Filesystem services

fsp-ldr

This is "nn::fssrv::sf::IFileSystemProxyForLoader".

Cmd	Name
0	#OpenCodeFileSystem
1	#IsArchivedProgram
2	[4.0.0+] #SetCurrentProcess

OpenCodeFileSystem

Takes an ProgramId and a #ContentPath. Returns an #IFileSystem.

[10.0.0+] This now takes an additional type-0x1A output buffer.

IsArchivedProgram

Takes an u64 ProcessId. Returns a bool (1 if the process id's #ContentPath ends in ".nca").

SetCurrentProcess

Takes a ProcessId descriptor.

fsp-pr

This is "nn::fssrv::sf::IProgramRegistry".

Cmd	Name
0	#RegisterProgram
1	#UnregisterProgram
2	[4.0.0+] #SetCurrentProcess
256	[1.0.0-9.2.0] #SetEnabledProgramVerification

RegisterProgram

Takes a StorageId, an u64 ProcessId, a ProgramId, a 0x1C type-A buffer for the FS Access Header, and a 0x2C type-A buffer for the FS Access Control

Final FS permissions are stored as (ACI0_perms & ACID_perms). Will panic(svcBreak) when buffer sizes from ipc-rawdata are invalid.

UnregisterProgram

Takes a pid. Removes registered FS permissions for that PID.

SetEnabledProgramVerification

Seems to sets a global flag to inputval & 1.

When the flag is zero, it will set ret=0 instead of ret={error} when verifying the fixed-key NPDM ACID signature fails. This also skips verifying the NCA Header signature using the ACID key. Note that if verifying the fixed-key ACID signature is successful, and verifying the ACID-key NCA header signature fails, it will throw an error and abort.

[10.0.0+] This was moved to Loader.

fsp-srv

This is "nn::fssrv::sf::IFileSystemProxy".

Cmd	Name
0	[1.0.0] #OpenFileSystem
1	#SetCurrentProcess
2	OpenDataFileSystemByCurrentProcess
7	[2.0.0+] #OpenFileSystemWithPatch
8	[2.0.0+] #OpenFileSystemWithId
9	[3.0.0+] OpenDataFileSystemByProgramId
11	#OpenBisFileSystem
12	#OpenBisStorage
13	InvalidateBisCache
17	OpenHostFileSystem
18	OpenSdCardFileSystem
19	[2.0.0+] FormatSdCardFileSystem
21	#DeleteSaveDataFileSystem
22	#CreateSaveDataFileSystem
23	#CreateSaveDataFileSystemBySystemSaveDataId
24	RegisterSaveDataFileSystemAtomicDeletion
25	[2.0.0+] DeleteSaveDataFileSystemBySaveDataSpaceId
26	[2.0.0+] FormatSdCardDryRun
27	[2.0.0+] IsExFatSupported
28	[4.0.0+] DeleteSaveDataFileSystemBySaveDataAttribute
30	#OpenGameCardStorage
31	#OpenGameCardFileSystem
32	[3.0.0+] ExtendSaveDataFileSystem
33	[5.0.0+] DeleteCacheStorage
34	[5.0.0+] GetCacheStorageSize
35	[6.0.0+] #CreateSaveDataFileSystemWithHashSalt
36	[9.0.0+] OpenHostFileSystemWithOption
51	#OpenSaveDataFileSystem
52	#OpenSaveDataFileSystemBySystemSaveDataId
53	[2.0.0+] #OpenReadOnlySaveDataFileSystem
57	[3.0.0+] #ReadSaveDataFileSystemExtraDataBySaveDataSpaceId
58	#ReadSaveDataFileSystemExtraData
59	[2.0.0+] WriteSaveDataFileSystemExtraData
60	#OpenSaveDataInfoReader
61	#OpenSaveDataInfoReaderBySaveDataSpaceId
62	[5.0.0+] OpenSaveDataInfoReaderOnlyCacheStorage
64	[5.0.0+] OpenSaveDataInternalStorageFileSystem
65	[5.0.0+] UpdateSaveDataMacForDebug
66	[5.0.0+] WriteSaveDataFileSystemExtraDataWithMask
67	[6.0.0+] #FindSaveDataWithFilter
68	[6.0.0+] #OpenSaveDataInfoReaderWithFilter
69	[8.0.0+] ReadSaveDataFileSystemExtraDataBySaveDataAttribute
70	[8.0.0+] WriteSaveDataFileSystemExtraDataWithMaskBySaveDataAttribute
71	[10.0.0+] ReadSaveDataFileSystemExtraDataWithMaskBySaveDataAttribute
80	OpenSaveDataMetaFile
81	[4.0.0+] #OpenSaveDataTransferManager
82	[5.0.0+] #OpenSaveDataTransferManagerVersion2
83	[6.0.0+] #OpenSaveDataTransferProhibiter
84	[6.0.0+] #ListAccessibleSaveDataOwnerId
85	[9.0.0+] #OpenSaveDataTransferManagerForSaveDataRepair
86	[10.0.0+] #OpenSaveDataMover
100	OpenImageDirectoryFileSystem
110	#OpenContentStorageFileSystem
120	[6.0.0-9.2.0] #OpenCloudBackupWorkStorageFileSystem
130	[7.0.0+] #OpenCustomStorageFileSystem
200	OpenDataStorageByCurrentProcess
201	[3.0.0+] OpenDataStorageByProgramId
202	#OpenDataStorageByDataId
203	OpenPatchDataStorageByCurrentProcess
204	[7.0.0+] #OpenDataFileSystemWithProgramIndex
205	[7.0.0+] #OpenDataStorageWithProgramIndex
400	#OpenDeviceOperator
500	#OpenSdCardDetectionEventNotifier
501	#OpenGameCardDetectionEventNotifier
510	[5.0.0+] OpenSystemDataUpdateEventNotifier
511	[5.0.0+] NotifySystemDataUpdateEvent
520	[6.0.0+] #SimulateDeviceDetectionEvent
600	[1.0.0-3.0.2] SetCurrentPosixTime
601	QuerySaveDataTotalSize
602	#VerifySaveDataFileSystem
603	CorruptSaveDataFileSystem
604	CreatePaddingFile
605	DeleteAllPaddingFiles
606	[2.0.0+] GetRightsId
607	[2.0.0+] RegisterExternalKey
608	[2.0.0+] UnregisterAllExternalKey
609	[2.0.0+] GetRightsIdByPath
610	[3.0.0+] GetRightsIdAndKeyGenerationByPath
611	[4.0.0+] SetCurrentPosixTimeWithTimeDifference
612	[4.0.0+] GetFreeSpaceSizeForSaveData
613	[4.0.0+] VerifySaveDataFileSystemBySaveDataSpaceId
614	[4.0.0+] CorruptSaveDataFileSystemBySaveDataSpaceId
615	[5.0.0+] QuerySaveDataInternalStorageTotalSize
616	[6.0.0+] #GetSaveDataCommitId
617	[7.0.0+] UnregisterExternalKey
620	[2.0.0+] #SetSdCardEncryptionSeed
630	[4.0.0+] SetSdCardAccessibility
631	[4.0.0+] IsSdCardAccessible
640	[4.0.0-7.0.1] IsSignedSystemPartitionOnSdCardValid
700	[5.0.0+] #OpenAccessFailureDetectionEventNotifier
701	[5.0.0+] GetAccessFailureDetectionEvent
702	[5.0.0+] IsAccessFailureDetected
710	[5.0.0+] ResolveAccessFailure
720	[5.0.0+] AbandonAccessFailure
800	[2.0.0+] GetAndClearErrorInfo
810	[7.0.0+] RegisterProgramIndexMapInfo
1000	[1.0.0-9.2.0] SetBisRootForHost
1001	#SetSaveDataSize
1002	#SetSaveDataRootPath
1003	DisableAutoSaveDataCreation
1004	#SetGlobalAccessLogMode
1005	#GetGlobalAccessLogMode
1006	#OutputAccessLogToSdCard
1007	[4.0.0+] RegisterUpdatePartition
1008	[4.0.0+] OpenRegisteredUpdatePartition
1009	[4.0.0+] GetAndClearMemoryReportInfo
1010	[5.1.0-6.2.0] SetDataStorageRedirectTarget
1011	[7.0.0+] #GetProgramIndexForAccessLog
1012	[9.0.0+] GetFsStackUsage
1013	[9.0.0+] UnsetSaveDataRootPath
1014	[10.0.0+] OutputMultiProgramTagAccessLog
1100	[4.0.0+] OverrideSaveDataTransferTokenSignVerificationKey
1110	[6.0.0+] CorruptSaveDataFileSystemByOffset
1200	[6.0.0+] #OpenMultiCommitManager
1300	[10.0.0+] #OpenBisWiper

Permissions

Every time permissions are checked, the process registration #fsp-pr is loaded using the session processID. The permission data is populated with data from the NPDM.

If the processID is <= 6 (which happens only for built-in sysmodules), it will use a hardcoded registration data. The default mask in this case is 0x8000000000000000.

Note that the functions check whether or not at least one bit is set in the mask. This means that, you don't need to set 0xFFFFFFFFFFFFFFFF to get all permissions: it suffices to set 0x8000000000000000.

If the code were to request an invalid input type, panic. But this never happens.

The output values for #ReadWrite CanMountRegisteredUpdatePartition and #Call CanRegisterUpdatePartition are masked with the cached value of DebugMode.

ReadWrite

AccessibilityType	Name	Mask	Permission	Used by
0x0	CanMountLogo	0x8000000000000801	R-	#OpenFileSystem, #OpenFileSystemWithPatch, #OpenFileSystemWithId
0x1	CanMountContentMeta	0x8000000000000801	R-	#OpenFileSystem, #OpenFileSystemWithPatch, #OpenFileSystemWithId
0x2	CanMountContentControl	0x8000000000000801	R-	#OpenFileSystem, #OpenFileSystemWithPatch, #OpenFileSystemWithId
0x3	CanMountContentManual	0x8000000000000801	R-	#OpenFileSystem, #OpenFileSystemWithPatch, #OpenFileSystemWithId
0x4	CanMountContentData	0x8000000000000801	R-	#OpenFileSystem, #OpenFileSystemWithPatch, #OpenFileSystemWithId
0x5	CanMountApplicationPackage	0x8000000000000801	R-	#OpenFileSystem, #OpenFileSystemWithPatch, #OpenFileSystemWithId
0x6	CanMountSaveDataStorage	0x8000000000000000	RW
0x7	CanMountContentStorage	0x8000000000000800	RW	#OpenContentStorageFileSystem
0x8	CanMountImageAndVideoStorage	0x8000000000001000	RW	#OpenImageDirectoryFileSystem
([1.0.0-5.1.0] 0x9)		0x8000000000000084
([6.0.0-9.2.0] 0x9)	CanMountCloudBackupWorkStorage	0x8000000200000000	RW	OpenCloudBackupWorkStorageFileSystem
0x9	CanMountCustomStorage0	0x8000000000000000	RW	OpenCustomStorageFileSystem
([1.0.0-5.1.0] 0xA)		0x8000000000000080
([6.0.0-6.2.0] 0xA)		0x8000000000000084
([7.0.0-7.0.1] 0xA)		0x4000000000000000
([8.0.0-9.2.0] 0xA)		0x8000000000000000
0xA	CanMountBisCalibrationFile	0x8000000000000084	RW	#OpenBisFileSystem
([1.0.0-5.1.0] 0xB)		0x8000000000008080
([6.0.0-6.2.0] 0xB)		0x8000000000000080
([7.0.0-9.2.0] 0xB)		0x8000000000000084
0xB	CanMountBisSafeMode	0x8000000000000080	RW	#OpenBisFileSystem
([1.0.0-6.2.0] 0xC)		0x8000000000008080
([7.0.0-9.2.0] 0xC)		0x8000000000000080
0xC	CanMountBisUser	0x8000000000008080	RW	#OpenBisFileSystem
([1.0.0-5.1.0] 0xD)		0x8000000000000080
([6.0.0-9.2.0] 0xD)		0x8000000000008080
0xD	CanMountBisSystem	0x8000000000008080	RW	#OpenBisFileSystem
([1.0.0-2.3.0] 0xE)		0xC000000000200000
([3.0.0-6.2.0] 0xE)		0x8000000000000080
([7.0.0-9.2.0] 0xE)		0x8000000000008080
0xE	CanMountBisSystemProperEncryption	0x8000000000000080	RW	#OpenBisFileSystem
([1.0.0-2.3.0] 0xF)		0x8000000000000010
([3.0.0-5.1.0] 0xF)		0xC000000000200000
([6.0.0-9.2.0] 0xF)		0x8000000000000080
0xF	CanMountBisSystemProperPartition	0x8000000000000080	RW	#OpenBisFileSystem
([1.0.0-2.3.0] 0x10)		0x8000000000040020
([3.0.0-5.1.0] 0x10)		0x8000000000000010
([6.0.0-6.2.0] 0x10)		0xC000000000200000
([7.0.0-9.2.0] 0x10)		0x8000000000000080
0x10	CanMountSdCard	0xC000000000200000	RW	#OpenSdCardFileSystem
([1.0.0-2.3.0] 0x11)		0x8000000000000028
([3.0.0-5.1.0] 0x11)		0x8000000000040020
([6.0.0-6.2.0] 0x11)		0x8000000000000010
([7.0.0-9.2.0] 0x11)		0xC000000000200000
0x11	CanMountGameCard	0x8000000000000010	R-	#OpenGameCardFileSystem
([1.0.0-2.3.0] 0x12)		0x8000000000000020
([3.0.0-5.1.0] 0x12)		0x8000000000000028
([6.0.0-6.2.0] 0x12)		0x8000000000040020
([7.0.0-9.2.0] 0x12)		0x8000000000000010
0x12	CanMountDeviceSaveData	0x8000000000040020	RW	#OpenSaveDataFileSystem
([1.0.0-5.1.0] 0x13)		0x8000000000000020
([6.0.0-6.2.0] 0x13)		0x8000000000000028
([7.0.0-9.2.0] 0x13)		0x8000000000040020
0x13	CanMountSystemSaveData	0x8000000000000028	RW	#OpenSaveDataFileSystemBySystemSaveDataId
([1.0.0-2.3.0] 0x14)		0x8000000000010082
([3.0.0-6.2.0] 0x14)		0x8000000000000020
([7.0.0-9.2.0] 0x14)		0x8000000000000028
0x14	CanMountOthersSaveData	0x8000000000000020	RW	#OpenSaveDataFileSystem
([1.0.0-2.3.0] 0x15)		0x8000000000010080
([3.0.0-5.1.0] 0x15)		0x8000000000010082
([6.0.0-9.2.0] 0x15)		0x8000000000000020
0x15	CanMountOthersSystemSaveData	0x8000000000000020	RW	#OpenSaveDataFileSystemBySystemSaveDataId
([1.0.0-5.1.0] 0x16)		0x8000000000010080
([6.0.0-6.2.0] 0x16)		0x8000000000010082
([7.0.0-9.2.0] 0x16)		0x8000000000000020
0x16	CanOpenBisPartitionBootPartition1Root	0x8000000000010082	RW	#OpenBisStorage
([1.0.0-2.3.0] 0x17)		0x8000000000010080
([3.0.0-5.1.0] 0x17)		0x8000000000000080
([6.0.0-6.2.0] 0x17)		0x8000000000010080
([7.0.0-9.2.0] 0x17)		0x8000000000010082
0x17	CanOpenBisPartitionBootPartition2Root	0x8000000000010080	RW	#OpenBisStorage
([1.0.0-5.1.0] 0x18)		0x8000000000010080
([6.0.0-6.2.0] 0x18)		0x8000000000000080
([7.0.0-9.2.0] 0x18)		0x8000000000010080
0x18	CanOpenBisPartitionUserDataRoot	0x8000000000000080	RW	#OpenBisStorage
([6.0.0-6.2.0] 0x19)		0x8000000000010080
([7.0.0-9.2.0] 0x19)		0x8000000000000080
0x19	CanOpenBisPartitionBootConfigAndPackage2Part1	0x8000000000010080	RW	#OpenBisStorage
([1.0.0-9.2.0] 0x1A)		0x8000000000010080
0x1A	CanOpenBisPartitionBootConfigAndPackage2Part2	0x8000000000010080	RW	#OpenBisStorage
([1.0.0-9.2.0] 0x1B)		0x8000000000010080
0x1B	CanOpenBisPartitionBootConfigAndPackage2Part3	0x8000000000010080	RW	#OpenBisStorage
([1.0.0-9.2.0] 0x1C)		0x8000000000010080
0x1C	CanOpenBisPartitionBootConfigAndPackage2Part4	0x8000000000010080	RW	#OpenBisStorage
([1.0.0-2.3.0] 0x1D)		0x8000000000000084
([3.0.0-9.2.0] 0x1D)		0x8000000000010080
0x1D	CanOpenBisPartitionBootConfigAndPackage2Part5	0x8000000000010080	RW	#OpenBisStorage
([1.0.0-5.1.0] 0x1E)		0x8000000000000084
([6.0.0-9.2.0] 0x1E)		0x8000000000010080
0x1E	CanOpenBisPartitionBootConfigAndPackage2Part6	0x8000000000010080	RW	#OpenBisStorage
([1.0.0-5.1.0] 0x1F)		0x8000000000000080
([6.0.0-6.2.0] 0x1F)		0x8000000000000084
([7.0.0-9.2.0] 0x1F)		0x8000000000010080
0x1F	CanOpenBisPartitionCalibrationBinary	0x8000000000000084	RW	#OpenBisStorage
([1.0.0-5.1.0] 0x20)		0x8000000000000080
([6.0.0-9.2.0] 0x20)		0x8000000000000084
0x20	CanOpenBisPartitionCalibrationFile	0x8000000000000084	RW	#OpenBisStorage
([6.0.0-6.2.0] 0x21)		0x8000000000000080
([7.0.0-9.2.0] 0x21)		0x8000000000000084
0x21	CanOpenBisPartitionSafeMode	0x8000000000000080	RW	#OpenBisStorage
([1.0.0-9.2.0] 0x22)		0x8000000000000080
0x22	CanOpenBisPartitionUser	0x8000000000000080	RW	#OpenBisStorage
([1.0.0-2.3.0] 0x23)		0xC000000000200000
([3.0.0-9.2.0] 0x23)		0x8000000000000080
0x23	CanOpenBisPartitionSystem	0x8000000000000080	RW	#OpenBisStorage
([1.0.0-2.3.0] 0x24)		0x8000000000000100
([3.0.0-9.2.0] 0x24)		0x8000000000000080
0x24	CanOpenBisPartitionSystemProperEncryption	0x8000000000000080	RW	#OpenBisStorage
([1.0.0-2.3.0] 0x25)		0x8000000000100008
([3.0.0-5.1.0] 0x25)		0xC000000000200000
([6.0.0-9.2.0] 0x25)		0x8000000000000080
0x25	CanOpenBisPartitionSystemProperPartition	0x8000000000000080	RW	#OpenBisStorage
([1.0.0-2.3.0] 0x26)		0xC000000000400000
([3.0.0-5.1.0] 0x26)		0x8000000000000100
([6.0.0-6.2.0] 0x26)		0xC000000000200000
([7.0.0-9.2.0] 0x26)		0x8000000000000080
0x26	CanOpenSdCardStorage	0xC000000000200000	RW
([3.0.0-5.1.0] 0x27)		0x8000000000100008
([6.0.0-6.2.0] 0x27)		0x8000000000000100
([7.0.0-9.2.0] 0x27)		0xC000000000200000
[3.0.0+] 0x27	CanOpenGameCardStorage	0x8000000000000100	RW	#OpenGameCardStorage, #EraseGameCard (bit1), #WriteToGameCard (bit1), #GetGameCardErrorInfo (bit1), #EraseAndWriteParamDirectly (bit1), #ReadParamDirectly (bit1), #ForceEraseGameCard (bit1)
([3.0.0-5.1.0] 0x28)		0xC000000000400000
([6.0.0-6.2.0] 0x28)		0x8000000000100008
([7.0.0-9.2.0] 0x28)		0x8000000000000100
[3.0.0+] 0x28	CanMountSystemDataPrivate	0x8000000000100008	R-	#OpenFileSystem, #OpenDataStorageByDataId
([4.0.0-5.1.0] 0x29)		0x8000000000010000
([6.0.0-6.2.0] 0x29)		0xC000000000400000
([7.0.0-9.2.0] 0x29)		0x8000000000100008
[4.0.0+] 0x29	CanMountHost	0xC000000000400000	RW	#OpenHostFileSystem
([5.0.0-5.1.0] 0x2A)		0x8000000000000000
([6.0.0-6.2.0] 0x2A)		0x8000000000010000
([7.0.0-9.2.0] 0x2A)		0xC000000000400000
[5.0.0+] 0x2A	CanMountRegisteredUpdatePartition	0x8000000000010000	R-	#OpenRegisteredUpdatePartition
([6.0.0-6.2.0] 0x2B)		0x8000000000000000
([7.0.0-9.2.0] 0x2B)		0x8000000000010000
[6.0.0+] 0x2B	CanOpenSaveDataInternalStorage	0x8000000000000000	RW	#OpenSaveDataInternalStorageFileSystem
([7.0.0-9.2.0] 0x2C)		0x8000000000000000
[7.0.0+] 0x2C	CanNotMount	0x0000000000000000	--	OpenCustomStorageFileSystem
([7.0.0-9.2.0] 0x2D)		0x0000000000000000

Call

OperationType	Name	Mask	Used by
0x0	CanInvalidateBisCache	0x8000000000000080	#InvalidateBisCache
0x1	CanEraseMmc	0x8000000000000080	EraseMmc
0x2	CanGetGameCardDeviceCertificate	0x8000000000000010	GetGameCardDeviceCertificate
0x3	CanGetGameCardIdSet	0x8000000000000010	GetGameCardIdSet
0x4	CanFinalizeGameCardDriver	0x8000000000000200	FinalizeGameCardDriver
0x5	CanGetGameCardAsicInfo	0x8000000000000200	GetGameCardAsicInfo
0x6	CanCreateSaveData	0x8000000000002020	#CreateSaveDataFileSystem
0x7	CanDeleteSaveData	0x8000000000000060	#DeleteSaveDataFileSystem, RegisterSaveDataFileSystemAtomicDeletion
0x8	CanCreateSystemSaveData	0x8000000000000028	CreateSaveDataFileSystemBySystemSaveDataId
0x9	CanCreateOthersSystemSaveData	0x8000000000000020	CreateSaveDataFileSystemBySystemSaveDataId
0xA	CanDeleteSystemSaveData	0x8000000000004028	#DeleteSaveDataFileSystem, RegisterSaveDataFileSystemAtomicDeletion
0xB	CanOpenSaveDataInfoReader	0x8000000000000060	#OpenSaveDataInfoReaderBySaveDataSpaceId, #OpenSaveDataInfoReader
0xC	CanOpenSaveDataInfoReaderForSystem	0x8000000000004020	#OpenSaveDataInfoReaderBySaveDataSpaceId, #OpenSaveDataInfoReader
([1.0.0-5.1.0] 0xD)		0x8000000000020000
0xD	CanOpenSaveDataInfoReaderForInternal	0x8000000000000040	#OpenSaveDataInfoReaderWithFilter
([1.0.0-5.1.0] 0xE)		0x8000000000000400
0xE	CanOpenSaveDataMetaFile	0x8000000000020000	OpenSaveDataMetaFile
([1.0.0-5.1.0] 0xF)		0x8000000000004060
0xF	CanSetCurrentPosixTime	0x8000000000000400	SetCurrentPosixTime, SetCurrentPosixTimeWithTimeDifference
([1.0.0-5.1.0] 0x10)		0x8000000000080000
0x10	CanReadSaveDataFileSystemExtraData	0x8000000000004060	#ReadSaveDataFileSystemExtraData
0x11	CanSetGlobalAccessLogMode	0x8000000000080000	#SetGlobalAccessLogMode
([1.0.0-5.1.0] 0x12)	CanDebug	0xC000000000000000
0x12	CanSetSpeedEmulationMode	0x8000000000080000	SetSpeedEmulationMode
([1.0.0-5.1.0] 0x13)		0xC000000000800000
0x13	CanDebug	0xC000000000000000
([1.0.0-5.1.0] 0x14)		0xC000000001000000
0x14	CanFillBis	0xC000000000800000	CreatePaddingFile, DeleteAllPaddingFiles
([1.0.0-4.1.0] 0x15)		0xC000000002000000
([5.0.0-5.1.0] 0x15)		0x8000000001000060
0x15	CanCorruptSaveData	0xC000000001000000	CorruptSaveDataFileSystem, CorruptSaveDataFileSystemBySaveDataSpaceId
([2.0.0-4.1.0] 0x16)		0x8000000004000000
([5.0.0-5.1.0] 0x16)		0x8000000000000060
[2.0.0+] 0x16	CanCorruptSystemSaveData	0x8000000001000060	CorruptSaveDataFileSystem, CorruptSaveDataFileSystemBySaveDataSpaceId
([2.0.0-4.1.0] 0x17)		0x8000000008000000
([5.0.0-5.1.0] 0x17)		0xC000000002000000
[2.0.0+] 0x17	CanVerifySaveData	0x8000000000000060	#VerifySaveDataFileSystem, VerifySaveDataFileSystemBySaveDataSpaceId
([2.0.0-4.1.0] 0x18)		0x8000000010000000
([5.0.0-5.1.0] 0x18)		0x8000000004000000
[2.0.0+] 0x18	CanDebugSaveData	0xC000000002000000	#CreateSaveDataFileSystem, #OpenSaveDataFileSystem, #SetSaveDataRootPath
([2.0.0-4.1.0] 0x19)		0x8000000000000800
([5.0.0-5.1.0] 0x19)		0x8000000008000000
[2.0.0+] 0x19	CanFormatSdCard	0x8000000004000000	FormatSdCardFileSystem
([2.0.0-4.1.0] 0x1A)		0x8000000000004020
([5.0.0-5.1.0] 0x1A)		0x8000000010000000
[2.0.0+] 0x1A	CanGetRightsId	0x8000000008000000	GetRightsId, GetRightsIdAndKeyGenerationByPath, GetRightsIdByPath
([3.0.0-4.1.0] 0x1B)		0x8000000000002020
([5.0.0-5.1.0] 0x1B)		0x8000000000000800
[3.0.0+] 0x1B	CanRegisterExternalKey	0x8000000010000000	RegisterExternalKey, UnregisterAllExternalKey
([3.0.0-4.1.0] 0x1C)		0x8000000000000028
([5.0.0-5.1.0] 0x1C)		0x8000000000004020
[3.0.0+] 0x1C	CanSetEncryptionSeed	0x8000000000000800	#SetSdCardEncryptionSeed
([4.0.0-4.1.0] 0x1D)		0x8000000020000000
([5.0.0-5.1.0] 0x1D)		0x8000000000000000
[4.0.0+] 0x1D	CanWriteSaveDataFileSystemExtraDataTimeStamp	0x8000000000000020	WriteSaveDataFileSystemExtraData, WriteSaveDataFileSystemExtraDataWithMask
([4.0.0-4.1.0] 0x1E)		0x8000000040000000
([5.0.0-5.1.0] 0x1E)		0x8000000000002020
[4.0.0+] 0x1E	CanWriteSaveDataFileSystemExtraDataFlags	0x8000000000004020	WriteSaveDataFileSystemExtraData, WriteSaveDataFileSystemExtraDataWithMask
([4.0.0-4.1.0] 0x1F)		0x8000000000000000
([5.0.0-5.1.0] 0x1F)		0x8000000000000028
[4.0.0+] 0x1F	CanWriteSaveDataFileSystemExtraDataCommitId	0x8000000000000020	WriteSaveDataFileSystemExtraData, WriteSaveDataFileSystemExtraDataWithMask
([4.0.0-4.1.0] 0x20)		0x8000000000000000
([5.0.0-5.1.0] 0x20)		0x8000000020000000
[4.0.0+] 0x20	CanWriteSaveDataFileSystemExtraDataAll	0x8000000000000000	WriteSaveDataFileSystemExtraData, WriteSaveDataFileSystemExtraDataWithMask
([5.0.0-5.1.0] 0x21)		0x8000000040000000
[5.0.0+] 0x21	CanExtendSaveData	0x8000000000002020	ExtendSaveDataFileSystem
([5.0.0-5.1.0] 0x22)		0x0000000080000002
[5.0.0+] 0x22	CanExtendSystemSaveData	0x8000000000000028	ExtendSaveDataFileSystem
([5.0.0-5.1.0] 0x23)		0x8000000000000000
([6.0.0-9.2.0] 0x23)		0x8000000020000000
[5.0.0+] 0x23	CanExtendOthersSystemSaveData	0x8000000000000020	ExtendSaveDataFileSystem
([5.0.0-5.1.0] 0x24)		0x8000000000000000
([6.0.0-9.2.0] 0x24)		0x8000000040000000
[5.0.0+] 0x24	CanRegisterUpdatePartition	0x8000000020000000	RegisterUpdatePartition
([5.0.0-5.1.0] 0x25)		0x8000000080200000
([6.0.0-9.2.0] 0x25)		0x8000000200000000
[5.0.0+] 0x25	CanOpenSaveDataTransferManager	0x8000000040000000	#OpenSaveDataTransferManager
([5.0.0-5.1.0] 0x26)		0x8000000080000110
([6.0.0-8.1.0] 0x26)		0x8000000200002000
([9.0.0-9.2.0] 0x26)		0x8000000200000000
[5.0.0+] 0x26	CanOpenSaveDataTransferManagerVersion2	0x8000000200000000	#OpenSaveDataTransferManagerVersion2
([5.0.0-5.1.0] 0x27)		0x8000000000100008
([6.0.0-7.0.1] 0x27)		0x8000000200002000
([8.0.0-8.1.0] 0x27)		0x8000000240002000
([9.0.0-9.2.0] 0x27)		0x8000000000000000
[5.0.0+] 0x27	CanOpenSaveDataTransferManagerForSaveDataRepair	0x8000000200000000	OpenSaveDataTransferManagerForSaveDataRepair
([5.0.0-5.1.0] 0x28)		0x8000000080010000
([6.0.0-8.1.0] 0x28)		0x8000000000000000
([9.0.0-9.2.0] 0x28)		0x8000000200002000
[5.0.0+] 0x28	CanOpenSaveDataTransferManagerForSaveDataRepairTool	0x8000000000000000	OpenSaveDataTransferManagerForSaveDataRepair
([5.0.0-5.1.0] 0x29)		0x0000000080000001
([6.0.0-8.1.0] 0x29)		0x8000000000000000
([9.0.0-9.2.0] 0x29)		0x8000000240002000
[5.0.0+] 0x29	CanOpenOpenSaveDataTransferProhibiter	0x8000000200002000	#OpenSaveDataTransferProhibiter
([5.0.0-5.1.0] 0x2A)		0x0000000080000001
([6.0.0-8.1.0] 0x2A)		0x8000000080200000
([9.0.0-9.2.0] 0x2A)		0x8000000000000000
[5.0.0+] 0x2A	CanOpenSaveDataMover	0x8000001000000000	#OpenSaveDataMover
([5.0.0-5.1.0] 0x2B)		0x0000000080000001
([6.0.0-8.1.0] 0x2B)		0x8000000080000110
([9.0.0-9.2.0] 0x2B)		0x8000000000000000
[5.0.0+] 0x2B	CanOpenBisWiper	0x8000000000000800	#OpenBisWiper
([5.0.0-5.1.0] 0x2C)		0x0000000080000001
([6.0.0-8.1.0] 0x2C)		0x8000000000100008
([9.0.0-9.2.0] 0x2C)		0x8000000080200000
[5.0.0+] 0x2C	CanListAccessibleSaveDataOwnerId	0x8000000240002000	#ListAccessibleSaveDataOwnerId
([5.0.0-5.1.0] 0x2D)		0x0000000080000001
([6.0.0-8.1.0] 0x2D)		0x8000000000010000
([9.0.0-9.2.0] 0x2D)		0x8000000080000110
[5.0.0+] 0x2D	CanControlMmcPatrol	0x8000000000000000	SuspendMmcPatrol, ResumeMmcPatrol
([5.0.0-5.1.0] 0x2E)		0x8000000040000000
([6.0.0-8.1.0] 0x2E)		0x8000000100000000
([9.0.0-9.2.0] 0x2E)		0x8000000000100008
[5.0.0+] 0x2E	CanOverrideSaveDataTransferTokenSignVerificationKey	0x8000000000000000	OverrideSaveDataTransferTokenSignVerificationKey
([5.0.0-5.1.0] 0x2F)		0x8000000080200000
([6.0.0-8.1.0] 0x2F)		0x8000000100000000
([9.0.0-9.2.0] 0x2F)		0x8000000000010000
[5.0.0+] 0x2F	CanOpenSdCardDetectionEventNotifier	0x8000000080200000	#OpenSdCardDetectionEventNotifier
([5.1.0-6.0.0] 0x30)		0x8000000080080000
([6.0.1-9.2.0] 0x30)		0x8000000100000000
[5.1.0+] 0x30	CanOpenGameCardDetectionEventNotifier	0x8000000080000110	#OpenGameCardDetectionEventNotifier
([6.0.0-9.2.0] 0x31)		0x8000000100000000
[6.0.0+] 0x31	CanOpenSystemDataUpdateEventNotifier	0x8000000000100008	OpenSystemDataUpdateEventNotifier
([6.0.0-9.2.0] 0x32)		0x8000000100000000
[6.0.0+] 0x32	CanNotifySystemDataUpdateEvent	0x8000000000010000	NotifySystemDataUpdateEvent
([6.0.0-8.1.0] 0x33)		0x8000000040000000
([9.0.0-9.2.0] 0x33)		0x8000000100000000
[6.0.0+] 0x33	CanOpenAccessFailureDetectionEventNotifier	0x8000000100000000	#OpenAccessFailureDetectionEventNotifier
([6.0.0-8.1.0] 0x34)		0x8000000200000020
([9.0.0-9.2.0] 0x34)		0x8000000100000000
[6.0.0+] 0x34	CanGetAccessFailureDetectionEvent	0x8000000100000000	GetAccessFailureDetectionEvent
([6.0.0-8.1.0] 0x35)		0x8000000000200000
([9.0.0-9.2.0] 0x35)		0x8000000040000000
[6.0.0+] 0x35	CanIsAccessFailureDetected	0x8000000100000000	IsAccessFailureDetected
([6.0.0-8.1.0] 0x36)		0x4000000000000000
([9.0.0-9.2.0] 0x36)		0x8000000200000020
[6.0.0+] 0x36	CanResolveAccessFailure	0x8000000100000000	ResolveAccessFailure
([6.0.0-6.2.0] 0x37)		0x8000000000080000
([7.0.0-8.1.0] 0x37)		0x8000000000000000
([9.0.0-9.2.0] 0x37)		0x8000000000200000
[6.0.0+] 0x37	CanAbandonAccessFailure	0x8000000100000000	AbandonAccessFailure
([6.0.0-6.2.0] 0x38)		0x8000000000000000
([7.0.0-8.1.0] 0x38)		0x8000000400000000
([9.0.0-9.2.0] 0x38)		0x4000000000000000
[6.0.0+] 0x38	CanQuerySaveDataInternalStorageTotalSize	0x8000000040000000	QuerySaveDataInternalStorageTotalSize
([8.0.0-8.1.0] 0x39)		0x8000000000000010
([9.0.0-9.2.0] 0x39)		0x8000000000000000
[8.0.0+] 0x39	CanGetSaveDataCommitId	0x8000000200000020	#GetSaveDataCommitId
([9.0.0-9.2.0] 0x3A)		0x8000000400000000
[9.0.0+] 0x3A	CanSetSdCardAccessibility	0x8000000000200000	SetSdCardAccessibility
([9.0.0-9.2.0] 0x3B)		0x8000000000000010
[9.0.0+] 0x3B	CanSimulateDevice	0x4000000000000000	SimulateDeviceDetectionEvent, SetSimulationEvent, ClearSimulationEvent
([9.0.0-9.2.0] 0x3C)		0x8000000800000000
[9.0.0+] 0x3C	CanCreateSaveDataWithHashSalt	0x8000000000000000	#CreateSaveDataFileSystem, #CreateSaveDataFileSystemWithHashSalt
([9.0.0-9.2.0] 0x3D)		0x8000000800000000
[9.0.0+] 0x3D	CanRegisterProgramIndexMapInfo	0x8000000400000000	RegisterProgramIndexMapInfo
([9.0.0-9.2.0] 0x3E)		0x8000000800000000
[9.0.0+] 0x3E	CanChallengeCardExistence	0x8000000000000010	ChallengeCardExistence
([9.0.0-9.2.0] 0x3F)		0x8000000800000000
[9.0.0+] 0x3F	CanCreateOwnSaveData	0x8000000800000000	#CreateSaveDataFileSystem, CreateSaveDataFileSystemWithHashSalt
([9.0.0-9.2.0] 0x40)		0x8000000800000000
[9.0.0+] 0x40	CanReadOwnSaveDataFileSystemExtraData	0x8000000800000000	#ReadSaveDataFileSystemExtraData
[10.0.0+] 0x41	CanExtendOwnSaveData	0x8000000800000000	ExtendSaveDataFileSystem
[10.0.0+] 0x42	CanOpenOwnSaveDataTransferProhibiter	0x8000000800000000	#OpenSaveDataTransferProhibiter
[10.0.0+] 0x43	CanFindOwnSaveDataWithFilter	0x8000000800000000	#FindSaveDataWithFilter

OpenFileSystem

Takes a type-0x19 input #ContentPath and a #FileSystemProxyType as parameters. Returns an #IFileSystem.

[2.0.0+] This function was removed.

SetCurrentProcess

Takes a pid-descriptor.

OpenFileSystemWithPatch

Takes an input #FileSystemProxyType and an u64 title-id. Returns an #IFileSystem.

Web-applet loads the #FileSystemProxyType (which must be Manual) from u32_table[inparam].

Note: web-applet strings refer to both this cmd and #OpenFileSystemWithId as "MountContent", but official nn_sf_sync symbols use "OpenXX" names.

OpenFileSystemWithId

Takes a type-0x19 input buffer, an #FileSystemProxyType and an u64 title-id. Returns an #IFileSystem.

The #IFileSystem must be Meta if the NCA type is 0.

The input buffer is the output string path from GetApplicationContentPath.

May return errors when attempting to access NCA-paths for an update-title with a gamecard, when the gamecard isn't inserted. May return error 0x7D402 in some cases with update-titles. Non-val2 in32 values with NCA-type1 are unusable, even for normal titles.

The official "MountApplicationPackage" func uses this with in64=0 and #FileSystemProxyType Package.

After the #FileSystemProxyType specific permissions are checked, it then gets the func retval for permissions-type 0x25 and func0.

When #FileSystemProxyType is Meta, it uses in64=0xffffffffffffffff internally, otherwise it checks if in64 is set to 0xffffffffffffffff then throws an error if so. When the in64 used internally is not 0xffffffffffffffff, it's compared with the NCA ProgramId, then an error is thrown on mismatch.

OpenBisFileSystem

Takes a type-0x19 input buffer string and a #BisPartitionId. Official user-process code sets instr[0] = 0 normally. Returns an #IFileSystem.

Only partitionIDs for FAT partitions are usable with this, otherwise error 0x2EE202 is returned. Seems to be about the same as #OpenBisStorage except this mounts the partition filesystem instead of allowing direct access to the partition sectors.

OpenBisStorage

Takes a u32 partition ID, returns 0x2EE202 for partitions which do not exist, 0x320002 for partitions which cannot be opened and a valid #IStorage handle otherwise.

InvalidateBisCache

Seems to invalidate the Bis cache for MBR/GPT after overwriting that data via the OpenBisStorage IStorage. Used by SystemInitializer.

DeleteSaveDataFileSystem

Takes an input u64.

CreateSaveDataFileSystem

Takes a 0x40-byte #SaveDataAttribute, a 0x40-byte #SaveDataCreationInfo, and a 0x10-byte input struct.

Only the first 0x5-bytes in the 0x10-byte struct are initialized: all-zero when automatically creating savedata during savecommon mount by official user-processes. In the dedicated save-creation code in official user-processes: +0 u32 = 0x40060, +4 u8 = 1.

Creates regular savedata.

CreateSaveDataFileSystemBySystemSaveDataId

Takes a 0x40-byte #SaveDataAttribute and a 0x40-byte #SaveDataCreationInfo.

Creates savedata in the SYSTEM NAND partition.

OpenGameCardStorage

Takes two input u32s (gamecard handle, partition ID), and returns an #IStorage for the partition.

OpenGameCardFileSystem

Takes two input u32s, with the second u32 located at +4 in rawdata after the first u32. Returns an #IFileSystem.

Mounts a gamecard partition.

CreateSaveDataFileSystemWithHashSalt

Takes a total of 0xB0-bytes of input, no output.

OpenSaveDataFileSystem

Takes an input u8 #SaveDataSpaceId and a 0x40-byte #SaveDataAttribute. Official user-process code is only known to use value 1 for the u8.

Returns an #IFileSystem.

Permissions aren't checked until the specified save is successfully found.

Only one process (specifically only one #IFileSystem session) can mount a given savedata at any given time (this includes SystemSaveData).

OpenSaveDataFileSystemBySystemSaveDataId

Takes an input u8 #SaveDataSpaceId and a 0x40-byte #SaveDataAttribute. Web-applet only uses value0 for the input u8.

Returns an #IFileSystem.

Mounts savedata in the SYSTEM NAND partition.

OpenReadOnlySaveDataFileSystem

Takes an input u8 #SaveDataSpaceId and a 0x40-byte #SaveDataAttribute, and returns an #IFileSystem.

Mounts SaveData as ReadOnly.

ReadSaveDataFileSystemExtraDataBySaveDataSpaceId

Takes an input u8 #SaveDataSpaceId, an input u64 saveID, and a type-0x6 output buffer containing the #SaveDataFileSystemExtraData.

ReadSaveDataFileSystemExtraData

Takes an input u64 saveID and a type-0x6 output buffer containing the #SaveDataFileSystemExtraData.

OpenSaveDataInfoReader

No input, returns an output #ISaveDataInfoReader.

OpenSaveDataInfoReaderBySaveDataSpaceId

Takes an input u8 #SaveDataSpaceId, returns an output #ISaveDataInfoReader.

FindSaveDataWithFilter

Takes a total of 0x50-bytes of input, returns 8-bytes of output and a type-0x6 output buffer.

OpenSaveDataInfoReaderWithFilter

Takes a total of 0x50-bytes of input, returns an #ISaveDataInfoReader.

OpenSaveDataTransferManager

No input, returns an #ISaveDataTransferManager.

OpenSaveDataTransferManagerVersion2

No input, returns an #ISaveDataTransferManagerWithDivision.

OpenSaveDataTransferProhibiter

Takes an input u64, returns an #ISaveDataTransferProhibiter.

ListAccessibleSaveDataOwnerId

Takes a total of 0x10-bytes of input, returns 4-bytes of output and a type-0x6 output buffer.

OpenSaveDataTransferManagerForSaveDataRepair

No input, returns an output #ISaveDataTransferManagerForSaveDataRepair.

OpenSaveDataMover

Takes 2 input #SaveDataSpaceId, an input u64 size and a TransferMemory handle. Returns an output #ISaveDataMover.

OpenContentStorageFileSystem

Takes a #ContentStorageId. Invalid values return 0x2EE202.

Returns an #IFileSystem with NCA files. The read data from these files is identical to the data read by NCM_services#ReadContentIdFile.

OpenCloudBackupWorkStorageFileSystem

Takes 4-bytes of input, returns an #IFileSystem.

OpenCustomStorageFileSystem

Takes a #CustomStorageId. Invalid values return 0x2EE202.

Returns an #IFileSystem from either User:/CustomStorage0 or Sdcard:/Nintendo/CustomStorage0. If on the SD card, an AesXtsFileSystem is created using a key source specifically for custom storage.

OpenDataStorageByDataId

Takes a StorageID and a DataId.

Returns a domain object ID implementing the #IStorage interface for data archives.

OpenDataFileSystemWithProgramIndex

Takes an input u8, returns an #IFileSystem.

OpenDataStorageWithProgramIndex

Takes an input u8, returns an #IStorage.

OpenDeviceOperator

This command returns a session to a port implementing the #IDeviceOperator interface.

OpenSdCardDetectionEventNotifier

This command returns a session to a port implementing the #IEventNotifier interface.

OpenGameCardDetectionEventNotifier

This command returns a session to a port implementing the #IEventNotifier interface.

SimulateDeviceDetectionEvent

Takes a total of 0xC-bytes of input, no output.

VerifySaveDataFileSystem

Takes an unknown input u64 and a type-0x6 output buffer.

The input u64 high-byte must be non-zero, otherwise an error is returned(0xE02).

GetSaveDataCommitId

Takes an input u8 and u64, returns an output u64.

SetSdCardEncryptionSeed

Takes in the 0x10 byte SD card encryption seed, and loads it into FS-module state.

NS-module reads the 0x10 bytes from SdCard:/Nintendo/Contents/private, and compares them to the first 0x10 bytes of the ns_appman:/private (in system savedata 0x8000000000000043). If they match, NS calls this command using bytes 0x10-0x20 from ns_appman:/private. The rest of this file (0x1F0 bytes total) is (usually/always?) all-zero (however in some cases the byte at offset 0x20 is value 0x1).

OpenAccessFailureDetectionEventNotifier

Takes 8-bytes of input and returns an #IEventNotifier.

[8.0.0+] Now takes an additional 8-bytes of input.

SetSaveDataSize

Takes two input u64s "size" and "journal_size", and writes them to fsp-srv object member variables.

These variables are normally initialized with 32 MiB (0x2000000) and 16 MiB (0x1000000), respectively.

These variables don't seem to be actually used anywhere else (?)

SetSaveDataRootPath

Takes an input path, and does snprintf(<fsp-srv object>->m_save_data_root_path, FS_MAX_PATH-1, "/%s", input_path);

This path is normally all-zero. When this path is non-zero, the internal OpenSaveDataFileSystem function will create a DirectorySaveDataFileSystem if the target save is a user-save + a directory exists, instead of the normal savedata filesystem object.

SetGlobalAccessLogMode

Takes an input u32.

SetGlobalAccessLogMode

Takes an input u32.

GetGlobalAccessLogMode

Returns an output u32.

GlobalAccessLogMode is normally 0.

OutputAccessLogToSdCard

Takes a type-0x5 input buffer.

The input buffer is the string to output to the log. User-processes normally include a newline at the end.

User-processes only use this when the value previously loaded from #GetGlobalAccessLogMode has bit1 set.

When bit1 in GlobalAccessLogMode is clear, FS-module will just return 0 for OutputAccessLogToSdCard. However even with that set the log doesn't show up SD, unknown why.

The input buffer is written to the "$FsAccessLog:/FsAccessLog.txt" file, where "$FsAccessLog" is the SD-card mount-name. It's written to the current end of the file(appended).

GetProgramIndexForAccessLog

No input, returns two 32-bit values "version" and "program_index".

OpenMultiCommitManager

No input, returns an output #IMultiCommitManager.

OpenBisWiper

Takes an input u64 size and a TransferMemory handle. Returns an output #IWiper.

IStorage

This is "nn::fssrv::sf::IStorage".

This is the interface for a raw device, usually a block device.

Cmd	Name
0	#Read
1	#Write
2	#Flush
3	#SetSize
4	#GetSize
5	[4.0.0+] OperateRange

Read

Takes a type-0x46 buffer, an offset and length.

Write

Takes a type-0x45 buffer, an offset and length.

Flush

No input.

SetSize

Takes a size.

GetSize

Returns a size.

IFileSystem

This is "nn::fssrv::sf::IFileSystem".

There are two main implementations of this interface:

• nn::fs::fsa::IFileSystem: The main IFileSystem implementation. Filesystem classes implement this interface, and FS code usually operates on this interface.
• nn::fssrv::sf::IFileSystem: Used for sending an IFileSystem over IPC. Not used outside of IPC code.

There are two adapter classes to convert between these interfaces:

• nn::fssrv::detail::FileSystemInterfaceAdapter: Allows access to an nn::fs::fsa::IFileSystem via the nn::fssrv::sf::IFileSystem interface.
• nn::fs::detail::FileSystemServiceObjectAdapter: Allows access to an nn::fssrv::sf::IFileSystem via the nn::fs::fsa::IFileSystem interface.

When the FS process returns a filesystem, it will wrap the filesystem object in a FileSystemInterfaceAdapter to return it over IPC. Then when FS application code receives that filesystem, it will wrap the nn::fssrv::sf::IFileSystem object in a FileSystemServiceObjectAdapter before using it.

Cmd	Name
0	CreateFile
1	DeleteFile
2	CreateDirectory
3	DeleteDirectory
4	DeleteDirectoryRecursively
5	RenameFile
6	RenameDirectory
7	#GetEntryType
8	#OpenFile
9	#OpenDirectory
10	#Commit
11	#GetFreeSpaceSize
12	#GetTotalSpaceSize
13	[3.0.0+] #CleanDirectoryRecursively
14	[3.0.0+] #GetFileTimeStampRaw
15	[4.0.0+] QueryEntry

GetEntryType

Takes a type-0x9 input buffer for the path and returns #DirectoryEntryType as an output u32.

OpenFile

Takes a type-0x19 input buffer for the path, and an u32 mode. mode controls how the file is opened, based on which bits are set:

• When bit 0 is set, the file is Readable: you can use the Read operation.
• When bit 1 is set, the file is Writable: you can use the Write operation.
• When bit 2 is set, the file is Appendable: unless this bit is set, you will not be able to write beyond the end of a file (such writes will result in an error 0x307202)

OpenDirectory

Takes a type-0x9 input buffer for the path and an u64 filter_flags. filter_flags controls what type of entries are read by the #IDirectory: bitmask 0x1 = directories, bitmask 0x2 = files.

Commit

Like 3DS, this has to be used after writing to savedata for the changes to take affect.

GetFreeSpaceSize

Takes a type-0x9 input buffer for the path and returns an output byte-size u64 for the total free space with this FS.

GetTotalSpaceSize

Takes a type-0x9 input buffer for the path and returns an output byte-size u64 for the total space available with this FS(free+used).

CleanDirectoryRecursively

Takes a type-0x9 input buffer for the path and clears the contents of the directory specified in the path.

GetFileTimeStampRaw

Takes a type-0x19 input buffer for the path and returns a 0x20-byte struct. This contains 3 u64s and an u8.

IDirectory

This is "nn::fssrv::sf::IDirectory".

Cmd	Name
0	#Read
1	#GetEntryCount

Read

Takes a type-0x6 output buffer. Returns an output u64(?) for the total number of read entries, this is 0 when no more entries are available.

The output buffer contains the read array of #DirectoryEntry. This doesn't include entries for "." and "..".

GetEntryCount

Returns an u64 for the total number of readable entries.

DirectoryEntry

This is "nn::fs::DirectoryEntry".

Offset	Size	Description
0x0	0x301	Path
0x301	0x1	File attributes (bit 0 = is directory; bit 1 = archive bit)
0x302	0x2	Padding?
0x304	0x1	#DirectoryEntryType
0x305	0x3	Padding?
0x308	0x8	Filesize, 0 for directories.

DirectoryEntryType

This is "nn::fs::DirectoryEntryType".

An s8 value indicating a directory entry type. The current values are:

Value	Description
0	Directory
1	File

IFile

This is "nn::fssrv::sf::IFile".

Cmd	Name
0	Read
1	Write
2	Flush
3	SetSize
4	GetSize
5	[4.0.0+] OperateRange

ISaveDataInfoReader

This is "nn::fssrv::sf::ISaveDataInfoReader".

Cmd	Name
0	#ReadSaveDataInfo

ReadSaveDataInfo

Takes a type-0x6 output buffer. Returns an output u64 for total output entries. This buffer contains an array of #SaveDataInfo.

This is used to get #SaveDataInfo for all savedata on the system (or all savedata for the current #SaveDataSpaceId). When used multiple times, it will resume reading where it left off, until no more entries are available (in that case the out u64 is value 0).

IDeviceOperator

This is "nn::fssrv::sf::IDeviceOperator".

Cmd	Name
0	IsSdCardInserted
1	GetSdCardSpeedMode
2	[2.0.0+] GetSdCardCid
3	[2.0.0+] GetSdCardUserAreaSize
4	[2.0.0+] GetSdCardProtectedAreaSize
5	[2.0.0+] GetAndClearSdCardErrorInfo
100	GetMmcCid
101	GetMmcSpeedMode
110	EraseMmc
111	GetMmcPartitionSize
112	[2.0.0+] GetMmcPatrolCount
113	[2.0.0+] GetAndClearMmcErrorInfo
114	[2.0.0+] GetMmcExtendedCsd
115	[4.0.0+] SuspendMmcPatrol
116	[4.0.0+] ResumeMmcPatrol
200	#IsGameCardInserted
201	EraseGameCard
202	#GetGameCardHandle
203	#GetGameCardUpdatePartitionInfo
204	FinalizeGameCardDriver
205	GetGameCardAttribute
206	#GetGameCardDeviceCertificate
207	GetGameCardAsicInfo
208	GetGameCardIdSet
209	WriteToGameCardDirectly
210	SetVerifyWriteEnalbleFlag
211	GetGameCardImageHash
212	[2.0.0+] GetGameCardDeviceIdForProdCard
213	[2.0.0+] EraseAndWriteParamDirectly
214	[2.0.0+] ReadParamDirectly
215	[2.0.0+] ForceEraseGameCard
216	[2.0.0+] GetGameCardErrorInfo
217	[2.1.0+] GetGameCardErrorReportInfo
218	[3.0.0+] GetGameCardDeviceId
219	[8.0.0+] #ChallengeCardExistence
220	[9.0.0+] #GetGameCardCompatibilityType
300	SetSpeedEmulationMode
301	GetSpeedEmulationMode
400	[5.0.0+] SuspendSdmmcControl
401	[5.0.0+] ResumeSdmmcControl
402	[6.0.0+] #GetSdmmcConnectionStatus
500	[6.0.0+] #SetDeviceSimulationEvent
501	[6.0.0+] #ClearDeviceSimulationEvent

IsGameCardInserted

No input, returns a bool.

GetGameCardHandle

No input, returns an u32 GameCardHandle.

GetGameCardUpdatePartitionInfo

Returns a ProgramId and the title-version for it.

• Output u32 with ARMS-gamecard: title-version v131162. This is the title-version for 2.1.0, which is the sysupdate included with this gamecard. Launch-day gamecards return title-version v450.
• Output u64 with ARMS-gamecard: ProgramId 0100000000000816.

NS appears to only use this with NCM for checking whether a sysupdate is required.

GetGameCardDeviceCertificate

Takes a type-0x6 output buffer, an u32 GameCardHandle and an u64 DeviceCertificateBufferSize. No output.

ChallengeCardExistence

Takes a type-0x6 output buffer, two type-0x5 input buffers and an u32 GameCardHandle. No output.

[9.0.0+] The account system module uses this as part of a new challenge-response mechanism for application authentication.

GetGameCardCompatibilityType

Takes an u32 GameCardHandle, returns an u8 CompatibilityType (0x00 = Global, 0x01 = China) from Gamecard Info.

GetSdmmcConnectionStatus

Takes a total of 4-bytes of input, returns a total of 8-bytes of output.

SetDeviceSimulationEvent

Takes a total of 0x14-bytes of input, no output.

ClearDeviceSimulationEvent

Takes a total of 4-bytes of input, no output.

IEventNotifier

This is "nn::fssrv::sf::IEventNotifier".

Cmd	Name
0	#GetEventHandle

GetEventHandle

No input, returns an output Event handle. With official sw the EventClearMode is user-specified.

ISaveDataTransferManager

This is "nn::fssrv::sf::ISaveDataTransferManager".

This was added with 4.0.0.

Cmd	Name
0	#GetChallenge
16	#SetToken
32	#OpenSaveDataExporter
64	#OpenSaveDataImporter

GetChallenge

No input/output, takes a type-0x6 output buffer.

SetToken

No input/output, takes a type-0x5 input buffer.

OpenSaveDataExporter

Takes an input u8 #SaveDataSpaceId and u64, returns an #ISaveDataExporter.

OpenSaveDataImporter

Takes an input u8 #SaveDataSpaceId and a 0x10-byte userID, and a type-0x5 input buffer. Returns an output u64 and an #ISaveDataImporter.

ISaveDataTransferManagerForSaveDataRepair

This is "nn::fssrv::sf::ISaveDataTransferManagerForSaveDataRepair".

This was added with 9.0.0.

Cmd	Name
0	#GetChallenge
16	#SetKeyPackage
80	#OpenSaveDataExporterAndGetEncryptedKey
81	#PrepareOpenSaveDataImporter
90	#OpenSaveDataImporter
91	#OpenSaveDataImporter2
100	#OpenSaveDataExporterWithKey
110	#OpenSaveDataImporterWithKey

SetKeyPackage

No input/output, takes a type-0x5 input buffer.

OpenSaveDataExporterAndGetEncryptedKey

Takes a total of 0x10-bytes of input and a type-0x1A output buffer to receive a RsaEncryptedKey. Returns an #ISaveDataDivisionExporter.

PrepareOpenSaveDataImporter

Takes a type-0x1A output buffer to receive a RsaEncryptedKey.

OpenSaveDataImporter

Takes a total of 0x18-bytes of input and two type-0x5 input buffers, returns an #ISaveDataDivisionImporter.

OpenSaveDataImporter2

Takes a total of 0x18-bytes of input and a type-0x5 input buffer, returns an #ISaveDataDivisionImporter.

OpenSaveDataExporterWithKey

Takes a total of 0x20-bytes of input, returns an #ISaveDataDivisionExporter.

OpenSaveDataImporterWithKey

Takes a total of 0x28-bytes of input and a type-0x5 input buffer, returns an #ISaveDataDivisionImporter.

ISaveDataMover

This is "nn::fssrv::sf::ISaveDataMover".

This was added with 10.0.0.

Cmd	Name
8	#Register
16	#Process
18	#Cancel

Register

Takes an input u64, no output.

Process

Takes an input u64, returns an output u64.

Cancel

No input/output.

ISaveDataExporter

This is "nn::fssrv::sf::ISaveDataExporter".

This was added with 4.0.0.

Cmd	Name
0	#GetSaveDataInfo
1	#GetRestSize
16	#Pull
17	#PullInitialData

GetSaveDataInfo

No input/output, takes a type-0x1A #SaveDataInfo output buffer.

The actual name for this is the SaveDataExporter constructor. This is used automatically after #OpenSaveDataExporter by official sw.

GetRestSize

No input, returns an output u64.

Pull

Takes a type-0x6 output buffer, returns an output u64.

PullInitialData

No input/output, takes a type-0x6 output buffer.

ISaveDataImporter

This is "nn::fssrv::sf::ISaveDataImporter".

This was added with 4.0.0.

Cmd	Name
0	#GetSaveDataInfo
1	#GetRestSize
16	#Push
17	#Finalize

GetSaveDataInfo

No input/output, takes a type-0x1A #GetSaveDataInfo output buffer.

The actual name for this is the SaveDataImporter constructor. This is used automatically after #OpenSaveDataImporter by official sw.

GetRestSize

No input, returns an output u64.

Push

No input/output, takes a type-0x5 input buffer.

Finalize

No input/output.

ISaveDataTransferManagerWithDivision

This is "nn::fssrv::sf::ISaveDataTransferManagerWithDivision".

This was added with 5.0.0.

Cmd	Name
0	#GetChallenge
16	#SetKeySeedPackage
32	#OpenSaveDataExporter
33	#OpenSaveDataExporterForDiffExport
34	[6.0.0+] #OpenSaveDataExporterByContext
64	[5.0.0-5.1.0] OpenSaveDataImporter
	[6.0.0+] #OpenSaveDataImporterDeprecated
65	#OpenSaveDataImporterForDiffImport
66	[6.0.0+] #OpenSaveDataImporterForDuplicateDiffImport
67	[6.0.0+] #OpenSaveDataImporter
68	[6.0.0+] #OpenSaveDataImporterByContext
69	[6.0.0+] #CancelSuspendingImport
70	[10.0.0+] DecryptAndVerifyInitialData

GetChallenge

No input/output, takes a type-0x6 output buffer containing the Challenge.

SetKeySeedPackage

No input/output, takes a type-0x5 input buffer containing the KeySeedPackage.

OpenSaveDataExporter

Takes an input u8 #SaveDataSpaceId and u64. Returns an #ISaveDataDivisionExporter.

OpenSaveDataExporterForDiffExport

Takes an input u8 #SaveDataSpaceId, an u64, and a type-0x5 input buffer #InitialDataVersion2. Returns an #ISaveDataDivisionExporter.

OpenSaveDataExporterByContext

No input/output, takes a type-0x5 input buffer, returns an #ISaveDataDivisionExporter.

OpenSaveDataImporterDeprecated

Takes an input u8 #SaveDataSpaceId, a 0x10-byte userID, and a type-0x5 input buffer #InitialDataVersion2. Returns an #ISaveDataDivisionImporter.

OpenSaveDataImporterForDiffImport

Takes an input u8 #SaveDataSpaceId, an u64, and a type-0x5 input buffer #InitialDataVersion2, returns an #ISaveDataDivisionImporter.

OpenSaveDataImporterForDuplicateDiffImport

Takes an input u8 and an u64, and a type-0x5 input buffer, returns an #ISaveDataDivisionImporter.

OpenSaveDataImporter

Takes an input u8, an u8(bool), a 0x10-byte struct, and a type-0x5 input buffer, returns an #ISaveDataDivisionImporter.

OpenSaveDataImporterByContext

No input/output, takes a type-0x5 input buffer, returns an #ISaveDataDivisionImporter.

CancelSuspendingImport

Takes an input u64 and a 0x10-byte struct, no output.

ISaveDataDivisionExporter

This is "nn::fssrv::sf::ISaveDataDivisionExporter".

This was added with 5.0.0.

Cmd	Name
0	#SetDivisionCount
1	[6.0.0+] #GetSaveDataInfo
16	#OpenSaveDataDiffChunkIterator
48	#OpenSaveDataChunkExporter
64	[6.0.0-8.1.0] #FinalizeFullExport
65	[6.0.0-8.1.0] #FinalizeDiffExport
66	[6.0.0+] #CancelExport
67	[6.0.0+] #SuspendExport
70	[6.0.0+] #GetKeySeed
71	[6.0.0+] #GetInitialDataMac
72	[6.0.0+] #FinalizeExport
73	[9.0.0+] #GetInitialDataMacKeyGeneration
80	[6.0.0+] #GetImportInitialDataAad
81	[6.0.0+] #SetExportInitialDataAad
96	[6.0.0+] #GetReportInfo

SetDivisionCount

Takes an input u32, no output.

OpenSaveDataChunkExporter

Takes an input u32, returns an #ISaveDataChunkExporter.

FinalizeFullExport

No input, returns two 0x10-byte output structs.

FinalizeDiffExport

No input, returns an output 0x10-byte struct.

CancelExport

No input/output.

SuspendExport

No input/output, takes a type-0x6 output buffer.

GetKeySeed

No input, returns an output 0x10-byte struct.

GetInitialDataMac

No input, returns an output 0x10-byte struct.

FinalizeExport

No input/output.

SetExportInitialDataAad

Takes an input 0x20-byte struct, no output.

ISaveDataDivisionImporter

This is "nn::fssrv::sf::ISaveDataDivisionImporter".

This was added with 5.0.0.

Cmd	Name
0	[6.0.0+] #GetSaveDataInfo
16	#OpenSaveDataDiffChunkIterator
32	#InitializeImport
33	#FinalizeImport
34	[6.0.0+] #CancelImport
35	[6.0.0+] #GetImportContext
36	[6.0.0+] #SuspendImport
48	#OpenSaveDataChunkImporter
64	[6.0.0+] #GetImportInitialDataAad
80	[6.0.0+] #GetReportInfo

GetSaveDataInfo

No input/output, takes a type-0x6 output buffer.

OpenSaveDataDiffChunkIterator

No input, returns an #ISaveDataChunkIterator.

InitializeImport

No input, returns an output u64.

FinalizeImport

No input/output.

CancelImport

No input/output.

GetImportContext

No input/output, takes a type-0x6 output buffer.

SuspendImport

No input/output.

OpenSaveDataChunkImporter

Takes an input u32, returns an #ISaveDataChunkImporter.

GetImportInitialDataAad

No input, returns an output 0x20-byte struct.

GetReportInfo

No input, returns an output 0x20-byte struct.

ISaveDataChunkIterator

This is "nn::fssrv::sf::ISaveDataChunkIterator".

This was added with 5.0.0.

Cmd	Name
0	#Next
1	#IsEnd
16	#GetId

Next

No input/output.

IsEnd

No input, returns an output u8.

GetId

No input, returns an output u32.

ISaveDataChunkExporter

This is "nn::fssrv::sf::ISaveDataChunkExporter".

This was added with 5.0.0.

Cmd	Name
0	#Pull
16	[6.0.0+] #GetRestRawDataSize

Pull

Takes an input u64 and a type-0x6 output buffer, returns an output u64.

GetRestRawDataSize

No input, returns an output u64.

ISaveDataChunkImporter

This is "nn::fssrv::sf::ISaveDataChunkImporter".

This was added with 5.0.0.

Cmd	Name
0	#Push

Push

Takes an input u64 and a type-0x5 input buffer, no output.

ISaveDataTransferProhibiter

This was added with 6.0.0.

This doesn't seem to handle any commands (?).

IMultiCommitManager

This was added with 6.0.0.

Cmd	Name
1	#Add
2	#Commit

Add

Takes an input #IFilesystem, no output.

Commit

No input/output.

IWiper

This is "nn::fs::IWiper".

This was added with 10.0.0.

Cmd	Name
0	Startup
16	Process

Startup

No input. Returns an u64.

Process

No input. Returns an u64.

FileSystemProxyType

This is "nn::fs::FileSystemProxyType".

Value	Name
0	Code
1	Rom
2	Logo
3	Control
4	Manual
5	Meta
6	Data
7	Package
8	[4.0.0+] RegisteredUpdate

ContentType

This is "nn::fs::ContentType".

Value	Name
0	Meta
1	Control
2	Manual
3	Logo
4	Data

ContentStorageId

This is "nn::fs::ContentStorageId".

Value	Name
0	System
1	User
2	SdCard

SaveDataSpaceId

This is "nn::fs::SaveDataSpaceId".

Value	Name
0	System
1	User
2	SdSystem
3	[3.0.0+] Temporary
4	[4.0.0+] SdUser
100	[3.0.0+] ProperSystem
101	[3.0.0+] SafeMode

Determines the storage where the savedata is stored.

SaveDataType

This is "nn::fs::SaveDataType".

Value	Name
0	System
1	Account
2	Bcat
3	Device
4	[3.0.0+] Temporary
5	[3.0.0+] Cache
6	[4.0.0+] SystemBcat

SaveDataRank

This is "nn::fs::SaveDataRank".

Value	Name
0	Primary
1	Secondary

SaveDataEnumerateOption

This is "nn::fs::SaveDataEnumerateOption".

Value	Name
1	AllRank

SaveDataFlags

This is "nn::fs::SaveDataFlags".

Value	Name
1	KeepAfterResettingSystemSaveData
2	KeepAfterRefurbishment
4	KeepAfterResettingSystemSaveDataWithoutUserSaveData
8	NeedsSecureDelete

SaveDataMetaType

This is "nn::fs::SaveDataMetaType".

Value	Name
0	None
1	Thumbnail
2	ExtensionContext

ImageDirectoryId

This is "nn::fs::ImageDirectoryId".

Value	Name
0	Nand
1	SdCard

CloudBackupWorkStorageId

This is "nn::fs::CloudBackupWorkStorageId".

Value	Name
0	Nand
1	SdCard

CustomStorageId

This is "nn::fs::CustomStorageId".

Value	Name
0	System
1	SdCard

Priority

This is "nn::fs::Priority".

Value	Name
0	Realtime
1	Normal
2	Low

PriorityRaw

This is "nn::fs::PriorityRaw".

Value	Name
0	Realtime
1	Normal
2	Low
3	Background

AbortSpecifier

This is "nn::fs::AbortSpecifier".

Value	Name
0	Default
1	Abort
2	ReturnResult

OperationId

This is "nn::fs::OperationId".

Value	Name
0	Clear
1	ClearSignature
2	InvalidateCache
3	QueryRange

MountHostOption

This is "nn::fs::MountHostOption".

Value	Name
1	PseudoCaseSensitive

BisPartitionId

This is "nn::fs::BisPartitionId".

Value	Name
0	BootPartition1Root
10	BootPartition2Root
20	UserDataRoot
21	BootConfigAndPackage2Part1
22	BootConfigAndPackage2Part2
23	BootConfigAndPackage2Part3
24	BootConfigAndPackage2Part4
25	BootConfigAndPackage2Part5
26	BootConfigAndPackage2Part6
27	CalibrationBinary
28	CalibrationFile
29	SafeMode
30	User
31	System
32	SystemProperEncryption
33	SystemProperPartition
34	SignedSystemPartitionOnSafeMode

MmcSpeedMode

This is "nn::fs::MmcSpeedMode".

Value	Name
0	Identification
1	LegacySpeed
2	HighSpeed
3	Hs200
4	Hs400
5	Unknown

MmcPartition

This is "nn::fs::MmcPartition".

Value	Name
0	UserData
1	BootPartition1
2	BootPartition2

GameCardPartition

This is "nn::fs::GameCardPartition".

Value	Name
0	Update
1	Normal
2	Secure
3	[4.0.0+] Logo

GameCardPartitionRaw

This is "nn::fs::GameCardPartitionRaw".

Value	Name
0	NormalReadOnly
1	SecureReadOnly
2	RootWriteOnly

GameCardAttribute

This is "nn::fs::GameCardAttribute".

Value	Name
1	AutoBootFlag
2	HistoryEraseFlag
4	[4.0.0+] RepairToolFlag
8	[9.0.0+] DifferentRegionCupToTerraDeviceFlag
16	[9.0.0+] DifferentRegionCupToGlobalDeviceFlag

GameCardSize

This is "nn::fs::GameCardSize".

Value	Name
1	Size1GB
2	Size2GB
4	Size4GB
8	Size8GB
16	Size16GB
32	Size32GB

GameCardClockRate

This is "nn::fs::GameCardClockRate".

Value	Name
25	ClockRate25MHz
50	ClockRate50MHz

SimulatingDeviceType

This is "nn::fs::SimulatingDeviceType".

Value	Name
0	eMMC
1	SdCard
2	GameCard

SimulatingDeviceDetectionMode

This is "nn::fs::SimulatingDeviceDetectionMode".

Value	Name
0	NoSimulation
1	DeviceAttached
2	DeviceRemoved

SimulatingDeviceAccessFailureEventType

This is "nn::fs::SimulatingDeviceAccessFailureEventType".

Value	Name
0	None
1	AccessTimeoutFailure
2	AccessFailure
3	DataCorruption

SimulatingDeviceTargetOperation

This is "nn::fs::SimulatingDeviceTargetOperation".

Value	Name
1	Read
2	Write

SpeedEmulationMode

This is "nn::fs::SpeedEmulationMode".

Value	Name
0	None
1	Faster
2	Slower
3	Random

ContentPath

These are the 0x300 paths to NCA files for the various filesystems FS can access, beginning with @. They're passed via X descriptors, and returned via various ncm/lr commands.

Path	Notes
@SystemContent
@UserContent
@SdCardContent
@CalibFile
@Safe
@User
@System
@Sdcard
@Host
@GcApp	Gamecard App partition (Partition 2)
@GcXYYYYYYYY	Gamecard Contents. X is the partition type (U - Update, N - Normal, S - Secure). Y is the gamecard handle as a 32-bit hex value
@upp	Gamecard update partition (Partition 0)
[4.0.0+] @RegUpdate	Registered update partition

SaveDataAttribute

This is "nn::fs::SaveDataAttribute".

Offset	Size	Description
0x0	0x8	ApplicationId (0 for SystemSaveData) SaveData: 0 can be used for accessing the savedata associated with the current FS session ApplicationId, otherwise when set this is the ApplicationId associated with the savedata to access.
0x8	0x10	UserId For user-specific savedata(saveuser) when set, otherwise when zero this indicates the common savedata(savecommon). This is loaded from Account_services.
0x18	0x8	SystemSaveDataId (0 for SaveData)
0x20	0x1	#SaveDataType
0x21	0x1	#SaveDataRank
0x22	0x2	SaveDataIndex
0x24	0x4	Padding
0x28	0x8	0 for SystemSaveData/SaveData.
0x30	0x8	0 for SystemSaveData/SaveData.
0x38	0x8	0 for SystemSaveData/SaveData.

Total size is 0x40-bytes.

For DeviceSaveData, this struct is all-zero except for the #SaveDataType field (and optionally the ApplicationId if specified).

SaveDataCreationInfo

This is "nn::fs::SaveDataCreationInfo".

Offset	Size	Description
0x0	0x8	SaveDataSize
0x8	0x8	JournalSize
0x10	0x8	AvailableSize 0x4000 for SystemSaveData/SaveData/DeviceSaveData/BcatSaveData.
0x18	0x8	OwnerId Official user-processes only uses 0 here for SystemSaveData/SaveData. For the dedicated save-creation code with SaveData/DeviceSaveData, this value comes from an input param with official user-processes. For BcatSaveData, this is the hard-coded ProgramId of the bcat-sysmodule.
0x20	0x4	#SaveDataFlags Written using an input param for official user-processes. Hard-coded 0 for BcatSaveData.
0x24	0x1	#SaveDataSpaceId Official user-processes only uses 0 here for SystemSaveData, 1 for SaveData/DeviceSaveData/BcatSaveData.
0x25	0x1	Unknown. 0 for SystemSaveData/SaveData.
0x26	0x1A	Not initialized for SystemSaveData/SaveData.

Total size is 0x40-bytes.

DeviceSaveData

This is accessed using the same commands for SaveData with the same input u8, the only difference compared to SaveData is the #SaveDataAttribute.

BcatSaveData

This is accessed using the same commands for SaveData with the same input u8. The #SaveDataAttribute is the same as DeviceSaveData (besides the SaveDataType), except that the ApplicationId field is always set to <input ApplicationId> (unlike DeviceSaveData where it's optional). See above regarding #SaveDataCreationInfo.

The 0x10-byte struct passed to #CreateSaveDataFileSystem has the first 0x5-bytes set to all-zero.

MountSystemBcatSaveData uses #OpenSaveDataFileSystemBySystemSaveDataId with #SaveDataSpaceId System. The #SaveDataAttribute is all-zero, except for the SaveDataType, and SystemSaveDataId is set to the input param.

SaveDataInfo

This is "nn::fs::SaveDataInfo".

Offset	Size	Description
0x0	0x8	SaveDataId
0x8	0x1	#SaveDataSpaceId
0x9	0x1	#SaveDataType
0xA	0x6	Padding?
0x10	0x10	UserId
0x20	0x8	SystemSaveDataId (0 for regular SaveData)
0x28	0x8	ApplicationId (for regular SaveData)
0x30	0x8	Raw saveimage size
0x38	0x2	SaveDataIndex
0x3A	0x1	#SaveDataRank
0x3B	0x25	Unknown. Usually zeros?

This is a 0x60-byte struct.

SaveDataFileSystemExtraData

This is a 0x200-byte struct. Appears to match Savegames#Extra_data.

InitialDataVersion2

This is a 0x8210-byte struct used by #ISaveDataTransferManagerWithDivision.