Utilizing IAGL with Flatpak Kodi Launching Flatpak Retroarch

[zach-morris]

You can use Kodi in an OS that uses Flatpak, to Launch Retroarch on the same system also installed by Flatpak. Setup is non-standard for those Flatpak's however, and you will be required to alter the permissions of the Kodi Flatpak. This will remove some of the sandboxing protection that Flatpak otherwise provides. It's up to you on if this is acceptable, but as far as I can tell, it's the only way to get it to work.

1. Install Kodi via Flatpak:
   https://flathub.org/apps/tv.kodi.Kodi
2. Install Retroarch via Flatpak:
   https://flathub.org/apps/org.libretro.RetroArch
3. Launch Retroarch Flatpak. Using the online updater, update all cores, assets, info files, databases, etc.
4. Make note of the retroarch configuration path and cores path in Retroarch settings. You will need these paths in IAGL settings:

6. You'll then need to update the permissions of the Kodi flatpak to that it can see the filepaths within the Retroarch flatpak, and also update the ability for the Kodi flatpak to spawn a host command / other flatpak:

From the command line (I used root/su for this, but it will likely depend on your system):
Provide file system permissions:

flatpak override tv.kodi.Kodi --filesystem=..path_to/.var/app/org.libretro.RetroArch

Or provide parent folder permissions too (likely depends on your system):

flatpak override tv.kodi.Kodi --filesystem=..path_to/.var/app

Provide host / spawn permissions:

flatpak override --talk-name=org.freedesktop.Flatpak tv.kodi.Kodi

7. Now launch Kodi, ensure IAGL is installed. In IAGL settings:
   System Type: Linux

Retroarch App Location can be left blank, we'll have to manually enter the command later

Retroarch CFG Location:

..path_to/.var/app/org.libretro.RetroArch/config/retroarch/config/retroarch.cfg

(Advanced Setting) Manually set Retroarch Directories: Enabled

Retroarch Core Directory: Copy the path to core directories noted in step 4. Mine for example was:

..path_to/.var/app/org.libretro.RetroArch/config/retroarch/cores

Retroarch Info Directory: Copy the path to info directories noted in step 4. Mine for example was:

..path_to/.var/app/org.libretro.RetroArch/config/retroarch/info

Change the advanced setting for the default download path, as the Retroarch flatpak needs to have access to the same file path. For example:
\home\username\Download

Alternatively, you can change the download path on a per game list basis.

9. Now browse to the game list of choice. We'll have to manually set the command line launch parameters. Bring up the context menu for the game list. Example for NES below:

• Update launcher to External
• Update launch command, select manually entered command.
• Command will look like the following:
  flatpak-spawn --host flatpak run org.libretro.Retroarch -L "..path_to/.var/app/org.libretro.RetroArch/config/retroarch/cores/nestopia_libretro.so" "XXROM_PATHXX"

Now the game list will send the correct command, and have the correct permissions to launch. Wow, and it only took 9 crazy steps! Easy as pie! Repeat entering the manual command for each game list of choice in IAGL. Thankfully you only have to do this once for each list.