For the time being I will only provide the instructions for building the kernel. In the future I will also provide the dockerfile and docker image to build the kernel using docker.
These instructions have been verified for Fedora 29 and kernel 5.0.9 (x86_64).
In order to enable sound for this system, I've taken code from https://github.com/heikomat/linux/tree/cx2072x_5.0 and https://github.com/conexant/codec_drivers/tree/rpi-4.4.y. The former provides the sources for the Cherrytrail with CX2072X codec Intel Machine driver for and the latter provides the sources for the Conexant CX2072 codec.
https://github.com/heikomat/linux/tree/cx2072x_5.0 also provides the sources for the Conexant CX2072 codec but I preferred to use the Conexant source code directly. In order for that to work, I changed enable_detect(component) to enable_jack_detect(component) in https://github.com/heikomat/linux/blob/cx2072x_5.0/sound/soc/intel/boards/cht_cx2072x.c.
Let's start by setting up fedora for building the kernel (from https://fedoraproject.org/wiki/Building_a_custom_kernel):
sudo dnf install fedpkg fedora-packager rpmdevtools ncurses-devel pesign
Add the user doing the build to /etc/pesign/users and run the authorize user script:
sudo /usr/libexec/pesign/pesign-authorize-users
Checkout the source of the kernel anonymously:
fedpkg clone -a kernel
cd kernel
Switch to the Fedora 29 branch (type fedpkg switch-branch to list all the different branches):
fedpkg switch-branch f29
Move the patch 0001-set-configs-for-cx2072x.patch to the current directory and apply it:
git apply 0001-set-configs-for-cx2072x.patch
This sets the proper configurations in the configs directory for compiling the kernel with cx2072x codec support. Rebuild the configs for the kernels:
./build_configs.sh
and update the kernel.spec to include 0001-asus-e200ha-Enable-sound.patch (do not apply this patch, just move it to the directory):
./scripts/newpatch.sh 0001-asus-e200ha-Enable-sound.patch
Change the buildid in the kernel.spec file from 0001_asus_e200ha_Enable_sound.patch to a small identifier (if you do not do this the build will fail because the identifier is too long). I used the identifier cht:
sed -i 's/buildid .0001_asus_e200ha_Enable_sound.patch/buildid .cht/g' kernel.spec
Fetch any dependencies need for compilation:
sudo dnf builddep kernel.spec
Optionally, you can configure the kernel at this point to remove drivers and so on:
cd /usr/src/kernels/$(uname -r)
zcat /proc/config.gz >.config
make oldconfig
make menuconfig
Now you are ready to compile. You can execute the script ``scripts/fast-build.sh```:
fedpkg srpm
./scripts/fast-build.sh x86_64 kernel-{the version of the kernel to be compiled and buildid}.src.rpm
to build the kernel without debugging information, perf or tools. Otherwise execute:
fedpkg local
to build both debug and release kernels. Another option for fedpkg is to run:
fedpkg local --with baseonly --without debuginfo
to compile only the release kernel.
If you are building the rawhide branch and debugging is not needed, remember to run make release before fedpkg local since all master branch kernels are built with debugging capabilities by default.
If you build the kernel with fedpkg local and you haven't changed the configuration of the kernel to reduce the drivers that are going to be built, you will need at least 64GB of space.
In the first case the resulting rpms reside in ~/rpmbuild/RPMS/x86_64 and the second case they reside in kernel/x86_64.
Now you can install the kernel with dnf install kernel*.rpm. Be sure that you have the linux-firmware package installed.
Lastly, update your grub configuration with sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg. Reboot and hopefully, enjoy.
You will probably get two warnings when compiling the modules for the cx2072x codec, I will look into them in the future.