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SARC file format
[[Category:File formats]]
=SARC File Format=
.sarc files are similar to the [[ARC]] format with a slightly different structure.
== File Format ==
=== SARC Header ===
{| class="wikitable" border="1"
|-
! 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 ===
{| class="wikitable" border="1"
|-
! 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 ===
{| class="wikitable" border="1"
|-
! 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 ===
{| class="wikitable" border="1"
|-
! 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 =
[https://github.com/ObsidianX/3dstools] - SARC Extractor/Creator with TAR-like command line flags. Can decompress a .zlib SARC file (4-byte size header + ZLIB data).
=SARC File Format=
.sarc files are similar to the [[ARC]] format with a slightly different structure.
== File Format ==
=== SARC Header ===
{| class="wikitable" border="1"
|-
! 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 ===
{| class="wikitable" border="1"
|-
! 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 ===
{| class="wikitable" border="1"
|-
! 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 ===
{| class="wikitable" border="1"
|-
! 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 =
[https://github.com/ObsidianX/3dstools] - SARC Extractor/Creator with TAR-like command line flags. Can decompress a .zlib SARC file (4-byte size header + ZLIB data).