FlashPi

https://github.com/decipher2k/FlashPi/releases


An ultra fast booting Retroflag GPI Image - Gameboy / Gameboy Color only


FlashPi uses a striped down and optimized RetroPi image based on the SupremeTeam release, a patched version of Gnuboy as the emulator, and a custom shell based menu.
The boot time can be reduced to about 20 seconds by using a microSDXC UHS-I card.




Usage:
-The rom files have got to be put into the directory /boot/roms/…
-Exit emu: left shoulder button
-Save game state: Y button (feature not yet implemented)
-Load game state: X button (feature not yet implemented)




v1.2
-Moved ROM directory to /boot (no more ext3 driver needed)
-Increased size of boot partition to 1GB
-Added subdirectory support
-Removed requirement for file renaming
-Added Gameboy Color support
-Reduced required time for booting to 20s


Caveats:
-If you do only see a blinking cursor after the bootlogo has been displayed, then there are no rom files present in the /boot/roms directory.