up frequency or how many steps the mechanism should traverse until reaching the maximum frequency. The higher the value, the more performance you get. Respectively, the higher the value, the sooner and the more often the frequency is switched up. |
GetCPUFreqPerformance | Int | CPUFreq.NoSuitableGovernor | Get the tuning value for the governor. | |
SetCPUFreqConsiderNice | Void | Bool consider_niced_processes | CPUFreq.NoSuitableGovernor | Whether or not niced processes should be considered on CPU load calculation. If niced processes are considered, they can cause a frequency increment although their absolute load percentage wouldn't trigger the scaling mechanism to switch up the frequency. The default setting is 'false'. |
GetCPUFreqConsiderNice | Bool | CPUFreq.NoSuitableGovernor | Whether nice'ed processes are considered by the governor. |
This interface does not emit any signals.
This interface provides a mechanism to deal with dock stations.
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
Undock | Int | Void | DockStation.NotDocked | Undock the system from a dock station |
This interface does not emit any signals.
This interface provides a mechanism to get/set the brightness of the keyboard backlight. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetBrightness | Int | Get the current brightness. | ||
SetBrightness | Int brightness | Set the current brightness. |
This interface does not emit any signals.
This interface provides a mechanism for both querying whether a radio is on as well as turning it on and off. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetPower | Int | Returns 1 if, and only if, the power is on. | ||
SetPower | Bool | Set the power of the radio. |
This interface does not emit any signals.
This interface provides a mechanism to get/set the brightness of a LED (light-emitting diode). The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetBrightness | Int | Get the current brightness of the LED. | ||
SetBrightness | Int brightness | Set the current brightness of the LED. The value 0 deactivate normally the LED, any higher value active the LED again. |
This interface does not emit any signals.
This interface provides a mechanism to get/set the brightness of a laptop panel. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetBrightness | Int | Get the current brightness. | ||
SetBrightness | Int brightness | Set the current brightness. |
This interface does not emit any signals.
This interface provides a mechanism to get information from a light sensor. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetBrightness | Int[] | The current brightness as measured by the light sensor. |
This interface does not emit any signals.
This interface provides a mechanism to interact with a storage device. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
Eject | Int | String[] options | Volume.PermissionDenied, Volume.NotMounted, Volume.NotMountedByHal, Volume.Busy, Volume.InvalidEjectOption | Unmounts all volumes and possibly ejects the media. Note that this method is not only restricted to optical drives. |
CloseTray | Int | String[] options | Storage.InvalidCloseTrayOption | Attempts to close the tray. Only really makes sense for (optical) drives that uses a tray loading mechanism. |
This interface does not emit any signals.
This interface provides a mechanism to interact with a storage device that uses removable media. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
CheckForMedia | Bool | Polls a storage device for media. |
This interface does not emit any signals.
This interface provides a mechanism to affect system-wide power
management. Normally only the root computer device object
(/org/freedesktop/Hal/devices/computer
)
implements this interface. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
Suspend | Int | Int num_secs_to_wakeup | SystemPowerManagement.NotSupported, SystemPowerManagement.AlarmNotSupported |
Puts the system in a suspended state (typically ACPI S3)
for num_secs_to_wakeup seconds. If
the given time is zero, the system is put in the
suspended state indefinitely. If wake-up isn't supported
the the AlarmNotSupported exception is thrown. Latency
for the system to return to an operational state is in
the order of magnitude of 5 seconds.
|
Hibernate | Int | SystemPowerManagement.NotSupported | Save system state to persistent storage and power off the system (typically ACPI S4). Latency for the system to return to an operational state is in the order of magnitude of one minute. | |
SuspendHybrid | Int | Int num_secs_to_wakeup | SystemPowerManagement.NotSupported, SystemPowerManagement.AlarmNotSupported |
Puts the system in a suspended state (typically ACPI S3)
for num_secs_to_wakeup seconds but
also write the system state to persistent storage so the
system can resume even if power is removed. Like with
Suspend(), if the given time is zero, the system is put
in the suspended state indefinitely. If wake-up isn't
supported the the AlarmNotSupported exception is thrown.
|
Shutdown | Int | SystemPowerManagement.NotSupported | Shut down the system. | |
Reboot | Int | SystemPowerManagement.NotSupported | Reboot the system. | |
SetPowerSave | Int | Bool should_save_power | SystemPowerManagement.NotSupported |
If the boolean passed is TRUE, the system will be
configured to save as much power as possible by
e.g. enabling laptop mode to avoid
spinning up disks. Typically, power management daemons
will call this method when it determines that the system
is running on battery power.
|
This interface does not emit any signals.
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. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
Mount | Int | String mount_point, String fstype, String[] options | Volume.PermissionDenied, Volume.AlreadyMounted, Volume.InvalidMountOption, Volume.UnknownFilesystemType, Volume.InvalidMountPoint, Volume.MountPointNotAvailable, Volume.CannotRemount | Mounts a volume. |
Unmount | Int | String[] options | Volume.PermissionDenied, Volume.NotMounted, Volume.NotMountedByHal, Volume.Busy, Volume.InvalidUnmountOption | Unmount a volume. |
Eject | Int | String[] options | Volume.PermissionDenied, Volume.NotMounted, Volume.NotMountedByHal, Volume.Busy, Volume.InvalidEjectOption | Unmounts all volumes from the originating drive and possibly ejects the media. Note that this method is not only restricted to optical drives. |
This interface does not emit any signals.
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.freedesktop.Hal.Device.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.freedesktop.Hal.Device.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. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
Setup | Int | String passphrase | Volume.Crypto.CryptSetupMissing, Volume.Crypto.SetupError, Volume.Crypto.SetupPasswordError | Unlocks an encrypted file system. If successful, a cleartext volume will appear. |
Teardown | Int | Volume.Crypto.TeardownError | Teardown the cleartext volume. |
This interface does not emit any signals.
For objects implementing this interface, it will also be checked
if the caller is locked out of the Volume interface on the
device (and per the section called “org.freedesktop.Hal.Device.Volume interface” this
includes checking whether the caller is locked out of
the org.freedesktop.Hal.Device.Storage
interface for the storage device that the volume originates
from).
This interface provides a mechanism to configure Wake On LAN capabilities. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetSupported | Bool | WakeOnLan.NoEthtool | Get if device supports Wake On LAN | |
GetEnabled | Bool | WakeOnLan.NoEthtool | Get if Wake On LAN is enabled | |
SetEnabled | Void | Bool | WakeOnLan.NoEthtool | Enable or disable Wake On LAN |
This interface does not emit any signals.
Only the /org/freedesktop/Hal/Manager
object
implements this interface. It's primarily used to discover
devices. The following methods are available:
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
GetAllDevices | Objref[] | Get all UDI's in the database. | ||
DeviceExists | Bool | Determines if a given object exists. | ||
FindDeviceStringMatch | Objref[] | String key, String value | Find devices for which the given string property assumes the given value. | |
FindDeviceByCapability | Objref[] | String capability | Finds devices of the given capability. | |
NewDevice | Objref | PermissionDenied | Creates a new device object in the temporary device list (TDL) and return the UDI. Caller must be uid 0. | |
Remove | Objref tmp_udi | NoSuchDevice, PermissionDenied | Removes a device object that was created in the TDL. Caller must be uid 0. | |
CommitToGdl | Objref tmp_udi, Objref udi | NoSuchDevice, PermissionDenied | Moves a device from the temporary device list (TDL) to the global device list (GDL). Caller must be uid 0. | |
AcquireGlobalInterfaceLock | String interface_name, Bool exclusive | Device.InterfaceAlreadyLocked | Acquires a global lock on an interface. See Chapter 4, Locking for details. | |
ReleaseGlobalInterfaceLock | String interface_name | Device.InterfaceNotLocked | Releases a global lock on an interface. See Chapter 4, Locking for details. | |
SingletonAddonIsReady | String command_line | PermissionDenied, SyntaxError | Called by singleton addons to signal that they are ready to handle devices. A singleton addon should implement the org.freedesktop.Hal.Singleton interface. |
The following signals are emitted:
Signal | Parameters | Description |
---|---|---|
DeviceAdded | Objref obj | A device was added to the global device list (GDL). |
DeviceRemoved | Objref obj | A device was removed from the global device list (GDL). |
NewCapability | Objref obj, String cap | A device gained a new capability. |
GlobalInterfaceLockAcquired | String lock_name, String lock_owner, Int num_holders | Sent when a process acquires a global interface lock. |
GlobalInterfaceLockReleased | String lock_name, String lock_owner, Int num_holders | Sent when a process releases a global interface lock. |
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.
It should be exported on the path
/org/freedesktop/Hal/Manager
.
Method | Returns | Parameters | Throws | Description |
---|---|---|---|---|
DeviceAdded
|
|
Called by the HAL Manager when a device is added that has
this singleton listed in
An addon implementing this function should start handling the device before returning, and keep track that is is handling this udi. | ||
DeviceRemoved
|
|
Called by the HAL Manager when a device is added that has
this singleton listed in
The implementer of this function should keep track of which devices it is still handling and exit when no longer handling any devices. |
This interface does not export any methods.