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- [Instructor] Since we want to talk about

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using the kernel source,

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we need to start by talking about getting the kernel source.

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Well, if you want official kernel releases,

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I often get kernels from here.

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You can go to kernel.org, underneath pub/linux/kernel,

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various versions are there

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and you get tarballs of the source and you get patch files.

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I often download a tarball from there.

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For example, just using the wget like this

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would get the compressed tarball

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for the Linux kernel version 6.9.9.

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You can also use Git.

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Git clone, the official Torvalds Linux kernel tree,

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if you want to get the latest stuff

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and see all the changes and whatnot.

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All the cool things you can do with Git.

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If you want to get the Ubuntu kernel source code,

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then what they recommend is using Git

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and getting their Git tree

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and the version you get, you have to pick the codename

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for the distribution.

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If you want to get for your current distribution,

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you can look at the file, etc/lsb-release,

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and in there will be a variable set called

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DISTRIB_CODENAME.

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So this is a little bit of shell stuff,

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but if you source that file,

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it will set environment variables in your shell for you.

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And then you can use that variable

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and it'll be in capital letters perhaps.

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So I translate it to lowercase

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because that's what you want for the path name.

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So in mine the DISTRIB_CODENAME variable

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had the value NOBLE, all in uppercase.

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So this shell variable name will be noble in lowercase.

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And then I can just use that name

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and this Git clone with this will go to the internet

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and copy that old Git tree

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and that will probably be pretty big.

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That particular one was more than four gigabytes long.

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And it's got, because it's Git tree,

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all their different related kernel releases,

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and they've tagged them.

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So you can check out one of the tags if you want

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to look at a particular version.

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So they have a nice write up about it

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in their kernel Git guide if you want more information.

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And there's the path for that.

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All right, so go get yourself some source.

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We're going to need it.