plymouth - graphical boot animation and logger



Plymouth is an application that runs very early in the boot process

(even before the root filesystem is mounted!) that provides a graphical

boot animation while the boot process happens in the background.



It is designed to work on systems with DRM modesetting drivers.  The

idea is that early on in the boot process the native mode for the

computer is set, plymouth uses that mode, and that mode stays throughout

the entire boot process up to and after X starts.  Ideally, the goal is

to get rid of all flicker during startup.



For systems that don't have DRM mode settings drivers, plymouth falls

back to text mode.



In either text or graphics mode, the boot messages are completely

occluded.  After the root file system is mounted read-write, the

messages are dumped to /var/log/boot.log.  Also, the user can see the

messages at any time during boot up by hitting the escape key.



Plymouth isn't really designed to be built from source by end users.

For it to work correctly, it needs integration with the distribution.

Because it starts so early, it needs to be packed into the

distribution's initial ram disk, and the distribution needs to poke

plymouth to tell it how boot is progressing.



plymouth ships with two binaries: /sbin/plymouthd and /bin/plymouth



The first one, plymouthd, does all the heavy lifting. It logs the

session and shows the splash screen. The second one, /bin/plymouth, is

the control interface to plymouthd.



It supports things like plymouth --show-splash, or plymouth

--ask-for-password, which trigger the associated action in plymouthd.



plymouth supports various "splash" plugins which are analogous to

screensavers, but happen at boot time.  Currently there are three

graphical splash plugins: solar, fade-in, and spinfinity.  There are

also three non-graphical plugins which are for text mode and the

detailed view.



The graphical plugins need a logo image and background color to

function.  Distributions are expected to set these up in their packages

at ./configure time, but there are some placeholder values set up if

./configure doesn't get those options.



Plymouth isn't done yet.  It's still under active development and isn't

ready for distros to use as-is.  That should change in the near future

though.