Determining the Status of a Device

To display the entire device tree, starting with the root, use !devnode 0 1:

kd> !devnode 0 1 

Identify the devnode for which you are searching, either by examining the driver or the bus that exposed it.

The devnode status flags describe the status of the device. For details, see Device Node Status Flags.

In the example for the !devnode command in the Extensions for Debugging Plug and Play Drivers section, the swenum device was created by the PnP Manager, so the DNF_MADEUP (0x00000001) flag is set.

The following example shows a device that was created by the PCI bus. This device does not have the DNF_MADEUP flag set.

0: kd> !devnode 0xfffffa8004483490
DevNode 0xfffffa8004483490 for PDO 0xfffffa800448d060
  Parent 0xfffffa80036766d0   Sibling 0xfffffa8004482010   Child 0xfffffa80058ad720
  InstancePath is "PCI\VEN_8086&DEV_293C&SUBSYS_2819103C&REV_02\3&21436425&0&D7"
  ServiceName is "usbehci"
  State = DeviceNodeStarted (0x308)
  Previous State = DeviceNodeEnumerateCompletion (0x30d)
  StateHistory[09] = DeviceNodeEnumerateCompletion (0x30d)
  StateHistory[08] = DeviceNodeEnumeratePending (0x30c)
  StateHistory[07] = DeviceNodeStarted (0x308)
  StateHistory[06] = DeviceNodeStartPostWork (0x307)
  ...
  Flags (0x6c0000f0)  DNF_ENUMERATED, DNF_IDS_QUERIED, 
                      DNF_HAS_BOOT_CONFIG, DNF_BOOT_CONFIG_RESERVED, 
                      DNF_NO_LOWER_DEVICE_FILTERS, DNF_NO_LOWER_CLASS_FILTERS, 
                      DNF_NO_UPPER_DEVICE_FILTERS, DNF_NO_UPPER_CLASS_FILTERS
  CapabilityFlags (0x00002000)  WakeFromD3

Examples

  1. A devnode for a device with insufficient resources:
kd> !devnode 0xff0d06e8 6

DevNode 0xff0d06e8 for PDO 0xff0d07d0 at level 0x3
  Parent 0xff0d1408   Sibling 0000000000   Child 0000000000
  InterfaceType 0xffffffff  Bus Number 0xfffffff0
  InstancePath is "ISAPNP\SUP2171\00000067"
  ServiceName is "Modem"
  TargetDeviceNotify List - f 0xff0d074c  b 0xff0d074c
  Flags (..........)  DNF_PROCESSED, DNF_ENUMERATED,
                      DNF_INSUFFICIENT_RESOURCES, DNF_ADDED,
                      DNF_HAS_BOOT_CONFIG
                      Unknown flags 0x40000000

  IoResList at 0xe133e7a8 : Interface 0x1  Bus 0  Slot 0
    Alternative 0 (Version 1.1)
      Preferred Descriptor 0 - NonArbitrated/ConfigData (0x80) Shared (0x3)
        Flags (0000) -
        Data:              : 0x0 0x61004d 0x680063
      Preferred Descriptor 1 - Port (0x1) Undetermined Sharing (0)
        Flags (0x11) - PORT_IO 16_BIT_DECODE
        0x000008 byte range with alignment 0x000001
        2f8 - 0x2ff
      Preferred Descriptor 2 - Interrupt (0x2) Shared (0x3)
        Flags (0x01) - LATCHED
        0x3 - 0x3

Note that the devnode has no CM Resource List, because it is not started and is not using resources, although it has requested resources.

  1. Note that there are no resources stored in this devnode for a legacy driver.
kd> !devnode 0xff0d1648 6

DevNode 0xff0d1648 for PDO 0xff0d22d0 at level 0x2
  Parent 0xff0d2e28   Sibling 0xff0d1588   Child 0000000000
  InterfaceType 0xffffffff  Bus Number 0xffffffff
  InstancePath is "PCI\VEN_102B&DEV_0519\0&60"
  ServiceName is "mga_mil"
  TargetDeviceNotify List - f 0xff0d16ac  b 0xff0d16ac
  Flags (0x6000500b)  DNF_PROCESSED, DNF_STARTED,
                      DNF_ENUMERATED, DNF_ADDED,
                      DNF_LEGACY_DRIVER, DNF_HAS_BOOT_CONFIG
                      Unknown flags 0x40000000

You can retrieve the device object list for the driver for the following types of devices:

kd> !drvobj mga_mil

Driver object (ff0bbc10) is for:
 \Driver\mga_mil
Driver Extension List: (id , addr)

Device Object list:
ff0bb900

You can then dump the data for this device object:

kd> !devobj ff0bb900

Device object (ff0bb900) is for:
 Video0 \Driver\mga_mil DriverObject ff0bbc10
Current Irp 00000000 RefCount 1 Type 00000023 Flags 0000204c
DevExt ff0bb9b8 DevNode ff0bb808
Device queue is not busy.

Finally, you can dump the devnode referred by the device object. This devnode is not linked in the device tree. It represents a "pseudo-devnode" used to claim resources for the legacy device. Note the DNF_RESOURCE_REPORTED flag that indicates the device is a reported detected device.

kd> !devnode ff0bb808 6

DevNode 0xff0bb808 for PDO 0xff0bb900 at level 0xffffffff
  Parent 0xff0daf48   Sibling 0000000000   Child 0000000000
  InterfaceType 0xffffffff  Bus Number 0xffffffff
  TargetDeviceNotify List - f 0xff0bb86c  b 0xff0bb86c
  Flags (0x00000400)  DNF_RESOURCE_REPORTED
  CmResourceList at 0xe12474e8  Version 0.0  Interface 0x5  Bus #0
    Entry 0 - Port (0x1) Shared (0x3)
      Flags (0x01) - PORT_MEMORY PORT_IO
      Range starts at 0x3c0 for 0x10 bytes
    Entry 1 - Port (0x1) Shared (0x3)
      Flags (0x01) - PORT_MEMORY PORT_IO
      Range starts at 0x3d4 for 0x8 bytes
    Entry 2 - Port (0x1) Shared (0x3)
      Flags (0x01) - PORT_MEMORY PORT_IO
      Range starts at 0x3de for 0x2 bytes
    Entry 3 - Memory (0x3) Device Exclusive (0x1)
      Flags (0000) - READ_WRITE
      Range starts at 0x0000000040000000 for 0x4000 bytes
    Entry 4 - Memory (0x3) Device Exclusive (0x1)
      Flags (0000) - READ_WRITE
      Range starts at 0x0000000040800000 for 0x800000 bytes

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