This page describes the format of the icon stored at CXI ExeFS:/icon and CIA icons. The size of icons is 0x36c0 bytes. The CXI icon is displayed by Home Menu and System Settings(3DS Software Management), while CIA icons are dummies and not yet utilised by Dev 3DS' (as of rev 47586).
|0x8||0x2000||16 application titles structs, each 0x200 bytes|
 Application Titles
All encoded in UTF-16. There are 16 app title structs(currently only 12 are used), each one for separate languages.
The languages by order of appearance:
- 1st: Japanese title name
- 2nd: English title name
- 3rd: French title name
- 4th: German title name
- 5th: Italian title name
- 6th: Spanish title name
- 7th: Simplified Chinese title name
- 8th: Korean title name
- 9th: Dutch title name
- 10th: Portuguese title name
- 11th: Russian title name
- 12th: Traditional Chinese title name
 Application Settings
Most of these flags are only used by the Home Menu. All of these are represented in SMDH files in little endian. But when documented below, the tables represent values in big endian.
|0x2008||0x10||Region Specific Game Ratings (For use with Parental Controls)|
|0x201C||0xC||Match Maker IDs (Online Play)|
|0x2030||0x4||'Optimal Animation Default Frame' (for BNR)|
|0x2034||0x4||CEC (StreetPass) ID (So the Home Menu knows which application icon to show the 'Green' CEC notification for)|
 Region Specific Game Age Ratings
These flags tell the 3DS the 'Age Rating' of the software for the below regions:
|0x200C||0x1||PEGI GEN (Europe)|
|0x200E||0x1||PEGI PRT (Portugal)|
|0x200F||0x1||PEGI BBFC (England)|
|0x2011||0x1||GRB (South Korea)|
Active ratings have a bitmask of 0x80, and inactive ratings have no bitmask at all. Ratings without the 0x80 bitmask are ignored. 0x40 bitmask indicates Rating Pending. 0x20 bitmask indicates No Age Restriction.
 Region Lockout
This flag is what the Home Menu uses in order to determine the Region Lockout of a title. These are bitmask flags. Byte is currently the only byte used, the rest are reserved.
As these are bitmask flags, multiple regions can be 'allowed' access to a title if Nintendo chose. Nintendo decided to group Europe and Australia together, with European games including both bitmasks. Though at time of writing, Nintendo has not released any 3DS' which actually check the Australian region lock bitmask. A "Region Free" title would have each byte = 0xff. (For reference, the Nintendo's implementation of "region free", has bytes[0-2] = 0xff, and byte = 0x7f)
 Match Maker IDs
These IDs are an application's online gaming IDs.
|0x201C||0x4||Match Maker ID|
|0x2020||0x8||Match Maker BIT ID|
These are a collection of bit-mask flags.
|Visibility Flag (Required for visibility on the Home Menu)||0x01|
|Auto-boot this gamecard title||0x02|
|Allow use of 3D? (For use with parental Controls. An application can use the 3D affect, even when this flag isn't set)||0x04|
|Require accepting CTR EULA(see below)||0x08|
|Autosave on exit?||0x10|
|Uses an Extended Banner?||0x20|
|Region game rating required||0x40|
|Uses save data?||0x80|
|Application usage is to be recorded. If this is not set, it causes the application's usage to be omitted from the Home Menu's icon cache, as well as in other places.||0x01|
|Disables SD Savedata Backups for this title.||0x04|
 EULA Version
This is the EULA version which is checked when the Accept EULA flag is set, the version is compared to one stored in the 3DS. If the SMDH version is greater, then the user will be prompted to accept the EULA.
|0x202C||0x01||EULA Version Minor|
|0x202D||0x01||EULA Version Major|
 'Optimal Animation Default Frame' (for BNR)
Purpose of this flag: If using an animated BNR, it's the most representative frame for the animation.
This value is generated by taking an input value(default BNR frame) as a float, then representing it a hexadecimal array.
 CEC (StreetPass) ID
This u32 represents the application CEC ID. This is likely loaded by applications for use with the CEC services as well.
 Icon graphics
At offset 0x2040, there are two icons:
|0x2040||0x480||Small - 24x24 (shown on top screen when pausing the app)|
|0x24C0||0x1200||Large - 48x48 icon (the general icon)|
Both of the icons are encoded in RGB565 meaning 16bpp. Although both icons are known to be RGB565, developers have the option of encoding icons (and banners) with the following encodings :
This does not necessarily mean the other encodings will be used, it is just that those are the options when compiling. Like we've seen with Super Mario 3D Land Nintendo has changed save file encryption, and likewise they can encode icons and banners differently should they choose to. Currently we've seen just RGB565 so don't be fooled if an icon doesn't show up right! It is probably one of these formats above. Although we will probably not see other formats used for a while it's nice to know they have an opportunity to change.
There's a header of 0x40 bytes and then comes the raw data.
The data is encoded in tiles (starting from size 8x8, continuing recursively).
If the buffer is like this:
Then the image would look like this:
CiTRUS - (GUI)(Windows Only) Generating ICN files
3DSExplorer - (GUI)(Windows Only) Parsing ICN files