CNMT

This is the metadata file that ends in ".cnmt{.nca}" or "meta0.ncd". This seems to replace the TMD format.

The official name for CNMT is "PackagedContentMeta".

Header

Offset	Size	Description
0x0	0x8	ID
0x8	0x4	Version
0xC	0x1	Content Meta Type
0xD	0x1	Reserved
0xE	0x2	Extended Header Size
0x10	0x2	Content Count
0x12	0x2	Content Meta Count
0x14	0x1	Content Meta Attributes (0=None, 1=IncludesExFatDriver, 2=Rebootless)
0x15	0x3	Reserved
0x18	0x4	Required Download System Version
0x1C	0x4	Reserved

SystemUpdate Extended Header

Offset	Size	Description
0x0	0x4	Extended Data Size

Application Extended Header

Offset	Size	Description
0x0	0x8	Patch ID
0x8	0x4	Required System Version
0xC	0x4	Required Application Version

Patch Extended Header

Offset	Size	Description
0x0	0x8	Application ID
0x8	0x4	Required System Version
0xC	0x4	Extended Data Size
0x10	0x8	Reserved

AddOnContent Extended Header

Offset	Size	Description
0x0	0x8	Application ID
0x8	0x4	Required Application Version
0xC	0x4	Reserved

Delta Extended Header

Offset	Size	Description
0x0	0x8	Application ID
0x8	0x4	Extended Data Size
0xC	0x4	Reserved

Packaged Content Info

Offset	Size	Description
0x0	0x20	Hash (SHA256 of the referenced content)
0x20	0x10	Content ID
0x30	[15.0.0+] 0x5 ([1.0.0-14.1.2] 0x6)	Size
0x35	0x1	[15.0.0+] Content Attributes
0x36	0x1	Content Type (0=Meta, 1=Program, 2=Data, 3=Control, 4=HtmlDocument, 5=LegalInformation, 6=DeltaFragment)
0x37	0x1	ID Offset

Content Meta Info

Offset	Size	Description
0x0	0x8	ID
0x8	0x4	Version
0xC	0x1	Content Meta Type
0xD	0x1	Content Meta Attributes (0=None, 1=IncludesExFatDriver, 2=Rebootless)
0xE	0x2	Reserved

This is used for SystemUpdate, see here: NCM_services#ReadEntryMetaRecords.

SystemUpdate Extended Data

If the Version field is 1, the format is:

Offset	Size	Description
0x0	0x4	Version
0x4	0x4	Variation Count
0x8	0x20 * Variation Count	Firmware Variation Info (Version 1)

If the Version field is 2, the format is:

Offset	Size	Description
0x0	0x4	Version
0x4	0x4	Variation Count
0x8	0x4 * Variation Count	Firmware Variation ID
	0x20 * Variation Count	Firmware Variation Info (Version 2)
	0x10 * Meta Count (From Firmware Variation Info (Version 2))	Content Meta Info (If Refer To Base is False)

Firmware Variation Info (Version 1)

Offset	Size	Description
0x0	0x4	Firmware Variation ID
0x4	0x1C	Reserved

Firmware Variation Info (Version 2)

Offset	Size	Description
0x0	0x1	Refer To Base (0=False, 1=True)
0x1	0x3	Reserved
0x4	0x4	Meta Count
0x8	0x18	Reserved

Patch Extended Data

Offset	Size	Description
0x0	0x4	History Count
0x4	0x4	Delta History Count
0x8	0x4	Delta Count
0xC	0x4	Fragment Set Count
0x10	0x4	History Content Count
0x14	0x4	Delta Content Count
0x18	0x4	Reserved
0x1C	0x38 * History Count	History Headers
	0x28 * Delta History Count	Delta Histories
	0x28 * Delta Count	Delta Headers
	0x34 * Fragment Set Count	Fragment Sets
	0x18 * History Content Count	History Content Info (Packaged Content Info without the Hash entry)
	0x38 * Delta Content Count	Delta Packaged Content Info
	0x4 * Fragment Indicator Count (From Fragment Sets)	Fragment Indicators

History Header

Offset	Size	Description
0x0	0x10	Content Meta Key (Slightly different Content Meta Info)
0x10	0x20	Digest
0x30	0x2	Content Info Count
0x32	0x6	Reserved

Delta History

Offset	Size	Description
0x0	0x8	Source Patch ID
0x8	0x8	Destination Patch ID
0x10	0x4	Source Version
0x14	0x4	Destination Version
0x18	0x8	Download Size
0x20	0x8	Reserved

Delta Header

Offset	Size	Description
0x0	0x8	Source Patch ID
0x8	8	Destination Patch ID
0x10	0x4	Source Version
0x14	0x4	Destination Version
0x18	0x2	Fragment Set Count
0x1A	0x6	Reserved
0x20	0x2	Content Info Count
0x22	0x6	Reserved

Fragment Set

Offset	Size	Description
0x0	0x10	Source Content ID
0x10	0x10	Destination Content ID
0x20	0x6	Source Size
0x26	0x6	Destination Size
0x2C	0x2	Fragment Indicator Count
0x2E	0x1	Fragment Target Content Type (0=Meta, 1=Program, 2=Data, 3=Control, 4=HtmlDocument, 5=LegalInformation, 6=DeltaFragment)
0x2F	0x1	Update Type (0=ApplyAsDelta, 1=Overwrite, 2=Create)
0x30	0x4	Reserved

Fragment Indicator

Offset	Size	Description
0x0	0x2	Content Info Index
0x2	0x2	Fragment Index

Delta Extended Data

Offset	Size	Description
0x0	0x8	Source Patch ID
0x8	0x8	Destination Patch ID
0x10	0x4	Source Version
0x14	0x4	Destination Version
0x18	0x2	Fragment Set Count
0x1A	0x6	Reserved
0x20	0x34 * Fragment Set Count	Fragment Sets
	0x4 * Fragment Indicator Count (From Fragment Sets)	Fragment Indicators

Digest

Always found at the end of the file.

Offset	Size	Description
0x0	0x20	Digest