Hacking 3DS flashing without using a flashcard?

[Alex3DSU]

Is there a way to put homebrew on a 3DS without having to use a flashcard? It would be helpful because it is easier just booting the homebrew from an SD card

 

[DarkFlare69]

If it was possible, obviously people would have done it by now.

EDIT: If you mean CFW, that doesn't require a flashcart.