As mentioned earlier, this section is meant for those of you who have downloaded a particular Linux kernel from the repository, https://www.kernel.org, and aim to build it. In this book, we use the 5.4 LTS kernel release. On the other hand, if you have performed git clone on the mainline Linux Git tree, as shown in the immediately preceding section, you can safely skip this section and move on to the next one on kernel configuration.
Now that the download is done, let's proceed further. The next step is to extract the kernel source tree – remember, it's a tar-ed and compressed (typically .tar.xz) file.
We assume that, as shown in detail earlier in this chapter, you have by now downloaded the Linux kernel version 5.4 code base as a compressed file (into the ~/Downloads directory):
$ cd ~/Downloads ; ls -lh linux-5.4.tar.xz
-rw-rw-r-- 1 llkd llkd 105M Nov 26 08:04 linux-5.4.tar.xz
The simple way to extract...
