fdi(4) File Formats fdi(4)NAMEfdi - HAL device information file format
SYNOPSIS
/usr/share/lib/xml/dtd/fdi.dtd.1
DESCRIPTION
The hardware abstraction layer facility, described in hal(5), uses an
XML-based file format to merge arbitrary properties onto device
objects. The way device information files works is that once all physi‐
cal 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 for devices.
Each device information file has a number of match directives that are
tested against the properties of the device object. The directives have
the form:
<match key="property" [string|int|bool|..]="value">
If all the match directives pass, then the device information can
include the following property directives in the form:
<[merge|append|prepend] key="property" type="[string|int|bool|..]">
These directives are used to merge new properties or append to existing
properties on the device object. Any previously property stemming from
device detection can be overridden by a device information file.
The match, merge, append, and prepend directives require that the key
attribute be either a property name on the device object in question or
a path to a property on another device object. The path to a property
is expressed either through direct specification of the UDI, such as
/org/freedesktop/Hal/devices/computer:foo.bar or through indirect ref‐
erences such as "@info.parent:baz", meaning 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. For example, for a volume on a USB memory stick, the
indirection "@block.storage_device:@storage.physical_device:usb.ven‐
dor_id" references the "usb.vendor_id" property on the device object
representing the USB interface.
When the property to match has been determined, the following
attributes can be used within the "match" tag:
string Match a string property. For example, <match key=
"foo.bar" string="baz"> matches only if "foo.bar"
is a string property assuming the value "baz".
int Match an integer property
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">. This
attribute can be used with "true" and "false",
respectively to match when a property exists or
does not exist.
empty This attribute can only be used on string proper‐
ties with "true" and "false". The semantics for
"true" is to match only when the string is non-
empty.
is_absolute_path Matches only when a string property represents an
absolute path (the path does not have to exist).
This attribute can be can be used with "true" or
"false".
is_ascii Matches only when a string property contains ASCII
characters. This attribute can be used with "true"
or "false".
compare_lt This attribute can be used with int, uint64, double
and string properties to compare with a constant.
It matches when the given property is less than the
given constant using the default ordering.
compare_le Similar to compare_lt, but matches when the given
property is less than or equal than the given con‐
stant using the default ordering.
compare_gt Similar to compare_lt, but matches when the given
property is greater than the given constant using
the default ordering.
Similar to compare_lt, but matches when the given
property is greater than or equal than the given
constant using the default ordering.
This attribute 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 matches if the
given string matches a item in the list.
contains_ncase Similar to contains, but the property and the given
key are converted to lowercase before it is
checked.
The merge, append, and prepend directives all require the attribute
type which specifies what is to be merged. The following values are
supported:
string The value is copied to the property. For example,
<merge key="foo bar" type="string"> baz</merege>
merges the value "baz" into the property "foo.bar".
strlist For merge, the value is copied to the property and the
current property is overwritten. For append and
prepend, the value is appended or prepended to the
list as a new item.
bool This attribute 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.par‐
ent:baz.bat</merge> merges 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 requires only a key and can be used with all keys.
For strlist, there is also a special syntax to remove a item from the
string list. For example, to remove item "bla" from property "foo.bar",
use the following syntax:
<remove key="foo.bar" type="strlist">bla</merge>
Device Information files are stored in the following standard hierachy
with the following default top level directories information, policy
and preprobe:
information Device information files to merge device information.
10freedesktop Device information files included with
the hal tarball.
20thirdparty Device information files from the
device manufacturer and installed from
media accompanying the hardware.
30user Device information for specific
devices.
policy Device information files to merge policy propertys
10osvendor Device information files included with
the hal tarball and supplied by the
operating system vendor for policy rules
20thirdparty Policy rules from the device manufac‐
turer and installed from media accompa‐
nying the hardware
30user Policy rules for specific devices.
preprobe Device information files to merge information before
probe devices.
10osvendor Device information files included with
the hal tarball and supplied by the
operating system vendor.
20thirdparty Device information files from the device
manufacturer and installed from media
accompanying the hardware.
30user Device information for specific devices.
All device information files are matched for every hal device object.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │service/hal │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Volatile │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOhald(1M), attributes(5), hal(5), locale(5), smf(5)SunOS 5.11 5 Sept 2006 fdi(4)
