The WinDbg host computer can also be local to the target Windows NT computer. WinDbg runs on the Windows NT host computer and communicates through an industry-standard null-modem serial cable with the target Windows NT computer. For local Kernel debugging, the target computer has to be prepared in the same way as it is for remote Kernel debugging.
To debug Windows NT Executive messages using a local debugging system, you need to prepare the host and target computers and then connect the two computers with an industry-standard null-modem serial cable. Be sure to start the host computer before restarting the target computer.
A standard, commercially available null-modem serial cable has the following configuration:
For 9-pin and 25-pin D-subminiature connectors, the cable connects as follows:
The WinDbg logic does not depend on any control pins (such as Data Terminal Ready, Data Set Ready, Request To Send, or Clear To Send). However, in the connectors on both ends of the cable, you may have to put a jumper from Data Terminal Ready to Data Set Ready and from Request To Send to Clear To Send.
Preparing the target computer for local Kernel debugging is the same as for remote Kernel debugging. The only difference is that instead of connecting a modem to one of the target computer's communications ports, you connect a null-modem serial cable. See "Configuring a System for Debugging," earlier in this chapter, for detailed procedures.
Which port you use (COM1 or COM2) depends on what you did to prepare your target and host computers. The default connection is from COM1 of the host computer to COM2 of the target computer. However, you may change that by editing the boot configuration on the target computer or by changing the command line parameters used when you start WinDbg.
The Windows NT Setup program does not install WinDbg as part of the Windows NT installation process. However, you can easily copy the WinDbg program directly onto the hard disk of the host computer. It is distributed on the Windows NT CD-ROM in an uncompressed format under the \SUPPORT\DEBUG directory.
Note If you do not have a CD-ROM drive, the WinDbg program is also available from Microsoft Support Network. You can request that they send you the software on a floppy disk, or ask for instructions on how to download it from CompuServe.
Notice that the communications port can be different for the host and target computers.
EECXXALP.DLL | IMAGEHLP.DLL | TLLOC.DLL |
EECXXMIP.DLL | KDEXTALP.DLL | TLPIPE.DLL |
EECXXX86.DLL | KDEXTMIP.DLL | TLSER.DLL |
EMALP.DLL | KDEXTX86.DLL | WINDBG.EXE |
EMMIP.DLL | SHCV.DLL | WINDBG.HLP |
EMX86.DLL | SYMCVT.DLL | WINDBGRM.EXE |
<path> windbg -k <target platform> <com port> <speed> -y <symbol path> -v
where:
Path is the path to the WINDBG.EXE file.
-k invokes the Kernel-debug mode.
Target platform refers to the hardware platform of the target computer and corresponds to the name of the directory from which you obtained the WinDbg files, such as I386, MIPS, or ALPHA.
Com port is the port to which you have connected the null-modem serial cable.
Speed is the baud rate.
-y indicates that the next parameter is the symbol path.
Symbol path is the path to the \SYMBOLS directory created in step 2.
The following is an example of such a command:
c:\ windbg -k i386 com1 19200 -y c:\windows\symbols
For more information on WinDbg settings, see the online Help file.
Once you have prepared the two computers and connected them, you can start a debugging session. There can be many objectives for a debugging session; this chapter discusses the objective of collecting information (in the debug-session log file on the host computer) about the events leading up to a particular Windows NT Executive message on the target computer.
Note Once you are in the Kernel-debug mode of WinDbg, you can display a list of commands by typing help or ? at the KD command prompt on the host computer. The Kernel-debug character-mode command-line interface has a vocabulary of about four dozen commands, plus it supports advanced debugging features such as watches and breakpoints. For more information on the commands and advanced features, see the online Help file.
Quitting WinDbg on the host computer at the end of a local debugging session will also save the debug-session log file.