Roll your own Linux distro

David M Williams
Tuesday, 26 June 2007 10:18

Business IT - Open Source

ROCK Linux is a flexible distribution build kit. It offers three broad options. The first is to simply use Crystal ROCK as your Linux distro of choice, and not actually do anything yourself. Obviously, this defeats the purpose of what we wish to do in this article, but it leads us nicely into ...

The second option is to target Crystal ROCK and customise it. In this case you do not actually build your own Linux as such but begin with a perfectly fine distro and tweak it to more suit your needs.

Commence by downloading the ROCK source tree from its Subversion repository. http://www.rocklinux.net/svn.html Change directory into the top-level scripts directory and execute the Config script. This presents the ROCK's build menu, to modify the Crystal trunk. You have options to specify the target hardware architecture, included languages and a variety of other options. Once your chosen options are set, a long wait begins: ROCK needs to download the sources for the packages you elect to include, and then compile them. It will opt for the fastest mirror it can find but both the download and subsequent compile can take anyware between hours and days to longer depending on your options and the power of your system.

You now have your very own Linux distro! However, although it exists on your hard disk, it's not easily deployed. To make a bootable CD or DVD run the Config script again any select the bootdisk target. Build this and finally run the Create-ISO script to make your target media.

The third option is to build your own Linux distro, doing with it as you wish.

You begin this way the same as above, by downloading the ROCK source tree. Before executing any scripts, you must create configuration files called preconfig.in and config.in. preconfig.in holds basically just a label for your distro that can be used to reference in. config.in is much more detailed. This contains a list of every package your distribution will supply, and whether it is to be included by default.

You next must make your own build script to actually compile all the necessary packages. As this reads from preconfig.in you really do not need to modify the build script to make your distro work, but here you really can employ all your creative powers to tailor the compilation and packaging of your distro however you wish. Any conceivable option can be implemented so long as you can imagine it and you can code it. A variety of build.sh scripts are provided to give inspiration. It is worthwhile reading through these and tinkering with them.

Finally, build with the bootdisk target and execute the Create-ISO script as above to send your custom distro to a bootable CD or DVD.

That's ROCK in a nutshell. We've been brief, but really there is little more to the process. Besides having loads of hard disk space spare and the patience to wait for your distro to build, ROCK really simplifies the job. Whichever method you choose, you'll find easy instructions with precise commands at the ROCK Linux web site.