SignageWithAlpineLinux

Signage with Alpine linux on the raspberry pi

hardware

This guide works for the Raspberry Pi3 and Raspberry Pi4.

In case you want to run a viewer for Schlangenprogrammiernacht you'll need a Raspberry Pi4 as the javascript viewer ist quite demanding

setup image

• Format SD-Card as FAT32 with a MSDOS partition table
• Grab the base file system from the alpine linux website (pick aarch64)
• Mount new partition and unzip archive directly to SDcard
• umount and plug SDcard into raspberry pi
• boot and log in as "root" without entering a password
• Make sure the raspberry-pi is connected to the internet

prepare base system

• start "setup-alpine"
  • select keyboard language (e.g. de-nodeadkeys)
  • choose hostname (e.g. "signage")
  • chose interface to listen for DHCP for (e.g. eth0)
  • select timezone (e.g. Europe/Berlin)
  • add user e.g. "sign"
  • Agree to install on /dev/mmcblk0p1
  • install as "sys"
• reboot the system
• (optional) continue via SSH
• select correct repositories

root> apk update
root> apk add nano
root> nano /etc/apk/repositories #uncomment the community repository
root> apk update

setup base system

• setup boot parameters
• add file /boot/usercfg.txt with the following content

root> echo "disable_overscan=1
dtoverlay=vc4-kms-v3d
gpu_mem=128" > /boot/usercfg.txt

• (optional) switch to udev

root> setup-devd

setup windowmanager

• install window manager

root> apk add screen
root> apk add seatd wlr-randr mesa-dri-gallium sway tinydm dbus
root> apk add wlr-randr wtype

• start seatd on boot and add "sign" to its group

root> rc-service seatd start
root> rc-update add seatd default
root> adduser sign seat # grant sign access to seatd

• copy and edit sway config for user "sign"

root> su - sign
sign> mkdir -p ~/.config/sway
sign> cp /etc/sway/config ~/.config/sway
sign> echo "
# hide cursor
seat seat0 hide_cursor 8000
# force fullhd
output HDMI-A-1 mode 1920x1080
exec ~/swaystart.sh &" >> ~/.config/sway/config
sign> touch ~/swaystart.sh

• setup autostart for user "sign"

root> echo "AUTOLOGIN_UID=1000" >> /etc/conf.d/tinydm
root> rc-update add tinydm default
root> tinydm-set-session -s /usr/share/wayland-sessions/sway.desktop

• fix file permissions

sign> chmod +x ~/swaystart.sh

• configure XDG_RUNTIME_DIR

sign> echo "if test -z \"\${XDG_RUNTIME_DIR}\"; then
  export XDG_RUNTIME_DIR=/tmp/\$(id -u)-runtime-dir
  if ! test -d \"\${XDG_RUNTIME_DIR}\"; then
    mkdir \"\${XDG_RUNTIME_DIR}\"
    chmod 0700 \"\${XDG_RUNTIME_DIR}\"
  fi
fi" > ~/.profile

setup browser (chromium)

You can use pretty much any browser that supports wayland. The default is chromium.

• install and autostart chromium

root> apk add chromium font-noto
sign> echo "#!/bin/sh

URL=https://schlangen.bytewerk.org/watch/

chromium-browser --kiosk -incognito \
--enable-features=UseOzonePlatform --ozone-platform=wayland \
--start-fullscreen --noerrdialogs --disable-infobars --disk-cache-dir=/dev/null \
--disk-cache-size=1 $URL &
while true; do
  # after a while all browsers begin to stutter. Here is a crude fix
  sleep 600
  WAYLAND_DISPLAY=wayland-1 wtype -P F5
done" > ~/swaystart.sh

setup browser (falkon)

In case you don't want to use chromium you can also use another browser. For instance falkon.

• install and autostart falkon

sign> apk add falkon font-noto
sign> echo "#!/bin/sh

URL=http://example.com/

falkon -e -i -f $URL &
while true; do
  # after a while all browsers begin to stutter. Here is a crude fix
  sleep 600
  WAYLAND_DISPLAY=wayland-1 wtype -P F5
done" > ~/swaystart.sh

setup SPN viewer

root> apk add font-noto-emoji # for snake emojis