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/debug

The /debug parameter establishes a kernel debugging connection.

Syntax for Microsoft Windows 2000 and Windows XP only.


    /debug

   

    /debug /debugport=COMx [ /baudrate=BaudRate ] 

   

    /debug /debugport=1394 [/channel=Channel ] 

   

    /debug /debugport=usb /targetname=String

   

Syntax for Microsoft Windows Server 2003 only.


    /debug

   

    /debug[={autoenable | disable | noumex},...] /debugport=COMx [ /baudrate=BaudRate ]

   

    /debug[={autoenable | disable | noumex},...] /debugport=1394 [/channel=Channel ]

   

    /debug[={autoenable | disable | noumex},...] /debugport=usb /targetname=String

   

Subparameters

/debugport

Specifies the serial port used by the kernel debugger.

With COMx, /debugport enables debugging with a debug (null modem) cable.

With 1394, /debugport enables debugging with an IEEE 1394 cable.

With usb, /debugport enables debugging with a USB 2.0 debugging cable.

COMx

Specifies the communications port used for kernel debugging with a null modem cable. Valid values are any valid COM port, such as COM1 or COM2.

/baudrate

Specifies the speed of a kernel debugger connection when using the /debugport=COMx parameter.

BaudRate

Specifies the speed of a kernel debugger connection in BPS. Valid values for BaudRate are 9600, 19200, 38400, 57600, and 115200. The default is 19200.

1394

Specifies debugging with an IEEE 1394 (FireWire) cable. This feature is supported only if your target computer and your host computer are both running Windows XP or a later version of Windows.

Note   To perform kernel debugging with a 1394 cable when the target computer is running Windows Server 2003 (with no service packs installed) or Windows XP with Service Pack 1 (SP1), you must disable the 1394 host controller on the target computer and install the 1394 virtual driver that is included in the Debugging Tools for Windows package on the host computer. For instructions, see the Disabling the 1394 Host Controller and Installing the 1394 Virtual Driver topics in the Debugging Tools for Windows documentation on MSDN.

/channel

Specifies the 1394 bus channel used when debugging with an IEEE 1394 cable. The default value is 0.

Channel

Specifies the 1394 channel. The default value is 0. The value of Channel must be a decimal integer between 0 and 62, inclusive, and must match the channel number used by the host computer. The channel specified in this parameter does not depend on the physical 1394 port chosen on the adapter.

usb

Specifies debugging with a USB 2.0 debugging cable. This feature is supported only if your host computer is running Windows 2000 or later, and your target computer is running Windows Vista or later.

Note   Before you perform kernel debugging over a USB 2.0 cable, additional configuration is required. For more information, see the Setting Up a USB 2.0 Debug Cable Connection topic in Debugging Tools for Windows documentation on MSDN.

/targetname

Specifies a string to use as the identification for the USB 2.0 connection. This string can be any value.

String

Specifies a string to use as the identification for the USB 2.0 connection. String can be any value.

autoenable

Specifies that the kernel debugger is enabled automatically when an exception or other critical event occurs. Until then, the debugger is active but is disabled.

disable

Specifies that the kernel debugger is enabled when you type kdbgctrl to clear the enable block. Until then, the debugger is active but is disabled.

The /debug=disable parameter is designed to be a preferred alternative to /crashdebug. For more information about the KDbgCtrl tool, see the Debugging Tools for Windows documentation.

noumex

Specifies that the kernel debugger does not break for user-mode exceptions. By default, the kernel debugger breaks for particular user-mode exceptions, such as STATUS_BREAKPOINT and STATUS_SINGLE_STEP. The /debug=noumex parameter is effective only when there is no user-mode debugger attached to the process.

Comments

The /debug parameter is supported only on Windows Server 2003, Windows XP, and Windows 2000. In Windows Vista and later versions of Windows, use BCDEdit and the /dbgsettings parameter and its subparameters to establish debugger settings for all boot entries. Then, use the /debug parameter to enable debugging for a particular boot entry.

To enable local (one computer) debugging, use only the /debug parameter.

To enable debugging with a debug (null-modem) cable, use the /debug parameter with the /debugport=COMx and /baudrate subparameter.

To enable debugging with an IEEE 1394 (FireWire) cable, use the /debug parameter with the /debugport=1394 and /channel subparameters.

Because the /debugport subparameter reserves the specified port, do not use it unless you plan to debug the computer.

When you enable kernel debugging on a serial port, Windows removes the specified port from the system device list. As a result, on computers with an ACPI BIOS, the port does not appear in any device lists, such as the one in Device Manager. On computers that do no have an ACPI BIOS, the port appears with an error message, such as "Not enough resources to use this port." These messages indicate that the port is under the control of the host debugging computer; they do not indicate a malfunction.

To test a cable connection, start your test after connecting the cable, but before enabling debugging.

When you configure a boot entry for debugging, the boot loader appends a bracketed phrase, [debugger enabled], to the friendly name that appears in the boot menu. However, the boot loader omits the bracketed phrase from the boot menu when the friendly name and the bracketed phrase together exceed 70 characters. To restore the bracketed phrase, shorten the friendly name.

On Windows Server 2003, you can use the autoenable, disable, and noumex subparameters of /debug to enable the debugger only when you need it. You can use more than one subparameter at a time. To use multiple subparameters, separate each subparameter with a comma. (Do not type /debug more than once. If you do, Windows uses the first instance and ignores all others.)

For example, /debug=autoenable, noumex enables the kernel debugger on an exception or critical event, but not for user-mode events.

For detailed examples of the use of the /debug parameter and its variations, see Boot Parameters to Enable Debugging.

Examples


multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /debug

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /debug /debugport=COM1 /baudrate=115200

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /debug /debugport=1394 /channel=44

multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows Server 2003, Standard" /noexecute=optout /fastdetect /debug=autoenable /debugport=1394 /channel=44

multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows Server 2003, Standard" /noexecute=optout /fastdetect /debug=disable,noumex /debugport=COM1 /baudrate=115200

Bootcfg Commands


bootcfg /debug ON /ID 1
bootcfg /debug ON /port=COMx [/baud=115200] /ID 2
bootcfg /dbg1394 ON /channel=44 /ID 3

 

 

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