Persistent state on the Wii is kept in an encrypted filesystem on the 512MB NAND Flash chip. Most of this is accessible from code running on the Broadway using IOS_Read() calls.
- /dev: There are a number of "resources" stored inside the /dev tree, but these are not actually present in Flash; they're "virtual".
- /import: This is used as a scratchpad / staging area during import of new contents / titles
- /meta: Generic opening.bnr files for the Photo, Shop, Mii, Forecast, and News channels. They don't resemble the actual opening.bnr files for those channels.
- /shared1: "Shared" contents that are installed by various channels are installed here.
- /shared2: Miscellaneous info that is not specific to one title.
- /shared2/ec: State kept by the Wii Store (EC = "Electronic Commerce", probably)
- /shared2/menu: Public state, managed by the menu
- /shared2/sys/SYSCONF: Most settings that are managed in the Wii Menu (calendar, screen size, etc)
- /shared2/sys/net: Network connection profiles
- /shared2/test2: Diagnostic files kept by the System Menu; no known purpose.
- /shared2/wc24: Data files used by WiiConnect24. Most communication with WC24 is done by reading and writing these files
- /sys: Files used by IOS internally to track state
- /ticket: Tickets for installed titles
- /title: Contents of installed titles
- /tmp: Used as a temporary area by IOS and various other programs; often, files are created here and then immediately moved elsewhere. This directory is automatically cleaned up whenever IOS boots.