SARC

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SARC File Format[edit]

.sarc files are similar to the ARC format with a slightly different structure.

File Format[edit]

SARC Header[edit]

Offset Size Description
0x00 0x04 Magic Bytes "SARC"
0x04 0x02 Header Length
0x06 0x02 Byte-order marker (0xFEFF = big, 0xFFFE = little)
0x08 0x04 File Length
0x0C 0x04 Data Offset (absolute)
0x10 0x04 Unknown (always 0x00000100)

SFAT Header[edit]

Offset Size Description
0x00 0x04 Magic bytes "SFAT"
0x04 0x02 Header Length
0x06 0x02 Node Count
0x08 0x04 Filename Hash Multiplier (usually 0x65)

SFAT Node[edit]

Offset Size Description
0x00 0x04 Name Hash
0x04 0x04 SFNT Filename Offset (relative to SFNT data section)
0x08 0x04 File Data Start (relative to SARC data start)
0x0C 0x04 File Data End (relative to SARC data end)

Node hashing function[edit]

The node hash is calculated via:

Python:

def calc_hash(name, hash_multiplier):
    result = 0
    
    for c in name:
        result = ord(c) + (result * hash_multiplier)
        # ensure the result is a 32-bit value
        result &= 0xFFFFFFFF
    
    return result

C:

uint32_t calc_hash(char *name, int hash_multiplier) {
    uint32_t result = 0;
    
    for(int i = 0; i < strlen(name); i++) {
        result = name[i] + (result * hash_multiplier)
    }
    
    return result;
}

SFNT Header[edit]

Offset Size Description
0x00 0x04 Magic bytes "SFNT"
0x04 0x02 Header Length
0x06 0x02 Unknown (padding?)

SFNT Data[edit]

SFNT data immediately follows the SFNT header and consists of NULL-terminated ASCII strings.

File Data[edit]

File data begins after SFNT with 0x100 (256) byte alignment with all subsequent files aligned to 0x80 bytes.

File Sort Order[edit]

Files are sorted by their hash in the SFAT table. Games seem to require this sorting as any other sort order prevents them from booting.


Tools[edit]

[1] - SARC Extractor/Creator with TAR-like command line flags. Can decompress a .zlib SARC file (4-byte size header + ZLIB data).