Installing GRUB bootloader fails with cryptic error message “Could not prepare Boot variable: Function not implemented” and “grub-install: error: efibootmgr failed to register the boot entry: Input/output error.”

When trying to install a new Linux distribution (Debian or Mageia or Arch Linux) on my new machine, the installation failed with the following error messages:


The installation of grub-install dummy has failed
Unable to install grub-install dummy : Fatal Error

Mageia/Arch Linux:

Installing for x86_64-efi platform.
Could not prepare Boot variable: Function not implemented
grub-install: error: efibootmgr failed to register the boot entry: Input/output error.


I’m using an Arch Linux image to boot into a shell environment.

fdisk /dev/sda

This displays information about the partition table. It displays “Disklabel type: dos” which means that the partition is of type DOS/MBR which could cause trouble (according to the documentation in the ArchWiki).

Furthermore, in the UEFI/BIOS of my machine under “Advanced | OS selection” there is the option “UEFI CSM” set to “always”. CSM means Compatibility Support Module and it enables the legacy (BIOS) boot mode. This could be a problem.


Set the “UEFI CSM” (Compatibility Support Module) to “never” in the UEFI BIOS and reinstall the Linux distribution (or just the GRUB bootloader). The system now boots using UEFI. The partition type is still “dos”.

Setting up dnf on Mageia 7

As you can see with dnf repolist, only the core repository and the update repository are activated on Mageia 7 by default.

The repositories nonfree and tainted are pre-configured in configuration files within /etc/yum.repos.d/ but disabled by default. You can easily activate them by executing the following command:

# dnf config-manager --set-enabled mageia-x86_64-nonfree updates-x86_64-nonfree mageia-x86_64-tainted updates-x86_64-tainted

That’s it. Now, when you try to install a package or upgrade the system, the nonfree and the tainted repository are considered as well.

Watching maxdome video streams on Linux

Edit: Currently (about two month later), it does not seem to work anymore =(

It worked on my machine with a Firefox 60.9.0esr. But at first, there were two things that hindered the playback:

  • The Ad-Blocker – I had to disable it.
  • The user agent setting of Firefox has to be something like “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3835.0 Safari/537.36”. This can easily be achieved with the Firefox addon User-Agent Switcher and Manager.

You also have to make sure, that the Firefox Addon “Widevine Content Decryption Module provided by Google Inc.” is installed and activated (see Watch DRM content on Firefox).

In my opinion, it is pretty silly that you have to fake your user agent in order to watch the movies. But according to the customer support this is done on purpose:

Da wir Linux nicht unterst├╝tzen ist ein funktionierender Abruf ├╝ber die entsprechenden Systeme nicht vorgesehen.

Reply from the “maxdome Kundenservice” on my inquiry (December 8th, 2019)