Hi,
I’ve been playing with the concept to cover up the boot messages on startup and shutdown for the DietPi, thought it could be handy for some people who want to provide DietPi’s to non-technical users. Tried following RPi guides but most are out of date and don’t work for me. If it could be included in the package that would be cool. If not, I wouldn’t mind a nudge in the right direction.
Thanks!
Yes. I also want to see a simple solution to this problem.
Does this work? (Raspberry Pi only!)
apt install plymouth-themes
sed -i '1s/$/ quiet splash plymouth.ignore-serial-consoles/' /boot/cmdline.txt
reboot
there is no file /boot/cmdline.txt
As stated above, this would be working on Raspberry Pi. But you did not share what SBC you are using. Means @MichaIng did an assumption.
Sorry, Dietpi on Rock64.
Generally the same flags can be added to /boot/dietpiEnv.txt or /boot/armbianEnv.txt (older images) on most non-RPi SBCs, to the end of the extraargs= line. And then:
update-initramfs -u
does this solved your issue?
Yes, in this file /boot/dietpiEnv.txt changed console=tty1 to console=none
That helped!
I want to try the spinner theme. Please tell me why it doesn’t work.
Installation went well
sudo apt install plymouth
sudo apt install plymouth-themes
sudo plymouth-set-default-theme spinner
But when boot I don’t see any changes
/boot/dietpiEnv.txt file
Add the required kernel command-line parameters like this:
sed -i '/^extraarga=/s/$/ quiet splash plymouth.ignore-serial-consoles/' /boot/dietpiEnv.txt
So the three parameters quiet splash plymouth.ignore-serial-consoles' to the end of the extraargs=` line.
Everything is working. Thanks a lot.
I see a black screen, after a few seconds I see a splash picture. Then I see a black screen again for a few seconds, then I see authorization. Can splash be hidden a little later so that we don’t see auto authorization?
Great that it works. Auto-login is actually after the boot process, so I think this cannot be achieved easily. That it’s a few seconds black screen instead of seamless switch to and from splash screen isn’t perfect. But I don’t know much about it, so we’d need to read into it. E.g. not sure if one part is a pure kernel feature or everything manually loaded from initramfs/init, and if so what the initramfs is used for (probably allows optionally showing the splash screen earlier).
Does this change something?
update-initramfs -u
Always after changes in the dietpiEnv.txt file, I ran this command:
update-initramfs -u.
As far as I understand, it saves these parameters in boot.
It doesn’t 
. Bootloader (dietpiEnv.txt) and initramfs are two different things. But okay, then at least it doesn’t seem to be possible make the splash screen appear earlier on this device. Let’s see whether we can make it stop a little later. Can you show the output of this shell command:
systemctl cat plymouth-quit-wait
Added. The difference is not visible.
extraarga=quiet splash plymouth.ignore-serial-consoles systemctl cat plymouth-quit-wait
Oh, this was a shell command to show the plymouth service, not meant to be added to the kernel command-line. Luckily it simply ignores unknown parameters .
just as a hint, try to avoid doing screen prints. You should be able to copy everything from SSH terminal. This would be way better readable 
