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Line 193: − + − + + + + + − + − + + + + + + + + + − + − + − + + + + + + + + + − + − + − + − + − + − + − + − |- − | 0x1100 − | 0x100 − | Copy of first NCCH header (excluding RSA signature) Line 128:
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no edit summary
== Overview ==
== Overview ==
There are two known specialisations of the NCSD container format. The CTR Cart Image (CCI) format and the CTR System Update (CSU). CCI is the format of retail game ROM dumps. CSU is used with developer system updates and tools
There are two known specialisations of the NCSD container format. The CTR Cart Image (CCI) format and the 3DS' raw [[Flash Filesystem#NAND structure|NAND format]]. CCI is the format of game ROM images.
NCSD images start with a NCSD header, followed by up to a maximum of 8 [[NCCH]] partitions. The first partition([[NCCH]] 0) usually starts at 0x4000, this is generally the main [[NCCH#CXI|NCCH]] (Executable). The following info on partitions 1, 2, and 7 are only valid for .CCI. The second partition([[NCCH]] 1) contains the game's Electronic Manual(The partitionID-high for the Instruction Manual .[[NCCH#CFA|CFA]] is always 0x00050000). The third partition([[NCCH]] 2) contains the download play "Child"(The partitionID-high for the .[[NCCH#CFA|CFA]] containing the DLP Child is always 0x00060000). The eighth block([[NCCH]] 7) contains "Update Data"(The partitionID-high for the .[[NCCH#CFA|CFA]] containing the [[System_Update_CFA|Update Data]] is always 0x80000000). The format of partitions can be determined from the partition FS flags, while the contents can be determined from the partitions flags.
'''CTR System Update (CSU)''' is a variant of CCI, where the only difference is in the file extension. This is used with developer System Updates and associated [[3DS Development Unit Software|Tools]].
NCSD images start with a NCSD header, followed by up to a maximum of 8 [[NCCH]] partitions.
For CCI images, the partitions are reserved as follows:
{| class="wikitable" border="1"
|-
! [[NCCH]] Index
! Reserved Use
|-
| 0
| Executable Content ([[NCCH#CXI|CXI]])
|-
| 1
| E-Manual ([[NCCH#CFA|CFA]])
|-
| 2
| [[Download Play]] Child container ([[NCCH#CFA|CFA]])
|-
| 6
| New3DS [[System_Update_CFA|Update Data]] ([[NCCH#CFA|CFA]])
|-
| 7
| [[System_Update_CFA|Update Data]] ([[NCCH#CFA|CFA]])
|}
The format of partitions can be determined from the partition FS flags (normally these are zero for CCI/CSU NCSD Images).
== NCSD header ==
== NCSD header ==
| 0x110
| 0x110
| 8
| 8
| Partitions FS type
| Partitions FS type (0=None, 1=Normal, 3=FIRM, 4=AGB_FIRM save)
|-
|-
| 0x118
| 0x118
| 8
| 8
| Partitions crypt type
| Partitions crypt type (each byte corresponds to a partition in the partition table)
|-
|-
| 0x120
| 0x120
| 0x40=(4+4)*8
| 0x40=(4+4)*8
| Offset & Length partition table
| Offset & Length partition table, in media units
|-
| 0x160
| 0xA0
| ...
|}
For carts,
{| class="wikitable" border="1"
|-
! Offset
! Size
! Description
|-
|-
| 0x160
| 0x160
| 0x188
| 0x188
| 8
| 8
| Partition Flags: byte[5]-byte[7] indicate content type ( system update, application, manual, ... ) size of media units ( 512*2^byte[6] ) and encryption.
| Partition Flags (See Below)
|-
|-
| 0x190
| 0x190
|-
|-
| 0x1D0
| 0x1D0
| 0x30
| 0x20
| Reserved
| Reserved
|-
| 0x1F0
| 0xE
| Reserved?
|-
| 0x1FE
| 0x1
| Support for this was implemented with [[9.6.0-24|9.6.0-X]] FIRM. Bit0=1 enables using bits 1-2, it's unknown what these two bits are actually used for(the value of these two bits get compared with some other value during NCSD verification/loading). This appears to enable a new, likely hardware-based, antipiracy check on cartridges.
|-
| 0x1FF
| 0x1
| Support for this was implemented with [[9.6.0-24|9.6.0-X]] FIRM, see below regarding save crypto.
|}
|}
For NAND,
{| class="wikitable" border="1"
|-
! Offset
! Size
! Description
|-
| 0x160
| 0x5E
| Unknown
|-
| 0x1BE
| 0x42
| Encrypted MBR partition-table, for the TWL partitions(key-data used for this keyslot is console-unique).
|}
=== NCSD Signature ===
The RSA public key used for gamecard NCSD is stored in [[Memory_layout|ITCM]]. The separate public key used for NAND NCSD is stored in Process9 .(ro)data instead of ITCM, and in [[Bootloader|boot ROM]].
For the boot ROM check, sighax may be used to fake-sign NAND headers. Process9's check will fail, however, unless patched.
=== Partition Flags ===
=== Partition Flags ===
|-
|-
| 0
| 0
| Unknown, NATIVE_FIRM loads this flag from the gamecard NCSD header starting with [[6.0.0-11]].
| Backup Write Wait Time (The time to wait to write save to backup after the card is recognized (0-255 seconds)).NATIVE_FIRM loads this flag from the gamecard NCSD header starting with [[6.0.0-11]].
|-
| 3
| Media Card Device (1 = NOR Flash, 2 = None, 3 = BT) (SDK 3.X+)
|-
| 4
| Media Platform Index (1 = CTR)
|-
| 5
| Media Type Index (0 = Inner Device, 1 = Card1, 2 = Card2, 3 = Extended Device)
|-
| 6
| Media Unit Size i.e. u32 MediaUnitSize = 0x200*2^flags[6];
|-
| 7
| Media Card Device (1 = NOR Flash, 2 = None, 3 = BT) (Only SDK 2.X)
|}
=== Partition Flags (In Terms of Save Crypto Determination) ===
{| class="wikitable" border="1"
|-
! Byte Index
! Description
|-
|-
| 1
| 1
| Starting with [[6.0.0-11]] NATIVE_FIRM will use this flag to determine the gamecard [[Savegames|savegame]] keyY method, when flag[3] is set. 2 = hashed keyY, 3 = [[Savegames|new]] keyY method implemented with [[6.0.0-11]].
| Starting with [[6.0.0-11]] NATIVE_FIRM will use this flag to determine the gamecard [[Savegames|savegame]] keyY method, when flag[3] is set. 0 = [[2.0.0-2]] hashed keyY, 1 = [[Savegames|new]] keyY method implemented with [[6.0.0-11]]. 0x0A = implemented with [[9.3.0-21|9.3.0-X]]. On Old3DS this is identical to the [[2.2.0-4]] crypto. On New3DS this is identical to the [[2.2.0-4]] crypto, except with New3DS-only gamecard savedata [[AES|keyslots]].
Starting with [[9.6.0-24|9.6.0-X]] FIRM, Process9 now sets <savecrypto_stateval> to partitionflag[1] + <the u8 value from NCSD+0x1FF>, instead of just setting it to partitionflag[1].
|-
|-
| 3
| 3
| Support for this flag was implemented in NATIVE_FIRM with [[2.0.0-2]]. When this flag is set the hashed gamecard [[Savegames|savegame]] keyY method is used, this likely still uses the repeating-CTR however. With [[6.0.0-11]] the system will determine the gamecard savegame keyY method via flag[1], instead of just using the hashed keyY via this flag
| Support for this flag was implemented in NATIVE_FIRM with [[2.0.0-2]]. When this flag is set the hashed gamecard [[Savegames|savegame]] keyY method is used, this likely still uses the repeating-CTR however. With [[6.0.0-11]] the system will determine the gamecard savegame keyY method via flag[1], instead of just using the hashed keyY via this flag.
|-
|-th
| 7
| 7
| This flag enables using the hashed gamecard [[Savegames|savegame]] keyY method, support for this flag was implemented in NATIVE_FIRM with [[2.2.0-4]]. All games with the NCSD image finalized since [[2.2.0-4]](and contains [[2.2.0-4]]+ in the system update partition) have this flag set, this flag also enables using new CTR method as well.
| This flag enables using the hashed gamecard [[Savegames|savegame]] keyY method, support for this flag was implemented in NATIVE_FIRM with [[2.2.0-4]]. All games with the NCSD image finalized since [[2.2.0-4]](and contains [[2.2.0-4]]+ in the system update partition) have this flag set, this flag also enables using new CTR method as well.
|}
|}
Starting with [[9.6.0-24|9.6.0-X]] FIRM, Process9 will just write val0 to a state field then return 0, instead of returning an error when the save crypto type isn't recognized. This was the *only* actual functionality change in the Old3DS Process9 function for gamecard savedata crypto init.
== Card Info Header ==
== Card Info Header ==
|-
|-
| 0x200
| 0x200
| 8
| 4
| Card Info
| CARD2: Writable Address In Media Units (For 'On-Chip' Savedata). CARD1: Always 0xFFFFFFFF.
|-
| 0x204
| 4
| Card Info Bitmask
|-
|-
| 0x208
| 0x208
| 0xDF8
| 0xF8
| Reserved1
| Reserved
|-
| 0x300
| 4
| Filled size of cartridge
|-
| 0x304
| 0xC
| Reserved
|-
|-
| 0x1000
| 0x310
| 8
| 2
| Media ID (same as first NCCH partitionId)
| Title version
|-
| 0x312
| 2
| Card revision
|-
| 0x314
| 0xC
| Reserved
|-
|-
| 0x1008
| 0x320
| 8
| 8
| Reserved2
| Title ID of [[CVer]] in included update partition
|-
|-
| 0x1010
| 0x328
| 0x30
| 2
| Initial Data
| Version number of [[CVer]] in included update partition
|-
|-
| 0x1040
| 0x32A
| 0xC0
| 0xCD6
| Reserved
| Reserved
|}
|}
! SIZE
! SIZE
! DESCRIPTION
! DESCRIPTION
|-
| 0x1000
| 0x200
| InitialData
|-
|-
| 0x1200
| 0x1200
| 0x1400
| 0x1400
| 0x10
| 0x10
| TitleKey
| TitleKeyData
|-
|-
| 0x1410
| 0x1410
| 0xF0
| 0x1BF0
| CardDeviceReserved2
| CardDeviceReserved2
|-
| 0x3000
| 0x1000
| TestData
|}
|}
TitleKeyData contains the decrypted version of the title key found in the InitialData. This field appears to be what development--and maybe production?--cards read to know what card encryption seed to use in the CTR protocol.
The CardDeviceReserved areas have random-looking data whose purpose is unknown, other than perhaps to hide the TitleKey.
Note that a particular flashcard vendor puts what many refer to as "private headers" here in place of actual development card information. This header is constituted by a cartridge-unique ID obtained from [[Process_Services_PXI|pxi:ps9::GetRomId]] and the title-unique cart ID (identical for all carts of the same title; can be retrieved using the NTR gamecard protocol command 0x90 or through the CTR protocol commands 0x90 or 0xA2).
=== InitialData ===
{| class="wikitable" border="1"
|-
! OFFSET
! SIZE
! DESCRIPTION
|-
| 0x0
| 0x10
| Seed (keyY used to decrypt the title key - keyX is keyslot 0x3B for production cards, or a key of all zeroes for development cards)
|-
| 0x10
| 0x10
| TitleKey (AES-CCM encrypted)
|-
| 0x20
| 0x10
| Mac
|-
| 0x30
| 0xC
| Nonce
|-
| 0x3C
| 0xC4
| Reserved
|-
| 0x100
| 0x100
| NcchHeader (copy of the first NCCH header, excluding the RSA signature)
|}
=== TestData ===
The test data is the same one encountered in development DS/DSi cartridges. Its layout is as follows:
{| class="wikitable" border="1"
|-
! OFFSET
! SIZE
! DESCRIPTION
|-
| 0x0
| 0x8
| The bytes FF 00 FF 00 AA 55 AA 55.
|-
| 0x8
| 0x1F8
| An ascending byte sequence equal to the offset mod 256 (08 09 0A ... FE FF 00 01 ... FF).
|-
| 0x200
| 0x200
| A descending byte sequence equal to 255 minus the offset mod 256 (FF FE FD ... 00 FF DE ... 00).
|-
| 0x400
| 0x200
| Filled with 00 (0b00000000) bytes.
|-
| 0x600
| 0x200
| Filled with FF (0b11111111) bytes.
|-
| 0x800
| 0x200
| Filled with 0F (0b00001111) bytes.
|-
| 0xA00
| 0x200
| Filled with F0 (0b11110000) bytes.
|-
| 0xC00
| 0x200
| Filled with 55 (0b01010101) bytes.
|-
| 0xE00
| 0x1FF
| Filled with AA (0b10101010) bytes.
|-
| 0xFFF
| 0x1
| The final byte is 00 (0b00000000).
|}
Production cards always return FF when attempting to read 0x1200-0x3FFF. They probably actually have the same data as development cards, but there's no way to read it.
== Tools ==
== Tools ==