The !usbkd._ehcitd command displays information from a usbehci!_TRANSFER_CONTEXT structure. Use this command to display information about asynchronous endpoints (that is, control and bulk endpoints).

!usbkd._ehcitd StructAddr


Address of a usbehci!_TRANSFER_CONTEXT structure.




This example shows one way to get the address of a usbehci!_TRANSFER_CONTEXT structure. Use !_ehciep to display information about an endpoint.

0: kd> !_ehciep ffffe000001ab618
dt usbehci!_ENDPOINT_DATA ffffe000001ab618
Flags: 0x00000000
dt usbehci!_HCD_QUEUEHEAD_DESCRIPTOR ffffd00021e65080
*HwQH ffffd00021e65080
     HwQH.HLink dea2e002
     HwQH.EpChars 02002201
         DeviceAddress: 0x1
         IBit: 0x0
         EndpointNumber: 0x2
slot[0] dt usbehci!_ENDPOINT_SLOT ffffe000001ab798 - slot_NotBusy
     dt usbehci!_HCD_TRANSFER_DESCRIPTOR ffffd00021e65100

In the preceding output, ffffd00021e65100 is the address of a usbehci!_TRANSFER_CONTEXT structure. Pass this address to !_ehcitd.

0: kd> !_ehcitd ffffd00021e65100
*USBEHCI TD 21e65100
Sig 20td
     Next_qTD: d83cc200
     AltNext_qTD: d83cc180
     Token: 0x00000c00
         PingState: 0x0
         SplitXstate: 0x0
         MissedMicroFrame: 0x0
         XactErr: 0x0
         BabbleDetected: 0x0
         DataBufferError: 0x0
         Halted: 0x0
         Active: 0x0
         Pid: 0x0 - HcTOK_Out
         ErrorCounter: 0x3
         C_Page: 0x0
         InterruptOnComplete: 0x0
         BytesToTransfer: 0x0
         DataToggle: 0x0
     BufferPage[0]: 0x 0bad0-000  0bad0000  BufferPage64[0]: 00000000
     BufferPage[1]: 0x 0bad0-000  0bad0000  BufferPage64[1]: 00000000
     BufferPage[2]: 0x 0bad0-000  0bad0000  BufferPage64[2]: 00000000
     BufferPage[3]: 0x 0bad0-000  0bad0000  BufferPage64[3]: 00000000
     BufferPage[4]: 0x 0bad0-000  0bad0000  BufferPage64[4]: 00000000
Packet:00 52 e6 21 00 d0 ff ff 
PhysicalAddress: d83cc100
EndpointData: 001ab618
TransferLength : 0000001f
TransferContext: 00000000
Flags: 00000041
NextHcdTD: 21e65200
AltNextHcdTD: 21e65180
SlotNextHcdTD: 21e65200

See also

USB 2.0 Debugger Extensions

Universal Serial Bus (USB) Drivers

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