Plymouth is the application which provides the graphical "bootsplash" for Ubuntu.

Quick Facts

Plymouth:

• Uses KMS (Kernel Mode Setting) (where possible) and the framebuffer to set the screen resolution.
• Comprises 3 components:

  • A daemon (server) process called plymouthd
    

    • The daemon is responsible for the graphical display, animation and logging.

  • A client application called plymouth
    

    • The client sends commands to the daemon

  • A library libply.so to allow applications to be written to talk to the daemon
    

    • (The plymouth command is linked to libply.so for this reason).

• Supports themes.

• Is scriptable (see package plymouth-theme-script)

• Runs at system startup and system shutdown:
  • Boot

    • plymouthd is started in the initramfs
      

      • (see file /usr/share/initramfs-tools/scripts/init-top/plymouth)

    • plymouthd is stopped at the point the Display Manager is starting
      

      • (see Upstart job configuration file file /etc/init/plymouth-stop.conf).

  • Shutdown

    • plymouthd is started by Upstart
      

      • (see Upstart job configuration file file /etc/init/plymouth.conf).

• Writes a log to /var/log/boot.log.

Options

Daemon

plymouthd runs in one of two modes which are set by specifing the appropriate command-line option:

• --mode=boot

• --mode=shutdown

This allows Plymouth to display potentially different content based on whether the system is starting or stopping.

Testing

Running Plymouth "post-boot"

You can experiment with Plymouth after your system has booted. To start the Plymouth daemon:

1. Boot system and login as usual

2. [RECOMMENDED] Install plymouth-x11 package (allows you to see the boot screen in an X11 window)

   • sudo apt-get install plymouth-x11

3. Start a terminal (such as gnome-terminal)

4. Start the Plymouth daemon by running the following:

   • sudo plymouthd --debug --tty=`tty` --no-daemon

Plymouth is now running, so we can have some fun:

• To check if Plymouth really is running:
  

  • sudo plymouth --ping && echo plymouth is running || echo plymouth NOT running

• To show a message on our "boot" screen

  1. Start another gnome-terminal terminal/tab

  2. Run the following to show the Plymouth window:
     

     • sudo plymouth show-splash

  3. Display a message

     • sudo plymouth message --text="hello world"

• A slightly more useful example
  1. Show the splash screen

     • sudo plymouth show-splash

  2. Stop the graphical progress indicator

     • sudo plymouth pause-progress

  3. Display a message

     • sudo plymouth message --text="pausing boot - press 'c' or space bar to continue"

  4. Wait for the user to type either 'c', 'C' or space (no return required)

     • sudo plymouth watch-keystroke --keys="cC " --command="tee /tmp/c_key_pressed"

  5. Change the on-screen message

     • sudo plymouth message --text="resuming boot"

  6. Resume the graphical progress indicator

     • sudo plymouth unpause-progress

To stop the Plymouth daemon:

• sudo plymouth --quit

Debugging

This section is for advanced users only.

Showing old Text-based Boot

If you want to see the text-based boot messages, press ESCAPE at any point when Plymouth is running. Note that the ESCAPE key acts as a toggle, so you can keep switching between graphical and text mode if required.

Enabling Logging

You can set Plymouth to overlay internal debug messages by passing the following command-line option:

• plymouth:debug

For example, if you are running Ubuntu Maverick (10.10):

1. Power on system

2. Hold down the SHIFT key until the Grub boot menu appears

3. Type "e" to edit the default kernel command-line

4. Use the arrow keys to go to the end of the line which starts "linux /boot/vmlinuz ..."

5. Add a space character, followed by "plymouth:debug"
   Notes:

   • If you're interested in the overall boot, you may wish to remove the "quiet" keyword too)

6. Type CONTROL+x to boot

7. Once the system has booted, you can view all the Plymouth debug output in file var/log/plymouth-debug.log.

Notes:

• If you are using the live CD, the process is slightly different:
  1. Power on system
  2. Hold down the SHIFT key until ISOLINUX "boot:" prompt appears

  3. Type, "live plymouth:debug"

Additional

"plymouth ask-question"

Note that the standard Ubuntu plymouth theme does not implement the display_question callback (see bug 509384).

This means that "plymouth ask-question" will not work. However, similar functionality is provided by a combination of "plymouth message" and "plymouth watch-keystroke".

CategoryBoot