Difference between revisions of "Savegames"

Revision as of 23:09, 26 September 2018

This page describes the format of savegames contained in NAND. NAND savegames do not use an container with the entire file encrypted. Various areas of the saveimage is uninitialized data, resulting in encrypted data in those areas (like 3DS did).

Main header

The header is 0x4000 bytes long.

There are 2 headers stored at 0x0 and 0x4000, presumably for commit and rollback purposes.

Image offset	Length	Description
0x000	0x100	AES-CMAC header
0x100	0x200	DISF header
0x300	0x44	Duplex header
0x344	0xC4	Integrity verification header
0x408	0x200	Journal header
0x608	0x48	Save header
0x650	0x40	Main data remap header
0x690	0x40	Meta data remap header
0x6D0	0x8	Unknown
0x6D8	0x200	Extra data A
0x8D8	0x200	Extra data B
0xAD8	0x3528	Additional storage

The additional storage at the end of the header is used to store any extra header data. This data's structure is determined by offsets stored in the main part of the header.

AES CMAC header

Image offset	Length	Description
0x00	0x10	AES-CMAC over DISF header (size 0x200)
0x10	0xF0	Zero padding

The final CMAC key used for this is generated using GenerateAesKek with a kek source and the device key, along with and LoadAesKey and a set key seed.

DISF

This is located @ 0x100 in the image, following the CMAC header.

Start	Length	Description
0x000	4	Magic ("DISF")
0x004	4	Magic Number (0x40000)
0x008	32	Hash of start of DPFS to end of 0x4000 block (usually/always? 0x300-0x3FFF)
0x028	8	Primary Partition Table Offset
0x030	8	Primary Partition Table Size
0x038	8	Secondary Partition Table Offset
0x040	8	Secondary Partition Table Size
0x048	8	Save Partition Offset
0x050	8	Save Partition Size
0x258		End

DPFS

This is located @ 0x300 in the image, following DISF.
Block sizes are log2

Start	Length	Description
0x00	4	Magic ("DPFS")
0x04	4	Magic Number (0x10000)
0x08	8	Offset 0
0x10	8	Size 0
0x18	4	Block Size 0, in log 2
0x1C	8	Offset 1
0x24	8	Size 1
0x2C	4	Block Size 1, in log 2
0x30	8	Offset 2
0x38	8	Size 2
0x40	4	Block Size 2, in log 2

IVFC

Generally follows DPFS, similar to 3DS.

Start	Length	Description
0x00	4	Magic ("IVFC")
0x04	4	Magic Number (0x20000)
0x08	8	Master hash size?
0x10	8	Level 1 offset
0x18	8	Level 1 size
0x20	4	Level 1 block size, in log2
0x24	4	Reserved
0x28	8	Level 2 offset
0x30	8	Level 2 size
0x38	4	Level 2 block size, in log2.
0x3C	4	Reserved
0x40	8	Level 3 offset
0x48	8	Level 3 size
0x50	4	Level 3 block size, in log2.
0x54	4	Reserved
0x58	8	Level 4 offset
0x60	8	Level 4 size
0x68	4	Level 4 block size, in log2.
0x6C	4	Reserved
0x70	48	Unknown, reserved?
0xA0	32	Hash

JNGL

Generally follows IVFC

Start	Length	Description
0x00	4	Magic ("JNGL")
0x04	4	Magic Number (0x10000)
0x08	8	Savedata Size
0x10	8	Unknown, Size
0x18	8	Savedata Blocksize?
0x20	4	Unknown
0x24	4	Unknown
0x28	8	Unknown
0x30	464	Padding?

SAVE

Generally follows JNGL, structure is different from 3DS.

Start	Length	Description
0x00	4	Magic ("SAVE")
0x04	4	Magic Number (0x60000)
0x08	8	Unknown, number
0x10	8	Unknown, block size
0x18	8	Unknown, block size
0x20	8	Unknown

RMAP

There are generally two RMAP blocks in sequence.

Start	Length	Description
0x00	4	Magic ("RMAP")
0x04	4	Magic Number (0x10000)

Files

File Offset Table

Indexes 0 and 1 are reserved to point towards the folder and file tables.

File Offset Table Entry

Start	Length	Description
0x00	3	Data offset, in blocks
0x03	1	Unknown, 80
0x04	4	Unknown, 0

File/Folder Table Entry

The root file/folder index is generally 2

Start	Length	Description
0x00	4	Parent Folder Index
0x04	64	Filename
0x44	4	File/Folder Index?
0x48	4	File offset index in offset table, 0 for folders
0x4c	8	File size, or number of files for folders
0x54	8	Unknown
0x5c	4	Next File Index, same as folder index for folders

@@ Line 1: / Line 1: @@
 This page describes the format of savegames contained in NAND. NAND savegames do not use an container with the entire file encrypted. Various areas of the saveimage is uninitialized data, resulting in encrypted data in those areas (like 3DS did).
+== Main header ==
+The header is 0x4000 bytes long.
+There are 2 headers stored at 0x0 and 0x4000, presumably for commit and rollback purposes.
+{| class="wikitable"
+|-
+! Image offset
+! Length
+! Description
+|-
+| 0x000
+| 0x100
+| AES-CMAC header
+|-
+| 0x100
+| 0x200
+| DISF header
+|-
+| 0x300
+| 0x44
+| Duplex header
+|-
+| 0x344
+| 0xC4
+| Integrity verification header
+|-
+| 0x408
+| 0x200
+| Journal header
+|-
+| 0x608
+| 0x48
+| Save header
+|-
+| 0x650
+| 0x40
+| Main data remap header
+|-
+| 0x690
+| 0x40
+| Meta data remap header
+|-
+| 0x6D0
+| 0x8
+| Unknown
+|-
+| 0x6D8
+| 0x200
+| Extra data A
+|-
+| 0x8D8
+| 0x200
+| Extra data B
+|-
+| 0xAD8
+| 0x3528
+| Additional storage
+|}
+The additional storage at the end of the header is used to store any extra header data. This data's structure is determined by offsets stored in the main part of the header.
 === AES CMAC header ===
@@ Line 327: / Line 390: @@
 |}
-=== Files ===
+== Files ==
-==== File Offset Table ====
+=== File Offset Table ===
 * Indexes 0 and 1 are reserved to point towards the folder and file tables.
-===== File Offset Table Entry =====
+==== File Offset Table Entry ====
 {| class="wikitable"
@@ Line 354: / Line 417: @@
 |}
-==== File/Folder Table Entry ====
+=== File/Folder Table Entry ===
 * The root file/folder index is generally 2