Preface

There are two mistakes one can make on the road to truth…not going all the way, and not starting.

Buddha

This is a book about a new way to solve an old set of problems that are persistent as well as fundamental, but not always well understood: How should you boot a computer? What sits at the reset vector? What can the operating system count on when it is loaded and initially receives control? What should the internal structures be between these two endpoints? How can the same basic structure work for handhelds and megaservers? How do we convince ourselves today’s design will work 10 or 20 years from now? How much will it cost to switch? How much will it cost steady state? What comes after BIOS (Basic Input/ Output System)?

Beyond BIOS is a book about a largely invisible subject. The general user, if they have any view of BIOS at all, tends to view it as ten unnecessary seconds on the way to booting the operating system or as setup. The community that knows and uses the BIOS has tended to view it as an uncontrolled place of kludge, myth, bug, and legend. The very small community of BIOS developers has viewed their code not only as highly mutable and embodying much of the compatibility that has made the PC and its offspring so successful, but also as their livelihood.

This is a book that is about what comes after BIOS, which we call the Unified Extensible Firmware Interface (UEFI) and Platform Initialization (PI). In doing so, it must also be a book at least partly about what a BIOS or its replacement is called upon to do. It is not a cookbook on how to port the PI from platform to platform. It is not a rehash of the specifications. Instead, it tries to fit in the middle ground between specifications and cookbook. It tries to focus on the concepts and constructs that are cross-platform and implied, if not stated, by the architecture. It is supposed to help to get to some of the “why” behind the specs and make the porting work make some sense.

This book is a child of its time. Both the UEFI and the PI are under the control of the UEFI Forum, an industry-wide group in which you are encouraged to participate. Beyond BIOS mainly focuses on the current state of the PI and UEFI since the 2005 formation of the Forum, its working groups, and its sub-teams. This is not to say that this is only a history book or a simple summary of the standard. Instead, we believe it remains valuable as an introduction to the newer versions of the specifications no matter who “has the pen.”

If you find this book to be useful, then we encourage you to obtain Harnessing the UEFI Shell: Moving the Platform beyond DOS by Rothman, Zimmer and Lewis, De|G Press, February 2017.