Updating your UEFI firmware under a Linux environment can pose certain challenges, particularly when dealing with specific hardware like the Thinkpad T450s and the latest UEFI version 1.21. It’s crucial to note that while I provide information to guide you through this process, any actions you take based on this information are entirely at your own risk.

Here’s what you’ll need for this guide:

  1. Arch Linux USB-Stick: This will be used to boot the UEFI Shell. You can refer to the Arch Wiki for instructions on setting up a bootable USB-Stick. Link
  2. The latest firmware as an .iso file: You can download this from the official Lenovo support website. Link
  3. Geteltorito Perl script: This script is essential for extracting content from the aforementioned .iso file. You can download it from here.

Once you have all the necessary files downloaded, follow these steps:

  1. Make the geteltorito script executable: Run the command chmod +x geteltorito.pl.
  2. Extract the content from the .iso file using geteltorito: geteltorito jbuj57wd.iso > bios.iso.
  3. Mount the newly generated bios.iso file: Use the commands kpartx -av bios.iso and mount /dev/mapper/loop0p1 /mnt.
  4. Copy the required files from the mounted bios.iso to your UEFI partition:

cp /mnt/EFI/boot/Bootx64.efi /boot/FLASH/
cp /mnt/Flash/SHELLFLASH.EFI /boot/FLASH/
cp -r /mnt/Flash/JBET56WW/ /boot/FLASH/

Once your system is prepared for the firmware update, follow these steps:

  • Boot from your Arch Linux USB-Stick and select the option “UEFI Shell x86_64 v2”.


  • Switch to the appropriate EFI partition in the UEFI Shell. For example, if it’s fs1, use the command fs1:.
  • Navigate to the FLASH directory: cd FLASH.
  • Run the Bootx64.efi file and follow the on-screen instructions. You might need to select option 2 to update the system program.


  • Allow your machine to complete the firmware flash process. You’ll see a progress bar during the reboot.


  • Wait until the flash process is fully finished.

Congratulations! Your system should now be up to date. Be sure to verify the successful update before continuing to use your machine.