communication with bulk driver

NTDEV
1

Hi,
I have a sample driver which needs to communicate with bulk driver
passing an IRP to it…I have tried IOGetDeviceObjectPointer passing the
string which contains the EnumeratedDeviceID and GUID…but it returns
STATUS_OBJECT_NAME_NOT_FOUND…The only problem is BulkUSB calls
IOCreateDevice with NULL in place of device name and instead it sets the
device interface…How do I get the device object pointer for BulUSB ?.

Thanks in Advance,
Best Regards,
Sai Prasad

From: Gary Little[SMTP:xxxxx@Broadstor.com]
Reply To: NT Developers Interest List
Sent: Tuesday, January 29, 2002 1:14 AM
To: NT Developers Interest List
Subject: [ntdev] [NTDEV] Awaiting an event during boot up

* Or, am I chasing a white rabbit and a check condition’s sense data has
nothing to do with why the system will not continue initialization?

It appears that I was chasing a very large white rabbit. Where as the
check
condition might cause problems, it had no affect on this one. The problem
stemmed from trying to use IOCTL_SCSI_MINPORT. I was checking the
signature
to see if I had made the call and ignoring the request if not … but I
was
NOT completing the SRB, which then was causing the system to stall.

Gary G. Little
Broadband Storage, Inc.
xxxxx@broadstor.com
xxxxx@inland.net

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2

Hi,

you are trying a development anyway, isn’t it?

If IoCreateDevice is called with NULL then the device object does not get a name (unnamed object). Therefore, you are not able to open it by means of IoGetDeviceObjectPointer.
A device interface on the other hand is in fact a symbolic link that will be created when the interface is enabled by the driver.
You can open a symbolic by using ZwCreateFile (at PASSIVE_LEVEL only). Then you have to convert the returned handle to a pointer by using ObReferenceObjectByHandle. After that, you can close the handle. Note that handles are process-specific, pointers are not.
You can then use the device object pointer to talk to the lower driver. Call ObDereferenceObject when are done with it.

–
Udo Eberhardt
Thesycon GmbH, Germany
xxxxx@thesycon.de
www.thesycon.de

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com]On Behalf Of Sai_Prasad
Sent: Friday, February 15, 2002 9:51 AM
To: NT Developers Interest List
Subject: [ntdev] communication with bulk driver

Hi,
I have a sample driver which needs to communicate with bulk driver
passing an IRP to it…I have tried IOGetDeviceObjectPointer passing the
string which contains the EnumeratedDeviceID and GUID…but it returns
STATUS_OBJECT_NAME_NOT_FOUND…The only problem is BulkUSB calls
IOCreateDevice with NULL in place of device name and instead it sets the
device interface…How do I get the device object pointer for BulUSB ?.

Thanks in Advance,
Best Regards,
Sai Prasad

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