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

usb:ds

Used for Switch<>PC USB comms, aka Switch-as-device. This service is used during factory setup by manu.

This service session is used as an IPC domain by manu. All of these {get-session} commands also return an output u8 and the u32 <domainID>, for using those sessions as domains.

Cmd Name Notes
0 #BindComplex
1 #BindClientProcess
2 #GetDsInterface
3 #GetStateChangeEvent
4 No input. Returns an output u32.
5 #SetVidPidBcd

Initialization done by manu:

Configuration

The following is the default USB config strings, when the usbds service wasn't used. These can be set with #SetVidPidBcd. The default string for Product is loaded from settings config.

 Product: Nintendo Switch
 Manufacturer: Nintendo
 SerialNumber: SerialNumber

The following is the default lsusb -v {...} output when the usbds service wasn't used. The endpoints are configured using #GetDsEndpoint, the total number of endpoints is the number of open #IDsEndpoint sessions.

 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

BindComplex

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

BindClientProcess

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

GetDsInterface

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

GetStateChangeEvent

Returns an event handle for state changes.

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 bcdUSB
0x6 0x20 Manufacturer
0x26 0x20 Product
0x46 0x20 SerialNumber

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

IDsInterface

Cmd Name
0 #GetDsEndpoint
1 #GetSetupEvent
2
3 #EnableInterface
4 #DisableInterface
5
6
7 #GetCtrlInCompletionEvent
8
9 #GetCtrlOutCompletionEvent
10
11

GetDsEndpoint

Takes a type-5 buffer and returns 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.
  • Second endpoint: Same as above except byte2 is 0x00.

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

This structure matches libusb_endpoint_descriptor.

GetSetupEvent

Returns an event handle for interface setup changes.

EnableInterface

Takes no arguments. Enables the current interface.

DisableInterface

Takes no arguments. Disables the current interface.

GetCtrlInCompletionEvent

Returns an event handle for polling the completion of input control commands.

GetCtrlOutCompletionEvent

Returns an event handle for polling the completion of output control commands.

IDsEndpoint

Cmd Name
0 #PostBufferAsync
1
2
3 #GetReportData
4
5

PostBufferAsync

Takes an u32 (size) and an u64 (buffer).

GetReportData

Returns 0x84 bytes of report data from the endpoint.

usb:hs

General USB devices usage, used by hid-sysmodule and bsdsockets-sysmodule.

usb:pd

Only system-titles with access to this are PTM and AM.

usb:pd:c

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

usb:pm

Presumably Power Management, only system-title using this is PTM.