RPU
Raspberry Pi based 3DS unbricker
This tool is erotic cartoon ware.
If you like it please send one erotic cartoon picture to rpu.bkifft.gbatemp@gmail.com (even if you draw one in paint yourself, everyone likes to draw the cock and balls).
WARNING: Do not run this tool with a kernel that has the MMC/SD subsystem enabled! (The supplied linux image has those drivers disabled. Also the tool should refuse to run if those drivers are loaded.)
This tool can be used to unbrick a launcher.dat bricked 3DS.
WARNING: It seems that as of 2015-12-04 whoever is responsible for GW launcher.dat based bricks changed the MMC lock key. Therefore it's now impossible to unlock without a good NAND dump (at least for now, perhaps forever)!
Check RPU_guide.txt for requirements and instructions.
Para visitar el tutorial en Español pulsa el siguiente enlace (Traducido por egarrote): http://www.elotrolado.net/hilo_tutorial-reparar-bricks-con-raspberry-pi-y-backup-de-la-nand_1979374
Per leggere la guida in italiano (traduzione by StandardBus) visita http://www.moddingstudio.com/content.php?1697-Guida-al-recupero-dei-3DS-brickati-(Gateway-brick)
Deutsche Version dieses Guides (übersetzt von didi) auf http://www.psxtools.de/thread.php?threadid=61918