“no bootable devices found” after installation of Mageia Linux

After the installation of Mageia 9 my Dell laptop refuses to boot with the following error: “No bootable devices found”

Background: Before, Ubuntu 22.04 was installed on the laptop. But I erased it completely and rearranged the partitions, too.


Manually create a boot option using the DELL setup utility (aka UEFI BIOS):

  1. Press F2 to open the setup utility
  2. Go to: General | Boot Sequence
  3. Under “Boot list option”: Make sure UEFI is selected
  4. Click on “Add Boot Option”
  5. Enter a meaningful “Boot Option Name”, e. g. “Mageia 9”
  6. Click on “…” to select a file name
  7. Navigate to \EFI\mageia\grubx64.efi
  8. Done.

Further information

In the setup utility, I have Secure Boot disabled.

An official Knowledge Base Article of DELL recommends to set System Configuration | SATA Operation to “AHCI” for linux installations. Unfortunately, mine is set to “RAID on”. Maybe that is causing the issue…

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”.

Using the eID function of the german identity card on Linux

Here is a short step-by-step guide for setting up your RPM-based distribution for using the eID function of the german identity card:

Hardware requirements: I’m going to use the “REINERSCT cyberJack RFID basis” device for reading my identity card.


  1. Install the package ccid (which contains the “Generic USB CCID smart card reader driver”): dnf install ccid
  2. As eID client I’m going to use the Open eCard client (an alternative to AusweisApp): Download it and install it using rpm -i open-ecard-app-...rpm
  3. Connect your RFID device to your computer
  4. Put your ID card on the device
  5. Open the Open eCard client
  6. At first, if you haven’t used eID before, you’ll have to replace the transport PIN (5 digits) with a custom PIN (6 digits). Just select the “PIN management” option in the Open eCard client and follow the instructions. The custom PIN is now your PIN for unlocking your data on the identity card. Make sure to remember it!

eID process (example)

If the setup is done and the Open eCard client is running you can start an eID process from your browser. This is pretty straightforward. In my example I had to identify myself for activating my prepaid SIM card from ja!mobil/congstar which I bought at a local supermarket. In that particular case, the eID process is integrated in the so called “POSTIDENT” method (provided by Deutsche Post AG):

  1. Select “eID function” as identification method
  2. On the second page, ignore the Smartphone app instructions and click on the link “start the AusweisApp2 here” instead (you’ll find it at the bottom of the page)
  3. Now, the Open eCard App will guide you the the procedure and ask for your PIN in order to unlock your data.
  4. A success message will be displayed in your browser.

Screenshots of the eID process with POSTIDENT

Step1: Select eID function
Step 2: Click at the link at the bottom.
Step 3: Follow the instructions of the Open eCard App
Step 4: Done =)

Replicate a foreign Subversion repository

If you want to replicate/mirror an existing repository which you do not own (i. e. svnadmin dump cannot be used), you can use the svnsync command.

At first: Create a new and empty destination repository on your server:

svnadmin create mirror

Next, create a so called “pre-revprop-change hook script”. This is needed for the subsequent steps.

nano /srv/subversion/mirror/hooks/pre-revprop-change
if [ "$USER" = "yolo" ]; then exit 0; fi
echo "Only the syncuser user may change revision properties" >&2
exit 1

This limits the synchronizing mechanism to the specified user and is executed by Subversion automatically.

Now, initialize and perform the synchronization of the repositories:

svnsync init svn://YOUR_HOST/mirror/ SOURCE_REPOSITORY
svnsync sync svn://YOUR_HOST/mirror/

If the process comes to a halt, you can abort it using Ctrl+C and restart it without breaking anything. The process will continue were it was aborted (as everything is versioned this is not a problem).

For details: Chapter “Replication with svnsync” in the Subversion book.

Installing a Subversion server on CentOS 8

We are going to use the server “svnserve” which is contained in the subversion package of CentOS. This package contains also the svnadmin tool for creating a subversion repositories.


dnf install subversion

Service configuration

The default location for Subversion (SVN) repositories is /var/svn. We are going to change it to /srv/subversion like this (as root):

mkdir /srv/subversion
nano /etc/sysconfig/svnserve
OPTIONS="-r /srv/subversion"

By default, svnserve is executed as root – holy cow! For security reasons, we’re going to change it to a different user. We edit the systemd unit file and add the following lines under the section “[Service]”:

nano /usr/lib/systemd/system/svnserve.service

You can create the user e. g. with useradd -m yolo.

Make sure that our “yolo” user can access /srv/subversion properly:

chown -R yolo:yolo /srv/subversion

Furthermore, another change is necessary due to the new user which executes the service: The directory /run/svnserve/ contains a file where the service stores its process ID. But the directory is only accessible by the root owner. Changing the file permissions with chown is NOT sufficient because this folder will be recreated after reboot and thus the old permissions will be restored. We have to change the entry in the appropriate configuration file which is responsible for the recreation of this folder (see man tmpfiles.d for details):

nano /usr/lib/tmpfiles.d/svnserve.conf
D /run/svnserve 0700 yolo yolo -

Now, we can start the service (and enable it if you want to start it automatically):

systemctl start svnserve
systemctl status svnserve
systemctl enable svnserve

Create a test repository

Use our “yolo” user which also runs the svnserve process for the following commands:

cd /srv/subversion
svnadmin create repo1

Configure user authentication:

cd repo1
nano conf/svnserve.conf
anon-access = none # disallow anonymous access completely
password-db = passwd # file with credetials

Add some credetials:

nano conf/passwd
user = pw

Check it out

The repository set-up is complete. Now, we should be able to check it out with a Subversion client on a remote computer:

svn co svn://HOST/repo1 --username USER

Surveillance cam HWI-B140H-M (HIKVISION HiWatch Series)

I recently bought the HWI-B140H-M from HIKVISION in order to test it on Linux. But the results were quite disappointing:

  • You can access the cam via browser but for some features (e. g. configuring areas for motion detection) you need either their windows client software (iVMS) or you need an old browser (Chrome 44.x, Firefox 51.x or lower) with browser plugins. Fun fact: They don’t tell you which plugins are meant. So without windows, you have a hard time.
  • Interestingly enough, the manual says that when the WebSocket function is activated, you could use all features in your current browser without plugins (which contradicts the information at the beginning). But there is no such function (in the windows client not either) although the most recent firmware is installed.
  • I updated the firmware to the most recent version (V5.5.80 build 180911) using the windows client in a VirtualBox Windows VM. After the update, I could not access the web interface anymore. It turned out, that they are blocking my browser’s user-agent ID. How dare you! With the Firefox addon user-agent switcher and manager and an IE 11 user-agent the web interface is accessible again.
  • My FritzBox router has a NAS function. So i set up a Samba (SMB) share and finally configured it in the web interface of the cam. It worked but the cam showed the Samba device as “uninitialized”. The cam’s manual instructs you to click on “Format” to solve this but it did not work. I tried several configurations, tested the Samba share on nautilus but I always got an error (permission blabla). Some folks had the same trouble in 2014 (cctvforum.com). No working solution, so I gave it up.
  • The user manual of the cam is the worst manual I’ve ever seen. It contains contradicting informations (see above) and many sections only apply to a certain device but they don’t mention the device. Furthermore, it’s more a listing of features than explaining hands-on how to configure the device properly. “Here are the information, deal with it”.

My advice: Don’t buy it.

Best open source music player for Android (custom rom)

I’m now using VLC from the f-droid.org repository. You can navigate to any folder you want and hit play and VLC will play back all tracks in the current folder. So no need for setting up indexing on particular folders and having trouble with files outside of that folder.

Before that, I used the App Vanilla Music but yesterday, it drove me up the wall. Every time when I copy new music or audio books to my smartphone, I had to restart the entire phone because only then Vanilla Music updated its file index and displayed the new tracks. Furthermore, I had files outside of the indexed folder. The playback of these files was nearly impossible. Although you could navigate to these files within Vanilla Music, the playback did not work. You could start the playback from the file manager but you had to enqueue file by file – m3u playlists did not seem to work either. That’s why I switched to VLC.

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)


Using Amaze file manager to transfer data between your PC and your Android phone

Instead of using a USB cable to transfer data between your PC and your smartphone using MTP, you can also use a wireless connection and Amaze file manager app and an FTP client.

  1. Install the Amaze file manger on your Android phone (e. g. available at F-Droid app store).
  2. Establish a connection to your wireless router, i. e. activate WiFi.
  3. Open Amaze and navigate to the hamburger menu
  4. Click on “FTP Server”
  5. Optional: Configure the settings
  6. Click on “Start” to launch the FTP server
  7. After starting the server, Amaze will show the IP address and port number of the FTP server (if it does not work, chek your router settings – DHCP should be configured to automatically assign an IP address to connecting devices)
  8. Important: Do NOT lock your device i. e. leave the screen on – otherwise, the following connection attempt might fail.
  9. Use the shown IP address and port number on your FTP client (on your PC) as to connect to the FTP server. Good FTP clients are FileZilla or Nautilus.
In the hamburger menu, click on “FTP Server”
This dialog will be shown