Restore UEFI Boot Entries

I recently loaded the setup defaults on my ThinkPad after trying to diagnose a boot problem and this cleared the UEFI boot entries leaving me unable to boot my installed OS. In this article, I'll show you how to recreate a new boot entry using efibootmgr.

You'll need a live OS to boot from that has efibootmgr. You might be able to use the Debian netinst rescue mode, but I would recommend the full live install images. I used Tails, a Debian-based live OS focused on privacy, because it's what I had on hand. If you do use Tails, make to enable the administration password at the Tails Greeter.

Whatever you choose, boot into it and get yourself to a root prompt.

Identify the device name for your system partition. In my case, my EFI System partition is sda1, which is always a FAT filesystem and is usually the first partition on a disk.

root@amnesia:~# lsblk -o NAME,FSTYPE,MODEL,SIZE
NAME                      FSTYPE      MODEL                   SIZE
sda                                   SB2                   223.6G
├─sda1                    vfat                                512M
├─sda2                    ext2                                244M
└─sda3                    crypto_LUKS                       222.9G
  └─sda3_crypt            LVM2_member                       222.8G
    ├─thinkpad--vg-root   ext4                                 28G
    ├─thinkpad--vg-swap_1 swap                               11.9G
    └─thinkpad--vg-home   ext4                                183G
sdb                                   USB_2.0_FD              7.5G
├─sdb1                    vfat                                  4G
└─sdb2                    crypto_LUKS                         3.5G

I recommend mounting the EFI system partition to check you have the right disk and also to verify the path to the UEFI binary we'll need next. Unmount when you're done.

root@amnesia:~# mount /dev/sda1 /mnt
root@amnesia:~# find /mnt

Now that you've identified the correct disk, use efibootmgr to create a new entry. --disk is the disk of the system partition, not the partition itself! --part is the partition number, starting at 1. --loader is the path to the UEFI binary. You will need to use shimx64.efi instead of grubx64.efi if you're using SecureBoot. You must use backslashes as the path separator.

root@amnesia:~# efibootmgr --verbose --create --disk /dev/sda --part 1 --loader "\efi\debian\grubx64.efi" --label "Debian"
BootCurrent: 0008
Timeout: 2 seconds
BootOrder: 0012,0000,0001,0002,0003,0007,0008,0009,000A,000B,000C,000D
Boot0000  Setup	FvFile(721c8b66-426c-4e86-8e99-3457c46ab0b9)
Boot0001  Boot Menu	FvFile(126a762d-5758-4fca-8531-201a7f57f850)
Boot0002  Diagnostic Splash Screen	FvFile(a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380)
Boot0012* Debian	HD(1,GPT,3b9ed62c-c28d-4866-842e-29c9bc7b0ac7,0x800,0x100000)/File(\efi\debian\grubx64.efi)

Assuming everything went OK, efibootmgr will list all the entries (which I trimmed here) and your new one should be at the bottom. Confirm everything looks correct and reboot. Fingers crossed!