Difference between revisions of "Savegames"

From Nintendo Switch Brew
Jump to navigation Jump to search
Line 82: Line 82:
 
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.
 
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 ====
+
=== DISF ===
  
 
This section contains information about the structure of the save file.
 
This section contains information about the structure of the save file.
Line 265: Line 265:
 
|}
 
|}
  
−
==== DPFS ====
+
=== Duplex header ===
  
−
* This is located @ 0x300 in the image, following DISF.
+
* Block sizes are stored as powers of 2
−
* Block sizes are log2
 
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 286: Line 285:
 
| 0x08
 
| 0x08
 
| 8
 
| 8
−
| Offset 0
+
| Master bitmap offset
 
|-
 
|-
 
| 0x10
 
| 0x10
 
| 8
 
| 8
−
| Size 0
+
| Master bitmap size
 
|-
 
|-
 
| 0x18
 
| 0x18
 
| 4
 
| 4
−
| Block Size 0, in log 2
+
| Master bitmap block size power
 
|-
 
|-
 
| 0x1C
 
| 0x1C
 
| 8
 
| 8
−
| Offset 1
+
| Level 1 offset
 
|-
 
|-
 
| 0x24
 
| 0x24
 
| 8
 
| 8
−
| Size 1
+
| Level 1 size
 
|-
 
|-
 
| 0x2C
 
| 0x2C
 
| 4
 
| 4
−
| Block Size 1, in log 2
+
| Level 1 block size power
 
|-
 
|-
 
| 0x30
 
| 0x30
 
| 8
 
| 8
−
| Offset 2
+
| Level 2 offset
 
|-
 
|-
 
| 0x38
 
| 0x38
 
| 8
 
| 8
−
| Size 2
+
| Level 2 size
 
|-
 
|-
 
| 0x40
 
| 0x40
 
| 4
 
| 4
−
| Block Size 2, in log 2
+
| Level 2 block size power
 
|-
 
|-
 
|}
 
|}
  
−
==== IVFC ====
+
=== Integrity verification header ===
  
−
* Generally follows DPFS, similar to 3DS.
+
* Offsets for levels 1-3 come from the metadata remap storage
 +
* Offsets for level 4 comes from the main data remap storage
 +
* This is the same header used in NCA files
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 341: Line 342:
 
|-
 
|-
 
| 0x08
 
| 0x08
−
| 8
 
−
| Master hash size?
 
−
|-
 
−
| 0x10
 
−
| 8
 
−
| Level 1 offset
 
−
|-
 
−
| 0x18
 
−
| 8
 
−
| Level 1 size
 
−
|-
 
−
| 0x20
 
 
| 4
 
| 4
−
| Level 1 block size, in log2
+
| Master hash size
 
|-
 
|-
−
| 0x24
+
| 0xC
 
| 4
 
| 4
−
| Reserved
+
| Number of levels (Unused in save files)
 
|-
 
|-
−
| 0x28
+
| 0x10
−
| 8
+
| 0x18*6
−
| Level 2 offset
+
| Level information for up to 6 levels
 
|-
 
|-
−
| 0x30
+
| 0xA0
−
| 8
+
| 32
−
| Level 2 size
+
| Salt seed
 
|-
 
|-
−
| 0x38
+
|}
−
| 4
+
 
−
| Level 2 block size, in log2.
+
==== Level information ====
 +
 
 +
* 0x18 bytes long
 +
* Block sizes are stored as powers of 2
 +
 
 +
{| class="wikitable"
 
|-
 
|-
−
| 0x3C
+
! Start
−
| 4
+
! Length
−
| Reserved
+
! Description
 
|-
 
|-
−
| 0x40
+
| 0x00
 
| 8
 
| 8
−
| Level 3 offset
+
| Offset
 
|-
 
|-
−
| 0x48
+
| 0x08
 
| 8
 
| 8
−
| Level 3 size
+
| Size
 
|-
 
|-
−
| 0x50
+
| 0x10
 
| 4
 
| 4
−
| Level 3 block size, in log2.
+
| Block size power
 
|-
 
|-
−
| 0x54
+
| 0x14
 
| 4
 
| 4
 
| Reserved
 
| 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 ====
+
=== Journal header ===
−
 
 
−
* Generally follows IVFC
 
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 434: Line 402:
 
| 0x04
 
| 0x04
 
| 4
 
| 4
−
| Magic Number (0x10000)
+
| Magic Number (0x10000 or less)
 
|-
 
|-
 
| 0x08
 
| 0x08
 
| 8
 
| 8
−
| Savedata Size
+
| Total size (Incl. journal)
 
|-
 
|-
 
| 0x10
 
| 0x10
 
| 8
 
| 8
−
| Unknown, Size
+
| Journal size
 
|-
 
|-
 
| 0x18
 
| 0x18
 
| 8
 
| 8
−
| Savedata Blocksize?
+
| Block size
 
|-
 
|-
 
| 0x20
 
| 0x20
 
| 4
 
| 4
−
| Unknown
+
| Unknown (Must be 0 or 1)
 
|-
 
|-
 
| 0x24
 
| 0x24
 
| 4
 
| 4
−
| Unknown
+
| Main data block count
 
|-
 
|-
 
| 0x28
 
| 0x28
 
| 8
 
| 8
−
| Unknown
+
| Journal block count
 
|-
 
|-
−
| 0x30
+
| 0x200
−
| 464
+
|  
−
| Padding?
+
| End
 
|-
 
|-
 
|}
 
|}
  
−
==== SAVE ====
+
=== Save FS header ===
  
−
* Generally follows JNGL, structure is different from 3DS.
+
* Structure is different than 3DS.
  
 
{| class="wikitable"
 
{| class="wikitable"
Line 486: Line 454:
 
| 0x08
 
| 0x08
 
| 8
 
| 8
−
| Unknown, number
+
| Number of blocks. Does not change if save file is resized.
 
|-
 
|-
 
| 0x10
 
| 0x10
 
| 8
 
| 8
−
| Unknown, block size
+
| Block Size
 +
|-
 +
|
 +
|
 +
| The below fields are read separately from the above fields
 
|-
 
|-
 
| 0x18
 
| 0x18
 
| 8
 
| 8
−
| Unknown, block size
+
| Block size
 
|-
 
|-
 
| 0x20
 
| 0x20
 
| 8
 
| 8
−
| Unknown
+
| FAT offset
 +
|-
 +
| 0x28
 +
| 4
 +
| FAT entry count
 +
|-
 +
| 0x2C
 +
| 4
 +
| Padding
 +
|-
 +
| 0x30
 +
| 8
 +
| Data offset
 +
|-
 +
| 0x38
 +
| 4
 +
| Data block count
 +
|-
 +
| 0x3C
 +
| 4
 +
| Padding
 +
|-
 +
| 0x40
 +
| 8
 +
| Directory table block index
 +
|-
 +
| 0x48
 +
| 8
 +
| File table block index
 
|-
 
|-
 
|}
 
|}
  
−
==== RMAP ====
+
=== RMAP ===
  
 
* There are generally two RMAP blocks in sequence.
 
* There are generally two RMAP blocks in sequence.

Revision as of 03:20, 30 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 section contains information about the structure of the save file.

Start Length Description
0x000 4 Magic ("DISF")
0x004 4 Magic Number (0x40000)
0x008 32 Hash of start of DPFS to end of 0x4000 block (0x300-0x3FFF)
0x028 8 Main data remap mapping table offset
0x030 8 Main data remap mapping table size
0x038 8 Meta data remap mapping table offset
0x040 8 Meta data remap mapping table size
0x048 8 Main data remap offset
0x050 8 Main data remap size
0x058 8 Duplex level 1 virtual offset A
0x060 8 Duplex level 1 virtual offset B
0x068 8 Duplex level 1 size
0x070 8 Duplex level 2 virtual offset A
0x078 8 Duplex level 2 virtual offset B
0x080 8 Duplex level 2 size
0x088 8 Journal storage virtual offset
0x090 8 Journal storage data size A
0x098 8 Journal storage data size B
0x0A0 8 Journal storage journal size
0x0A8 8 Duplex master bitmap offset A
0x0B0 8 Duplex master bitmap offset B
0x0B8 8 Duplex master bitmap size
0x0C0 8 IVFC master hash offset A
0x0C8 8 IVFC master hash offset B
0x0D0 8 IVFC master hash size
0x0D8 8 Journal block table virtual offset
0x0E0 8 Journal block table size
0x0E8 8 Virtual offset of bitmap of modified physical journal blocks
0x0F0 8 Size of bitmap of modified physical journal blocks
0x0F8 8 Virtual offset of bitmap of modified virtual journal blocks
0x100 8 Size of bitmap of modified virtual journal blocks
0x108 8 Virtual offset of bitmap of free journal blocks
0x110 8 Size of bitmap of free journal blocks
0x118 8 IVFC level 1 virtual offset
0x120 8 IVFC level 1 size
0x128 8 IVFC level 2 virtual offset
0x130 8 IVFC level 2 size
0x138 8 IVFC level 3 virtual offset
0x140 8 IVFC level 3 size
0x148 8 File allocation table virtual offset
0x150 8 File allocation table size
0x158 1 Index of the active duplex master bitmap
0x200 End

Duplex header

  • Block sizes are stored as powers of 2
Start Length Description
0x00 4 Magic ("DPFS")
0x04 4 Magic Number (0x10000)
0x08 8 Master bitmap offset
0x10 8 Master bitmap size
0x18 4 Master bitmap block size power
0x1C 8 Level 1 offset
0x24 8 Level 1 size
0x2C 4 Level 1 block size power
0x30 8 Level 2 offset
0x38 8 Level 2 size
0x40 4 Level 2 block size power

Integrity verification header

  • Offsets for levels 1-3 come from the metadata remap storage
  • Offsets for level 4 comes from the main data remap storage
  • This is the same header used in NCA files
Start Length Description
0x00 4 Magic ("IVFC")
0x04 4 Magic Number (0x20000)
0x08 4 Master hash size
0xC 4 Number of levels (Unused in save files)
0x10 0x18*6 Level information for up to 6 levels
0xA0 32 Salt seed

Level information

  • 0x18 bytes long
  • Block sizes are stored as powers of 2
Start Length Description
0x00 8 Offset
0x08 8 Size
0x10 4 Block size power
0x14 4 Reserved

Journal header

Start Length Description
0x00 4 Magic ("JNGL")
0x04 4 Magic Number (0x10000 or less)
0x08 8 Total size (Incl. journal)
0x10 8 Journal size
0x18 8 Block size
0x20 4 Unknown (Must be 0 or 1)
0x24 4 Main data block count
0x28 8 Journal block count
0x200 End

Save FS header

  • Structure is different than 3DS.
Start Length Description
0x00 4 Magic ("SAVE")
0x04 4 Magic Number (0x60000)
0x08 8 Number of blocks. Does not change if save file is resized.
0x10 8 Block Size
The below fields are read separately from the above fields
0x18 8 Block size
0x20 8 FAT offset
0x28 4 FAT entry count
0x2C 4 Padding
0x30 8 Data offset
0x38 4 Data block count
0x3C 4 Padding
0x40 8 Directory table block index
0x48 8 File table block index

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
Retrieved from "https://switchbrew.org/w/index.php?title=Savegames&oldid=5124"