NCM services

ncm

Cmd	Name	Notes
0		Takes a u8 as input.
1		Takes a u8 as input.
2		Takes a u8 as input.
3		Takes a u8 as input.
4	GetContentStorage
5	GetContentMetaDatabase
8		Takes a u8 as input.
9	InitializeStorageForMediaId
10	UninitializeStorageForMediaId
11	InitializeDatabaseForMediaId
12	UninitializeDatabaseForMediaId

IContentStorage

Cmd	Name	Notes
0	#GetRootEntry
1		Takes two 0x10-sized entries, and a u64.
2		Takes a 0x10-sized entry.
3		Takes a 0x10-sized entry, returns a bool/u8.
4		Takes a 0x10-sized entry, a u64, and type-5 array.
5		Takes two 0x10-sized entries.
6	DeleteContent?	Takes a 0x10-sized entry.
7		Takes a 0x10-sized entry, returns a bool/u8.
8		Takes a type-0x1A string and a 0x10-sized entry.
9		Takes a type-0x1A string and a 0x10-sized entry.
10		Void.
11		Takes a type-6 buffer, each entry 0x10 bytes, and returns a u32.
12	#GetNumberOfEntries
13	#GetEntries
14	#GetEntrySize
15		Void.
16		Takes three 0x10-sized entries.
17		Takes a 0x10-sized entry and a u64.
18	#ReadEntryRaw
19		Takes a 0x10-sized entry and returns another 0x10-sized entry.
20	#GetNcaTitleInfo
21		Takes a 0x10-sized entry, a u64, and a type5 buffer.
22	GetFreeSpace
23	GetTotalSpace

GetRootEntry

Returns an entry of 16 completely random-looking bytes. It is not possible to read this entry.

Changes on reboot?

GetNumberOfEntries

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

GetEntries

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?).

GetEntrySize

Takes a #NcaID as input.

Returns the total size readable by ReadEntryRaw. This is the same as the size field from offset 0x28 in the NAX0 header in the "<NcaID>.nca/00" file. This matches <filesize of that file>-0x4000.

ReadEntryRaw

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

Returns encrypted looking data. Doesn't match the encrypted raw data in the "<NcaID>.nca/00" file.

See GetEntrySize for the total size readable with this.

GetNcaTitleInfo

Takes a #NcaID and returns the following 0x10-sized entry.

With some NcaIDs this may return 0 with an all-zero output entry. This seems to be the case for most/all (?) NandSystem NcaIds?

Offset	Size	Description
0x0	0x8	Big-endian titleID
0x8	0x8	Unknown. Usually zero?

IContentMetaDatabase

Cmd	Name	Notes
0	InsertContentEntry?	Takes a 0x10-sized entry, a type-5 buffer and a u64.
1		Takes a 0x10-sized entry, a type-6 buffer and a u64. Returns a u64.
2		Takes a 0x10-sized entry.
3		Takes a 0x10-sized entry and a bool/u8. Returns an 0x10-sized entry.
4		Takes a type-6 buffer, each entry being 24 bytes, 0x10-sized entry and a u32. Returns a u32.
5	Iterate	Takes a type-6 buffer, each entry being 16 bytes, a 0x10-sized entry, and a u32. Returns a u32.
6	#GetTitleIdInfo
7	#GetTitleList	Takes a type-6 buffer, each entry being 24 bytes, and a u8/bool. Returns two u32's.
8		Takes a 0x10-sized entry. Returns a bool/u8.
9		Takes a type-5 buffer, each entry being 16 bytes. Returns a bool/u8.
10		Takes a 0x10-sized entry. Returns a u64.
11		Takes a 0x10-sized entry. Returns a u32.
12		Takes a 0x10-sized entry. Returns a u64.
13		Void.
14		Takes a type-6 byte buffer, and a type-5 buffer with each entry being 16 bytes.
15	EndIteration	Void.
16		Takes two 0x10-sized entries. Returns a bool/u8.
17		Takes a type-6 buffer, each entry being 16 bytes, a 0x10-sized entry and a u32. Returns a u32.
18		Takes a 0x10-sized entry. Returns a bool/u8.
19		Takes a 0x10-sized entry. Returns a u32.

GetTitleIdInfo

Takes a u64 title-id as input, returns same title-id together with info struct.

struct title_info {
  u32  version;
  u8   type;
  u8   pad[3];
};

GetTitleList

Each 24-byte entries is as follows:

 u64    title_id_update;
 struct title_info info;
 u64    title_id;

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).