SMDH

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).

Format

OFFSET	SIZE	DESCRIPTION
0x00	0x04	Magic 'SMDH'
0x04	0x04	Reserved
0x8	0x2000	16 application titles structs, each 0x200 bytes
0x2008	0x30	Application Settings
0x2038	0x8	Reserved
0x2040	0x1680	Icon graphics

Application Titles

START	SIZE	DESCRIPTION
0x00	0x80	Short Description
0x80	0x100	Long Description
0x180	0x80	Publisher

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.

START	SIZE	DESCRIPTION
0x2008	0x10	Region Specific Game Ratings (For use with Parental Controls)
0x2018	0x4	Region Lockout
0x201C	0xC	Match Maker IDs (Online Play)
0x2028	0x4	Flags
0x202C	0x2	EULA Version
0x202E	0x2	Reserved
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:

START	SIZE	DESCRIPTION
0x2008	0x1	CERO (Japan)
0x2009	0x1	ESRB (USA)
0x200A	0x1	Reserved
0x200B	0x1	USK (German)
0x200C	0x1	PEGI GEN (Europe)
0x200D	0x1	Reserved
0x200E	0x1	PEGI PRT (Portugal)
0x200F	0x1	PEGI BBFC (England)
0x2010	0x1	COB (Australia)
0x2011	0x1	Reserved For Future Use
0x2012	0x1	Reserved
0x2013	0x1	Reserved For Future Use
0x2014	0x1	Reserved For Future Use
0x2015	0x1	Reserved
0x2016	0x1	Reserved For Future Use
0x2017	0x1	Reserved For Future Use

Active ratings have a bitmask of 0x80, and inactive ratings have no bitmask at all. Ratings without the 0x80 bitmask are ignored.

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[0] is currently the only byte used, the rest are reserved.

REGION	BITMASK
Japan	0x01
North America	0x02
Europe	0x04
Australia	0x08
China	0x10
Korea	0x20
Taiwan	0x40

As these are bitmask flags, multiple regions can be 'allowed' access to a title if Nintendo chose. 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[3] = 0x7f)

Match Maker IDs

These IDs are an application's online gaming IDs.

START	SIZE	DESCRIPTION
0x201C	0x4	Match Maker ID
0x2020	0x8	Match Maker BIT ID

Flags

These are a collection of bit-mask flags.

INDEX	DESCRIPTION
0	See Below
1	See Below
2	Unused
3	Unused

Byte[0]

FLAG	BITMASK VALUE
Visibility Flag (Required for visibility on the Home Menu)	0x01
Auto-boot this title? (Game Card titles only?)	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?	0x08
Autosave on exit?	0x10
Uses an Extended Banner?	0x20
Region game rating required?	0x40
Uses save data?	0x80

Byte[1]

FLAG	BITMASK VALUE
Icon Database related (Most applications have this set)	0x01

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.

START	SIZE	DESCRIPTION
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:

START	SIZE	DESCRIPTION
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 :

RGBA8
RGB8
RGBA5551
RGB565
RGBA4
LA8
HILO8
L8
A8
LA4
L4
ETC1
ETC1A4

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:

0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16

Then the image would look like this:

x=0	x=1	x=2	x=3	x=4
0	1	4	5	16
2	3	6	7	...
8	9	12	13
10	11	14	15

Tools

CiTRUS - (GUI)(Windows Only) Generating ICN files

make_banner - (CMD)(Windows/Linux) Generating/Parsing ICN files

3DSExplorer - (GUI)(Windows Only) Parsing ICN files