Comment 458 for bug 1734147

FOR USERS WITH ACTIVE BASH LINE
Hello after a long loong looooong struggle and learning and with the above patch

http://people.canonical.com/~ypwong/lp1734147/linux-image-4.15.0-041500rc6-generic_4.15.0-041500rc6.201712312330+clear+debug_amd64.deb

I successfully restored UEFI BIOS on Lenovo B50-80.

The only solution working for me, if I hadn't played with windows efi boot manager:
First I installed Ubuntu 16.04 in Oracle Virtual Box on Windows PC on a flash drive
- must be at least 16GB.
I had to forbid creating any virtual disks.
Assigned live CD from iso and then simply attached Flash drive.
It was better on Windows than Live Linux.

After successful install on USB Flash drive, I plugged the Flash drive to the affected Lenovo. From
minimal Bash-line I found the grub.cfg location on USB. usually - ls (hd0,XY)/boot/grub
I used the configfile command - configfile (hd0,msdos1)/boot/grub/grub.cfg - in my case.
Grub 2.02 started without hesitation and allowed me to pick to run Ubuntu 16.04 on the USB drive.

Booted in the system I did all the necessary updates
sudo apt update
sudo apt upgrade

I also used boot-repair, that allowed me to see grub graphical interface straightaway
after reboot. But I think this is not necessary.

I did not use ukuu for a kernel upgrade, I just simply used wget command.
Nice inspiration is here: http://sourcedigit.com/22874-update-linux-kernel-4-14-rc7-ubuntu-systems/

UEFI BIOS started to work only after the last upgrade which you can find here in this forum,
and allowed me to change anything permanently after exit.

Then I was able to boot any bootable CD or USB Drive. However I did
Lenovo One key recovery, which magically started to work after UEFI BIOS was unlocked.

Good luck for those still struggling.