3DS HomeMenu extdata Tool 3DS

3DS HomeMenu extdata Tool is a Nintendo 3DS homebrew tool for accessing the Home Menu SD extdata, this is usable from Ninjhax. This allows reading/writing the home-menu SD extdata SaveData.dat, and the extdata theme-cache.

This essentially allows user to write custom themes to SD extdata (e.g. Ninjhax/Gateway), which home-menu will automatically load at Home Menu process next startup.

Installation

Installing

Copy the folder containing .3dxs and .smdh to the the 3ds folder on your SD card. Launch it via homebrew launcher.

Compiling

This requires the latest ctrulib from git.

If you build a CXI/CIA for this, the accessinfo must have bitmask 0x01 set (in the RSF that's FileSystemAccess with field - CategorySystemApplication).

User guide

Before modifying

Backing up extdata before modifying it at all is recommended:

You can copy the data from sdmc:/Nintendo 3DS/{ID0}/{ID1}/extdata/00000000/{extdataIDlow}/ to elsewhere, where extdataIDlow is the extdataIDs for home-menu extdata and theme extdata.

Main menu

• Copy extdata SaveData.dat to sd - Option to backup your SaveData.dat to SD (this contains the current theme settings and other things).
• Copy SaveData.dat from sd to extdata - Option to restore your SaveData.dat from SD.
• Enable normal theme-cache - Ooption to enable using the theme-data from SD. Do not use this if you don't have any theme DLC installed, use the below menu option instead.
• Enable persistent theme-cache - Same as above except the custom themes are persistent even without any theme DLC installed.
• Copy theme-data from extdata to sd - Option to backup the theme-data stored in extdata.
• Copy theme-data from sd to extdata - Option to write a custom theme to extdata.

Theme-data

The data this app reads/writes to/from sdmc is located in the same directory that the app runs from (SD root for CXI/CIA). The theme-data this app uses on sdmc is the following.

• ThemeManage.bin - Copied from extdata to sdmc.
  • This can be copied to extdata from sdmc, if it doesn't exist on sdmc for that then data is generated for it then writen to extdata.
• BodyCache.bin and body_LZ.bin - The former is copied from extdata to sdmc.
  • When copying from sdmc to extdata, the app will first attempt to use BodyCache.bin, then body_LZ.bin.
  • When ThemeManage.bin exists on sdmc with sdmc->extdata, this body-data is only copied when the size field in ThemeManage.bin for this is non-zero.
  • When copying to extdata, the filesize must be smaller than or exactly 0x150000-bytes.
• BgmCache.bin and bgm.bcstm - Handled basically the same way as the body-data, except with the bgm sizes.
  • When copying to extdata, the filesize must be smaller than or exactly 0x337000-bytes.
  • When writing BGM to extdata, Home Menu must not be already using any BGM from the theme-cache (prior to when this tool wrote anything to extdata).

Disable theme-cache

To disable using the theme-cache, you can:

• Either enter home-menu theme-settings then select none, restore a backup of SaveData.dat with this tool, restore the entire home-menu and/or theme extdata with the above backup.
• Or delete the homemenu and/or theme extdata.

Controls

D-Pad/C-Pad - Select a menu entry

A - Enter a menu

B - Return to the hbmenu

Known issues

Please refer to reported issues.

Changelog

v1.1.1

• Updated for latest ctrulib+devkitARM.
• Set the icon strings to proper values.
• Replaced the 5-second-delay with a press-button-wait.

v1.1 6 Jan 2015

• Custom theme persistence even without any theme DLC installed, and other minor fixes/changes.

v1.0 31 Dec 2014

• Initial release. Extract this to the root of your SD for use with ninjhax.

External links

• GitHub - https://github.com/yellows8/3ds_homemenu_extdatatool
• 3dbrew - http://3dbrew.org/wiki/Home_Menu