SARC

SARC File Format

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

File Format

SARC Header

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

SFAT Header

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

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

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

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

SFNT Data

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

File Data

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

File Sort Order

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

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