Linux Device Drivers

Version Numbering

As the last point before digging in to programming, I’d like to comment on the unusual version numbering scheme used in Linux and what version this book refers to.

First of all, note that every software package used in a Linux system has its own release number, and there are often interdependencies across them: you need a particular version of one package to run a particular version of another package. The creators of Linux distributions usually handle the messy problem of matching packages, and the user who installs from a prepackaged distribution doesn’t need to deal with version numbers. Those who replace and upgrade system software, on the other hand, are on their own. Fortunately, some modern distributions allow the upgrade of single packages by checking interpackage dependencies, and this greatly simplifies things for the user who needs to keep system software up to date.

In this book, I’ll assume you have version 2.6.3 or newer of the gcc compiler, version 1.3.57 or newer of the module utilities, and a recent-enough version of the GNU tools (the most important being gmake) for program development. Those requirements aren’t particularly strict, as nearly every Linux installation is equipped with GNU tools, and these versions are relatively old (besides, kernel versions 2.0 and later refuse to compile with a gcc older than 2.6). Note that recent kernels include a file called Documentation/Changes, which lists the software needed to proficiently compile ...