How to Change the Default Core on Onion OS (for all games)

---

So I was messing around with my Miyoo Mini Plus running Onion OS 4.3.1-1 stable, and hit a weird snag. I wanted achievements in my SNES games, and decide to install Snes9x, one of the few (if not the only?) core that works with the RetroAchievements website. Tried one game, worked fine. Naturally I decided that I want all games from the SNES system to use Snes9X instead of the default core Beetle_Supafaust.

Surprise, surprise, there is no option to change the full system to use a different core. Game by game is fine, but I don’t have the nerves to scroll through thousands of games just so I can enable achievements on few.

This is the Way

Turns out, you can actually set a new default core system-wide by editing a script. You will need a computer, microSD card reader and something like Notepad++

1. Open the launch.sh script that you want to change the core fore, in this example \Emu\SFC\Launch.sh – for the SNES (SFC)
2. Find the line that launches the core and change it to the one you want (like Snes9x).
3. Backup the original first, then save your changes, reinsert the SD card, and reboot.

To find exact core filenames, browse:
\RetroArch\.retroarch\cores\

Here is how the launch.sh file looks now:

#!/bin/sh
echo $0 $*
progdir=`dirname "$0"`
homedir=`dirname "$1"`

cd /mnt/SDCARD/RetroArch/
HOME=/mnt/SDCARD/RetroArch/ $progdir/../../RetroArch/retroarch -v -L $progdir/../../RetroArch/.retroarch/cores/snes9x_libretro.so "$1"

One more tip

Again, backup everything since one wrong character will break the script. Furthermore, for CPS 1, 2 and arcade games, try the Final Burn Neo core (fbneo_libretro.so), it supports achievements as well, but it does run slower on the Miyoo Mini Plus.

---

Dejan B.