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 homemenu, while CIA icons are only displayed while selecting CIAs from SD card on a dev 3DS.
Header
| START | SIZE | DESCRIPTION |
|---|---|---|
| 0x00 | 0x04 | Magic 'SMDH' |
| 0x04 | 0x04 | Reserved = 0 |
This header is immediately followed by meta-data:
Application Titles
| START | SIZE | DESCRIPTION |
|---|---|---|
| 0x00 | 0x80 | Short Description |
| 0x80 | 0x100 | Long Description |
| 0x180 | 0x80 | Publisher |
All encoded in UCS-2. There's 11 app title struct blocks, 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: Chinese title name
- 8th: Korean title name
- 9th: Dutch title name
- 10th: Portuguese title name
- 11th: Russian title name
Icon graphics
At offset 0x2400, there are two icons:
- Small - 24x24 (shown on top screen when pausing the app)
- 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 encodingsĀ :
- 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 |