I am planning to get into windows driver development and start to learn windows wdk
But I know that windows blocks loading unsigned drivers and I have to purchase a digital certificate but it's too expensive for me and I won't be developing drivers that I'll distribute to customers now
I'll be only testing on my home computer
I knew that I could turn off the signature enforcement and restart but the problem is that I am not the only one who uses the computer and can't make the test mode on all the time , and need my driver to be running
So when I load the driver in test mode then restart and go back to default settings will the driver load again ? Or I'll have to be running in test mode all the time ?
I mean with loading it permanently that I don't need to boot in test mode every time I want my driver to be running but load it once and return back with the driver running
My current windows is 8.1 64 bit
I recommend you to use a VM to this, thats how I does it. Enter the VM to TEST MODE and also you can attach WinDbg KD to the VM so you will be able to debug your driver. Without being able to debug your driver it will be very hard for you to write drivers and run them.
TESTMODE - https://technet.microsoft.com/en-us/ff553484%28v=vs.96%29?f=255&MSPPError=-2147217396
VM Kernel Debugging - https://learn.microsoft.com/en-us/windows-hardware/drivers/debugger/attaching-to-a-virtual-machine--kernel-mode-
Try to disable integrity check - bcdedit /set nointegritychecks on
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I'm remote-debugging a Windows kernel-mode driver using WinDbg. The driver has issues in the initialization routine, leading to a bugcheck/crash when installing the device driver. When I detach the debugger, the target PC reboots and runs again into the same bugcheck.
In order to test a new version of the driver, I therefore have to boot into safe mode, uninstall the device using device manager and reboot into normal mode.
Is there any way to simplify this workflow so that the device driver is automatically removed upon rebooting after a bugcheck?
Additional infos:
I'm using dpinst to install the driver on the target PC
use .Kdfiles to pull a replacement driver during boot
Documentation From MS
Write Up in Nt Insider From Osr Online
if you are using windows 10 then you can leverage the -m option to provide a partial name
and forego the dospath C:\ NtPath \.\xx , %SystemRoot%
confusions in the map file formats ,
or as described here
Doing windows driver development for first time, I want to deploy my first driver.
But I don't have a second computer.
Microsoft docs:
Typically when you test and debug a driver, the debugger and driver run on separate computers. The computer that runs the debugger is called the host computer, and the computer that runs the driver is called the target computer. The target computer is also called the test computer.
I am starting with vhidmini2 as my project base (the UMDF2 version).
I want to know if the Windows Sandbox feature can be used in place of test computer?
My driver will not be interacting with any hardware.
You can set up Windows Sandbox for kernel debugging with CmDiag (undocumented, but mentioned by Jonas L):
First you need to enable development mode (everything needs to be run from an Administrator command prompt):
CmDiag DevelopmentMode -On
Then enable network debugging (you can see additional options with CmDiag Debug):
CmDiag Debug -On -Net
This should give you the connection string:
Debugging successfully enabled.
Connection string: -k net:port=50100,key=cl.ea.rt.ext,target=<ContainerHostIp> -v
Now start WinDbg and connect to 127.0.0.1:
windbg.exe -k net:port=50100,key=cl.ea.rt.ext,target=127.0.0.1 -v
Then you start Windows Sandbox and it should connect:
Microsoft (R) Windows Debugger Version 10.0.22621.1 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.
Using NET for debugging
Opened WinSock 2.0
Using IPv4 only.
Waiting to reconnect...
Connected to target 127.0.0.1 on port 50100 on local IP <xxx.xxx.xxx.xxx>.
You can get the target MAC address by running .kdtargetmac command.
Connected to Windows 10 19041 x64 target at (Sun Aug 7 10:32:11.311 2022 (UTC + 2:00)), ptr64 TRUE
Kernel Debugger connection established.
(When I set this up initially I was getting some error when starting Windows Sandbox and I had to reboot, but this might not be necessary)
A few times I got error 0x80070020, this seems to be because the port isn't available (perhaps reserved by Hyper-V?). Switching to port 12345 fixed it for me.
The Windows Sandbox is basically a virtual machine, so you can load drivers into it as long as they do not need to interact with hardware.
But there is also one extra limitation: there does not seem to exist a way to disable the drivers signature check in the Windows Sandbox, as this requires a restart which is not possible for the sandbox. Thus, your driver has be signed to be loaded and tested.
EDIT: the Sandbox supports rebooting since Windows 11 Build 2250, so it should be possible to disable the drivers signature and install custom drivers now (cannot test though, still on W10).
I have configured my filter driver start type as SERVICE_SYSTEM_START in .inf file, Installed the filter driver manually using the instructions on the Light weight filter driver sample, rebooted the virtual machine to know if my driver is loaded. in the ntbtlog.txt which has all the driver information it says "Did not load driver ".
Starting with Windows Vista x64 platform, All the drivers that are not signed will not be loaded by the Windows, So that was the reason for Not loading Driver. To fix this I have used "Disable Signature Enforcement" option in the Boot menu by pressing F8 during the boot. This would disable the restriction while development of the driver.
I am new to windows driver development, so please bear with me if my question is being too stupid. Well, I am not sure why, as MSDN suggested and also the way I perceived, the host computer, e.g developing the driver, and the target computer, e.g debugging the driver, need to be two separate ones. why such separation? I did try to merge those two by deploying and debugging a driver on the host computer, in which I am developing a driver, and it seemed work with no objection from windows. Thanks.
PS. Source like this http://msdn.microsoft.com/en-us/library/windows/hardware/hh698272(v=vs.85).aspx got me think so.
Practically, when you are developing and testing a driver, in many situation you will get system crash (BSOD) and your system may not be bootable. In such situations your development + debugger environment is also gone/in-accessible.
Two separate machines are required for kernel debugging. You cannot debug self by obvious reasons (a debugger and a debuggee are in the same kernel and a deadlock appears). Of course, the target machine can be a virtual one.
When we develop a driver and test it the system will crash and a blue screen (called BSOD - blue screen of death)will show up. This is not the case like developing a User mode application and it crashed due to a memory error. Your driver will be running as a kernel mode application , If it crashes due to any illegal memory operation then the whole system is gone. It is not a simple issue to resolve , You need to log into safe mode and remove the driver from your system to recover it.
Due to this it is preferred to use a target machine mostly a VM on which the driver is installed and a host machine there we will be using a debugger to debug the driver.
I've got a driver for a custom PCI card, which builds and runs fine on XP. I'm trying to use this custom hardware on W7, and am trying to build and run my driver.
I've got the latest DDK from Microsoft, and build my driver for XP using Windows XP "x86 Free Build Environment". Everything installs & works fine. (Build using a DDK "build" command)
If I use the Windows 7 "x86 Free Build Environment" build environment, everything builds fine. I run it through the PREfast and staticdv code checkers, no errors from either. ( I get a couple of warnings about "The dispatch function 'FooFnc' does not have any __drv_dispatchType annotations" - are these likely to be the issue? )
When I install, the install starts OK (standard error about drivers not being signed), but gets to a certain point and then hangs, then fails with a timeout error. The device then shows up in device manager as installed. At this point the PC won't shutdown or boot, but hangs indefinitely. I'm forced to boot into Safe Mode and uninstall the driver from there.
So my question(s) are:
If there has been a change in the driver model between XP and W7, what's the best way to find it? I can't see anything on MSDN.
How would I go about debugging the driver? The box doesn't start, so it's not like I can run up WinDBG.
Any specific W7 driver gotchas that are hidden away?
I've tried to keep this as generic as possible, but if more detail would be helpful I'll provide more
AFAIK, the biggest changes have been made in video and network drivers. Other drivers retain backward compatibility and can be run on W7 even with no recompiling.
Run your driver under driver verifier and turn on generating crash dumps with a keyboard (very helpful in case of system hangs, you can manually generate crashdump, analyze it and find what was wrong).
Hope this helps!