This is the format used for storing the contents of a Nintendo Switch Gamecard.
Structure
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x1000 | #CardKeyArea |
| 0x1000 | 0x200 | #CardHeader |
| 0x1200 | 0x6E00 | ReservedArea |
| 0x8000 | 0x8000 | #CertArea |
| 0x10000 | Variable | #NormalArea |
| Variable | Variable | #RomArea |
| Invalid | Invalid | BackupArea |
CardKeyArea
This region cannot be read directly once written to the Gamecard. Therefore, it is hidden away during read/write operations on the raw Gamecard data.
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x200 | #InitialData |
| 0x200 | 0xD00 | #TitleKeyArea |
| 0xF00 | 0x100 | Reserved |
InitialData
This region is used for challengeāresponse authentication when changing to the Gamecard's secure mode.
FS calculates a SHA-256 hash over the whole 0x200 bytes and compares it with the hash stored at offset 0x160 in the #CardHeader.
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x8 | Package ID from #CardHeader at offset 0x110 |
| 0x8 | 0x8 | Empty |
| 0x10 | 0x10 | Challengeāresponse authentication data |
| 0x20 | 0x10 | Challengeāresponse authentication MAC |
| 0x30 | 0xC | Challengeāresponse authentication Nonce |
| 0x3C | 0x1C4 | Reserved (must be empty) |
TitleKeyArea
This region is stored encrypted and contains the title keys used by the #InitialData.
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x8 | TitleKey1 |
| 0x8 | 0x8 | TitleKey2 |
| 0x10 | 0xCF0 | Reserved |
CardHeader
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x100 | RSA-2048 PKCS #1 signature over the header (data from 0x100 to 0x200) |
| 0x100 | 0x4 | MagicCode ("HEAD") |
| 0x104 | 0x4 | RomAreaStartPageAddress (in Gamecard page units, which are 0x200 bytes) |
| 0x108 | 0x4 | BackupAreaStartPageAddress (always 0xFFFFFFFF) |
| 0x10C | 0x1 | TitleKeyDecIndex (high nibble) and KekIndex (low nibble) |
| 0x10D | 0x1 | #RomSize |
| 0x10E | 0x1 | CardHeaderVersion |
| 0x10F | 0x1 | #Flags |
| 0x110 | 0x8 | PackageId (used for challengeāresponse authentication) |
| 0x118 | 0x8 | ValidDataEndAddress (in Gamecard page units, which are 0x200 bytes) |
| 0x120 | 0x10 | Iv (reversed) |
| 0x130 | 0x8 | PartitionFsHeaderAddress |
| 0x138 | 0x8 | PartitionFsHeaderSize |
| 0x140 | 0x20 | PartitionFsHeaderHash (SHA-256 hash of the #PartitionFsHeader) |
| 0x160 | 0x20 | InitialDataHash (SHA-256 hash of the #InitialData) |
| 0x180 | 0x4 | SelSec (0x01 = T1, 0x02 = T2) |
| 0x184 | 0x4 | SelT1Key (always 2) |
| 0x188 | 0x4 | SelKey (always 0) |
| 0x18C | 0x4 | LimArea (in Gamecard page units, which are 0x200 bytes) |
| 0x190 | 0x70 | #CardInfo ( encrypted) |
CardInfo
This region is stored encrypted (AES-128-CBC).
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x8 | FwVersion (0x00 = Development, 0x01 = Retail, [4.0.0+] 0x02 = Retail, [11.0.0+] 0x04 = Retail) |
| 0x8 | 0x4 | AccCtrl1 (0x00A10011 = 25MHz access, 0x00A10010 = 50MHz access) |
| 0xC | 0x4 | Wait1TimeRead (always 0x1388) |
| 0x10 | 0x4 | Wait2TimeRead (always 0) |
| 0x14 | 0x4 | Wait1TimeWrite (always 0) |
| 0x18 | 0x4 | Wait2TimeWrite (always 0) |
| 0x1C | 0x4 | FwMode (the current SdkAddonVersion) |
| 0x20 | 0x4 | UppVersion |
| 0x24 | 0x1 | [9.0.0+] CompatibilityType (0x00 = Normal, 0x01 = Terra) |
| 0x25 | 0x3 | Empty |
| 0x28 | 0x8 | UppHash (SHA-256 hash of the #UpdatePartition) |
| 0x30 | 0x8 | UppId (always 0x0100000000000816) |
| 0x38 | 0x38 | Empty |
RomSize
FS retrieves this data as GameCardSize.
| Value | Description |
|---|---|
| 0xFA | 1GB |
| 0xF8 | 2GB |
| 0xF0 | 4GB |
| 0xE0 | 8GB |
| 0xE1 | 16GB |
| 0xE2 | 32GB |
Flags
FS retrieves this data as GameCardAttribute.
| Bits | Description |
|---|---|
| 0 | AutoBoot |
| 1 | HistoryErase |
| 2 | [4.0.0+] RepairTool |
| 3 | [9.0.0+] DifferentRegionCupToTerraDevice |
| 4 | [9.0.0+] DifferentRegionCupToGlobalDevice |
CertArea
This is the Gamecard's unique certificate.
FS retrieves this data with GetGameCardDeviceCertificate.
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x100 | RSA-2048 PKCS #1 signature over the data from 0x100 to 0x200 |
| 0x100 | 0x4 | MagicCode ("CERT") |
| 0x104 | 0x4 | Version |
| 0x108 | 0x1 | KekIndex |
| 0x109 | 0x7 | Reserved |
| 0x110 | 0x10 | DeviceId |
| 0x120 | 0x10 | Iv |
| 0x130 | 0xD0 | Data (encrypted) |
| 0x200 | 0x7E00 | Reserved |
NormalArea
This region contains all non-secure partitions of the Gamecard file system.
| Offset | Size | Description |
|---|---|---|
| Variable | Variable | RootPartitionHeader |
| Variable | Variable | UpdatePartitionHeader |
| Variable | Variable | #UpdatePartition |
| Variable | Variable | [4.0.0+] LogoPartitionHeader |
| Variable | Variable | [4.0.0+] #LogoPartition |
| Variable | Variable | NormalPartitionHeader |
| Variable | Variable | #NormalPartition |
UpdatePartition
This partition contains .cnmt.nca + .nca files for the entire system update required to play the game. Launch day carts contain a full copy of 1.0 ncas, newer carts contain newer sysupdate NCAs etc.
NormalPartition
This partition contains the .cnmt.nca and the game icondata nca. This is presumably for future compatibility so that if a future update changes the cryptographic protocol for the secure partition. Game icon data can still be shown in the home menu on old firmwares.
[4.0.0+] This partition is now empty.
LogoPartition
[4.0.0+] This partition now contains the contents of the #NormalPartition.
RomArea
This region contains all secure partitions of the Gamecard file system.
| Offset | Size | Description |
|---|---|---|
| Variable | Variable | SecurePartitionHeader |
| Variable | Variable | #SecurePartition |
SecurePartition
This partition contains an identical copy of the .cnmt.nca and game icondata nca, as well as all other ncas required for the game.
PartitionFs
This is the Gamecard file system which starts with magicnum "HFS0".
PartitionFsHeader
The "SHA-256 File System" or "HFS0" starts at offset 0x10000 in the Gamecard. The first 0x200 bytes act as a global header and represent the root partition which points to the other partitions ("normal", "logo", "update" and "secure).
A hash for this header is stored at offset 0x140 in the #CardHeader.
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x4 | MagicCode ("HFS0") |
| 0x4 | 0x4 | FileCount |
| 0x8 | 0x4 | StringTableSize |
| 0xC | 0x4 | Reserved |
| 0x10 | X | #FileEntryTable |
| 0x10 + X | Y | StringTable |
| 0x10 + X + Y | Z | RawFileData |
FileEntryTable
| Offset | Size | Description |
|---|---|---|
| 0x0 | 0x8 | Offset of file in Data |
| 0x8 | 0x8 | Size of file in Data |
| 0x10 | 0x4 | Offset of filename in String Table |
| 0x14 | 0x4 | Size of Hashed region of file (for HFS0s, this is the size of the pre-filedata portion, for NCAs this is usually 0x200) |
| 0x18 | 8 | Zero/Reserved |
| 0x20 | 0x20 | SHA-256 hash of the first (size of hashed region) bytes of filedata |
The string table is 00-padded to align the start of raw filedata with a sector/media unit boundary (usually?).