To update a modern thinkpad on linux, you can download a BIOS update as a bootable CD image. This cannot be used directy for a USB. We first need to use the ‘geteltorito’ tool. In debian, this tool is on the genisoimage package.
> sudo apt-get install genisoimage
Then we can use the tool to create a bootable iso:
geteltorito.pl -o bios.img n1wur26w.iso
To boot from this USB key you NEED to setup UEFI boot on the startup menu on the BIOS (Normally I have ‘Legacy only’, and with that option on the USB key does not boot)