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Simón
Asked: 2020-11-19 15:22:23 +0800 CST

How to specify EFI vendor boot logo image displayed when Ubuntu is loading?

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I have an old Dell Latitude E6330 laptop, it has this logo at boot time:

Dell logo in the center of the screen, and a small Energy Star Ally logo in the corner

I have dual boot, and when Windows boots, it correctly displays the large DELL circle logo.

But when Ubuntu boots, after the grub menu, it chooses the small Energy icon instead.

Small Energy Star Ally logo in the center of the screen, and the Ubuntu logo below

So I have not one but several questions related to this:

  • Why is Plymouth displaying the wrong image?
  • How does Ubuntu pick the logo image from EFI?
  • Can I help it choose the correct logo image to display during the boot process?
  • Or even better: can I customize it?
customization plymouth boot uefi logo

1 Answers

  1. Trying to answer your questions one by one. I do not know about that particular machine and it's BIOS, so a lot of it is guesswork; but it might help you to get closer to a solution.

    • Why is Plymouth displaying the wrong image?

    Maybe there is more than one entry in the UEFI BIOS' ACPI "BGRT" (Boot Graphics Resource Table) and Plymouth (probably more likely, the kernel, see below) is selecting the wrong one.

    • How does Ubuntu pick the logo image from EFI?

    The Kernel provides a view onto the BGRT in /sys/firmware/acpi/bgrt/*, with /sys/firmware/acpi/bgrt/image being the BMP image to display. You can copy it to e.g. /tmp/bgrt.bmp and open it from there to see what it looks like.

    • Can I help it choose the correct logo image to display during the boot process?
    • Or even better: can I customize it?

    Probably the easiest way is to provide your own image and load it instead of the BGRT image.

    The quickest way, IMHO, is to comment out all the UseFirmwareBackground=true lines in /usr/share/plymouth/themes/bgrt/bgrt.plymouth and place a screen-sized (e.g. 1920x1080) PNG with the logo you like as /usr/share/plymouth/themes/spinner/background-tile.png.

    As your modifications to bgrt.plymouth will likely be undone by a later update, you might want to copy it to /usr/share/plymouth/themes/fixed-background/fixed-background.plymouth and switch to it with update-alternatives --config default.plymouth, and make it available for future boots with update-initramfs -u.

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