SARC (File Format)
SARC Files are archive files used on Nintendo Switch, Wii U and Nintendo 3DS. Common extensions are .arc and .sarc (general), .pack (when the archive contains mostly other archive files), .bars (when it contains audio data), and .bgenv/.genvb (when it contains shader and post-effect files). SARC files are sometimes Yaz0 compressed into .szs files.
File Format
Header
Every SARC file begins with a 0x14 byte SARC header structure.
| Offset | Type | Description |
|---|---|---|
| 0x00 | Char[4] | File magic. Always SARC in ASCII. |
| 0x04 | UInt16 | Size of this header in bytes. |
| 0x06 | UInt16 | Byte-order-mark. FE FF for big endian, FF FE for little endian. |
| 0x08 | UInt32 | File size of the entire archive in bytes. |
| 0x0C | UInt32 | Data start offset. |
| 0x10 | UInt16 | Version number of the file format. Only version 0x0100 has been seen. |
| 0x12 | UInt16 | Reserved. |
SFAT
The Header is immediately followed by the SFAT section. It has the following structure:
| Offset | Type | Description |
|---|---|---|
| 0x00 | Char[4] | Section magic. Always SFAT in ASCII. |
| 0x04 | UInt16 | Size of this section in bytes. |
| 0x06 | UInt16 | Number of nodes. |
| 0x08 | UInt32 | Hash key. Always 0x65. |
Node
After the SFAT section comes all node entries. Each entry has the following structure:
| Offset | Type | Description |
|---|---|---|
| 0x00 | UInt32 | File Name Hash. Look below for the calculation. |
| 0x04 | UInt32 | File attribute. If flag 0x01000000 is set, bottom half (0xFFFF) is the name offset divided by 4 (relative to end of SFNT). |
| 0x08 | UInt32 | Start of file data, relative to the data start offset specified in the Header. |
| 0x0C | UInt32 | End of file data, relative to the data start offset specified in the Header. |
File Name Hash
The hash is calculated like this:
uint GetHash(string name, uint key)
{
uint result = 0;
for (int i = 0; i < name.Length; i++)
{
result = name[i] + result * key;
}
return result;
}
SFNT
The SFAT node array is immediately followed by the SFNT structure. It has the following layout:
| Offset | Type | Description |
|---|---|---|
| 0x00 | Char[4] | File magic. Always SFNT in ASCII. |
| 0x04 | UInt16 | Size of this section in bytes. |
| 0x06 | UInt16 | Reserved. |
After follows 4-byte aligned null-terminated strings that represent the filenames of the packed files.
File Data
The data begins at the data start offset specified in the SARC header. The alignment of the internal files vary between different files, but default is 4.
Tools
The following tools can handle SARC files:
- Every File Explorer, by Gericom
- SARC Tool, by AboodXD
- SARCTools, by NwPlayer123
- Uwizard, by Mr. Mysterio
- Uwizard.Woomy, by smb123w64gb
- Wexos's Toolbox, by Wexos
- WiiUExplorer, by Celcodioc
