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".

PackagedContentMetaHeader

This is "nn::ncm::PackagedContentMetaHeader".

Offset	Size	Description
0x0	0x8	Id
0x8	0x4	Version
0xC	0x1	ContentMetaType
0xD	0x1	Reserved
0xE	0x2	ExtendedHeaderSize
0x10	0x2	ContentCount
0x12	0x2	ContentMetaCount
0x14	0x1	ContentMetaAttributes (0=None, 1=IncludesExFatDriver, 2=Rebootless, 4=Compacted)
0x15	0x3	Reserved
0x18	0x4	RequiredDownloadSystemVersion
0x1C	0x4	Reserved

SystemUpdateMetaExtendedHeader

This is "nn::ncm::SystemUpdateMetaExtendedHeader".

Offset	Size	Description
0x0	0x4	ExtendedDataSize

ApplicationMetaExtendedHeader

This is "nn::ncm::ApplicationMetaExtendedHeader".

Offset	Size	Description
0x0	0x8	PatchId
0x8	0x4	RequiredSystemVersion
0xC	0x4	RequiredApplicationVersion

PatchMetaExtendedHeader

This is "nn::ncm::PatchMetaExtendedHeader".

Offset	Size	Description
0x0	0x8	ApplicationId
0x8	0x4	RequiredSystemVersion
0xC	0x4	ExtendedDataSize
0x10	0x8	Reserved

AddOnContentMetaExtendedHeader

This is "nn::ncm::AddOnContentMetaExtendedHeader".

Offset	Size	Description
0x0	0x8	ApplicationId
0x8	0x4	RequiredApplicationVersion
0xC	0x1	[15.0.0+] ContentAccessibilities ([1.0.0-14.1.2] Reserved)
0xD	0x3	Reserved
0x10	0x8	[15.0.0+] DataPatchId

DeltaMetaExtendedHeader

This is "nn::ncm::DeltaMetaExtendedHeader".

Offset	Size	Description
0x0	0x8	ApplicationId
0x8	0x4	ExtendedDataSize
0xC	0x4	Reserved

DataPatchMetaExtendedHeader

This is "nn::ncm::DataPatchMetaExtendedHeader".

This was added with [15.0.0+].

Offset	Size	Description
0x0	0x8	DataId
0x8	0x8	ApplicationId
0x10	0x4	RequiredApplicationVersion
0x14	0x4	ExtendedDataSize
0x18	0x8	Reserved

PackagedContentInfo

This is "nn::ncm::PackagedContentInfo".

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

ContentMetaInfo

This is "nn::ncm::ContentMetaInfo".

Offset	Size	Description
0x0	0x8	Id
0x8	0x4	Version
0xC	0x1	ContentMetaType
0xD	0x1	ContentMetaAttributes (0=None, 1=IncludesExFatDriver, 2=Rebootless, 4=Compacted)
0xE	0x2	Reserved

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

SystemUpdateMetaExtendedData

This is "nn::ncm::SystemUpdateMetaExtendedData".

If the Version field is 1, the format is:

Offset	Size	Description
0x0	0x4	Version
0x4	0x4	VariationCount
0x8	0x20 * VariationCount	FirmwareVariationInfo (Version 1)

If the Version field is 2, the format is:

Offset	Size	Description
0x0	0x4	Version
0x4	0x4	VariationCount
0x8	0x4 * VariationCount	FirmwareVariationId
Variable	0x20 * VariationCount	FirmwareVariationInfo (Version 2)
Variable	0x10 * MetaCount (from FirmwareVariationInfo (Version 2))	ContentMetaInfo (if ReferToBase is False)

FirmwareVariationInfo

This is "FirmwareVariationInfo ".

If the Version field is 1, the format is:

Offset	Size	Description
0x0	0x4	FirmwareVariationId
0x4	0x1C	Reserved

If the Version field is 2, the format is:

Offset	Size	Description
0x0	0x1	ReferToBase (0=False, 1=True)
0x1	0x3	Reserved
0x4	0x4	MetaCount
0x8	0x18	Reserved

PatchMetaExtendedData

This is "nn::ncm::PatchMetaExtendedData".

Offset	Size	Description
0x0	0x4	PatchHistoryHeaderCount
0x4	0x4	PatchDeltaHistoryCount
0x8	0x4	PatchDeltaHeaderCount
0xC	0x4	FragmentSetCount
0x10	0x4	PatchHistoryContentInfoCount
0x14	0x4	PatchDeltaPackagedContentInfoCount
0x18	0x4	Reserved
0x1C	0x38 * PatchHistoryHeaderCount	PatchHistoryHeader
Variable	0x28 * PatchDeltaHistoryCount	PatchDeltaHistory
Variable	0x28 * PatchDeltaHeaderCount	PatchDeltaHeader
Variable	0x34 * FragmentSetCount	FragmentSet
Variable	0x18 * PatchHistoryContentInfoCount	PatchHistoryContentInfo (PackagedContentInfo without the Hash entry)
Variable	0x38 * PatchDeltaPackagedContentInfoCount	PatchDeltaPackagedContentInfo
Variable	0x4 * FragmentIndicatorCount (from FragmentSet)	FragmentIndicator

PatchHistoryHeader

This is "nn::ncm::PatchHistoryHeader".

Offset	Size	Description
0x0	0x10	ContentMetaKey
0x10	0x20	Digest
0x30	0x2	ContentInfoCount
0x32	0x6	Reserved

PatchDeltaHistory

This is "nn::ncm::PatchDeltaHistory".

Offset	Size	Description
0x0	0x8	SourcePatchId
0x8	0x8	DestinationPatchId
0x10	0x4	SourceVersion
0x14	0x4	DestinationVersion
0x18	0x8	DownloadSize
0x20	0x8	Reserved

PatchDeltaHeader

This is "nn::ncm::PatchDeltaHeader".

Offset	Size	Description
0x0	0x8	SourcePatchId
0x8	8	DestinationPatchId
0x10	0x4	SourceVersion
0x14	0x4	DestinationVersion
0x18	0x2	FragmentSetCount
0x1A	0x6	Reserved
0x20	0x2	ContentInfoCount
0x22	0x6	Reserved

FragmentSet

This is "nn::ncm::FragmentSet".

Offset	Size	Description
0x0	0x10	SourceContentId
0x10	0x10	DestinationContentId
0x20	0x6	SourceSize
0x26	0x6	DestinationSize
0x2C	0x2	FragmentIndicatorCount
0x2E	0x1	FragmentTargetContentType (0=Meta, 1=Program, 2=Data, 3=Control, 4=HtmlDocument, 5=LegalInformation, 6=DeltaFragment)
0x2F	0x1	UpdateType (0=ApplyAsDelta, 1=Overwrite, 2=Create)
0x30	0x4	Reserved

FragmentIndicator

This is "nn::ncm::FragmentIndicator".

Offset	Size	Description
0x0	0x2	ContentInfoIndex
0x2	0x2	FragmentIndex

DeltaMetaExtendedData

This is "nn::ncm::DeltaMetaExtendedData".

Offset	Size	Description
0x0	0x8	SourcePatchId
0x8	0x8	DestinationPatchId
0x10	0x4	SourceVersion
0x14	0x4	DestinationVersion
0x18	0x2	FragmentSetCount
0x1A	0x6	Reserved
0x20	0x34 * FragmentSetCount	FragmentSet
Variable	0x4 * FragmentIndicatorCount (from FragmentSet)	FragmentIndicator

Digest

Always found at the end of the file.

Offset	Size	Description
0x0	0x20	Digest