Arch Linux on Samsung ARM Chromebook

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Computers
#arch linux#chromebook

This is an up-to-date collation of everything to get a good working base for Arch Linux on the Samsung ARM Chromebook XE303C12.

I took my Chromebook out of retirement over the week and experimented around with a few distros. This is an old device and there's not a lot of information going around on the Internet. I've taken everything I've found and updated it to work on latest Arch release. I've also included some of my own configurations together into this post.

I assume you are familiar with Linux so I won't be explaining what everything is and what it does.

Install Arch Linux following the official guide

Install Arch on the Chromebook using the official guide.

To install to the internal memory, use /dev/mmcblk0 as the path after launching Arch from a USB. For this to work you will need Internet (wifi-menu), wget and cgpt (pacman -S cgpt wget).

Set up Wi-Fi

On the first boot without a GUI, the command wifi-menu should work out of the box to pick a simple network. It does not support WPA2 Enterprise or Hidden Networks however.

Proper networking will be explained later on once we have a GUI ready.

Update the system

Simply run:

pacman -Syu

then reboot and hope everything still works.

Create a user

The next few steps require some files to be created in a user's home directory or preferences changed under their profile. This is would be a good time to do that unless you plan to use 'root' forever.

Create a new user

useradd -m -G wheel -s /bin/bash calvin

Set a new password

passwd calvin

Install sudo

pacman -S sudo

Add user to sudoers

$ visudo

...
...
calvin ALL=(ALL) ALL

Login to your new user and let's begin.

Get a GUI

Screenshot at 2016-07-31 19:58:07

I prefer MATE as it's light on resources (lighter than XFCE in my tests) and pretty usable. There a list to choose from on the wiki.

To install MATE and everything required for a desktop environment, run:

pacman -S mate mate-extra xorg-server

The Disk Utility and Account Manager are optional packages if you wish to install them. The built-in account manager seems to work but throws an error when launching.

pacman -S mate-disk-utility mate-accountsdialog

Finally if you need a Display Manager (Login screen) to launch MATE (or use xorg-xinit). MATE recommends using LightDM:

pacman -S lightdm lightdm-gtk-greeter

Then enable LightDM to run on startup:

systemctl enable lightdm.service

Reboot and try it out.

Fix the trackpad

Now the trackpad will not feel right. This is easily fixed with a config file and driver.

Install the driver first:

pacman -S xf86-input-synaptics

Then set-up the config file at /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
        Identifier "touchpad"
        Driver "synaptics"
        MatchIsTouchpad "on"
        Option "FingerHigh" "5"
        Option "FingerLow" "5"
        Option "TapButton1" "1"
        Option "TapButton2" "3"
        Option "TapButton3" "2"
        Option "HorizTwoFingerScroll" "on"
        Option "VertTwoFingerScroll" "on"
EndSection

Reboot when done.

This should enable a good working trackpad on boot with tapping working. Afterwards, you can edit trackpad settings under 'System > Preferences  > Hardware > Mouse' to enable two finger scrolling, two finger taps, three finger taps, etc.

Screenshot at 2016-07-31 19:59:29

Note: if it's really hard navigating with the broken trackpad, press CTRL + ALT + Refresh to return to the command line.

Networking

Install Network Manager and network-manager-applet:

pacman -S networkmanager network-manager-applet

Then enable Network Manager and reboot to find the applet:

systemctl enable NetworkManager.service

Screenshot at 2016-07-31 20:17:20

Brightness Control

First make controlling brightness available to every user by editing permissions at startup. Create /etc/tmpfiles.d/brightness.conf with:

f /sys/class/backlight/backlight.12/brightness 0666 - - - 800

Reboot to activate the new permissions.

Next create this brightness script wherever you want. I used /usr/local/bin/brightness

#!/bin/bash
cur_bri=$(/usr/bin/cat /sys/class/backlight/backlight.12/brightness)

if [ $1 == "up" ] ; then
    bri=$(($cur_bri+200))
    `echo $bri > /sys/class/backlight/backlight.12/brightness`
fi

if [ $1 == "down" ] ; then
    bri=$(($cur_bri-200))
    `echo $bri > /sys/class/backlight/backlight.12/brightness`
fi

if [ $1 == "-s" ]; then
    `echo $2 > /sys/class/backlight/backlight.12/brightness`
fi

Make the scripts executable:

chmod +x /usr/local/bin/brightness

Then create keyboard shortcuts through 'System > Preferences > Hardware > Keyboard Shortcuts' to map:

Screenshot at 2016-07-31 07:06:15

Screenshot at 2016-07-31 07:06:01 

Name: Brightness Down
Command: /usr/local/bin/brightness down
Shortcut F6

Name: Brightness Up
Command: /usr/local/bin/brightness up
Shortcut F7

If it doesn't work, make sure you have rebooted first to set the right permissions to the brightness file. Try running the scripts manually as well to see what the problem could be.

Sound

First install alsa-utils

pacman -S alsa-utils

Then run alsamixer

alsamixer

Go across the page (arrow keys) and press M to unmute

  • Left Speaker Mixer Left DAC1
  • Left Speaker Mixer Mono DAC2
  • Left Speaker Mixer Mono DAC3
  • Left Speaker Mixer Right DAC1
  • Right Speaker Mixer Left DAC1
  • Right Speaker Mixer Mono DAC2
  • Right Speaker Mixer Mono DAC3
  • Right Speaker Mixer Right DAC1

Screenshot at 2016-07-31 20:03:01

Press ESC when down and it should save itself.

Set the volume keyboard shortcuts by going to 'System > Preferences > Hardware > Keyboard Shortcuts'

Suspend on lid close

Forget about acpid and pm-utils in the wiki, sleeping works fine without them and it's easier to manage with systemd.

Install the relevant power manager for your environment, e.g. for MATE it should be:

pacman -S mate-power-manager

The trackpad has a tendency to wake up the computer as almost any movement to the computer will cause it to activate. To disable it from waking the computer during sleep, I use a systemd unit file /etc/systemd/system/tp-wake-disable.service

[Unit]
Description=Disable trackpad waking computer

[Service]
Type=oneshot
ExecStart=/bin/sh -c "echo disabled > /sys/devices/12c70000.i2c/i2c-1/1-0067/power/wakeup"

[Install]
WantedBy=multi-user.target

Then enable the unit:

systemctl enable tp-wake-disable.service

Suspend after idle

The Chromebook does not suspend after a period of inactivity in my tests, the display goes black and stays that way until woken again. I've found the easiest way to activate suspend is to edit /etc/systemd/logind.conf and change the IdleAction and IdleActionSec fields. This means 1 minute after the display is put to sleep it will suspend.  The time for the display to sleep is configured through Screensaver in 'System Preferences > Preferences > Look and Feel > Screensaver'.

...
#HoldoffTimeoutSec=30s
IdleAction=Suspend
IdleActionSec=1min
#RuntimeDirectorySize=10%
...

Screenshot at 2016-07-31 08:35:10

Reboot to apply.

Note: During startup, LightDM will not suspend the computer if no one logs on, just leaving the laptop awake at the prompt indefinitely. I have experimented with xautolock, running it as a systemd unit and LightDM script but nothing seems to fix it. Closing the lid will also not suspend the computer. Basically, don't leave it on at the login screen without anyone logged in.

Change Search key to Caps Lock

Install xmodmap:

pacman -S xorg-xmodmap

By default, LightDM will read the ~/.Xmodmap file and modify the keymaps listed within it.

keycode 133 = Caps_Lock

Delete/Home/End/Page Up/Page Down

Install xbindkeys (for creating shortcuts) and xvkbd (emulate keyboard input):

pacman -S xbindkeys xvkbd

Create the configuration file:

touch ~/.xbindkeysrc

Add the following to the configuration file:

"xvkbd -xsendevent -text "[Prior]""
    m:0x4 + c:111
    Control + Up

"xvkbd -xsendevent -text "[Next]""
    m:0x4 + c:116
    Control + Down

"xvkbd -xsendevent -text "[Delete]""
    m:0x4 + c:22
    Control + BackSpace

"xvkbd -xsendevent -text "[End]""
    m:0x4 + c:114
    Control + Right

"xvkbd -xsendevent -text "[Home]""
    m:0x4 + c:113
    Control + Left

I prefer using CTRL + Arrow keys as it's easier than ALT + Arrow keys. If you prefer ALT, change 'm:0x4' to 'm:0x8' and 'Control' to 'Alt'

To run the configuration file at startup, add it to the ~/.xprofile which is executed by LightDM.

echo 'xbindkeys &' >> ~/.xprofile

Enable Compositing

'System > Preferences > Look and Feel > Windows' and tick 'Enable software compositing window manager' in the General tab.

Screenshot at 2016-07-31 19:18:52

Set Hostname

hostnamectl set-hostname arch-chromebook

Set the Time Zone

First find your time zone:

$ timedatectl list-timezones | grep Sydney
Australia/Sydney

Then set the time zone:

timedatectl set-timezone Australia/Sydney

Other Notes

  • The trackpad sometimes doesn't work on boot. A restart fixes it (press the power button)
  • Can't seem to get PulseAudio working
  • Two finger clicks that are too wide apart don't register as a right click. Two finger taps do though
  • Current RAM usage for me is 123M, A LOT better than Chrome OS which always sits around 1.5GB
  • Still can't get 720p video to run smoothly. Chrome OS is a bit better here but even then it dies on a 720p60 video. Sticking to 480p seems to be the best thing to do
  • It is possible to get rid having to press CTRL + D on each boot, I did that once and totally forgot how to get it back. I eventually did but it was crazy stuff.