NFC services

nfc:am

This is "nn::nfc::am::detail::IAmManager".

Cmd	Name
0	CreateAmInterface

IAm

This is "nn::nfc::am::detail::IAm".

Cmd	Name
0	Initialize
1	Finalize
2	NotifyForegroundApplet

nfc:mf:u

This is "nn::nfc::mifare::detail::IUserManager".

Cmd	Name
0	CreateUserInterface

IUser

This is "nn::nfc::mifare::detail::IUser".

Cmd	Name
0	#Initialize
1	#Finalize
2	#ListDevices
3	StartDetection
4	#StopDetection
5	Read
6	Write
7	#GetTagInfo
8	GetActivateEventHandle
9	GetDeactivateEventHandle
10	#GetState
11	#GetDeviceState
12	#GetNpadId
13	[3.0.0+] GetAvailabilityChangeEventHandle

nfc:user

This is "nn::nfc::detail::IUserManager".

Cmd	Name
0	CreateUserInterface

IUser

This is "nn::nfc::detail::IUser".

Cmd	Name
0	InitializeOld
1	FinalizeOld
2	#GetStateOld
3	#IsNfcEnabledOld
400	[4.0.0+] #Initialize
401	[4.0.0+] #Finalize
402	[4.0.0+] #GetState
403	[4.0.0+] #IsNfcEnabled
404	[4.0.0+] #ListDevices
405	[4.0.0+] #GetDeviceState
406	[4.0.0+] #GetNpadId
407	[4.0.0+] #AttachAvailabilityChangeEvent
408	[4.0.0+] #StartDetection
409	[4.0.0+] #StopDetection
410	[4.0.0+] #GetTagInfo
411	[4.0.0+] #AttachActivateEvent
412	[4.0.0+] #AttachDeactivateEvent
1000	[4.0.0+] #ReadMifare
1001	[4.0.0+] #WriteMifare
1300	[4.0.0+] #SendCommandByPassThrough
1301	[4.0.0+] #KeepPassThroughSession
1302	[4.0.0+] #ReleasePassThroughSession

GetStateOld

No input, returns an output u32.

IsNfcEnabledOld

No input, returns an output bool.

This runs the same code as #IsNfcEnabled.

GetState

No input, returns an output u32.

This replaces #GetStateOld.

IsNfcEnabled

No input, returns an output bool.

This replaces #IsNfcEnabledOld.

StartDetection

Takes an input #DeviceHandle and a #NfcProtocol, no output.

StopDetection

Takes an input #DeviceHandle, no output.

ReadMifare

Takes an input #DeviceHandle, a type-0x6 output buffer containing an array of #MifareReadBlockData, a type-0x5 input buffer containing an array of #MifareReadBlockParameter, no output.

sdknso passes the same user-specified array-count for both buffers.

WriteMifare

Takes an input #DeviceHandle, a type-0x5 input buffer containing an array of #MifareWriteBlockParameter, no output.

SendCommandByPassThrough

Takes an input #DeviceHandle, a nn::TimeSpan timeout, a type-0x6 output buffer, a type-0x5 input buffer, returns an output u32 out_size.

sdknso copies the output u32 into an u64. This is the actual size which was copied into the output buffer.

This allows using a raw NFC command. The input buffer contains the command data (id + params), and the output buffer contains the response.

KeepPassThroughSession

Takes an input #DeviceHandle, no output.

ReleasePassThroughSession

Takes an input #DeviceHandle, no output.

nfc:sys

This is "nn::nfc::detail::ISystemManager".

Cmd	Name
0	CreateSystemInterface

ISystem

This is "nn::nfc::detail::ISystem".

Cmd	Name
0	#Initialize
1	#Finalize
2	#GetStateOld
3	#IsNfcEnabledOld
100	#SetNfcEnabledOld
400	[4.0.0+] InitializeSystem
401	[4.0.0+] FinalizeSystem
402	[4.0.0+] #GetState
403	[4.0.0+] #IsNfcEnabled
404	[4.0.0+] #ListDevices
405	[4.0.0+] #GetDeviceState
406	[4.0.0+] #GetNpadId
407	[4.0.0+] #AttachAvailabilityChangeEvent
408	[4.0.0+] #StartDetection
409	[4.0.0+] #StopDetection
410	[4.0.0+] #GetTagInfo
411	[4.0.0+] #AttachActivateEvent
412	[4.0.0+] #AttachDeactivateEvent
500	[4.0.0+] #SetNfcEnabled
510	[7.0.0+] #OutputTestWave
1000	[4.0.0+] #ReadMifare
1001	[4.0.0+] #WriteMifare
1300	[4.0.0+] #SendCommandByPassThrough
1301	[4.0.0+] #KeepPassThroughSession
1302	[4.0.0+] #ReleasePassThroughSession

SetNfcEnabledOld

Takes an input bool, no output.

This runs the same code as #SetNfcEnabled.

SetNfcEnabled

Takes an input bool, no output.

This replaces #SetNfcEnabledOld.

OutputTestWave

Takes an input bool and a #TestWaveType, no output.

nfp services

These are used for amiibo support (nfp = Nintendo Figurine Protocol, internal name for amiibo protocol).

Check Error codes for result codes that these commands may return on error.

nfp:user

This is "nn::nfp::detail::IUserManager".

Cmd	Name
0	CreateUserInterface

IUser

This is "nn::nfp::detail::IUser".

Cmd	Name
0	Initialize
1	Finalize
2	#ListDevices
3	#StartDetection
4	#StopDetection
5	#Mount
6	#Unmount
7	#OpenApplicationArea
8	#GetApplicationArea
9	#SetApplicationArea
10	#Flush
11	#Restore
12	#CreateApplicationArea
13	#GetTagInfo
14	#GetRegisterInfo
15	#GetCommonInfo
16	#GetModelInfo
17	#AttachActivateEvent
18	#AttachDeactivateEvent
19	#GetState
20	#GetDeviceState
21	#GetNpadId
22	#GetApplicationAreaSize
23	[3.0.0+] #AttachAvailabilityChangeEvent
24	[3.0.0+] #RecreateApplicationArea

nfp:sys

This is "nn::nfp::detail::ISystemManager".

Cmd	Name
0	CreateSystemInterface

ISystem

This is "nn::nfp::detail::ISystem".

Cmd	Name
0	InitializeSystem
1	FinalizeSystem
2	#ListDevices
3	#StartDetection
4	#StopDetection
5	#Mount
6	#Unmount
10	#Flush
11	#Restore
13	#GetTagInfo
14	#GetRegisterInfo
15	#GetCommonInfo
16	#GetModelInfo
17	#AttachActivateEvent
18	#AttachDeactivateEvent
19	#GetState
20	#GetDeviceState
21	#GetNpadId
23	[3.0.0+] #AttachAvailabilityChangeEvent
100	#Format
101	#GetAdminInfo
102	#GetRegisterInfoPrivate
103	#SetRegisterInfoPrivate
104	#DeleteRegisterInfo
105	#DeleteApplicationArea
106	#ExistsApplicationArea

nfp:dbg

This is "nn::nfp::detail::IDebugManager".

Cmd	Name
0	CreateDebugInterface

IDebug

This is "nn::nfp::detail::IDebug".

Cmd	Name
0	InitializeDebug
1	FinalizeDebug
2	#ListDevices
3	#StartDetection
4	#StopDetection
5	#Mount
6	#Unmount
7	#OpenApplicationArea
8	#GetApplicationArea
9	#SetApplicationArea
10	#Flush
11	#Restore
12	#CreateApplicationArea
13	#GetTagInfo
14	#GetRegisterInfo
15	#GetCommonInfo
16	#GetModelInfo
17	#AttachActivateEvent
18	#AttachDeactivateEvent
19	#GetState
20	#GetDeviceState
21	#GetNpadId
22	#GetApplicationAreaSize
23	[3.0.0+] #AttachAvailabilityChangeEvent
24	[3.0.0+] #RecreateApplicationArea
100	#Format
101	#GetAdminInfo
102	#GetRegisterInfoPrivate
103	#SetRegisterInfoPrivate
104	#DeleteRegisterInfo
105	#DeleteApplicationArea
106	#ExistsApplicationArea
200	#GetAll
201	#SetAll
202	#FlushDebug
203	#BreakTag
204	#ReadBackupData
205	#WriteBackupData
206	#WriteNtf
300	[3.0.0-3.0.2]
301	[3.0.0-3.0.2]
302	[3.0.0-3.0.2]
303	[3.0.0-3.0.2]
304	[3.0.0-3.0.2]
305	[3.0.0-3.0.2]
306	[3.0.0-3.0.2]
307	[3.0.0-3.0.2]
308	[3.0.0-3.0.2]
309	[3.0.0-3.0.2]
310	[3.0.0-3.0.2]
311	[3.0.0-3.0.2]
312	[3.0.0-3.0.2]
313	[3.0.0-3.0.2]
314	[3.0.0-3.0.2]

GetAll

Takes an input #DeviceHandle, a type-0x1A output buffer containing #NfpData, no output.

Requires the amiibo to be mounted with #MountType RAM.

Just converts data from the internal #Amiibo settings to the output data. The last write date is not validated here (unlike with #GetCommonInfo).

SetAll

Takes an input #DeviceHandle, a type-0x19 input buffer containing #NfpData, no output.

Requires the amiibo to be mounted with #MountType RAM.

Just converts data from the input data to the internal #Amiibo settings. No flushing / writing to the amiibo is done in this command.

FlushDebug

Takes an input #DeviceHandle, no output.

Requires the amiibo to be mounted with #MountType RAM.

Just calls internally the same function as #BreakTag with #BreakType 0.

BreakTag

Takes an input #DeviceHandle, an input u32 #BreakType, no output.

Calls an internal function with the input #BreakType. This first reads amiibo data (like #Mount and other commands), then saves the read amiibo in the #Backup data, then depending on the type performs some logic (this changes are thus not saved in the backup), and finally flushes the modified amiibo (writes it to the figurine).

#BreakType 0 does nothing (it is used as a flushing command, used by many other commands).

#BreakType 1 breaks the data SHA256 HMAC hash (doing "raw_fmt->data_sha256_hmac_hash[0] ^= 0x80u;", see #Amiibo settings)

#BreakType 2 sets the amiibo header magic (see #Amiibo settings) to 0x00 (which beaks the figurine since this magic is checked to be 0xA5 in several places).

ReadBackupData

Takes an input #DeviceHandle, a type-0x6 output buffer, and an output u32 (read_size).

This reads from the raw #Backup data.

WriteBackupData

Takes an input #DeviceHandle, a type-0x5 input buffer, no output.

This writes directly to the raw #Backup data. The buffer size must be less or equal than the backup data size (0x1FBD20).

WriteNtf

Takes an input #DeviceHandle, an input u32 #WriteType, a type-0x5 input buffer, no output.

The input buffer size must match 0x2A0. This handles Amiibo crypto, etc.

Common

Create*Interface

Returns an output interface (#IUser, #ISystem or #IDebug depending on the service).

Initialize*

Takes a PID, an AppletResourceUserId, an u64 placeholder for the PID, a type-0x5 input buffer containing an array of #RequiredMcuVersionData, no output.

Internally this is mostly the same for each service.

The input PID is internally used to get the process application ID when needed.

Finalize*

No input/output.

Internally this is mostly the same for each service.

ListDevices

Takes a type-0xA output buffer containing an array of #DeviceHandle, returns an output s32 total_out.

This can return a maximum of 0xA entries.

StartDetection

Takes an input #DeviceHandle, no output.

This runs the same code as nfc #StartDetection with #NfcProtocol = -1.

StopDetection

Takes an input #DeviceHandle, no output.

Mount

Takes an input #DeviceHandle, an input u32 #ModelType and an input u32 #MountTarget, no output.

Creates an internal object that manages mounted amiibo data. This step loads the amiibo #Raw format, saves it in #Backup data, and converts/decrypts it internally into a #Plain format.

Unmount

Takes an input #DeviceHandle, no output.

Requires the amiibo to be mounted. Disposes the internal object that manages mounted amiibo data.

OpenApplicationArea

Takes an input #DeviceHandle and an input u32 #Access ID, no output.

Requires the amiibo to be mounted with #MountType RAM, and the application area to exist (checks the #Amiibo flag). Just sets an internal flag to 1 if the provided access ID and the application area access ID match.

GetApplicationArea

Takes an input #DeviceHandle and a type-0x6 output #Application area data buffer, returns an output u32 size.

Requires the amiibo to be mounted with #MountType RAM, and the application area to exist and be opened (see #OpenApplicationArea).

Reads the buffer data in the application area and returns the size read from the application area.

SetApplicationArea

Takes an input #DeviceHandle and a type-0x5 input #Application area data buffer, no output.

Requires the amiibo to be mounted with #MountType RAM, and the application area to exist and be opened (see #OpenApplicationArea).

Writes the buffer data in the application area. The remaining data out of the total 0xD8-bytes is filled with randomly generated bytes.

Flush

Takes an input #DeviceHandle, no output.

Requires the amiibo to be mounted with #MountType RAM.

Performs CRC verifications, updates write counters (see #Amiibo settings) and then calls internally the same function as #BreakTag with #BreakType 0.

Restore

Takes an input #DeviceHandle, no output.

Reloads amiibo data (same internal functions as #Mount) and writes the data to the amiibo again. If reading the amiibo fails, it tries to load the #Raw data from the #Backup data.

CreateApplicationArea

Takes an input #DeviceHandle, an input u32 #Access ID and a type-0x5 input #Application area data buffer, no output.

Requires the amiibo to be mounted with #MountType RAM.

Sets the new application ID / access ID values (even if an application area already existed), updates CRC values, updates write counters (see #Amiibo settings), copies input data, fills remaining space with random bytes, and then calls internally the same function as #BreakTag with #BreakType 0.

GetTagInfo

Takes an input #DeviceHandle and a type-0x1A output buffer containing a #TagInfo.

GetRegisterInfo

Takes an input #DeviceHandle and a type-0x1A output buffer containing a #RegisterInfo.

Requires the amiibo to be mounted with #MountType RAM.

Just converts data from the internal #Amiibo settings to the output info.

GetCommonInfo

Takes an input #DeviceHandle and a type-0x1A output buffer containing a #CommonInfo.

Requires the amiibo to be mounted with #MountType RAM.

Converts data from the internal #Amiibo settings to the output info. The last write date is validated, defaulting it to 2000-1-1 if the validation fails.

GetModelInfo

Takes an input #DeviceHandle and a type-0x1A output buffer containing a #ModelInfo.

Requires the amiibo to be mounted with #MountType ROM.

Just converts data from the internal #Amiibo settings to the output info.

AttachActivateEvent

Takes an input #DeviceHandle, returns an output Event handle.

sdknso uses EventClearMode=1.

AttachDeactivateEvent

Takes an input #DeviceHandle, returns an output Event handle.

sdknso uses EventClearMode=1.

GetState

Returns an output u32 #State.

GetDeviceState

Takes an input #DeviceHandle, returns an output u32 #DeviceState.

The returned state is mapped from the internal state value through lookup tables. nfp services uses the same table, mifare uses a separate one, and the nfc services use another separate table.

GetNpadId

Takes an input #DeviceHandle, returns an output u32 NpadId.

GetApplicationAreaSize

Takes an input #DeviceHandle, returns an output u32 size.

Returns a hardcoded value of 0xD8.

AttachAvailabilityChangeEvent

No input, returns an output Event handle.

sdknso uses EventClearMode=1.

RecreateApplicationArea

Takes an input #DeviceHandle, an input u32 #Access ID and a type-0x5 input #Application area data buffer, no output.

Requires the amiibo to be mounted with #MountType RAM, and the application area to exist and be opened (see #OpenApplicationArea).

Performs the same logic as #SetApplicationArea but without checking the current access ID, just overwriting it.

Format

Takes an input #DeviceHandle, no output.

GetAdminInfo

Takes an input #DeviceHandle and a type-0x1A output buffer containing a #AdminInfo.

Requires the amiibo to be mounted with #MountType RAM.

Just converts data from the internal #Amiibo settings to the output info.

GetRegisterInfoPrivate

Takes an input #DeviceHandle and a type-0x1A output buffer containing a #RegisterInfoPrivate.

Requires the amiibo to be mounted with #MountType RAM.

Just converts data from the internal #Amiibo settings to the output info.

SetRegisterInfoPrivate

Takes an input #DeviceHandle and a type-0x19 input buffer containing a #RegisterInfoPrivate.

Requires the amiibo to be mounted with #MountType RAM.

Just converts data from the input info to the internal #Amiibo settings. No flushing / writing to the amiibo is done in this command.

DeleteRegisterInfo

Takes an input #DeviceHandle, no output.

Requires the amiibo to be mounted with #MountType RAM.

All #RegisterInfo-related fields in the internal #Amiibo settings are filled with random bytes, and the amiibo-initialized #Amiibo flag is removed. Finally, it calls internally the same function as #BreakTag with #BreakType 0.

DeleteApplicationArea

Takes an input #DeviceHandle, no output.

Requires the amiibo to be mounted with #MountType RAM.

All #Application area-related fields in the internal #Amiibo settings are filled with random bytes, and the corresponding #Amiibo flag is removed. Finally, it calls internally the same function as #BreakTag with #BreakType 0.

ExistsApplicationArea

Takes an input #DeviceHandle, returns an output u8/bool.

Requires the amiibo to be mounted with #MountType RAM.

Just returns whether the corresponding #Amiibo flag in the internal #Amiibo settings is set.

RequiredMcuVersionData

In sdknso, the global data containing the array data for this is "nn::nfc::client::RequiredMcuVersionData". The array entry is 0x20-bytes.

DeviceHandle

This is "nn::nfc::DeviceHandle". This is a 8-byte struct with 4-byte alignment.

NfcProtocol

This is s32 enum "nn::nfc::NfcProtocol". Value -1 can be used as a default.

TestWaveType

This is u32 enum "nn::nfc::TestWaveType".

MifareKey

This is a 0x10-byte struct.

Offset	Size	Description
0x0	0x1	MifareCommand
0x1	0x1	Unknown
0x2	0x6	Padding
0x8	0x6	Key data
0xE	0x2	Padding

MifareReadBlockData

This is "nn::nfc::MifareReadBlockData". This is a 0x18-byte struct.

Offset	Size	Description
0x0	0x10	Data
0x10	0x1	Block index
0x11	0x7	Padding

MifareReadBlockParameter

This is "nn::nfc::MifareReadBlockParameter". This is a 0x18-byte struct.

Offset	Size	Description
0x0	0x1	Block index
0x1	0x7	Padding
0x8	0x10	#MifareKey

MifareWriteBlockParameter

This is "nn::nfc::MifareWriteBlockParameter". This is a 0x28-byte struct.

Offset	Size	Description
0x0	0x10	Data
0x10	0x1	Block index
0x11	0x7	Padding
0x18	0x10	#MifareKey

State

Value	Description
0	NonInitialized
1	Initialized

DeviceState

Value	Description
0	Initialized
1	Searching for tag
2	Tag found
3	Tag removed
4	Tag mounted
5	Unavailable

State 5 is not used/exposed with all nfc commands :it is only used with nfp and mifare, see #GetDeviceState.

ModelType

Value	Description
0	Amiibo

MountTarget

Bit	Mask	Description
0	1	ROM
1	2	RAM

Date

This is "nn::nfp::Date":

Offset	Size	Description
0x0	0x2	Year
0x2	0x1	Month
0x3	0x1	Day

TagInfo

This is "nn::nfp::TagInfo". This is a 0x58-byte struct.

Offset	Size	Description
0x0	0xA	UUID
0xA	0x1	UUID length
0xB	0x15	Reserved
0x20	0x4	Protocol
0x24	0x4	Tag type
0x28	0x30	Reserved

RegisterInfo

This is "nn::nfp::RegisterInfo". This is a 0x100-byte struct.

Offset	Size	Description
0x0	0x58	Mii CharInfo (see mii services)
0x58	0x4	First write date (see #Date)
0x5C	0x29	Amiibo name (NUL-terminated UTF-8 string, converted from UTF-16)
0x85	0x1	Font region (masked bits from #Amiibo settings)
0x86	0x7A	Reserved

CommonInfo

This is ""nn::nfp::CommonInfo". This is a 0x40-byte struct.

Offset	Size	Description
0x0	0x4	Last write date (see #Date)
0x4	0x2	Write counter
0x6	0x1	Version
0x7	0x1	Padding
0x8	0x4	Application area size (hardcoded to be 0xD8, like in #GetApplicationAreaSize)
0xC	0x34	Reserved

ModelInfo

This is "nn::nfp::ModelInfo". This is a 0x40-byte struct.

Offset	Size	Description
0x0	0x3	Character ID (same as in #Amiibo ID)
0x3	0x1	Series ID (same as in #Amiibo ID)
0x4	0x2	Numbering ID (byte-swapped value in #Amiibo ID)
0x6	0x1	NFP type (same as in #Amiibo ID)
0x7	0x39	Reserved

Application area version

Note: unofficial name.

Value	Description
0xFF	Invalid (application area does not exist)
0	Nintendo 3DS
1	Nintendo Wii U
2	Nintendo 3DS (v2?)
3	Nintendo Switch

This value corresponds to hex-digit 7 of application IDs (3DS and Wii U title IDs have 0/1 at that position).

NFC computes it by taking (app_id_be >> 36) & 0xF.

Since Switch games do not follow this trend, the application ID in #Amiibo settings is stored as bswap64(application_id & 0xFFFFFFFF0FFFFFFF | 0x30000000) by #CreateApplicationArea, force-setting the hex-digit (presumably so that older consoles will recognize it).

AdminInfo

This is "nn::nfp::AdminInfo". This is a 0x40-byte struct.

Offset	Size	Description
0x0	0x8	Application ID of the game owning the application area (original value, see #Amiibo settings)
0x8	0x4	#Amiibo settings #Access ID (byte-swapped)
0xC	0x2	#Amiibo settings terminal ID CRC32 change counter
0xE	0x1	#Amiibo settings flags, bit-shifted: bit0=#Amiibo flag bit4 and so on
0xF	0x1	Unknown, hardcoded to 0x02 (tag type? amiibo version?)
0x10	0x1	#Application area version
0x11	0x7	Padding
0x18	0x28	Reserved

RegisterInfoPrivate

This is "nn::nfp::RegisterInfoPrivate". This is a 0x100-byte struct.

This is almost identical to #RegisterInfo, but containing mii data as a StoreData instead of a CharInfo and more reserved bytes.

Offset	Size	Description
0x0	0x44	Mii StoreData (see mii services)
0x44	0x4	First write date (see #Date)
0x48	0x29	Amiibo name (NUL-terminated UTF-8 string, converted from UTF-16)
0x71	0x1	Unknown
0x72	0x8E	Reserved

NfpData

This is "nn::nfp::NfpData". This is a 0x298-byte struct.

Offset	Size	Description
0x0	0x1	#Amiibo header magic (Always 0xA5)
0x1	0x1	Reserved
0x2	0x2	#Amiibo header write counter (byte-swapped)
0x4	0x4	#Amiibo settings terminal ID CRC32 (byte-swapped)
0x8	0x38	Reserved
0x40	0x40	Same contents as #CommonInfo
0x80	0x5C	#Amiibo settings mii Ver3StoreData, format used in 3DS (see https://www.3dbrew.org/wiki/Mii#Mii_format)
0xDC	0x2	Padding
0xDE	0x2	#Amiibo settings mii CRC16
0xE0	0x8	#Amiibo settings mii StoreDataExtension
0xE8	0x4	First write date (see #Date)
0xEC	0x16 (2*11)	Amiibo name (NUL-terminated UTF-16 string, byte-swapped from #Amiibo settings)
0x102	0x1	#Amiibo settings font region
0x103	0x1	Unknown, normally zero
0x104	0x4	#Amiibo settings mii CRC32 (byte-swapped)
0x108	0x14	#Amiibo settings unknown 0x14 bytes, normally zero
0x11c	0x64	Reserved
0x180	0x8	#Amiibo settings modified application ID (byte-swapped)
0x188	0x4	#Amiibo settings #Access ID (byte-swapped)
0x18c	0x2	#Amiibo settings terminal ID CRC32 change counter (byte-swapped)
0x18e	0x1	#Amiibo settings flags (bit-shifted, same as with #AdminInfo)
0x18f	0x1	Hardcoded to 0x02 (tag type? amiibo version?)
0x190	0x1	#Application area version
0x191	0x1	Application ID byte (see #Amiibo settings)
0x192	0x2E	Reserved
0x1c0	0xD8	#Application area

BreakType

This is "nn::nfp::BreakType". For more details, see #BreakTag.

Value	Description
0	Does no breaking, just flushes
1	Breaks the amiibo data SHA256 HMAC hash (see #Amiibo settings)
2	Breaks the amiibo header magic (see #Amiibo settings)

Value 0 is internally used in some places, aside for #BreakTag commands called externally.

WriteType

This is "nn::nfp::WriteType".

Value	Description
0	?
1	?

Application area

This is a 0xD8 byte region for per-game amiibo savedata. Only one game may use the application area.

Access ID

Access IDs are game-unique u32s used to access the amiibo application area.

Nintendo 3DS titles

For a list of Nintendo 3DS access IDs, see https://www.3dbrew.org/wiki/Amiibo#Games_using_Amiibo_AppData.

Nintendo Switch titles

Game	Access ID
Splatoon 2	0x10162B00
Shovel Knight: Treasure Trove	0x1016E100
The Legend of Zelda: Breath of the Wild	0x1019C800
Super Smash Bros. Ultimate	0x34F80200
Splatoon 3	0x38600500
The Legend of Zelda: Link's Awakening	0x3B440400

Backup data

Note: unofficial name.

Backup data is stored at data:/nfp_backup.dat. It has a total size of 0x1FBD20 bytes, and has the following format:

Offset	Size	Description
0x0	0x20	#Backup header
0x20	0x7D00 (0x20*1000)	#Backup entry header array
0x7D20	0x1F4000 (0x800*1000)	#Backup entry data array

There is a maximum of 1000 entries. This can be accessed by #ReadBackupData and #WriteBackupData commands.

Backup header

Note: unofficial name.

This is 0x20 bytes.

Offset	Size	Description
0x0	0x2	Unknown (zero?)
0x2	0x2	Entry count
0x4	0x2	Next free entry index
0x6	0x2	Unknown (zero?)
0x8	0x8	Unknown (zero?)
0x10	0x8	Unknown (zero?)
0x18	0x4	Unknown (zero?)
0x1C	0x4	CRC32 of the 0x1C bytes above

Backup entry header

Note: unofficial name.

This is 0x20 bytes.

Offset	Size	Description
0x0	0x1	UUID length
0x1	0xA	UUID
0xB	0x1	Padding
0xC	0x2	Packed date (when this entry was written)
0xE	0xE	Unknown (zero?)
0x1C	0x4	CRC32 of the 0x1C bytes above

Backup entry data

Note: unofficial name.

This is a 0x800 bytes (per-entry data).

NFC writes here the amiibo #Raw format, while the remaining 0x5E4 bytes are unused.

Amiibo

Raw format

Note: unofficial name.

This is 0x21C bytes.

This is the raw format initially read by NFC (as well as other amiibo dumping tools). It has the following format:

Offset	Size	Description
0x0	0x8	#NTAG215 data 1
0x8	0x8	#NTAG215 data 2
0x10	0x4	#Amiibo header
0x14	0x20	Encrypted section 1
0x34	0x20	Tag SHA256 HMAC hash: hash over plain tag data, see #Plain format
0x54	0x2C	#Amiibo ID entry
0x80	0x20	Data SHA256 HMAC hash: hash over plain data, see #Plain format
0xA0	0x114	Encrypted section 2
0x1B4	0x54	Encrypted section 3
0x208	0x4	#NTAG215 dynamic lock
0x20C	0x10	#NTAG215 config

All non-NTAG215 fields are specific of amiibo (located in the user memory pages of the tag). For more details on the page layout, see https://www.3dbrew.org/wiki/Amiibo.

The three encrypted sections combined in order (a total of 0x188 bytes) are decrypted to get the #Amiibo settings and the #Application area, in that order.

Plain format

This is 0x21C bytes.

Note: unofficial name.

This format contains reordered and decrypted amiibo data:

Offset	Size	Description
0x0	0x8	#NTAG215 data 2
0x8	0x20	Data SHA256 HMAC hash: hash over 0x1DF bytes, starting at offset 0x29 (#Amiibo header write counter) until #Amiibo ID entry
0x28	0x4	#Amiibo header
0x2C	0xB0	#Amiibo settings
0xDC	0xD8	#Application area
0x1B4	0x20	Tag SHA256 HMAC hash: hash over 0x34 bytes below (#NTAG215 data 1 and #Amiibo ID entry)
0x1D4	0x8	#NTAG215 data 1
0x1DC	0x2C	#Amiibo ID entry
0x208	0x4	#NTAG215 dynamic lock
0x20C	0x10	#NTAG215 config

When converting from #Raw format to #Plain format, both SHA256 HMAC hashes are tested, otherwise an error is returned internally.

NTAG215 data 1

This is 0x8 bytes.

Offset	Size	Description
0x0	0x8	NTAG215 9-byte manufacturer serial number (first 8 bytes)

NTAG215 data 2

This is 0x8 bytes.

Offset	Size	Description
0x0	0x1	NTAG215 9-byte manufacturer serial number (last byte)
0x1	0x1	Internal
0x2	0x2	Static lock bytes
0x4	0x4	Capability Container (CC) bytes

NFC checks that the static lock bytes match 0xE00F when converting from #Raw format to #Plain format.

NTAG215 dynamic lock

This is 0x4 bytes.

Offset	Size	Description
0x0	0x3	Dynamic lock bytes
0x3	0x1	RFUI

NFC checks the dynamic lock state when converting from #Raw format to #Plain format.

NTAG215 config

This is 0x10 bytes.

Offset	Size	Description
0x0	0x4	CFG0
0x4	0x4	CFG1
0x8	0x4	PWD
0xC	0x2	PACK
0xE	0x2	RFUI

NFC checks that the CFG0 and CFG1 match 0x4000000 and 0x5F when converting from #Raw format to #Plain format.

Amiibo header

This is 0x4 bytes.

Note: unofficial name.

Offset	Size	Description
0x0	0x1	Magic (0xA5)
0x1	0x2	Write counter (big-endian)
0x3	0x1	Version (0x00)

Amiibo ID

This is 0x8 bytes.

Offset	Size	Description
0x0	0x3	Character ID: bits0-9 = game ID, bits10-15 = character ID, bits16-23 = character variant
0x3	0x1	Series ID
0x4	0x2	Numbering ID (big-endian)
0x6	0x1	NFP type (figurine type)
0x7	0x1	Version? (0x02)

Amiibo ID entry

This is 0x2C bytes.

Note: unofficial name.

Offset	Size	Description
0x0	0x8	#Amiibo ID
0x8	0x4	Unknown
0xC	0x20	Unknown, maybe some hash

Amiibo flag

Bit	Mask	Description
4	0x10	Initialized in console settings
5	0x20	Application area exists (was created by some game)

Amiibo date

This is a date packed in 2 bytes:

Bits	Description
0-4	Day
5-8	Month
9-15	Year (relative to 2000)

Amiibo settings

This is 0xB0 bytes.

Note: unofficial name.

Offset	Size	Description
0x0	0x1	Font region (bits0-3) and #Amiibo flag (bits4-7)
0x1	0x2	Country code ID
0x2	0x2	Counter of the times the terminal ID CRC32 has changed (big-endian)
0x4	0x2	First write date (big-endian, see #Amiibo date for format in little-endian)
0x6	0x2	Last write date (big-endian, see #Amiibo date for format in little-endian)
0x8	0x4	CRC32 of NFC terminal ID (8 bytes, see below)
0xC	0x14 (2*10)	Amiibo name (UTF16-BE, not null-terminated)
0x20	0x5C	Mii in Ver3StoreData format, see https://www.3dbrew.org/wiki/Mii#Mii_format
0x7C	0x2	Unused/padding
0x7E	0x2	CRC16 of the mii data (0x60 bytes, last 4-bytes zeroed)
0x80	0x8	Application ID of the game owning the application area (big-endian) (modified, see #Application area version)
0x88	0x2	Write counter (big-endian)
0x8A	0x4	Access ID of the game owning the application area (big-endian)
0x8E	0x1	Application ID byte: (Application ID >> 28) & 0xFF
0x8F	0x1	Unknown1
0x90	0x8	Mii StoreDataExtension
0x98	0x14	Unknown2
0xAC	0x4	CRC32 of mii data (Ver3StoreData + pad + CRC16) + Application ID byte + Unknown1 + StoreDataExtension + Unknown2 (total of 0x7E bytes)

The country code ID is zeroed when calling #SetRegisterInfoPrivate.

The application ID byte contains the original application ID hex-digit (only used for Switcj games, see #Application area version), so it can be to restore the original value (which is needed for #GetAdminInfo).

The terminal ID is a randomly-generated 8-byte value that is re-generated every time #Initialize is called (thus every nfc/nfp/mifare session), and saved at data:/nfc_terminal_id.dat.

Play report

In nfp #Unmount and #Format commands, and if setting nfp!play_report is true, a play report is sent with the following fields: Uid, CharacterId, NumberingId, SeriesId, NfpType (from the current #Amiibo ID), ApplicationId, AccessInfo, DeviceType.

RomFS

[9.0.0+] The nfc-sysmodule RomFS contains:

 ST21NFCD_01_05_6811.bin

These are firmware files for the NFC IC inside Switch Lite units.