WSL2-Linux-Kernel VS WSA-Linux-Kernel

By the way, Microsoft publishes the WSL kernel source, under GPL, as they must: https://github.com/microsoft/WSL2-Linux-Kernel

From here on out it gets a bit hazy. For kernel builds you will have to use the Microsoft Linux Kernel (don't laugh, it's actually a thing). The USBIPD project walks through a WSL kernel build, so you can use that as a guide of sorts. Once you've done everything you need with the disk, the Gentoo project shows how to import it, but if you already have the VHDX file, I think the import-in-place option may be simpler. Take care in CH2 when making the filesystem. I'm not sure if WSL want's only one ext4 partition or if it walks the disk looking for root. There may be some .wslconfig settings for this, my first guess would be kernelCommandLine.

This was true for WSL1, but WSL2 does contain a Linux kernel. The source code for it is available at:

https://github.com/microsoft/WSL2-Linux-Kernel

git clone --branch mytag0.1 --depth 1 https://github.com/microsoft/WSL2-Linux-Kernel use tag for your version

But if you need a custom kernel then build it by taking Microsoft's kernel config as your base and then set the following up accordingly in your %USERPROFILE%\.wslconfig file:

It uses a customized version of the Linux kernel (repo) that integrates with the host Windows OS. You can build any distro on top of that kernel, as people have done with (of course) Arch. The distro isn't any less "real" than a distro that it run on QEMU (and with a level 1 hypervisor, all systems that uses one are technically virtualized already).

I recompiled the kernel using sources from https://github.com/microsoft/WSL2-Linux-Kernel with experimental genpatches applied.

KERNVER=$(uname -r | cut -f 1 -d'-') git clone --branch linux-msft-$KERNVER --depth 1 https://github.com/microsoft/WSL2-Linux-Kernel.git ~/kern-$KERNVER zcat /proc/config.gz > ~/kern-$KERNVER/.config make -C ~/kern-$KERNVER -j 4 make -C ~/kern-$KERNVER -j 4 modules_install ln -s /lib/modules/$KERNVER-microsoft-standard-WSL2+ /lib/modules/$KERNVER-microsoft-standard-WSL2

WSA kernel source is here: https://github.com/WSA-Community/WSA-Linux-Kernel/tree/source

I saw this repository https://github.com/WSA-Community/WSA-Linux-Kernel and it says that it's a mirror of the official source code, but I can't seem to find the official repo. I wanted to try this and modify the kernel to see if it's possible to get previously not working apps going.

Nah, there's definitely been people who have made custom WSA kernels, although not very recent (Lsposed and WSA-Community to name a few).