Let me know which direction works for you, and I'll write a thorough, responsible post.
When it comes to downloading ROMs of games like Pokémon Diamond and Pearl, users must be aware of the copyright laws in their country. Game ROMs are intellectual property owned by the game developers and publishers, in this case, Nintendo. Downloading ROMs of games you do not own can be considered piracy, which is illegal. Pokemon Diamond And Pearl Gba Download For Android