PSplash daemon snap

This snap contains the PSplash binary run as a daemon to hide terminal consoles on Ubuntu core devices if wanted.

PSplash is a userspace graphical boot splash screen for mainly embedded Linux devices supporting a 16bpp or 32bpp framebuffer. It has few dependencies (just libc), supports basic images and text and handles rotation. Its visual look is configurable by basic source changes.

The snap ships with the psplash-write untility to send messages to the screen from scripts or the commandline. There is also a service included that will print the ssh login credentials on the splash screen.

NOTE: this snap has to run in devmode, there is no snapd interface providing direct access to the framebuffer device with all additional bits (full /dev/tty0 ownership and sys_tty_config capability support) yet.

Building

To build this snap natively on an armhf machine just call

snapcraft

If you are cross building on an amd64 system, make sure to first install the gcc-arm-linux-gnueabihf package and then call snapcraft.

sudo apt install gcc-arm-linux-gnueabihf
snapcraft

Build time configuration

The tree ships a ./config file containing two variables.

SPLASH="core_black-orange_st_hex.png"
FONT="/usr/share/fonts/truetype/ubuntu-font-family/Ubuntu-R.ttf"

To ship your own image place it in the toplevel of the tree and replace core_black-orange_st_hex.png in the config file with the name of your png.

Likewise you can put your own truetype font into the toplevel tree and add its name to the config file (without full path) or, if the font is in an ubuntu package, you can add the package name to the "build-packages" stanza in snapcraft.yaml and define the full path to the ttf file in the config.

To disable the showing of the ssh command for remote logins, just remove the "showlogin" block from the apps: section in snapcraft.yaml

showlogin:
  command: showlogin.sh
  daemon: simple
  plugs: [network, network-bind]

Runtime configuration

If you want to avoid any login consoles to take over your screen from psplash, add the options

vt.handoff=2 quiet

to your kernel cmdline. To quieten any u-boot messages on boot set the "stdout" variable to "serial" in the u-boot configuration.

stdout=serial