Hacking Has anyone tried writing custom os for a hard mod 3ds?

[Yil]

One that completely replace the normal os and able to access games.

 

[weeandykidd]

Very little reason to do so considering CFW exists

 

[Margen67]

Very little reason to do so considering CFW exists

That and theme/homemenuhax

 

[Tony_93]

One that completely replace the normal os and able to access games.

You can't, IIRC the 3DS has some booting checks/mechanism that can't be bypassed, that's why we never had permanent CFW even having kernel access, if you tried re-writing anything there the 3DS would simply refuse to boot up.