The wiki is being retired!
Documentation is now handled by the same processes we use for code: Add something to the Documentation/ directory in the coreboot repo, and it will be rendered to https://doc.coreboot.org/. Contributions welcome!
This document is a work in progress.
What is JTAG?
If you are designing a new hardware and you are interested in supporting LinuxBIOS, you should make a JTAG port available and select chips which allow programming via JTAG.