[slackersc]

I don't know about the X220, but I can tell you about my experiences with setting up an X200 I bought off ebay. Its not quite trivial..

You need to get access to the SPI flash chip on the mother board. They sell some fancy little clips to attach wires, but I just had one of the hardware guys at work tac some wires directly to the chip. Then I used a raspberry pi to flash the image across using their tools. Maybe I had a dodgy connection, but it took several tries of flashing to get it to work correctly.

Once installed it isn't much of a bios. It is mostly just GRUB, you lose all the existing bios settings completely. It lets you boot from different images and thats about it. It does work well once it's set up though.

Here's a few low quality photos of the procedure. http://imgur.com/a/zAQRl