I setup debian 9 for a friend of mine. Now I got the laptop back and no bootable media is found on start.
I booted from the usb drive I installed from using the live mode and followed these steps: https://wiki.debian.org/GrubEFIReinstall which led me to here: https://help.ubuntu.com/community/Grub2/Installing#via_ChRoot
When I execute 12
grub-install /dev/sdb I get
Installing for x86_64-efi platform. error: cannot find EFI directory.
On sdb1 I got /EFI/debian/grubx64.efi On sdb2 I got /proc /sys /run etc.
I'm not sure if sdb1 is my boot-partition or not - I tried both skipping/executing 8
sudo mount /dev/sdXY /mnt/boot.
I used sdb2 for all other sdXY-commands.
When I execute 13
update-grub I get lots of
mkdir: cannot create directory '/var/lib/os-prober/mount': No such file or directory.
How do I recreate the bootloader?