This is a very brief writeup of how to upgrade the BIOS on a X1 Carbon (G1) from Linux.
For more information on this topic there is always the excellent Think Wiki.
How do I update Lenovo BIOS from Linux without using MS-Windows operating system with the help of a USB stick?
The BIOS update also fixes bugs in Intel ME, provides Intel CPU microcode and other vulnerabilities such as Meltdown and Spectre. Use Google or support.to search for “lenovo x230 bios”. Make sure you follow on screen info to update the BIOS.
One can use the wget command or curl command to grab the bootable CD: key and select USB mass storage device as boot source. This video will give all guidance without using an old-fashioned MS-Windows or CD.
After the custom image has been generated, boot the image via one of the methods shown below.
Download Free DOS and tools: Note If you simply wish to update your bios, there is no need to tinker with the Free DOS image on System Rescue CD. Boot on the usb stick and choose Dos tools --- FREEDOS from the systemrescuecd startup menu.