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07 March 2019 @ 02:09 pm
Flicker Free Boot FAQ  
There have been questions about the Fedora 30 Flicker Free Boot Change in various places, here is a FAQ which hopefully answers most questions:

1) I get a black screen for a couple of seconds during boot?

1.1) If you have an AMD or Nvidia GPU driving your screen, then this is normal. The graphics drivers for AMD and Nvidia GPUs reset the hardware when loading, this will cause the display to temporarily go black. There is nothing which can be done about this.

1b) If you have a somewhat older Intel GPU (your CPU is pre Skylake) then the i915 driver's support to skip the mode-reset is disabled by default (for now) to fix this add "i915.fastboot=1" to your kernel commandline. For more info on modifying the kernel cmdline, see question 6. .

1c) Do "ls /sys/firmware/efi/efivars" if you get a "No such file or directory" error then your system is booting in classic BIOS mode instead of UEFI mode, to fix this you need to re-install and boot the livecd/installer in UEFI mode when installing. Alternatively you can try to convert your existing install, note this is quite tricky, make backups first!

1d) Your system may be using the classic VGA BIOS during boot despite running in UEFI mode. Often you can select BIOS mode compatility in your BIOS settings aka the CSM setting. If you can select this on a per component level, set the VIDEO/VGA option to "UEFI only" or "UEFI first", alternatively you can try completely disabling the CSM mode.

2) I get a black background instead of the firmware splash while Fedora is booting?

Do "ls /sys/firmware/acpi/bgrt" if you get a "No such file or directory" error then try answers 1c and 1d . If you do have a /sys/firmware/acpi/bgrt directory, but you are still getting the Fedora logo + spinner on a black background instead of on top of the firmware-splash, please file a bug about this and drop me a mail with a link to the bug.

3) Getting rid of the vendor-logo/firmware-splash being shown while Fedora is booting?

If you don't want the firmware-splash to be used as background during boot, you can switch plymouth to the spinner theme, which is identical to the new bgrt theme, except that it does not use the firmware-splash as background, to do this execute the following command from a terminal: "sudo plymouth-set-default-theme -R spinner"

Note that the kernel will restore the vendor-logo early on at boot in case it got damaged by e.g. option ROM messages. If you are switching to the spinner theme you may also want to add "video=efifb:nobgrt" to your kernel commandline. See 6) below for how to edit the kernel commandline.

4) Keeping the firmware-splash as background while unlocking the disk?

If you prefer this, it is possible to keep the firmware-splash as background while the diskcrypt password is shown. To do this do the following:

  1. "sudo mkdir /usr/share/plymouth/themes/mybgrt"

  2. "sudo cp /usr/share/plymouth/themes/bgrt/bgrt.plymouth /usr/share/plymouth/themes/mybgrt/mybgrt.plymouth"

  3. edit /usr/share/plymouth/themes/mybgrt/mybgrt.plymouth, change DialogClearsFirmwareBackground=true to DialogClearsFirmwareBackground=false, change DialogVerticalAlignment=.382 to DialogVerticalAlignment=.6

  4. "sudo plymouth-set-default-theme -R mybgrt"

Note if you do this the disk-passphrase entry dialog may be partially drawn over the vendor-logo part of the firmware-splash, if this happens then try increasing DialogVerticalAlignment to e.g. 0.7 .

5) Get detailed boot progress instead of the boot-splash ?

To get detailed boot progress info press ESC during boot.

6) Always get detailed boot progress instead of the boot-splash ?

To always get detailed boot progress instead of the boot-splash, remove "rhgb" from your kernel commandline:

Edit /etc/default/grub and remove rhgb from GRUB_CMDLINE_LINUX and then if you are booting using UEFI (see 1c) run:
"grub2-mkconfig -o /etc/grub2-efi.cfg"
else (if you are booting using classic BIOS boot) run:
"grub2-mkconfig -o /etc/grub2.cfg".