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Diffstat (limited to 'src/grp-udev/systemd-hwdb/hwdb.xml')
| -rw-r--r-- | src/grp-udev/systemd-hwdb/hwdb.xml | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/src/grp-udev/systemd-hwdb/hwdb.xml b/src/grp-udev/systemd-hwdb/hwdb.xml new file mode 100644 index 0000000000..2b1e60fb22 --- /dev/null +++ b/src/grp-udev/systemd-hwdb/hwdb.xml @@ -0,0 +1,85 @@ +<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<refentry id="hwdb" conditional="ENABLE_HWDB"> + <refentryinfo> + <title>hwdb</title> + <productname>systemd</productname> + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Kay</firstname> + <surname>Sievers</surname> + <email>kay@vrfy.org</email> + </author> + <author> + <contrib>Developer</contrib> + <firstname>Tom</firstname> + <surname>Gundersen</surname> + <email>teg@jklm.no</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>hwdb</refentrytitle> + <manvolnum>7</manvolnum> + </refmeta> + + <refnamediv> + <refname>hwdb</refname> + <refpurpose>Hardware Database</refpurpose> + </refnamediv> + + <refsect1><title>Description</title> + <para>The hardware database is a key-value store for associating modalias-like keys to + udev-property-like values. It is used primarily by udev to add the relevant properties + to matching devices, but it can also be queried directly.</para> + </refsect1> + + <refsect1><title>Hardware Database Files</title> + <para>The hwdb files are read from the files located in the + system hwdb directory <filename>/usr/lib/udev/hwdb.d</filename> and + the local administration directory <filename>/etc/udev/hwdb.d</filename>. + All hwdb files are collectively sorted and processed in lexical order, + regardless of the directories in which they live. However, files with + identical filenames replace each other. Files in <filename>/etc</filename> + have the highest priority and take precedence over files with the same + name in <filename>/usr/lib</filename>. This can be used to override a + system-supplied hwdb file with a local file if needed; + a symlink in <filename>/etc</filename> with the same name as a hwdb file in + <filename>/usr/lib</filename>, pointing to <filename>/dev/null</filename>, + disables the hwdb file entirely. hwdb files must have the extension + <filename>.hwdb</filename>; other extensions are ignored.</para> + + <para>The hwdb file contains data records consisting of matches and + associated key-value pairs. Every record in the hwdb starts with one or + more match strings, specifying a shell glob to compare the database + lookup string against. Multiple match lines are specified in additional + consecutive lines. Every match line is compared individually, and they are + combined by OR. Every match line must start at the first character of + the line.</para> + + <para>The match lines are followed by one or more key-value pair lines, which + are recognized by a leading space character. The key name and value are separated + by <literal>=</literal>. An empty line signifies the end + of a record. Lines beginning with <literal>#</literal> are ignored.</para> + + <para>The content of all hwdb files is read by + <citerefentry><refentrytitle>systemd-hwdb</refentrytitle><manvolnum>8</manvolnum></citerefentry> + and compiled to a binary database located at <filename>/etc/udev/hwdb.bin</filename>, + or alternatively <filename>/usr/lib/udev/hwdb.bin</filename> if you want ship the compiled + database in an immutable image. + During runtime, only the binary database is used.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry> + <refentrytitle>systemd-hwdb</refentrytitle><manvolnum>8</manvolnum> + </citerefentry> + </para> + </refsect1> +</refentry> |