Welcome to the DEF ROM firmware generator. Upload your ROM, and we'll create a custom firmware with that ROM embedded.
Only Game Boy and Game Boy Color ROMs under 2MB are compatible.
This tool will automatically generate a valid UF2 or BIN v1.6 version of the firmware so you're free to choose what flashing method you want to use. Check the links to the repo for instructions if you're unsure how to flash them.
v1.6 brings back the credits screen on the badge, and unlocks the "Rickroll" menu, which can be used to rickroll other badges.
Feel free to open an issue on the GitHub Repo or message @jaku and I'll try to help as best as I can. If you found this useful please share with others, follow me on Twitter/Twitch. Thanks!
If your stuff breaks, follow the UF2 flashing instructions here to restore your badge to the original firmware. I am not responsible for any broken badges, use this at your own risk.
Additional firmware files in UF2 and BIN formats can be found on the repo which contains the following.