文档介绍：PREFACE
This is, on the surface, a book about writing device drivers for the Linux system.
That is a worthy goal, of course; the flow of new hardware products is not likely
to slow down anytime soon, and somebody is going to have to make all those
new gadgets work with Linux. But this book is also about how the Linux kernel
works and how to adapt its workings to your needs or interests. Linux is an open
system; with this book, we hope, it will be more open and accessible to a larger
community of developers.
Much has changed with Linux since the first edition of this book came out. Linux
now runs on many more processors and supports a much wider variety of hard-
war e. Many of the internal programming interfaces have changed significantly.
Thus, the second edition. This book covers the kernel, with all of the new fea-
tur es that it provides, while still giving a look backward to earlier releases for
those who need to support them.
We hope you’ll enjoy reading this book as much as we have enjoyed writing it.
Alessandro’s Introduction
As an electronic engineer and a do-it-yourself kind of person, I have always
enjoyed using puter to control external hardware. Ever since the days of
my father’s Apple IIe, I have been looking for another platform wher e I could con-
nect my custom circuitry and write my own driver software. Unfortunately, the PC
of the 1980s wasn’t powerful enough, at either the software or the hardware level:
the internal design of the PC is much worse than that of the Apple II, and the
available documentation has long been unsatisfying. But then Linux appeared, and
I decided to give it a try by buying an expensive 386 motherboard and no propri-
etary software at all.
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22 June 2001 16:32
Preface
At the time, I was using Unix systems at the university and was greatly excited by
the smart operating system, in particular when supplemented by the even smarter
utilities that the GNU project donate