More Kernels

Yesterday, we talked a bit about the Linux kernel. It’s the core of the operating system and it has some distinct differences between the kernels in other operating systems.

I want to take this series in a little different direction today. Let’s talk, at a high level, about the steps necessary to compile a kernel that suits your needs. I’ll give you an overview of the steps as a way of creating a framework for the rest of the series. If you plan on compiling a kernel of your own as the result of this series, hold on to today’s newsletter - you’ll need these guidelines when it’s all said and done.

Regardless of what you’ve probably heard about the complicated nature of compiling your own kernel, we’re going to lay out a simple ten step process that should work to recompile your kernel, regardless of your distribution. We’ll cover the details of these steps throughout the rest of the series, but here’s the general plan of action.

1. Configure your new kernel’s parameters. This will define the components and set of instructions that are both built into the kernel and those that are created as loadable modules. This step is, in some ways, the most time consuming step of the process.
2. Clean out any previous configurations using the make clean command. This assures that you’re compiling the kernel based on the parameters you’ve established in the first step.
3. Find and create all the dependencies for your new kernel, using the make dep command.
4. Build the actual kernel image using the make bzImage command.
5. Build the loadable modules (or device drivers) that will be needed for some of your devices and/or processes. This is done with the make modules command.
6. Install these newly-built modules using make modules_install.
7. Move the new kernel image to the /boot directory, or any other directory from which you’d like to boot the system.
8. Delete any symbolic links that point to the old kernel version and create new ones.
9. Modify lilo, or, at a minimum, make sure that it points to the new kernel image.
10. Commit lilo, using the /sbin/lilo command.

Be prepared to roll up your sleeves for the next several days, as we’ll start talking about these steps in detail tomorrow. Along the way, you’ll take a quantum leap in your understanding of the Linux system and your ability to customize it, at the most basic level, to meet your needs. Promise.