Device Drivers

Drive letter from WdfDeviceCreateSymbolicLink not removed when driverunloads
Hi, I'm building something like the ramdisk example in the WinDDK. It uses WdfDeviceCreateSymbolicLink to attach to a drive letter. The problem is that when the driver unloads, the drive letter doesn't completely go away. It remains in Windows Explorer as a disk with a red circle and a white question mark... 27 Mar 2008 13:11

mapping device memory to userspace through MDL direct io inter
Hi Gary, Thanks for very quick & short reply, could you be little more brief about your suggestions (or) plz provide any link about your suggesting for mapping kernel device memory to user space. I am currently following the method suggested in below paper: http://www.microsoft.com/whdc/driver/kernel/mem-mgm... 28 Mar 2008 14:24

WINDDK help fails to start w/ cannot open the file ...\winddk.col
sirip wrote: *When I try to start WINDDK documentation from Programs->Development Kits->Windows DDK 3790.1830->Help->DDK Documentation, it fails with following error Cannot open the file : C:\WINDDK\3790~1.183\help\winddk.col Any help would be very much appreciated. I've tried complete un... 27 Mar 2008 07:28

IoGetDeviceProperty returns STATUS_OBJECT_NAME_NOT_FOUND
In the AddDevice() handler from our driver for USB device, we call the IoGetDeviceProperty() and it returns STATUS_OBJECT_NAME_NOT_FOUND. We use the same PhysicalDeviceObject given as a parameter in the AddDevice() handler. Can you see one possible reason for this ? Our driver is BDA driver with USB WDM lowe... 31 Mar 2008 06:49

KeAcquireSpinLock or KeAcquireSpinLickAtDpc?
I have a function that uses KeAcquireSpinLock(). This function will be called for each packet in a data stream at DISPATCH_LEVEL and I was interested to tune the performance. Then I read documentation that KeAcquireSpinLockAtDpc() will improve performance. I also want to use this function in few places where it... 27 Mar 2008 14:49

Problem with reading from two drivers in Windows Service
Hello, When i try to read from two drivers (NDIS IM & TDI) in one Windows (XP) Service, Windows is crashing (PFN_LIST_CORRUPT (4e)). Why? When I read from one driver all is working correctly. Here is part of my code: 1. TDI: TDI-Based Open Source Personal Firewall for Windows http://tdifw.sourceforge.net/ ... 27 Mar 2008 13:11

Accessing card in USB card reader
I would like to issue an ATA Identity command to a CF card in a USB card reader. I understand that card readers in general (and in this specific case) are using USBSTOR.SYS which is a SCSI interface, so unless I were to make my own driver and have support for that in the unit, I really can't do that. What I ca... 27 Mar 2008 13:11

SMART_SEND_DRIVE_COMMAND
Hi, I'm trying to issue smart_send_drive_command with the sub command SMART_WRITE_LOG. Does anyone here has been able to successfully work with this command. Could you please provide a sample code. I was successful at issuing smart_rcv_drive_data with the sub command SMART_READ_LOG. The operating syste... 26 Mar 2008 14:04

Memory related questions
I have some memory related questions: 1. Is the object and handle allocated from paged/nonpaged pool? If yes, any tag will be there to track? 2. Can any allocation be there in paged/nonpaged memory without tag (even without wdm/ddk tag)? 3. If any handle/object leakage is there, can we catch this with Driv... 25 Apr 2008 11:47

Resetting a CD/DVD writer
I've got some code which does low level access to CD/DVD writers using SPTI. That's all fine, except when something goes wrong (usually, sadly, the result of my bugs :( ). Then I'm left with a device which thinks it's busy and I can do nothing to persuade it otherwise (save reboot the machine). What I thin... 26 Mar 2008 22:15