What is the cheat code to open all doors in Super Mario Bros X?

There is no cheat code to open all doors in Super Mario Bros. X.

* Super Mario Bros. X is a custom ROM hack. There is no official cheat code system implemented in the game.

* Custom ROM hacks may have their own cheat codes. The specific cheat codes would depend on the specific hack.

If you're looking for a way to open all doors in Super Mario Bros. X, you'll need to find a specific ROM hack that includes such a feature, or you'll have to use a save editor to unlock all doors.

Please remember: Modifying ROM files can be complex and may void your game's warranty. Always back up your files before making any changes.