Create ISO9660/Joliet/HFS filesystem with optional Rock Ridge attributes.
sudo apt install genisoimage
genisoimage [options] [-o filename] pathspec [pathspec ...]
Download newest BIOS from https://support.lenovo.com/nl/en/
geteltorito -o bios.img <bootable-iso>
sudo dd if=bios.img of=/dev/<usb> bs=1M
Boot from USB