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<h1 class="post-title">Orca, Emacspeak and Chromium Accessibility on A Raspberry Pi Running Manjaro ARM</h1>
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<time datetime="20-12-14" class="post-date">Monday, December 14 2020</time>
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</header>
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<hr>
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<p>I wanted to get a gift for my blind friend who has been interested in learning Linux for a while now.
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Just when I was about to start looking for something I decided to take a look at <a href="https://lbry.tv/@Lunduke:e/raspberry-pi-400-looks-rad:c">Brian Lunduke’s newest video</a> featuring the <a href="https://www.raspberrypi.org/products/raspberry-pi-400/?resellerType=home">Raspberry Pi 400</a>.
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The Raspberry Pi 400 has come full circle in terms of computing.
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It is a keyboard. All the computing is done from within the keyboard.
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Much like the Comodore64, this computer comes without a screen but is still technically fully functional without one.
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I had my ‘Aha!’ moment, and decided that the Raspberry Pi 400 would be a very cool present.</p>
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<h2 id="no-headphone-jack">No Headphone Jack</h2>
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<p>My first problem was that the Raspberry Pi 400 does not come with a headphone jack,
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even though every other Raspberry Pi A/B/B+ board with the exception of the compute modules and Zero series have included one.
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That said, the Raspberry Pi audio jacks are also known to crackle and pop due to either bad drivers or cheap manufacturing.</p>
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<p>To compensate, I got an external USB audio card.
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I ended up going with the <a href="https://www.amazon.ca/DuKabel-ProSeries-Mic-Supported-Headphone-External/dp/B07RS11M1T/">DuKabel USB to 3.5mm Jack Adapter (Amazon)</a>.</p>
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<p>There are cheaper options for sure, but when I was looking around Raspberry Pi forums and Amazon reviews, this specific model seemed to come out on top in terms of performance.
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It costed me around 40 Canadian dollars.
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I figure this isn’t too bad considering my friend doesn’t need a screen, haha!</p>
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<h2 id="distribution">Distribution</h2>
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<p>I wanted to choose something which will age well, and run the latest and greatest.
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For visually impaired users, the most important piece of software is the screen reader. If the screen reader doesn’t work, the rest of the work is toast!
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Some Raspberry Pi Orca installation guides <a href="https://techesoterica.com/getting-the-orca-screen-reader-working-on-a-raspberry-pi-4-with-raspbian-buster-and-the-mate-desktop/">like this one</a>,
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have actually asked the user to <em>compile Orca from source</em> to get the latest version due to how out-of-date Debian’s package repositories are.
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A distribution which has none of these fusses was top priority,
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especially because Orca receives frequent updates.</p>
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<p>I decided to go with <a href="https://manjaro.org/download/#raspberry-pi-4-xfce">Manjaro ARM Xfce</a>:</p>
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<ul>
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<li>Xfce is lightweight.</li>
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<li>Runs a 64-bit kernel.</li>
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<li>Is based on Arch Linux, so receives very frequent package updates.</li>
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<li>Has the AUR (<a href="#aur">with some effort</a>, as we’ll see).</li>
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</ul>
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<p>The only downside of Manjaro ARM, and likewise other Aarch64 (ARM 64-bit) architecture kernels is that it did not have HEVC nor H264 hardware decoding available.
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Apparently, support for the Raspberry Pi’s VC4 graphics is getting mainlined <a href="https://www.debugpoint.com/2020/12/linux-kernel-5-10-features/">in Linux kernel 5.10</a>.
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Unfortunately, running the release candidate (RC) kernel did not make the Raspberry Pi 400 use hardware decoding.
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Perhaps other applications like <code class="language-plaintext highlighter-rouge">ffmpeg</code> and Chromium need to add support as well before this works.</p>
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<h2 id="orca">Orca</h2>
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<p>As stated before, minimum requirement for a visually impaired desktop Linux user is a screen reader.
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The most used screen reader for Linux is Orca, headed by the <a href="https://wiki.gnome.org/Projects/Orca">GNOME Project</a>.
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This is relatively easy to install with a standard <code class="language-plaintext highlighter-rouge">pacman</code> command.</p>
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<pre class="terminal">
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# pacman -S orca
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</pre>
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<p>If logged in via SSH, you can start Orca with the <code class="language-plaintext highlighter-rouge">orca</code> command. This will start reading the screen to you so you can do the next parts.</p>
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<p>To activate Orca on login with LightDM, enable it in the ‘LightDM GTK+ Greeter Settings’ application. The ‘Misc.’ tab will have a drop-down for asking which screen reader you want to use.
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This will start Orca when the LightDM login system starts.</p>
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<p>LightDM’s Orca will not help us once we are logged in however.
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To activate Orca on login, open the ‘Session And Startup application’ program, then add Orca to the “startup” list of apps.</p>
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<p>And now Orca will be activated on boot and login.</p>
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<h2 id="aur">AUR</h2>
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<p>The AUR, or the Arch User Repository has community maintained and distributed packages.
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Basically, you download a file which will tell your computer how to download, build and install a package for you.</p>
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<p>To get the AUR working in a more automatic way, we need to install the <code class="language-plaintext highlighter-rouge">pacaur</code> helper.
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This merited its own article, so check that out here:
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<a href="/2020/12/01/pacaur-rpi/">How to Install Pacaur on Manjaro ARM</a></p>
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<p>The TL;DR is that we need to open the <code class="language-plaintext highlighter-rouge">/etc/makepkg.conf</code> file and replace any mention of <code class="language-plaintext highlighter-rouge">-march=armv8-a</code> with <code class="language-plaintext highlighter-rouge">-march=armv8-a+crypto</code>.</p>
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<p>This can be done as a oneliner, thanks to the <code class="language-plaintext highlighter-rouge">sed</code> command.</p>
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<pre class="terminal">
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# sed -i 's/-march=armv8-a/-march=armv8-a+crypto/' /etc/makepkg.conf
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</pre>
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<h2 id="emacspeak">Emacspeak</h2>
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<p><a href="https://www.gnu.org/software/emacs/">Emacs</a> is a scriptable document editor run by the <a href="https://gnu.org/">GNU Project</a>.
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Infamous for its high learning curve though it may be,
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there is a very extensive speech extension for it called <a href="http://emacspeak.sourceforge.net/">Emacspeak</a>.
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Emacspeak is built entirely by <a href="https://tvraman.github.io/vita/resume.html">T. V. Ramen</a> and has been freely available since its inception in 1999.
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Due to its age (and thus maturity), Emacspeak is an important tool in any “eyes-free” software developer toolkit.</p>
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<p>Lucky for me, Emacspeak appears to not only to be available in the AUR,
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but also compilable with the Aarch64 architecture—the architecture of the Raspberry Pi 400.
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So this is as easy to install as:</p>
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<pre class="terminal">
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$ pacaur -S emacspeak
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</pre>
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<h2 id="web-browsers">Web Browsers</h2>
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<p>I’ll cover a couple web browsers here based on how they worked.</p>
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<h3 id="firefox">Firefox</h3>
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<p>Firefox will run in accessibility mode with <a href="https://en.wikipedia.org/wiki/Caret_navigation">caret browsing</a> enabled automatically when it detects Orca is running.
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This makes Firefox <em>by far</em> the best browser for the job.</p>
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<h3 id="chromium">Chromium</h3>
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<p>Chromium… Ugh. So it works, sort of.
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You need to enable two special flags, and add an environment variable.</p>
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<p>To do this, I suggest editing the main profile in <code class="language-plaintext highlighter-rouge">/etc/profile</code>.
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Add the following line to the end of that file:</p>
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<pre class="file">
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export ENABLE_ACCESSIBILITY=1
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</pre>
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<p>Next, add two flags to the <code class="language-plaintext highlighter-rouge">$HOME/.config/chromium-flags.conf</code> file.</p>
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<pre class="file">
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--force-renderer-accessibility
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--enable-caret-browsing
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</pre>
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<p>You will need to relog to set the ENABLE_ACCESSIBILITY environment variable. Now Chromium should work with Orca.</p>
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<h3 id="badwolf">Badwolf</h3>
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<p>The <a href="https://www.mankier.com/1/badwolf">Badwolf browser</a>
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is based on the WebkitGTK engine, as opposed to Firefox’s Gecko and Google’s Blink engines.
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It <em>almost</em> works out of the box. It is really fast compared to the other two,
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but it lacks some features like announcing a page is done loading and it doesn’t appear to support caret browsing,
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which will cause some other problems.
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Interesting though for such a young browser to have a minimal level of accessibility so early!</p>
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<p>I would be interested where this goes in the future.</p>
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<h2 id="ps">P.S.</h2>
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<p>Somehow I forgot that you would need to setup the dummy display driver to work with the graphics without a display attached.
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To do this, install the <code class="language-plaintext highlighter-rouge">xf86-video-dummy</code> pacakge:</p>
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<pre class="terminal">
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# pacman -S xf86-video-dummy
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</pre>
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<p>Next, override any <code class="language-plaintext highlighter-rouge">/etc/X11/xorg.conf</code> you may have with this:</p>
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<pre class="file">
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Section "Monitor"
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Identifier "Monitor0"
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HorizSync 28.0-80.0
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VertRefresh 48.0-75.0
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# https://arachnoid.com/modelines/
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# 1920x1080 @ 60.00 Hz (GTF) hsync: 67.08 kHz; pclk: 172.80 MHz
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Modeline "1920x1080_60.00" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -HSync +Vsync
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EndSection
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Section "Device"
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Identifier "Card0"
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Driver "dummy"
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VideoRam 256000
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EndSection
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Section "Screen"
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DefaultDepth 24
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Identifier "Screen0"
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Device "Card0"
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Monitor "Monitor0"
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SubSection "Display"
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Depth 24
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Modes "1920x1080_60.00"
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EndSubSection
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EndSection
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</pre>
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<p>Now, when you boot, you should head ‘Screen reader on’.</p>
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<h2 id="conclusion">Conclusion</h2>
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<p>It took a bit of messing around to get this working, but I’m glad I did!
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Now I can nerd out with another Linux friend and given how well they seem to find problems with accessibility, hopefully a few upstream patches can be made.</p>
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<p>Happy hacking, for everyone!</p>
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This page will be mirrored on <a href="https://beta.tait.tech/2020/12/14/orca-raspberry-pi-manjaro/">beta.tait.tech</a>.
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