I've read that enabling SD card for application may corrupt FS on SD.
Want to try to figure out on which level it may happen. On file system access level, or on SD card lowlevel access (i.e. read/write sectors). Second will be hard to fix, while first one is relatively easy to avoid.
I'm working on SNEEK which uses SD card with 2 partitions. One of partition will be used exclusively for NAND emulation while other will be used by applications just like normal SD card.
Actually, it's already working like expected. I just didn't use too much homebrews, so didn't test enough if file system on any partition may be corrupted or not.
The main purpose why i decided to do this is:
a) If you use SNEEK, you can't use homebrew, because most of them use SD card.
b) If you use UNEEK, you can't use other USB devices. Homebrew using some large libraries (like emulators) won't able to use USB HDD.
So, I want to use both SD and USB as with real NAND
Most tricky part was to find the way to split and use 2 partitions on SD card under Windows. As you may know Windows doesn't support more than one partition on removable device. So i have to find some special driver to cheat windows and represent SD card as HDD
After some more tests, i will make guide about how to make it... If there will be demands.