Fail to boot after update efi grub

User Support
1

Hi everybody !

I am a happy qubes os user since 2019.

My objective was to restore the display of messages on boot (instead of the loading animation).

So for that:

  • I modified the necessary lines in the file: /etc/default/grub
  • then launched the command “grub2-mkconfig -o /boot/efi/EFI/qubes/grubx64.cfg” (efi mode)
  • And I restarted to test…

Unable to boot on Qubes OS after this change.

To try to correct the problem I:

  • Booted in rescue mode
  • Performed a chroot
  • Restored the original settings in /etc/default/grub
  • Generated a new boot configuration with grub2-mkconfig command
  • Check the entry in EFI firmware with efibootmgr -v command is correct

But … still unable to boot :frowning:

My last idea was to reinstall the grub efi with the command dnf reinstall grub2-efi but I don’t think this is the solution.

Would I have missed something? Do you have any ideas to help me? Thank you in advance for your help!

2

Maybe you meant to overwrite grub.cfg with grub2-mkconfig command, but accidentally overwrote grubx64.efi ?

3

Hi, thank you for your reply !

This is a possibility, what should be the approximate size of the .efi? I’ll check.

If it is necessary to reinstall it, how can I do it from rescue mode without a network?

4

This is a possibility, what should be the approximate size of the .efi? I’ll check.

Approximately 2MB.

If it is necessary to reinstall it, how can I do it from rescue mode without a network?

It should be possible to generate a custom grub image by referring to the following
qubes-lorax-templates/templates/efi.tmpl at v4.1.11 · QubesOS/qubes-lorax-templates · GitHub

5

It should be possible to generate a custom grub image by referring to the following https://github.com/QubesOS/qubes-lorax-templates/blob/v4.1.11/templates/efi.tmpl#L11-L33

Thank you very much for the information !
How did you find this file in the sources? (I would never have thought to search in qubes-lorax-templates)

But I didn’t understand this line (content of option -p):

    -p /EFI/BOOT ${grub_modules}

What is this path?

And is this code valid for version 4.1.2 that I am using?

Wouldn’t it be easier to download the grub2-efi package and install it offline? Or maybe this package doesn’t work for a system like XEN?

6

Ah, it should be replaced with /EFI/qubes. It specifies where grub will search by default (for grub.cfg, etc.)

Thus the command would look like:

grub2-mkimage -O x86_64-efi -o ./grubx64.efi -p /EFI/qubes \
    all_video boot btrfs cat configfile echo efifwsetup efinet ext2 \
    fat font gfxmenu gfxterm gzio halt hfsplus http increment \
    iso9660 jpeg loadenv loopback linux lvm lsefi lsefimmap	\
    mdraid09 mdraid1x minicmd net normal part_apple part_msdos \
    part_gpt password_pbkdf2 png reboot search search_fs_uuid \
    search_fs_file search_label serial sleep syslinuxcfg test tftp \
    video xfs backtrace chain usb usbserial_common usbserial_pl2303 \
    usbserial_ftdi usbserial_usbdebug multiboot2

Since Qubes OS’s grub2 is customized, it is better to boot an installation image of the same version as your machine has and use it’s rescue shell.

7

Thanks for your help @kommuni !