LuneOS potential target / development environment: Windows/WSL2

EricBlade

Hi all! I've started with making some progress on trying to see if it's possible to use Windows WSL2 as a reasonable environment to do some work in LuneOS. So far, I have the base operating system itself working, and you can get in and do command line type things just like if you were on a real device. GUI not presently working, although I have hope that it is possible with WSLg.

I'm going to use this to post notes as I discover things, so that I can hopefully bring anyone who might want to come along with me on the ride, and hopefully we can submit a coherent list of changes to make it all work right :-)

First, to get the system working at all in WSL2, you'll need to get an emulator build of LuneOS (though I hope in the future we can actually have a specific build target for it). You'll need the rootfs .tar.gz, so it's probably easiest if you just build the whole thing yourself.

if anyone wanted to replicate getting something operating in wsl: 1) build qemu per the luneos instructions

$$
MACHINE=qemux86-64 bitbake -k luneos-dev-emulator-appliance
$$
1. find the rootfs.tar.gz
  
  $$
  wslpath -a -w tmp-glibc/deply/images/qemux86-64/luneos-dev-image-qemux86.rootfs-testing-(datetime).tar.gz | xclip -sel clip
  $$
2. add it to the system with
  
  $$
  wsl --import LuneOS <(directory to store virtual hard disk in)> <paste .tar.gz file path>
  $$
3. BEFORE STARTING IT add /etc/wsl.conf and set systemd true and default user to root (open \wsl.localhost\LuneOS\etc\wsl.conf in an editor and paste, MAKE SURE YOU DO NOT USE WINDOWS CRLF LINE ENDINGS)
  
  $$
  [boot]
  systemd=true
  
  [user]
  default=root
  $$
4. explorer to \\wsl.localhost\LuneOS, find /var/log and delete it. create a new directory for /var/log. (this is to bypass something odd in the symlink you get by default)

… forgive some of the formatting here, I posted this originally on Discord, and Discord and this forum's formatting don't seem to entirely agree with each other. Hopefully you can make sense out of it :-)

EricBlade

WSL2 wants a directory in /etc/ld.so.conf.d, which although the included LuneOS /etc/ld.so.conf references, in the emulator the directory does not seem to exist. This looks like it might be an error in the image. I'm not sure what adding this will achieve exactly, but it will quiet the WSL2 kernel from complaining that it can't access /etc/ld.so.conf.d to write a configuration for WSL libs. This may help with networking and video and audio and other pieces, though.

EricBlade

connmand breaks networking in the entire WSL by eliminating the route table and changing the IP address. I don't know why it's doing it, but you can get it back working by doing a wsl --shutdown in windows, or by resetting the ip address and route table to what they are supposed to be after starting LuneOS in WSL. There's probably a way to fix this, but otoh if we build a specific target for wsl, we could just remove connman and it's dependencies.

EricBlade

GUI is clearly going to be the hardest part of this. I'm not familiar with the modern luna-surfacemanager, but my initial impression is that it might be easiest to bypass it, and see if applications "Just Work" by transmitting them to WSLg. LSM might be able to be engineered to become a Wayland client itself, in which case, it can composite and then transmit to the WSLg wayland server. I do not presently have the knowledge necessary to do that. WSL does not report any connected displays via /sys/class/drm, but i will try just passing in parameters that should work to the calls to the video drivers, and see if anything happens. But that's for a future day.

EricBlade

almost there! I've got graphics running pretty consistently, but anything in QML is crashing out, surface-manager is complaining that there's another compositor running… hoping i can bridge it to the WSLg compositor, but still just trying to get any actual webOS apps working first.

I've created a new layer for Yocto, which allows one to build a WSLg port https://github.com/ericblade/meta-wsl2

EricBlade

not all the way there yet, but got visuals!