Beyond BIOS

Chapter 6 – UEFI Console Services

Never test for an error condition you don’t know how to handle.

—Steinbach’s Guideline for Systems Programming

This chapter describes how UEFI extends the traditional boundaries of console support in the pre-boot phase and provides a series of software layering approaches that are commonly used in UEFI-compliant platforms. Most platforms, at minimum, would have a text-based console for a user to either locally or remotely interact with the system. A variety of mechanisms can accomplish this communication in UEFI. Whether it is through a remote interface, through a local keyboard and monitor, or even a remote network connection, each has a common root that can be thought of as the basic UEFI console support. This ...