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Problems using COM1 as a pipe to WinDbg

Posted: 19. Oct 2009, 18:03
by JeanLu
Hi,

I have an issue trying using a Virtual machine XP on an XP host. My goal is to perform kernel debugging using COM1 as a pipe to WinDbg.
It works... for some seconds; I can see several traces my driver generates and then the VM is blocked (no reaction with the mouse inside the OS under debug, Virtual Box GUI is OK) and Windbg has no control on the machine (it did not step into some breakpoint for instance).

Anyone experienced this? What can I do to investigate?

I used COM1 as a pipe for a very simple program and it did work. May be Windbg configuration has to be improved? I'm starting Windbg like this:
"C:\Program Files\Debugging Tools for Windows (x86)\windbg.exe" -b -k com:pipe,port=\\.\pipe\VirtualDbg,resets=0,reconnect

Thanks,
Jean

Re: Problems using COM1 as a pipe to WinDbg

Posted: 20. Oct 2009, 09:46
by JeanLu
Hi again,

just to add that I use the lastest VirtualBox 3.0.8.

Re: Problems using COM1 as a pipe to WinDbg

Posted: 20. Oct 2009, 15:25
by Perryg
Take a look at chapter 3.7.8. Serial ports of the VBox users guide. In particular the section 2. where it discusses a helper application. Maybe this will help.

Re: Problems using COM1 as a pipe to WinDbg

Posted: 21. Oct 2009, 12:09
by JeanLu
Hi,

thanks for the response. I found VirtualKD, a tool that solves (greatly!) my issue:
http://virtualkd.sysprogs.org/

Thanks,
Jean