Who writes Linux? (And how you can too!)

David M Williams
Monday, 25 August 2008 22:06

Opinion and Analysis

It is certainly true that anyone can modify the Linux kernel for their own means. This has happened in the past, and no doubt will continue to happen. An example is the popular TomTom line of satellite navigation devices. Varied TomTom devices have been Linux-based, with added functionality built in to the kernel to support the hardware.

Yet, the same GPL which permits such to happen also protects the Linux community from losing out on the benefits of effort expended by others. The GPL requires that any derivative product be similarly GPL’d and consequently that its source code be rendered freely available.

In the case of TomTom, they had failed to comply with the obligations of the GPL in making their work available for others. GNU-Violations.org brought them to task on this; agreement was reached and ever since TomTom have made their modified kernel available to any person who wishes to see it, for whatever reason.

So, on the one hand the Linux kernel has built-in protections that guarantee it can never be subverted by any person or organisation because whatever is done with it can not be performed in secret.

This isn’t the only reason why a company like Red Hat would offer their own development to the central kernel project repository. There are plentiful positive examples.

Firstly, any enhancements like support for specific items of hardware that are included in the official kernel will be similarly included in the next release of the kernel. If the definition of library routines and data structures used in the kernel are changed and the enhancements no longer compile this will be noticed and repaired. However, if the program code is out of the official kernel then it is incumbent on its developer to invest time and effort re-applying their changes to each subsequent kernel release.

Kernel code is not automatically included simply because someone contributes it and suggests it has value. It undergoes a stringent review process. No matter how skilled the original developer, the review process will often find ways that bolster the code’s efficiency, robustness and security. Submitting your work for the official kernel means you’ll be better known for beneficial additions rather than useful but buggy third-party add-ons.

Importantly, participating in the development process is a strong means to influence the direction of kernel development. Instead of complaining from the sidelines or blogging away in a quiet part of the web about how to change Linux for the better it’s those who actually submit work that have a strong voice and both the influence and ability to bring their desires into existence.

So far we’ve danced around the edges but let’s look at the lifecycle of a patch to the Linux kernel and the path it takes from a programmer’s keyboard through to powering your system.

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