Here is what worked for me.
I'm using an Odroid XU3 with wired ethernet. I believe this ought to work with other small computer boards running Batocera.
- Open up your text editor of choice (nano or vi) and create a new file for edit
vi /recalbox/share/system/custom.sh
- Paste/input this in:
#!/bin/bash
/usr/bin/connmanctl config `/usr/bin/connmanctl services | /bin/grep Wired | /usr/bin/awk '{print $3}'` --ipv4 manual 192.168.1.25 255.255.255.0 192.168.1.1
- Save and reboot, you should now have a statically addressed wired connector.
NOTE
My static IP here is 192.168.1.25 and my gateway is 192.168.1.1. Change these values to suite your needs.