NCM services

NCM contains services for internal file path and content management.

Location Resolver services

lr

This is "nn::lr::ILocationResolverManager".

Cmd	Name	Arguments	Notes
0	OpenLocationResolver	StorageID
1	OpenRegisteredLocationResolver	None
2	RefreshLocationResolver	StorageID
3	[2.0.0+] OpenAddOnContentLocationResolver	None

The only sysmodules which use this service are FS, Loader, and NS. boot2 has access but doesn't use it.

ILocationResolver

This is "nn::lr::ILocationResolver".

Cmd	Name
0	#ResolveProgramPath
1	#RedirectProgramPath
2	#ResolveApplicationControlPath
3	#ResolveApplicationHtmlDocumentPath
4	#ResolveDataPath
5	#RedirectApplicationControlPath
6	#RedirectApplicationHtmlDocumentPath
7	#ResolveApplicationLegalInformationPath
8	#RedirectApplicationLegalInformationPath
9	#Refresh
10	[5.0.0+] #SetProgramNcaPath2
11	[5.0.0+] #ClearLocationResolver2
12	[5.0.0+] #DeleteProgramNcaPath
13	[5.0.0+] #DeleteControlNcaPath
14	[5.0.0+] #DeleteDocHtmlNcaPath
15	[5.0.0+] #DeleteInfoHtmlNcaPath

If the supplied StorageID is 1 (Host), a different set of internal functions is used to handle these commands. In this more restricted set of functions, GetControlNcaPath is stubbed and only returns error 0x608.

The Get* commands load the ContentPath from linked-lists' entries in memory using the input TitleID. When the command fails to find an entry for the specified TitleID, 0x408 is returned for GetProgramNcaPath and 0xA08 is returned for the rest.

The Set* commands always return 0 and add a new entry to the list. If a matching entry is found, it's removed first.

ResolveProgramPath

Takes an u64 TitleID and a C descriptor. Used for NCA-type1.

RedirectProgramPath

Takes an u64 TitleID and a X descriptor with a ContentPath. Used for NCA-type1.

Inserts a new entry with flag set to 0.

ResolveApplicationControlPath

Takes an u64 TitleID and a C descriptor. Used for NCA-type3.

ResolveApplicationHtmlDocumentPath

Takes an u64 TitleID and a C descriptor. Used for NCA-type4.

ResolveDataPath

Takes an u64 TitleID and a C descriptor. Used for NCA-type3.

RedirectApplicationControlPath

Takes an u64 TitleID and a X descriptor with a ContentPath. Used for NCA-type3.

Inserts a new entry with flag set to 1.

RedirectApplicationHtmlDocumentPath

Takes an u64 TitleID and a X descriptor with a ContentPath. Used for NCA-type4.

Inserts a new entry with flag set to 1.

ResolveApplicationLegalInformationPath

Takes an u64 TitleID and a C descriptor. Used for NCA-type5.

RedirectApplicationLegalInformationPath

Takes an u64 TitleID and a X descriptor with a ContentPath. Used for NCA-type5.

Inserts a new entry with flag set to 1.

Refresh

Takes no input. Frees all linked-lists' entries that have flag set to 0.

SetProgramNcaPath2

Same as SetProgramNcaPath, but inserts a new entry with flag set to 1.

ClearLocationResolver2

Takes no input. Frees all linked-lists' entries that have flag set to 1.

DeleteProgramNcaPath

Takes an u64 TitleID. Used for NCA-type1.

Removes the entry that matches the input TitleID.

DeleteControlNcaPath

Takes an u64 TitleID. Used for NCA-type3.

Removes the entry that matches the input TitleID.

DeleteDocHtmlNcaPath

Takes an u64 TitleID. Used for NCA-type4.

Removes the entry that matches the input TitleID.

DeleteInfoHtmlNcaPath

Takes an u64 TitleID. Used for NCA-type5.

Removes the entry that matches the input TitleID.

IRegisteredLocationResolver

This is "nn::lr::IRegisteredLocationResolver".

This works like #ILocationResolver, but only two types of NCA paths can be gotten/set. In addition, each type has a fallback path that can be set for a single title ID at a time.

Cmd	Name	Arguments	Notes
0	ResolveProgramPath	u64 TitleID + C descriptor	Used for NCA-type1.
1	RegisterProgramPath	u64 TitleID + X descriptor ContentPath	Sets the Type 0 fallback TID and path to the provided arguments.
2	UnregisterProgramPath	u64 TitleID	If the Type 0 fallback TID is == argument TID, unregisters the fallback path. Otherwise, noop.
3	RedirectProgramPath	u64 TitleID + X descriptor ContentPath
4	[2.0.0+] ResolveHtmlDocumentPath	u64 TitleID + C descriptor
5	[2.0.0+] RegisterHtmlDocumentPath	u64 TitleID + X descriptor ContentPath	Sets the Type 1 fallback TID and path to the provided arguments.
6	[2.0.0+] UnregisterHtmlDocumentPath	u64 TitleID	If the Type 1 fallback TID is == argument TID, unregisters the fallback path. Otherwise, noop.
7	[2.0.0+] RedirectHtmlDocumentPath	u64 TitleID + X descriptor ContentPath

IAddOnContentLocationResolver

This is "nn::lr::IAddOnContentLocationResolver".

Cmd	Name	Arguments	Notes
0	ResolveAddOnContentPath	u64 TitleID + C descriptor
1	RegisterAddOnContentStorage	StorageID + u64 TitleID
2	UnregisterAllAddOnContentPath	None	Clears all registered titles here.

Location List Entry

Total size is 0x320 bytes.

Offset	Size	Description
0x0	0x8	Pointer to previous entry
0x8	0x8	Pointer to next entry
0x10	0x8	TitleID
0x18	0x300	ContentPath
0x318	0x4	Flag
0x31C	0x4	Padding

Content Manager services

ncm

This is "nn::ncm::IContentManager".

Cmd	Name	Notes
0	CreateContentStorage	Takes a StorageID.
1	CreateContentMetaDatabase	Takes a StorageID.
2	VerifyContentStorage	Takes a StorageID.
3	VerifyContentMetaDatabase	Takes a StorageID.
4	OpenContentStorage	Takes a StorageID, [2.0.0+] Only returns a storage if one has previously been opened globally via OpenIContentStorage.
5	OpenContentMetaDatabase	Takes a StorageID, [2.0.0+] Only returns a storage if one has previously been opened globally via OpenIContentStorage.
6	[1.0.0] CloseContentStorageForcibly	Takes a StorageID. Calls IContentStorage->CloseAndFlushStorage().
7	[1.0.0] CloseContentMetaDatabaseForcibly	Takes a StorageID. Calls IContentMetaDatabase->CloseMetaDatabase().
8	CleanupContentMetaDatabase	Takes a StorageID, and deletes the associated savedata.
9	[2.0.0+] OpenContentStorage2	Takes a StorageID, and opens an IContentStorage for the StorageID to be gotten with GetIContentStorage. Note: Name is not official.
10	[2.0.0+] CloseContentStorage	Takes a StorageID, and closes the associated IContentStorage. Note: Name is not official.
11	[2.0.0+] OpenContentMetaDatabase2	Takes a StorageID, and opens an IContentMetaDatabase for the StorageID to be gotten with GetIContentMetaDatabase. Note: Name is not official.
12	[2.0.0+] CloseContentMetaDatabase	Takes a StorageID, and closes the associated IContentMetaDatabase. Note: Name is not official.

IContentStorage

This is "nn::ncm::IContentStorage".

Cmd	Name	Notes
0	#GeneratePlaceHolderId	Returns a random UUID for the Content Storage.
1	CreatePlaceHolder	Takes two #NcaIDs, and a u64 filesize.
2	DeletePlaceHolder	Takes a #NcaID.
3	HasPlaceHolder	Takes a #NcaID.
4	WritePlaceHolder	Takes a #NcaID, a u64-offset, and type 5 buffer. Writes the buffer to the file for the NcaID's placeholder path at the specified offset.
5	Register	Takes two #NcaIDs, moves the Placeholder NCA content to the registered NCA path.
6	Delete	Takes a #NcaID.
7	Has	Takes a #NcaID.
8	GetPath	Takes a #NcaID. Returns a Content Path.
9	GetPlaceHolderPath	Takes a #NcaID. Returns a Content Path.
10	CleanupAllPlaceHolder	Deletes and re-creates the Placeholder directory.
11	ListPlaceHolder	This is like #GetNumberOfRegisteredEntries, but for the Placeholder directory.
12	#GetContentCount
13	#ListContentId
14	#GetSize
15	DisableForcibly	Closes/Flushes all resources for the storage, and causes all future IPC commands to the current session to return error 0xC805.
16	[2.0.0+] RevertToPlaceHolder	Takes three 0x10-sized #NcaIDs. Creates the registered directory NCA path, and renames the placeholder path to the registered NCA path.
17	[2.0.0+] SetPlaceHolderSize	Takes a #NcaID, and a u64 size
18	[2.0.0+] #ReadContentIdFile
19	[2.0.0+] GetRightsIdFromPlaceHolderId	Gets the Rights ID for the #NcaID's placeholder path.
20	[2.0.0+] GetRightsIdFromContentId	Gets the Rights ID for the #NcaID's registered path
21	[2.0.0+] WriteContentForDebug	Takes a #NcaID, a u64 offset, and a type 5 buffer. On debug units, writes the buffer to the NCA's registered path. On retail units, this just aborts.
22	[2.0.0+] GetFreeSpaceSize	Gets free space for the storage.
23	[2.0.0+] GetTotalSpaceSize	Gets total space for the storage.
24	[3.0.0+] FlushStorage	Flushes resources for the storage without closing it.
25	[4.0.0+]
26	[4.0.0+]

GeneratePlaceHolderId

Generates a random #NcaID for use as a placeholder.

Calls nn::util::GenerateUuid(), which internally calls nn::os::GenerateRandomBytes(16);

GetContentCount

Writes the total number of entries which can be read by GetEntries, to cmdreply <SFCO_offset>+0x10.

ListContentId

Takes an output buffer, u32 offset and gets all entries starting at that offset. Returns number of entries read.

Each entry is a #NcaID.

The total read entries is exactly the same as the number of "<hex>.nca" directories in the storage FS(or at least under the "registered" directory?).

GetSize

Takes a #NcaID as input.

Returns the total size readable by #ReadContentIdFile. This is the same as the size-field in the NAX0 "<NcaID>.nca/00" file.

ReadContentIdFile

Takes an output buffer, a #NcaID as input, and a u64 file offset.

Reads plaintext NCA file contents from the Registered path for the NcaID.

IContentMetaDatabase

This is "nn::ncm::IContentMetaDatabase".

Note the official name for Meta Record is "ContentMetaKey".

Cmd	Name	Notes
0	Set	Takes a Meta Record, a type-5 Content Records buffer and a u64 size.
1	Get	Takes a Meta Record, a type-6 buffer to write Content Records to and a u64 size. Returns the actual number of bytes read into the buffer. First 8 bytes of the data is header (u16 numExtraDataBytes, numContentRecords, numMetaRecords, padding). After the header is numExtraDataBytes of additional data, after which follow content records and meta records. Set takes this same data as input.
2	Remove	Takes a Meta Record, and removes the associated record.
3	GetContentIdByType	Takes a Meta Record and a u8 Title Type. Returns a #NcaID.
4	ListContentInfo	Takes a type-6 buffer to write Content Record entries to, a Meta Record, and a u32 index into the Content Record entries to start copying from. Returns a u32 entries_read.
5	List	Takes a type-6 buffer to write Meta Records to, a u32 Title Type, a u64 TID, a u64 TID_LOW, and u64 TID_HIGH. Writes into the buffer all Meta Records with low <= record->title_id <= high, and record->type == type. Returns u32 numEntriesTotal, numEntriesWritten. Additionally requires record->title_id == TID, if record->type is Application, Patch, Add-On, or Delta, otherwise, you can pass 0 for type to ignore the type and list them all in the range.
6	GetLatestContentMetaKey	Takes a u64 title id, and returns the Meta Record with the highest version field for that title id.
7	#ListApplication
8	Has	Takes a Meta Record and returns whether that record is present in the database.
9	HasAll	Takes a type-5 buffer containing Meta Records (code assumes there are size/sizeof(meta_record) records in the buffer), and returns whether all of those records are present in the database.
10	GetSize	Takes a Meta Record, and returns the size of the associated Content Records.
11	GetRequiredSystemVersion	Takes a Meta Record, and returns u32 from ContentRecords + 16 (only if the Meta record has type Application or Patch).
12	GetPatchId	Takes a Meta Record, and returns the update title id for that record.
13	DisableForcibly	Closes the meta database, and causes all future IPC commands to the current session to return error 0xDC05.
14	#LookupOrphanContent	Takes a type-6 byte buffer, and a type-5 buffer of #NcaIDs.
15	Commit	Flushes the in-memory database to savedata.
16	HasContent	Takes a Meta Record and an #NcaID. Returns whether the content records for that meta record contain the NcaID.
17	ListContentMetaInfo	Takes a type-6 Meta Record output buffer, a u32 eoffset into that buffer, and an input Meta Record.
18	GetAttributes	Takes a Meta Record, and returns u8 from ContentRecords + 6.
19	[2.0.0+] GetRequiredApplicationVersion	Does the same thing as GetEntryUnknownRecordSize, but for AddOnContents.
20	[5.0.0+]

ListApplication

Each 24-byte entry (officially "ApplicationContentMetaKey") is as follows:

 meta_record meta_record;
 u64    base_title_id;

This function takes in a type 6 buffer to write entries to, and a u8 "filter" type. If filter is zero, all update records will be copied to to the output buffer (space permitting). Otherwise, only titles with type == filter_type will be copied to the output buffer.

This func returns a u32 num_entries_total, and a u32 num_entries_written.

ReadEntryMetaRecords

Takes a type-6 Meta Record output buffer, a u32 eoffset into that buffer, and an input Meta Record entry. Returns a u32 for total_read_entries.

Reads the meta records stored in the entry's content records into the output buffer.

This is used, for example, with System Update title 0100000000000816, which contains Meta Records for all other systitles in its Content Records.

LookupOrphanContent

Takes a type-6 byte buffer, and a type-5 buffer containing #NcaIDs.

This function was stubbed to return 0xDC05 in 2.0.0.

On 1.0.0: Initialized the output buffer to all 1s. Then, for each #NcaID in the input buffer, it checks if that NcaID is present anywhere in the database, and if so writes 0 to the corresponding output byte.

In pseudocode, the function basically does the following:

for i in range(len(out_buf)):

   out_buf[i] = 1

for i, NcaID in NcaIDs:

   if is_present_in_database(NcaID):
       out_buf[i] = 0

NcaID

This is a 0x10-byte entry. This is originally from the hex portion of "<hex>.nca" directory-names from this storage FS(like SD). This is also referred to as "ContentId" in the official SDK.

The NcaID is the same as the first 0x10-bytes from the calculated SHA256 hash, from hashing the entire output from #ReadContentIdFile.

Enums

Title Types

Value	Description
0x01	SystemProgram (System Modules or System Applets)
0x02	SystemData (System Data Archives)
0x03	SystemUpdate
0x04	BootImagePackage (Firmware package A or C)
0x05	BootImagePackageSafe (Firmware package B or D)
0x80	Application
0x81	Patch
0x82	AddOnContent
0x83	Delta

ncm:v

This service doesn't normally exist on retail.