To get a feel for using the kbuild menu system via the convenient menuconfig target, let's step through the process to navigate to the tristate menu item called Kernel .config support. It will be off by default, so let's turn it on; that is, let's make it y, built into the kernel image. We can find it under the General Setup main menu item on the home screen.
What exactly does turning this feature on achieve? When turned on to y (or, of course, if made to M, then a kernel module will become available, and once it's loaded up), then the currently running kernel's configuration settings can be looked up at any time in two ways:
- By running the scripts/extract-ikconfig script
- By directly reading the content of the /proc/config.gz pseudo-file (of course, it's gzip(1)-compressed; first uncompress it, and then read it)
As a learning exercise, we will now learn how to configure our 5.4 Linux kernel...
