How to manage your .config files

Introduction

When we work with Linux Kernel, we have a precious file named .config, which describes how to compile the kernel. If you work in the kernel for a long time, the chances are that you have multiple config files for working with different devices. You probably end up with numerous .config files saved somewhere in your hard disk, and when you need it, you take a look at this old and dusty folder. What if we have a tool to manage these config files? What if I tell you that we already have it under kw? Yeah, we have it, and in this tutorial, we will learn about the config manager or just the kernel-config-manager feature.

Save your config file

If you are in a kernel tree with an important .config file, you can save it under kw by using the --save option, which requires giving a name for your config. For example, let’s suppose that you are working in the Raspberry Pi tree and you have a good config file; you can save it by using:

kw kernel-config-manager --save "RASP4"

The name you used in the --save option will be used later to retrieve the config file. You probably noticed that just using the name does not describe your config file well, and for this reason, kernel-config-manager also provides a description option to better describe your config file. For example, you could use:

kw kernel-config-manager --save "RASP4" -d "RASP4 config file used in the project LALA"

List config files under kw

To show all the config files saved using kw, you just need to use:

kw kernel-config-manager --list # kw k -l

The above command displays the configs labels and the descriptions associated to them.

Retrieve a config file

If you want to retrieve a specific config file, you can use the following command:

kw kernel-config-manager --get <label>

For example:

kw kernel-config-manager --get RASP4

This command will first check if you already have a .config file in your kernel tree; if you do, it will ask you whether to override it or not.

Conclusion

The kernel-config-manager option makes it easier for you to keep track of different config files. Another advantage of using this feature comes from the fact that the backup option also saves these files, enabling you to easily move your config files. Finally, under the hood, these config files are maintained by a folder structure managed by kw. If you want to see these files, they are stored inside this folder:

$XDG_DATA_HOME/kw/configs

Or:

$HOME/.local/share/kw/configs

Depending on your configurations.