Build the Kernel

The kernel is what makes Linux tick. Jonni Bidwell is happy to get his hands dirty and help you tune up those ticks…

- By Jonni Bidwell

Linux, if you want to be annoyingly precise about it, isn’t a complete operating system. It is but a kernel. And like the kernel of a seed pod, it requires all the surrounding bits to be useful.

A bootloader can happily load a Linux kernel with no init system specified, and it will just sit there. Without userspace applications (for example, systemd in the first instance) telling the kernel what to do it will simply idle. Yet it has the potential to do anything. The kernel includes everything you would think of as being a low-level component of the operating system, as well as some things you might think belong elsewhere. This includes drivers, filesystems, network protocols, schedulers (process and I/O), memory allocators and all kinds of other treasure.

In the early days of Linux, users would regularly have to face compiling their own kernels, sometimes to get new hardware support, sometimes to reconfigure their way out of brokenness, and sometimes to improve performance. Users of Linux From Scratch or Gentoo will be familiar with the kernel compilation process, since it’s more or less mandatory there. But it’s an option for any flavour of Linux, so we thought we’d have a go at making building kernels more accessible.