Default [Q] how to make a device tree and device repos

Help needed!!! i own the device samsung galaxy music duos (GT-S6012) this phone doesnt have a forum even!!! and the real problem is noone has made a device tree nor the repos neither there are any custom roms for this ...so i've been thinking of making one .....but its been really hard time finding repos and the device tree....... so my question is does anybody know to make a device tree and the repos?? .....i really need help on this one!!!!!