These files contain data relating to install/usage/management of installed 3DS titles. The database files are located at:
- sdmc/Nintendo 3DS/<ID0>/<ID1>/dbs
ID0 is the first 0x10-bytes from a SHA256 hash. The installation of SD Card titles was introduced in the 2.0.0-2 update and the SD dbs files are encrypted. These files are extdata images. The NAND extdata images are cleartext, however some of the images contain data encrypted with a console-unique keyslot.
There are only two files in this directory, for SD card:
"title.db" - With a fixed size of 0x31E400 bytes, this Extdata image embeds two almost identical copies(the latter is probably an older backup) of the Title Database. For each installed title, the following information is known to be stored:
- Title ID - Taken from the main CXI/TMD
- Product Code - Taken from the main CXI
- Title Size - This is generally larger than the total size of the Content.
- Title Type
- Title Version
- .tmd Content ID
- .cmd Content ID
- ExtdataID low (if the title uses ExtData)
- Whether or not a Electronic Manual is used
It is important to note the database doesn't contain a hash of the .cmd. So if a user has more than one valid set of application data for a given .cmd Content ID they can be manually interchanged without issue. Though renaming a .cmd file to match the Content ID which the title.db is expecting will result in an error, as the CTR for the per-console encryption layer changes depending on the file path, and the MAC of the .cmd is probably generated with the .cmd Content ID in mind.
"import.db" - The function of the file is not well understood. It appears to be related to the download/install of titles, as in the progress of downloading titles this file will have changed but the title.db will not be modified until the title has been properly downloaded.
- This file doesn't contain any title specific data which the AM has been noted to use in relation to installed titles, even though this file is modified when titles are installed/deleted. In fact, no matter what titles you install, if you use an old copy of the "import.db" with a recent copy of the "title.db", this creates no noticeable issues.
Note: It is quite unlikely that the either the import.db or title.db contain the cached icon and names of installed titles. The amount of data which changes in those two file when a title installed/deleted is not sufficient to contain the size of data required for the icons and names of the application, they are most likely cached in the NAND.