One symbol in USB-sysmodule is: "vtable for nn::usb::detail::UsbComplexTegra21x".

usb:ds

Pre-11.0.0 this was #IDsService.

Used for Switch<>PC USB comms, aka Switch-as-device. This seems to only be usable in handheld-mode with the Switch directly connected to a host via an USB cable, not(?) in docked-mode. This service is used during factory setup by manu. This is also used by capmtp.

This service session is used as an IPC domain by manu.

This service can be used by multiple processes at the same time, with separate interfaces. However, if one process does usbds shutdown, usbds will reset to defaults even if there's a process still using it.

Cmd	Name
0

Cmd0: No input, returns an #IDsService.

IDsService

This is "nn::usb::ds::IDsService".

Various cmds were updated/moved with [11.0.0+].

Cmd	Name
0	#BindDevice
1	#BindClientProcess
2	#GetDsInterface
3	#GetStateChangeEvent
4	#GetState
[2.0.0-4.1.0] 5	#SetVidPidBcd
[5.0.0+] 5	ClearDeviceData
6	[5.0.0+] AddUsbStringDescriptor
7	[5.0.0+] DeleteUsbStringDescriptor
8	[5.0.0+] SetUsbDeviceDescriptor
9	[5.0.0+] SetBinaryObjectStore
10	[5.0.0+] Enable
11	[5.0.0+] Disable
12	[8.0.0+]

Initialization done by manu:

Initial service init:
- Get service/etc.
- Uses #BindDevice.
- Uses #BindClientProcess.
- Uses #GetStateChangeEvent.
- Uses #SetVidPidBcd.
Interface init:
- Uses #GetDsInterface, then uses commands from that with the rest of the following.
- Uses #GetSetupEvent.
- Uses #GetCtrlInCompletionEvent.
- Uses #GetCtrlOutCompletionEvent.
Initializes two endpoints via using #GetDsEndpoint twice.

Configuration

The following is the default USB config strings, while the usbds service isn't being used. All of the below configuration will reset to the defaults when all usbds-related sessions are closed. These can be set with #SetVidPidBcd. The default string for Product is loaded from settings config. The default is referred to by usb-sysmodule as "Dummy".

 Product: Nintendo Switch
 Manufacturer: Nintendo
 SerialNumber: SerialNumber

The following is the default lsusb -v {...} output when the usbds service wasn't used.

pre-5.0.0: The endpoints are configured using #GetDsEndpoint, the total number of endpoints is the number of open #IDsEndpoint sessions. bInterfaceNumber is {0-based index for the enabled #IDsInterface session.} Some of the interface fields are configured using #GetDsInterface.

When usbds is in use where #SetVidPidBcd wasn't used, the VID/PID is 057e:3000.

 Bus 003 Device 006: ID 057e:2000 Nintendo Co., Ltd 
 Couldn't open device, some information will be missing
 Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               2.00
   bDeviceClass            0 (Defined at Interface level)
   bDeviceSubClass         0 
   bDeviceProtocol         0 
   bMaxPacketSize0        64
   idVendor           0x057e Nintendo Co., Ltd
   idProduct          0x2000 
   bcdDevice            1.00
   iManufacturer           1 
   iProduct                2 
   iSerial                 3 
   bNumConfigurations      1
   Configuration Descriptor:
     bLength                 9
     bDescriptorType         2
     wTotalLength           34
     bNumInterfaces          1
     bConfigurationValue     1
     iConfiguration          0 
     bmAttributes         0xc0
       Self Powered
     MaxPower              {...}
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       0
       bNumEndpoints           1
       bInterfaceClass         3 Human Interface Device
       bInterfaceSubClass      0 No Subclass
       bInterfaceProtocol      0 None
       iInterface              0 
         HID Device Descriptor:
           bLength                 9
           bDescriptorType        33
           bcdHID               2.00
           bCountryCode            0 Not supported
           bNumDescriptors         1
           bDescriptorType        34 Report
           wDescriptorLength      26
          Report Descriptors: 
            ** UNAVAILABLE **
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            3
           Transfer Type            Interrupt
           Synch Type               None
           Usage Type               Data
         wMaxPacketSize     0x0001  1x 1 bytes
         bInterval              16

BindDevice

Takes an u32 (complexId). Manu sends 0x02.

Binding more than once with the current session is not allowed. Once this command is used, the USB device will not be listed with lsusb until #EnableInterface is used.

Returns a not-found error when complexId isn't 0x02, for values 0x0-0x4 at least.

BindClientProcess

Takes 1 copy-handle for the current process (0xFFFF8001).

GetDsInterface

Takes 2 type-5 buffers and returns an output u8 and an #IDsInterface. Manu sends a 0x09-byte descriptor (e.g.: 0x09, 0x04, 0x04, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0x00) in the first buffer and a string ("usb") in the second buffer.

When the strlen output for the second buffer is >=0x40, size 0x40 is used instead for copying the string. This is the interface name, it's not sent over USB.

Returns an error when #BindDevice wasn't used.

Up to 4 interfaces can be used+enabled.

Structure of the first buffer(this is the same as libusb__interface__descriptor):

Offset	Size	Description
0x0	0x1	bLength. Must match 0x9.
0x1	0x1	bDescriptorType. Must match 0x4.
0x2	0x1	bInterfaceNumber. When 0x4, the bInterfaceNumber is automatically allocated(error will be thrown if no space). Otherwise, it's used directly and must be <=3.
0x3	0x1	bAlternateSetting. Must match 0x0.
0x4	0x1	bNumEndpoints. Ignored.
0x5	0x1	bInterfaceClass
0x6	0x1	bInterfaceSubClass
0x7	0x1	bInterfaceProtocol
0x8	0x1	iInterface. Ignored.

Only the first 0x9-bytes are used.

GetStateChangeEvent

Returns an event handle for when the state returned by #GetState changes. Signalled when Switch<->host USB comms change between started/stopped. USB cable connected/disconnected while at least 1 interface was enabled, or interface enabled/disabled while the USB cable was connected which then caused USB-comms state to change.

GetState

No input. Returns an output u32. Returns an error when #BindDevice wasn't used.

Returns the current state. Values:

0: Initial state.
6: Device init starting.
3: {Initialization}, previous state is 6.
4: {Initialization}, previous state is 3.
5: Initialization done, data-transfer is now available.

SetVidPidBcd

Takes a type-5 buffer with 0x66 bytes of USB descriptor data (see manu).

Offset	Size	Description
0x0	0x2	VID (idVendor)
0x2	0x2	PID (idProduct)
0x4	0x2	bcdDevice
0x6	0x20	Manufacturer
0x26	0x20	Product
0x46	0x20	SerialNumber

The last 3 blocks are ASCII strings. The data following each string is all-zero, for padding to size 0x20.

IDsInterface

This is "nn::usb::ds::IDsInterface".

Various cmds were updated/moved with [11.0.0+].

Cmd	Name	Notes
0	#GetDsEndpoint
1	#GetSetupEvent
2		Takes a type-0x6 output buffer, no other output. Memcpys data to outbuf with outsize, uses size 0x8 if outsize is too large.
3	#EnableInterface
4	#DisableInterface
5	#CtrlInPostBufferAsync
6	#CtrlOutPostBufferAsync
7	#GetCtrlInCompletionEvent
8	#GetCtrlInReportData
9	#GetCtrlOutCompletionEvent
10	#GetCtrlOutReportData
11	#StallCtrl
12	[5.0.0+] AppendConfigurationData

Commands cmd2, #CtrlInPostBufferAsync, #CtrlOutPostBufferAsync, and #StallCtrl, will throw an error if the interface is not enabled. #GetDsEndpoint will throw an error if the interface is enabled.

GetDsEndpoint

Takes a type-5 buffer and returns an output u8 and an #IDsEndpoint. Manu uses this twice for getting two endpoint sessions, with the following 0x7-byte buffer data:

First endpoint: 0x07, 0x05, 0x80, 0x02, 0x00, 0x02, 0x00
- bLength=0x7
- bDescriptorType=LIBUSB_DT_ENDPOINT
- bEndpointAddress=LIBUSB_ENDPOINT_IN
- bmAttributes=LIBUSB_TRANSFER_TYPE_BULK
- wMaxPacketSize=0x200
- bInterval=0
Second endpoint: Same as above except byte2 is 0x00(bEndpointAddress=LIBUSB_ENDPOINT_OUT).

Each field is an u8, except for offset 0x4-0x5 which is an u16.

This structure matches libusb_endpoint_descriptor, with audio-only-devices fields bRefresh and bSynchAddress removed.

The buffer size must be >=0x7. Only the first 0x7-bytes from the buffer are used.

Byte0(bLength) must match 0x7.
Byte1(bDescriptorType) must match 0x5.
Byte2(bEndpointAddress) is only compared with 0x80 to determine whether to use an input or output endpoint, the actual endpoint-number is allocated automatically by checking state. Hence, all input endpoints must use bEndpointAddress==0x80. Up to endpoint-number 0xF can be allocated for each endpoint-direction, for a total of 16 endpoints including control, and 15 for non-control endpoints(#IDsEndpoint sessions for each direction). This matches the Tegra maximum.

From the Tegra datasheet: "The maximum packet size supported on any endpoint is 1024 bytes in high-speed mode, for both device and host modes."

GetSetupEvent

Returns an event handle. Unknown what triggers signalling, not signalled during interface-enable / device<>host USB-comms init.

EnableInterface

Takes no arguments. Enables the current interface.

Only one interface can be enabled at a time per bInterfaceNumber. When bInterfaceNumber is auto-allocate(0x4) for #GetDsEndpoint this isn't an issue since the final bInterfaceNumber will be unique.

Once enabled, the device/interface can then actually be used over USB.

DisableInterface

Takes no arguments. Disables the current interface.

CtrlInPostBufferAsync

Same as #PostBufferAsync(with same input/output), except this uses control input endpoint 0x80.

CtrlOutPostBufferAsync

Same as #PostBufferAsync(with same input/output), except this uses control output endpoint 0x00.

GetCtrlInCompletionEvent

Returns an event handle for polling the completion of input control commands. Same as #GetCompletionEvent, except this uses control input endpoint 0x80.

GetCtrlInReportData

Same as #GetReportData(with same input/output), except this uses control input endpoint 0x80.

GetCtrlOutCompletionEvent

Returns an event handle for polling the completion of output control commands. Same as #GetCompletionEvent, except this uses control output endpoint 0x00.

GetCtrlOutReportData

Same as #GetReportData(with same input/output), except this uses control output endpoint 0x00.

StallCtrl

No input/output.

Calls a function with both control endpoints(0x80 and 0x00) with the same function. From strings: "m_pProtocol->Stall(0x80)" "m_pProtocol->Stall(0x00)".

IDsEndpoint

This is "nn::usb::ds::IDsEndpoint".

Cmd	Name	Notes
0	#PostBufferAsync
1		No input/output.
2	#GetCompletionEvent
3	#GetReportData
4	#Stall
5		Takes an input u8, no output.
6	[7.0.0+]	No input, returns an output u8.
7	[7.0.0+]	No input, returns an output handle.
8	[11.0.0+]	Takes an input u64 and a handle, no output. Stubbed, just returns an error.
9	[11.0.0+]	Takes an input u32 size, an u64 offset, returns an u32 urbId. Stubbed, just returns an error.

[11.0.0+] The official sw wrapper for PostBufferAsync can optionally use cmd9 instead, if an object state flag is set. offset=input_addr-object_addr_field, this will Abort if offset is >= object_size_field.

PostBufferAsync

Takes an u32 (size) and an u64 (buffer). Returns an output u32 (urbId). The output urbId can then be used while parsing the output of #GetReportData, after waiting for the CompletionEvent to be signalled.

The buffer address must be 0x1000-byte aligned. The input size doesn't matter. It helps to use svcSetMemoryAttribute to turn off caching on the buffer.

Used for data-transfer with input/output endpoints.

The user-process must flush dcache for the buffer before using this command.

When sending data where size is larger than wMaxPacketSize, it will automatically send multiple USB packets where last packet size = {remaining size}. Every {wMaxPacketSize}-bytes is a different packet. This only occurs in some cases. When size is ~0x1000000(exact size unknown), Switch-side silently hangs, while host-side will timeout(no traffic on USB bus indicating failure).

For receiving data, if size is less than {actual received USB packet size} the rest of the packet will be discarded. Later PostBufferAsync cmd(s) will only return data from new packets, not the remainder of the earlier packet(s).

GetCompletionEvent

No input. Returns an output event handle for polling the completion of #PostBufferAsync, even when it finished via #Stall.

GetReportData

No input. Returns 0x84 bytes of report data from the endpoint. Seems to be eventually loaded from state, since this doesn't trigger any USB bus activity. All-zero before PostBufferAsync was used at least once.

Offset	Size	Description
0x0	0x10*0x8(0x80)	0x8 entries 0x10-bytes each for each report.
0x80	0x4	u32 report count

Entry data:

Offset	Size	Description
0x0	0x4	u32 id (urbId from post-buffer commands)
0x4	0x4	u32 requestedSize
0x8	0x4	u32 transferredSize
0xC	0x4	u32 urb status, converted to error-codes. 0x3 = success, 0x4 = 0x828c, 0x5 = 0x748c. All other values are invalid.

Stall

No input/output.

Calls the same function used by #StallCtrl, except this uses the endpoint associated with the current session.

Stops in-progress data-transfer done by #PostBufferAsync.

usb:hs, usb:hs:a

This is "nn::usb::hs::IClientRootSession".

[7.0.0+] usb:hs:a opens an nn::usb::hs::IClientRootSession, but sets an "isSystemClient" field in the object (and in interfaces/eps opened by the session) to false.

Cmd	Name	Notes
[2.0.0+] 0	#BindClientProcess
1 ([1.0.0] 0)	#QueryAllInterfaces
2 ([1.0.0] 1)	#QueryAvailableInterfaces
3 ([1.0.0] 2)	#QueryAcquiredInterfaces
4 ([1.0.0] 3)	#CreateInterfaceAvailableEvent
5 ([1.0.0] 4)	#DestroyInterfaceAvailableEvent
6 ([1.0.0] 5)	#GetInterfaceStateChangeEvent
7 ([1.0.0] 6)	#AcquireUsbIf
8 ([1.0.0] 7)	[6.0.0+] ([1.0.0] #GetDescriptorString)
[1.0.0] 8		Takes an input u32, no output. Stubbed, just returns 0.

General USB devices usage, used by hid, bsdsockets, and [5.1.0+] audio.

Get-service-handle will fail if the current process is already using usb:ds, however it's successful if it's done separately from the process using usb:ds.

BindClientProcess

Takes 1 copy-handle for the current process (0xFFFF8001).

QueryAllInterfaces

Takes an #UsbHsInterfaceFilter and a type-0x6 output buffer, returns an output s32 total_entries.

The output buffer contains an array of #UsbHsInterface. This returns the same interfaces as #QueryAvailableInterfaces, followed by the interfaces also returned by #QueryAcquiredInterfaces. Except for the ID field in #UsbHsInterface, which is set to -1.

QueryAvailableInterfaces

Takes an #UsbHsInterfaceFilter and a type-0x6 output buffer, returns an output s32 total_entries.

The output buffer contains an array of #UsbHsInterface. This only returns interfaces which are not acquired by any process.

QueryAcquiredInterfaces

Takes a type-0x6 output buffer and returns an output s32 total_entries.

The output buffer contains an array of #UsbHsInterface, for each interface which was acquired with #AcquireUsbIf.

CreateInterfaceAvailableEvent

Takes an input u8 and an #UsbHsInterfaceFilter, and returns an output handle. The input value must be 0..2. This is used as an index in a table.

The struct is located at +2 from the u8 in IPC rawdata.

When signaled, this indicates that the user-process should use #QueryAvailableInterfaces and #AcquireUsbIf with the output interfaces (and the rest of interface setup).

DestroyInterfaceAvailableEvent

Takes an input u8, no output. The input value must be 0..2.

Clears state associated with the input index. This is the same state setup by #CreateInterfaceAvailableEvent.

GetInterfaceStateChangeEvent

No input, returns an output event handle with autoclear disabled.

When signaled, this indicates that the user-process should use #QueryAcquiredInterfaces and cleanup state for interfaces which were already initialized and don't have any matching ID in #UsbHsInterface +0x0. When total_entries is less than 1, this indicates that cleanup should be done for all currently open interfaces.

AcquireUsbIf

Takes an input u32 and a type-0x6 output buffer, returns an #IClientIfSession. On [3.0.0+] this takes an additional type-0x6 output buffer, before the original buffer. On [3.0.0+] the first buffer is 0x70-bytes, while the second one is 0x1B8. The user-process has the second buffer address immediately after the first one, which allows getting a complete #UsbHsInterface.

The input u32 is from the u32 at entry+0 from the associated #QueryAvailableInterfaces output entry. User-processes use size 0x1B8 for the first output buffer. The first output buffer contains the first 0x1B8-bytes from #UsbHsInterface.

This returns an error if the interface was already acquired by another process.

GetDescriptorString

Takes a type-0x6 output buffer, an input u8, an input u8 bool, and an u32. Returns an output u32.

The u32 is located at +4 from the first u8 in the IPC rawdata.

Gets a string from a string descriptor.

The UTF-16 string from descriptor+2 is copied to descriptor/outbuf +0, where each character is transferred using u8 not u16.

Official sw doesn't use this, #SubmitControlInRequest is used instead.

IClientIfSession

This is "nn::usb::hs::IClientIfSession".

Cmd	Name	Notes
0		No input, returns an output handle.
1	#SetInterface
2	#GetInterface
3	#GetAlternateInterface
4 [1.0.0] 5)	#GetCurrentFrame
[2.0.0+] 5	#CtrlXferAsync
6	([1.0.0] #SubmitControlInRequest)	No input, returns an output handle. Signaled when #CtrlXferAsync finishes.
7	#GetCtrlXferReport ([1.0.0] #SubmitControlOutRequest)
8	#ResetDevice
9 ([1.0.0] 4)	#OpenUsbEp

Official sw uses autoclear=false for the above events.

Immediately after opening the session, official sw uses cmd0 and cmd6.

SetInterface

Takes an input u8 and a type-0x6 output buffer, no output. The output buffer contains the first 0x1B8-bytes from #UsbHsInterface.

GetInterface

Takes a type-0x6 output buffer, no output. The output buffer contains the first 0x1B8-bytes from #UsbHsInterface.

GetAlternateInterface

Takes an input u8 and a type-0x6 output buffer, no output. The output buffer contains the first 0x1B8-bytes from #UsbHsInterface. The buffer size must match 0x1B8.

GetCurrentFrame

No input, returns an output u32.

On 1.0.0 this stubbed: this returns 0 with output u32 = hard-coded 0.

CtrlXferAsync

Takes 2 input u8s (bmRequestType and bRequest), 3 input u16s (wValue, wIndex, and wLength), and an input u64 buffer, no output.

GetCtrlXferReport

Takes a type-0x6 output buffer, no output. The output buffer contains a #XferReport.

SubmitControlInRequest

Takes a type-0x6 output buffer, 2 input u8s (bRequest and bRequestType), 3 input u16s (wValue, wIndex, and wLength), and an input u32 timeoutInMs. Returns an output u32 for the actual transferred size.

Official user-processes uses a buffer where the buffer address/size is page-aligned, where wLength is the original size before alignment. The user-process also flushes dcache for this buffer using wLength, before/after using this command. Official sw passes value 0 for timeoutInMs.

SubmitControlOutRequest

Takes a type-0x5 input buffer, 2 input u8s (bRequest and bRequestType), 3 input u16s (wValue, wIndex, and wLength), and an input u32 timeoutInMs. Returns an output u32 for the actual transferred size.

Official user-processes uses a buffer where the buffer address/size is page-aligned, where wLength is the original size before alignment. The user-process also flushes dcache for this buffer using wLength, before using this command. Official sw passes value 0 for timeoutInMs.

ResetDevice

No input/output.

Resets the device: has the same affect as unplugging the device and plugging it back in.

OpenUsbEp

Takes an input u16 and 4 input u32s, returns a 0x7-byte output struct and an #IClientEpSession.

The u16 is maxUrbCount. The u32s are: epType, epNumber, epDirection, and maxXferSize.

The user-process loads the input params from the endpoint descriptor. HID-sysmodule sets maxXferSize to wMaxPacketSize from the endpoint descriptor. However, other sysmodules pass hard-coded values for maxXferSize.

HID-sysmodule passes hard-coded value 0x1 for maxUrbCount, for bsd-sysmodule this is 0x2. For audio-sysmodule, this is 0x3 or 0x6.

epType is libusb_transfer_type+1. epNumber is bEndpointAddress & LIBUSB_ENDPOINT_ADDRESS_MASK. epDirection is 0x1 for LIBUSB_ENDPOINT_OUT, and 0x2 for LIBUSB_ENDPOINT_IN.

epType, epNumber, and epDirection must all match USB-sysmodule state for the associated endpoint. maxUrbCount must be <0x11. maxXferSize must be <=0xFF0000. maxUrbCount*maxXferSize must be non-zero.

IClientEpSession

This is "nn::usb::hs::IClientEpSession".

Cmd	Name	Notes
0	#Open ([1.0.0] #SubmitOutRequest)
1	#Close ([1.0.0] #SubmitInRequest)
2		No input, returns an output handle. Signaled when #PostBufferAsync finishes. ([1.0.0] #Open)
3	#Populate ([1.0.0] #Close)
[2.0.0+] 4	#PostBufferAsync
[2.0.0+] 5	#GetXferReport
[2.0.0+] 6	#PostBufferMultiAsync
[4.0.0+] 7		Takes a total of 0x10-bytes of input, no output.
[4.0.0+] 8		Takes a total of 0x4-bytes of input and an input handle, no output.

Official sw uses autoclear=false for the above event.

Immediately after opening the endpoint session, official sw uses #Populate and cmd2.

SubmitOutRequest

Takes an type-0x5 input buffer, an u32 size, and an u32 unk. Returns an output u32 for the actual transferred size.

Official user-processes uses a buffer where the buffer address/size is page-aligned, where size is the original size before alignment. The user-process also flushes dcache for this buffer using size, before using this command. Official sw passes value 0 for unk.

SubmitInRequest

Takes an type-0x6 output buffer, an u32 size, and an u32 unk. Returns an output u32 for the actual transferred size.

Official user-processes uses a buffer where the buffer address/size is page-aligned, where size is the original size before alignment. The user-process also flushes dcache for this buffer using size, before/after using this command. Official sw passes value 0 for unk.

Open

No input/output.

This is similar to #OpenUsbEp with the params being loaded from state instead.

This is likely intended for re-opening after #Close was used, but this is not known to be used by any official user-processes.

Close

No input/output.

Used by official sw prior to closing the endpoint session.

Populate

No input/output.

Used after opening the endpoint session (see above).

PostBufferAsync

Takes an input u32 size, an input u64 buffer, and an input u64 unk, returns an output u32 xferId.

HID-sysmodule passes value 0 for the last u64.

Starts a data transfer with a single urb.

GetXferReport

Takes an input u32 and a type-0x6 ([3.0.0+] type-0x22) output buffer, returns an output u32 count.

The input u32 specifies the total number of entries to read, this must fit within the specified buffer size. The output u32 is the total actual output entries.

The buffer contains an array of #XferReport.

PostBufferMultiAsync

Unofficial name.

Takes 3 input u32s (urbCount, unk1, and unk2), an input u64 buffer and u64 unk, and a type-0x5 ([3.0.0+] type-0x21) input buffer, returns an output u32 xferId.

Where unk is the same as #PostBufferAsync.

This uses the same func internally as #PostBufferAsync except multiple urbs are specified by the user: the input buffer contains an array of u32s for the size of each urb, where urbCount is the total number of entries in this array. With #PostBufferAsync the last 2 params passed to the internal func are hard-coded to 0, while with this command it's unk1 and unk2.

UsbHsInterface

Offset	Size	Description
0x0	0x4	ID value passed to other cmds. This is -1 with #QueryAllInterfaces output, hence this field is unused with that cmd.
0x4	0x4	deviceID
0x8	0x4	?
0xC	0x9	usb_interface_descriptor
0x15	0x7	Padding
0x1C	0x69	OUTPUT usb_endpoint_descriptors, 15 max.
0x85	0x7	Padding
0x8C	0x69	INPUT usb_endpoint_descriptors, 15 max.
0xF5	0x6	Padding
0xFB	0x5A	OUTPUT usb_ss_endpoint_companion_descriptors(?), 15 max.
0x155	0x6	Padding
0x15B	0x5A	INPUT usb_ss_endpoint_companion_descriptors(?), 15 max.
0x1B5	0x3	Padding
0x1B8	0x40	"HsDevice-/L<unk0>/P<portnum>/A<unk1>" string (this is "FsDevice..." for the Dock USB 3.0 bus).
0x1F8	0x4	busID
0x1FC	0x4	deviceID
0x200	0x12+0x9(0x1B)	usb_device_descriptor, then usb_config_descriptor immediately afterwards.
0x21B	0x5	Padding
0x220	0x8	Unknown u64 timestamp for when the device was inserted?

This is a 0x228-byte struct (unofficial name).

The INPUT/OUTPUT endpoint descriptors (usb_endpoint_descriptors/usb_ss_endpoint_companion_descriptors) were swapped with [8.0.0+] (above layout has the pre-8.0.0 layout), however the sysmodule code which writes this output struct was basically unchanged.

UsbHsInterfaceFilter

Offset	Size	Description
0x0	0x2	Flags
0x2	0x2	idVendor
0x4	0x2	idProduct
0x6	0x2	bcdDevice_Min
0x8	0x2	bcdDevice_Max
0xA	0x1	bDeviceClass
0xB	0x1	bDeviceSubClass
0xC	0x1	bDeviceProtocol
0xD	0x1	bInterfaceClass
0xE	0x1	bInterfaceSubClass
0xF	0x1	bInterfaceProtocol

This is a 0x10-byte struct (unofficial name).

This is used to filter #UsbHsInterface, the query commands will only return the interface when these checks pass. This is also used for events with #CreateInterfaceAvailableEvent. When a bit in Flags is set, the associated descriptor field and the field in this struct are compared, on mismatch the interface will be filtered out. Passing Flags=0 is equivalent to disabling filtering since none of these checks will run.

[7.0.0+]: The filter struct has to be unique, it can't match any existing filter structs used by #CreateInterfaceAvailableEvent (including other processes). Hence, Flags has to be non-zero. When initialized with usb:hs:a and VID and/or PID filtering is enabled, the VID/PID will be checked #HidGamepad, with an error being throw if a matching device is found with quirk "ApplicationBlacklist" (usb:qdb cmd1 is used internally for this with bcdDevice=0).

Flags bits 0..6 use usb_device_descriptor, while 7..9 use usb_interface_descriptor. Support for bits 2..6 and the associated fields was added with [6.0.0+].

Flags bits:

0: idVendor
1: idProduct
2: bcdDevice (Descriptor value must be >= struct bcdDevice_Min)
3: bcdDevice (Descriptor value must be <= struct bcdDevice_Max)
4: bDeviceClass
5: bDeviceSubClass
6: bDeviceProtocol
7: bInterfaceClass
8: bInterfaceSubClass
9: bInterfaceProtocol

HID-sysmodule uses the following for the input struct: 80 00 00 00 00 00 00 00 00 00 00 00 00 03 00 00

XferReport

Offset	Size	Description
0x0	0x4	xferId (Only set for #GetXferReport)
0x4	0x4	Result
0x8	0x4	requestedSize
0xC	0x4	transferredSize
0x10	0x8?	?

This is a 0x18-byte struct.

Official sw only uses the Result/size fields.

usb:pd

This is "nn::usb::pd::detail::IPdManager".

Cmd	Name
0	GetPdSession

Only system-titles with access to this are ptm and am.

IPdSession

This is "nn::usb::pd::detail::IPdSession".

Cmd	Name
0	BindNoticeEvent
1	UnbindNoticeEvent
2	GetStatus
3	GetNotice
4	EnablePowerRequestNotice
5	DisablePowerRequestNotice
6	ReplyPowerRequest

usb:pd:c

This is "nn::usb::pd::detail::IPdCradleManager".

Cmd	Name	Notes
0	GetPdCradleSession	Returns a session handle for the below.

USB-sysmodule symbols for this refer to "Cradle", which is the Dock.

IPdCradleSession

This is "nn::usb::pd::detail::IPdCradleSession".

Cmd	Name	Notes
0	VdmUserWrite	Input { u32 value; u32 VdmUserId; }. Output {}. If Cradle or RelayBox is connected, issues given VDM with value.
1	VdmUserRead	Input { u32 VdmUserId; }. Output { u32 value; }. If Cradle or RelayBox is connected, returns u32 response from issuing given VDM.
2	Vdm20Init	No input/output. If Cradle or RelayBox is connected, caches result of VDM 0x20.
3	[2.0.0+] GetFwType	No input. Returns an output u16.
4	[2.0.0+] GetFwRevision	No input. Returns an output u16.
5	[2.0.0+] GetManufacturerId	No input. Returns an output u16.
6	[2.0.0+] GetDeviceId	No input. Returns an output u16.
7	[3.0.0+]
8	[3.0.0+]

Note: The VdmUserId given to VdmUserRead/VdmUserWrite is translated from the given (enum) value to the actual cmd to send.

usb:pd:m

This is "nn::usb::pd::detail::IPdManufactureManager". This is only available on 1.0.0.

Cmd	Name	Notes
0		No input, returns an #IPdManufactureSession.

IPdManufactureSession

This is "nn::usb::pd::detail::IPdManufactureSession".

These commands just load the u16 from global state.

Cmd	Name	Notes
0		No input, returns an output u16.
1		No input, returns an output u16.
2		No input, returns an output u16.
3		No input, returns an output u16.

usb:pm

This is "nn::usb::pm::IPmService".

Cmd	Name
0
1
2
3
4
5

USB Port Manager, only system-title using this is ptm.

usb:qdb

Added with 7.0.0.

Cmd	Name
0
1

Cmd0

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

This loads data for #HidGamepad with the input .json.

Cmd1

Takes 6-bytes of input (u16s vid, pid, bcdDevice) and a type-0x5 input buffer, returns an output u8 bool indicating success.

Locates an entry in the #HidGamepad state with the input u16s, and checks for a quirks array entry where name matches the input buffer string. Returns 1 when found, 0 otherwise.

usb:obsv

Added with [8.0.0+].

Cmd	Name
0
1

HidGamepad

With [7.0.0+] usb-sysmodule now has .json data embedded in the codebin.

This contains a list of USB devices' VID/PID, with the following structure:

 [
     {
         "vid" : "<VID>",
         "pid" : "<PID>",
         "quirks" : [
             {
                 "name" : "<string>" //The .json has the following for <string> for various devices: "HidGamepadWhitelist", "ApplicationBlacklist", and "NoClearHaltOnEpInit".
             }
             //There can be multiple entries here.
         ]
     },
     <more entries>
 ]

USB services

usb:ds

IDsService

Configuration

BindDevice

BindClientProcess

GetDsInterface

GetStateChangeEvent

GetState

SetVidPidBcd

IDsInterface

GetDsEndpoint

GetSetupEvent

EnableInterface

DisableInterface

CtrlInPostBufferAsync

CtrlOutPostBufferAsync

GetCtrlInCompletionEvent

GetCtrlInReportData

GetCtrlOutCompletionEvent

GetCtrlOutReportData

StallCtrl

IDsEndpoint

PostBufferAsync

GetCompletionEvent

GetReportData

Stall

usb:hs, usb:hs:a

BindClientProcess

QueryAllInterfaces

QueryAvailableInterfaces

QueryAcquiredInterfaces

CreateInterfaceAvailableEvent

DestroyInterfaceAvailableEvent

GetInterfaceStateChangeEvent

AcquireUsbIf

GetDescriptorString

IClientIfSession

SetInterface

GetInterface

GetAlternateInterface

GetCurrentFrame

CtrlXferAsync

GetCtrlXferReport

SubmitControlInRequest

SubmitControlOutRequest

ResetDevice

OpenUsbEp

IClientEpSession

SubmitOutRequest

SubmitInRequest

Open

Close

Populate

PostBufferAsync

GetXferReport

PostBufferMultiAsync

UsbHsInterface

UsbHsInterfaceFilter

XferReport

usb:pd

IPdSession

usb:pd:c

IPdCradleSession

usb:pd:m

IPdManufactureSession

usb:pm

usb:qdb

Cmd0

Cmd1

usb:obsv

HidGamepad