While I'm not able to share my image currently, hopefully this will help:
The GBA on RetroPie requires an additional BIOS file that does not come with the initial download. Here is the file, gba_bin.bios, found on Google Drive.
Once downloaded, move the file to your Raspberry Pi. At this point, you must place the file into the correct directory:
/opt/retropie/emulators/gpsp/raspberrypi
For instance, if you saved the file to a USB drive, you could copy the file over:
sudo cp /media/usb0/gba_bin.bios /opt/retropie/emulators/gpsp/raspberrypi
As long as the ROMs and this file are now in the correct locations, you should be able to play the GBA games after you reboot.