From Nintendo Switch Brew
Revision as of 23:09, 26 September 2018 by Moosehunter (talk | contribs)
Jump to navigation Jump to search

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.


  • 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


  • 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


  • 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


  • 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?


  • 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


  • There are generally two RMAP blocks in sequence.
Start Length Description
0x00 4 Magic ("RMAP")
0x04 4 Magic Number (0x10000)


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