the kernels used in those images here are usually not packaged and that for

two reasons:

- flexibility: it is much easier to build new kernels for all those images

here with often different ways the kernels are built and provide them as a

simple tar archive than to also having to take care of their proper packaging

for all those different setups and requirements

- encouragement to build own kernels: i would recommend everyone to build your

own kernels as this way they can be updated whenever wanted or needed and

its a nice way to learn and know a bit more about the system - links to notes

on how the kernels can be built can be found for all supported systems in the

readme for the corresponding system - it is not that complicated to build an

own kernel

as a result there are no kernel header (= kernel include files) packages for

them available. this is not a problem if own kernels are built and if the

kernel sources are still around on the system. otherwise it is quite easy to

add the header files afterwards to the system when needed.

the kernel headers which are usually coming with the linux-headers-version

packages are referenced via symlinks in the /lib/modules/xyz directories - an

example (chromebookveyron using a v5.19.3 stb-cbr+ kernel):

root@mighty:~# ls -l /lib/modules/5.19.3-stb-cbr+/source lrwxrwxrwx 1 root root 37 Aug 24 10:50 /lib/modules/5.19.3-stb-cbr+/source -> /home/compile/source/linux-stable-cbr root@mighty:~# ls -l /lib/modules/5.19.3-stb-cbr+/build lrwxrwxrwx 1 root root 37 Aug 24 10:50 /lib/modules/5.19.3-stb-cbr+/build -> /home/compile/source/linux-stable-cbr

"/home/compile" on this system is symlinked from "/compile" which is the root

dir used for all kernel compiling described in the kernel build notes for the

different systems - "/home/compile/source/linux-stable-cbr" is the place where

the kernel sources are located. to make this work for a system where only the

kernel has been installed (but no kernel sources are around) the easiest way

is to simply install the kernel sources. for most cases the sources of a clean

kernel of the same version should be sufficient. so to keep the paths in the

above example (otherwise just change the symlinks to point to wherever else

the kernel sources get installed) the following commands have to be run (an

"apt-get install git" might be required beforehand):

mkdir -p /home/compile/source cd /home/compile/source git clone --depth 1 -b v5.19.3 https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-stable-cbr

that should be it. one thing to keep in mind is that not for all supported

systems the linux-stable git tree is used as a base - a look at the "gitrepo"

file of the dir containing the kernel build notes for the corresponding system

should tell which git repo to use - in most cases it is the one used in the

example above.