Below is a copy and paste from the Nintendont thread h
ere on GBATemp that explains the SD CARD layout for GC ISO's.
Game on SD Card
The game path expected by Nintendont is :
SD:/games/
whatever you want/game.iso
SD:/games/
whatever you want/disc2.iso
The non-bold part need to be written exactly like you see it above (the filename is
not the game's title, but the 4 letters "g+a+m+e")
If a game has two discs, the second ISO needs to be placed in the same folder than the first disc's ISO, and named to "disc2.iso".
Only the bold part "whatever you want" need to change.
For better compatibility with other loaders, you can put Game's Title and GameID in that part, like this :
SD or USB:/games/Zelda Wind Waker [GZLP01]/game.iso
SD or USB:/games/Tales of Symphonia [GQSEAF]/game.iso
SD or USB:/games/Tales of Symphonia [GQSEAF]/disc2.iso
For users who still don't understand that "game" doesn't refer to the game's title but to the single word "game":
/games/Zelda Wind Waker [GZLP01]/
Zelda.iso <--- WRONG
/games/Zelda Wind Waker [GZLP01]/
game.iso <--- Correct
/games/Tales of Symphonia [GQSEAF]/
disc2.iso <--- Correct
If you don't know the GameID, you don't need to use it.
/games/zelda/game.iso is working too.