27

I have an old-ish Lenovo ideapad 110-15ISK with Fedora 30 installed (and a LUKS-encrypted SSD as storage).

When I boot this machine:

  1. The "Lenovo" logo (actually just a text) is displayed, briefly.
  2. The boot manager screen is displayed with selectable kernels
  3. I select a kernel.
  4. The "Lenovo" logo is displayed, briefly.
  5. A password text entry widget is displayed with the "fedora(∫)" logo at the bottom of the screen.
  6. I enter the password to decrypt the LUKS-ified SSD.
  7. The boot process continues while the following is displayed:
    1. The "Lenovo" logo in the middle of the screen and
    2. The "fedora(∫)" logo at the bottom of the screen.
  8. Finally the KDE login screen takes over.

Why does (7) happen? How is it possible to have the "Logo mashup" unless Fedora comes with a special selection of manufacturer logos to display? Because at that point, it is systemd that is in charge of the monitor (maybe via the framebuffer). It is quite mysterious.

  • 6
    Windows 8 and later do the same thing. It's not Fedora-specific, and it's been a long time coming. – Michael Hampton Jun 20 at 13:48
45

This is the result of Hans de Goede’s work on flicker-free boot in Fedora. Hans developed a new Plymouth theme which takes the firmware bootsplash and adds the Fedora logo to it, until boot finishes and the desktop environment takes over.

This works because bootsplash logos are now exposed as an ACPI resource, which you can see in /sys/firmware/acpi/bgrt on systems which support this.

See also the flicker-free FAQ. (This also explains how to modify the Plymouth theme so that the logo is still displayed along with the disk decryption password prompt.)

3

Thats the new Plymouth theme. You can easily change the theme using

plymouth-set-default-theme --list
plymouth-set-default-theme <one from list output> - R

Source: https://fedoramagazine.org/howto-change-the-plymouth-theme/

2

On a very low level, the video memory is not automatically cleared when it is written to. Unless Fedora boot process explicitly clears the screen or changes the video mode, whatever it puts on screen will appear "on top" of what's already there.

  • 6
    I thought about this but I don't remember seeing "pixel crap" appear on a screen since the 90s except for a quarter of a second or so. Zeroing whatever the buffer is currently is the thing that is done (especially in the aesthetically patrolled boot process) – David Tonhofer Jun 21 at 8:13

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