For the content of the NCA FS which can be mounted, see here.
Metadata file
This is the file that ends in ".cnmt{.nca}" or "meta0.ncd". This seems to replace the TMD format.
There's at least 3 different filenames used for ".cnmt":
- "Application_{lower-case hex titleID}.cnmt"
- "Patch_{lower-case hex titleID}.cnmt"
- "SystemUpdate_{hex titleID}.cnmt"
It starts with a header:
| Offset | Size | Description |
|---|---|---|
| 0x0 | 8 | Title ID |
| 0x8 | 4 | u32 title-version |
| 0xC | 1 | Type (see Title Types) |
| 0xD | 1 | |
| 0xE | 2 | Offset to table relative to the end of this 0x20-byte header. |
| 0x10 | 2 | Number of content entries |
| 0x12 | 2 | Number of meta entries |
| 0x14 | 12 |
With SystemUpdate, the 4-bytes at offset 0xE are zero, with the entry-count field located at offset 0x12 instead(header size is the same).
An optional header can follow, depending on the title type.
At the end of the file following the entries is a 0x20-byte block, presumably a hash.
With Patch-format, there's additional data after the end of the entries specified in the header and before the ending hash.
Application header
| Offset | Size | Description |
|---|---|---|
| 0x20 | 8 | Patch title ID |
| 0x28 | 8 |
Patch header
| Offset | Size | Description |
|---|---|---|
| 0x20 | 8 | Original title ID |
| 0x28 | 8 |
Add-on content header
| Offset | Size | Description |
|---|---|---|
| 0x20 | 8 | Application title ID |
| 0x28 | 8 |
Content records
Each entry is 0x38 bytes:
| Offset | Size | Description |
|---|---|---|
| 0x0 | 32 | Hash |
| 0x20 | 16 | NcaId [same as first 16-bytes of hash] |
| 0x30 | 6 | Size, same as the output from Content_Manager_services#GetEntrySize. |
| 0x36 | 1 | Type (0=meta, 1=program, 2=data, 3=control, 4=offline-manual html, 5=legal html) |
| 0x37 | 1 |
Meta records
Each entry is 0x10 bytes:
| Offset | Size | Description |
|---|---|---|
| 0x0 | 8 | Title ID |
| 0x8 | 4 | Title version |
| 0xC | 1 | Type (see Title Types) |
| 0xD | 1 | ? bit0 set = don't install? |
| 0xE | 2 | Unused? |
This is used for SystemUpdate, see here: Content_Manager_services#GetUpdateTitleList.