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# Video driver:
Depends: ${xviddriver:Depends}, …
Provides: ${xviddriver:Provides}</code></pre>
</div></div>
<div class="paragraph"><p>For now, <code>${xinpdriver:Provides}</code> is always replaced with
<code>xorg-driver-input</code>, and <code>${xviddriver:Provides}</code> is always replaced
with <code>xorg-driver-video</code>. Hopefully provided packages will not change,
but using substitution variables is cheap, and makes it easy to add
tweaks afterwards if needed.</p></div>
</div>
<div class="sect2">
<h3 id="_driver_s_build_system">Driver’s build system</h3>
<div class="paragraph"><p>To set those variables, we ship a <code>dh_xsf_substvars</code> script in
<code>xserver-xorg-dev</code> starting with <code>2:1.9.4</code>, to be run before
<code>dh_gencontrol</code>. It iterates on the packages listed by
<code>dh_listpackages</code> (very old <code>debhelper</code> command) and does the
following work:</p></div>
<div class="ulist"><ul>
<li>
<p>
It reads variables from the files mentioned above.
</p>
</li>
<li>
<p>
If a package name ends with <code>-udeb</code>, it replaces
   <code>xserver-xorg-core</code> with <code>xserver-xorg-core-udeb</code>.
</p>
</li>
<li>
<p>
If a package name ends with <code>-dbg</code>, it does nothing for this
   package. Debug packages usually depend strictly on the non-debug
   packages, which in turn have appropriate dependencies.
</p>
</li>
<li>
<p>
If a package name starts with <code>xserver-xorg-input-</code>, it appends
   <code>xinpdriver:Depends=…</code> and <code>xinpdriver:Provides=…</code> to this
   package’s substvars file.
</p>
</li>
<li>
<p>
If a package name starts with <code>xserver-xorg-video-</code>, it appends
   <code>xviddriver:Depends=…</code> and <code>xviddriver:Provides=…</code> to this
   package’s substvars file.
</p>
</li>
</ul></div>
<div class="paragraph"><p>Why such heuristics? The idea is to avoid getting “unused substitution
variable” warning messages while building. And since there’s a clear
<code>xserver-xorg-{input,video}-*</code> namespace, we can use that to specify
only input-related variables for input drivers, and only video-related
variables for video drivers.</p></div>
<div class="paragraph"><p>To make it easy to compute substvars when using <code>dh</code>, a <code>dh</code> sequence
(<code>xsf.pm</code>) is shipped. As of <code>2:1.9.4-1</code>, it inserts
<code>dh_xsf_substvars</code> right before the <code>dh_gencontrol</code> call. Other
repetitive tasks could also be automated this way.</p></div>
<div style="page-break-after:always"></div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_sample_driver_packaging">Sample driver packaging</h2>
<div class="sectionbody">
<div class="paragraph"><p>The following assumes:</p></div>
<div class="ulist"><ul>
<li>
<p>
The upstream build system is sane enough, which lets us run
   <code>autoreconf</code> at build time.
</p>
</li>
<li>
<p>
It is a <code>video</code> driver. For an <code>input</code> driver, replace both
   <code>xviddriver</code> occurrences with <code>xinpdriver</code>.
</p>
</li>
</ul></div>
<div class="sect2">
<h3 id="_sample_debian_control_file">Sample debian/control file</h3>
<div class="listingblock">
<div class="content">
<pre><code>Build-Depends:
 debhelper (>= 8),
 dh-autoreconf,
 quilt,
 xserver-xorg-dev (>= 2:1.9.4),</code></pre>
</div></div>
<div class="listingblock">
<div class="content">
<pre><code>Depends:
 ${shlibs:Depends},
 ${misc:Depends},
 ${xviddriver:Depends},
Provides:
 ${xviddriver:Provides}</code></pre>
</div></div>
</div>
<div class="sect2">
<h3 id="_sample_debian_rules_file">Sample debian/rules file</h3>
<div class="listingblock">
<div class="content">
<pre><code>#!/usr/bin/make -f

# Configuration:
#override_dh_auto_configure:
#        dh_auto_configure -- --with-FOO --without-BAR

# Install in debian/tmp to retain control through dh_install:
override_dh_auto_install:
        dh_auto_install --destdir=debian/tmp

# Kill *.la files, and forget no-one:
override_dh_install:
        find debian/tmp -name '*.la' -delete
        dh_install --fail-missing

## Debug package:
#override_dh_strip:
#        dh_strip --dbg-package=xserver-xorg-video-DRIVER-dbg

# That's a plugin, use appropriate warning level:
override_dh_shlibdeps:
        dh_shlibdeps -- --warnings=6

%:
        dh $@ --with quilt,autoreconf,xsf --builddirectory=build/</code></pre>
</div></div>
<div class="paragraph"><p>Some comments:</p></div>
<div class="ulist"><ul>
<li>
<p>
<code>dh_auto_configure</code>: Commented out since there’s usually no
   specific option to pass when building drivers. Sometimes needed to
   get a related utility built.
</p>
</li>
<li>
<p>
<code>dh_auto_install</code>: It behaves differently when operating on a
   single package (it installs under <code>debian/PACKAGE</code> instead of
   <code>debian/tmp</code>), so make it use <code>debian/tmp</code> in all cases. This way,
   <code>dh_install</code> has to be used (see below). That also means that a
   binary package (<em>e.g.</em> a debug package) can be added without
   changing this part.
</p>
</li>
<li>
<p>
<code>dh_install</code>: No point in keeping the <code>.la</code> files. Also, using
   <code>--fail-missing</code> makes sure every file installed by upstream is
   installed in some package, or explicitly ignored.
</p>
</li>
<li>
<p>
<code>dh_strip</code>: Commented out, there’s only a few drivers shipping a
   debug package.
</p>
</li>
<li>
<p>
<code>dh_shlibdeps</code>: The comment really says it all.
</p>
</li>
<li>
<p>
<code>dh</code>: The order is important! We want patching to happen before
   autoreconfiguring (both <code>quilt</code> and <code>autoreconf</code> insert commands
   before <code>dh_auto_configure</code>, and after <code>dh_clean</code>). Also, we build
   out-of-tree. The <code>xsf</code> sequence is explained in the previous part.
</p>
</li>
</ul></div>
<div class="paragraph"><p>If one needs to build several flavours,
<a href="http://git.debian.org/?p=pkg-xorg/driver/xserver-xorg-video-fbdev.git;a=blob;f=debian/rules"><code>fbdev</code>’s rules file</a>
can be used as an example.</p></div>
<div style="page-break-after:always"></div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_handling_a_transition">Handling a transition</h2>
<div class="sectionbody">
<div class="paragraph"><p>When a new major version of the server comes up, it can be updated
following its <code>README.source</code>. Usually, drivers can be rebuilt using
binNMUs. Be sure <code>xorg-server</code> is marked as <code>Installed</code> on all
buildds, or set a <code>dep-wait</code>.</p></div>
<div class="paragraph"><p>On the release team side, a transition page can be asked for, to track
fully rebuilt drivers. For the input 12→13 and video 10→11
transitions, the settings are:</p></div>
<div class="ulist"><ul>
<li>
<p>
Affected: <code>.build-depends ~ /xserver-xorg-dev/</code>
</p>
</li>
<li>
<p>
Good: <code>.depends ~ /xorg-input-abi-13/ | .depends ~ /xorg-video-abi-11/</code>
</p>
</li>
<li>
<p>
Bad: <code>.depends ~ /xorg-input-abi-12/ | .depends ~ /xorg-video-abi-10/</code>
</p>
</li>
</ul></div>
<div style="page-break-after:always"></div>
</div>
</div>
<div class="sect1">
<h2 id="_staying_tuned">Staying tuned</h2>
<div class="sectionbody">
<div class="paragraph"><p>Staying informed of driver-related changes can be a bit difficult in
the following cases:</p></div>
<div class="ulist"><ul>
<li>
<p>
If one maintains a single driver within the X Strike Force, one
   might not notice the few mails about drivers in the heavy mail flow
   on <code>debian-x@</code>.
</p>
</li>
<li>
<p>
If one maintains a driver outside the X Strike Force, one is
   probably not subscribed to the mailing list at all.
</p>
</li>
</ul></div>
<div class="paragraph"><p>For those reasons, a mail alias is being set up to gather all
maintainers interested in receiving driver-related mails.</p></div>
</div>
</div>
</div>
<div id="footnotes"><hr /></div>
<div id="footer">
<div id="footer-text">
Last updated
 2018-12-14 12:34:22 UTC
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