OPEN_AGB_FIRM Forwarder

Boot GBA Roms with OPEN_AGB_FIRM from the 3DS Home Menu

Usage instructions: Needs FastBoot3ds or GodMode9 as Firm0 instead of B9S

Install the CIA
Launch the shortcut
???
Profit

(Note that if you are using FastBoot3ds, FCRAM Boot needs to be enabled. It is located under Boot Setup)

Building instructions:

Put the icon, banner image and banner sound in the assets folder
Change APP_TITLE, APP_DESCRIPTION, APP_AUTHOR, APP_PRODUCT_CODE and APP_UNIQUE_ID to your needs
Drop the payload and the splash screen (using the same method as Luma3ds splashes) in the romfs folder
run make
have fun!