Fixing your t480s after firmware updates via fwupd

So I did something stupid. I tried fwupd (nice project though!) and broke my t480s. To be more precise, after the update process finished, the reboot did get stuck and grub did not load. I assumed that the startup process could not locate grub, therefore I went with reinstalling grub via a live USB:

I used to identify the partition to mount:

fdisk -l
Device             Start        End   Sectors   Size Type
/dev/nvme0n1p1      2048    1050623   1048576   512M EFI System
/dev/nvme0n1p2   1050624    2099199   1048576   512M Linux filesystem
/dev/nvme0n1p3   2099200  983898111 981798912 468.2G Linux filesystem
/dev/nvme0n1p4 983898112 1000215182  16317071   7.8G Linux swap

Unencrypt the luks partition

sudo cryptsetup luksOpen /dev/nvme0n1 luks-partition

Next, mount the luks encrypted partition and chroot into it

sudo mkdir /mnt/arch
sudo mount /dev/mapper/luks-partition /mnt/arch
cd /mnt/arch
arch-chroot

Now in the chroot environment of my broken system, I mounted the boot and EFI partitions:

mount /dev/nvme0n1p2 /boot
mount /dev/nvme0n1p1 /boot/efi

And then regenerated the grub configuration and specify the EFI install location

grub-mkconfig -o /boot/grub/grub.cfg
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader id=antergos_grub

And reboot.

That's it. Short guide but took me hours to figure out. That's why this article is basically to future me as I will break my system again.