Warning:- This Article is not recommended for an average user as things may break and do not try this on your mission critical systems, there is no guarantee that this will work well, but give it a shot if you like but do not blame me for this ;-). I’ve found the exact commands as mentioned below here for reference I’ve considered sda5 as my concerned targeted partition, your mileage may vary so input with caution. These commands have been taken fro Makulu Linux forum and are working at the time of writing, however be prepared to mess around with your system IMO, have fun 🙂
Input these commands one by one after reading the above warning, strictly after entering into the recovery mode and do not miss or change the order as mentioned below:
sudo chroot "/mnt/boot-sav/sda5" dpkg --configure -a
sudo chroot "/mnt/boot-sav/sda5" apt-get install -fy
sudo chroot "/mnt/boot-sav/sda5" apt-get purge -y grub*-common shim-signed
If you’re in luck, go for this 😉
sudo chroot "/mnt/boot-sav/sda5" apt-get install -y grub-efi-amd64-signed shim-signed linux-headers-generic linux-signed-generic
===================================================================================An error occurred during the repair.
A new file (/var/log/boot-repair/20200401_094847/Boot-Info_20200401_0948.txt) will open in your text viewer.
In case you still experience boot problem, indicate its content to:
boot.repair@gmail.com
You can now reboot your computer.
Please do not forget to make your BIOS boot on sda2/EFI/makululinux/shimx64.efi file!
If your computer reboots directly into Windows, try to change the boot order in your BIOS.(note this is applicable if Windows is installed).
If your BIOS does not allow to change the boot order, change the default boot entry of the Windows bootloader.
For example you can boot into Windows, then type the following command in an admin command prompt:
bcdedit /set {bootmgr} path \EFI\makululinux\shimx64.efi
That’s all, have fun hacking !