BCDEdit /dbgsettings

The /dbgsettings option sets or displays the current global debugger settings for the computer. To enable or disable the kernel debugger, use the BCDEdit /debug option.

Note

Before setting BCDEdit options you might need to disable or suspend BitLocker and Secure Boot on the computer.

bcdedit /dbgsettings NET HOSTIP:ip PORT:port [KEY:key] [nodhcp] [newkey] [/start startpolicy] [/noumex] 

bcdedit /dbgsettings LOCAL [/start startpolicy] [/noumex] 

bcdedit /dbgsettings SERIAL [DEBUGPORT:port] [BAUDRATE:baud] [/start startpolicy] [/noumex] 

bcdedit /dbgsettings USB [TARGETNAME:targetname] [/start startpolicy] [/noumex] 

bcdedit /dbgsettings 1394 [CHANNEL:channel] [/start startpolicy] [/noumex] NOTE: The 1394 TRANSPORT IS DEPRECATED

Parameters

NET

Specifies that the target machine and the host machine will use an Ethernet network connection for debugging. When this option is used, the HOSTIP and PORT parameters must be included as well. The target computer must have a network adapter that is supported by Debugging Tools for Windows.

HOSTIP:ip
For network debugging, specifies the IP address of the host debugger.

KEY:key
For network debugging, specifies the key with which to encrypt the connection. [0-9] and [a-z] allowed only. Do not specify this parameter if you have specified the newkey parameter.

PORT:port
For network debugging, specifies the port to communicate with on the host debugger. Should be 49152 or higher.

newkey
For network debugging specifies that a new encryption key should be generated for the connection. Do not specify this parameter if you have specified a KEY parameter.

nodhcp

Setting nodhcp prevents use of DHCP to obtain the target IP address. This option is rarely required as even small routers provide support for DHCP. The nodhcp option should only be used if you know that there are no DHCP servers on the network. In most situations, the KDNET transport works best when this option is not set, and DHCP is enabled.

busparams=Bus.Device.Function Specifies the target controller when multiple controllers exist. Bus specifies the bus number, Device specifies the device number, and Function specifies the function number.

To specify the bus parameters, Open Device Manager, and locate the network adapter that you want to use for debugging. Open the property page for the network adapter, and make a note of the bus number, device number, and function number. In an elevated Command Prompt Window, enter the following command, where b, d, and f are the bus, device and function numbers in decimal format:

bcdedit /set "{dbgsettings}" busparams b.d.f

If you are manually configuring a debugger connection, you must specify the bus parameters. For more information, see Setting Up KDNET Network Kernel Debugging Manually and Setting Up Kernel-Mode Debugging over a USB 3.0 Cable Manually.

Examples

The following command configures the target computer to use an Ethernet connection for debugging and specifies the IP address of the host computer. The command also specifies a port number that the host computer can use to connect to the target computer.

bcdedit /dbgsettings net hostip:10.125.5.10 port:50000

The following command sets the global debugger settings to network debugging using IPv6 with a debugger host at 2001:48:d8:2f:5e:c0:42:28:4f5b communicating on port 50000:

bcdedit /dbgsettings NET HOSTIPV6:2001:48:d8:2f:5e:c0:42:28:4f5b PORT:50000

Important

Setting up a network debugging manually is a complex and error prone process. To set up network debugging automatically, see Setting Up KDNET Network Kernel Debugging Automatically. Using the KDNET utility is strongly recommended for all debugger users.

For more information on manual setup, see Setting Up Kernel-Mode Debugging over a Network Cable Manually.

LOCAL

The LOCAL option sets the global debugging option to local debugging. This is kernel-mode debugging on a single computer. In other words, the debugger runs on the same computer that is being debugged. With local debugging you can examine state, but not break into kernel mode processes that would cause the OS to stop running.

Example

The following command sets the global debugger settings to local debugging.

bcdedit /dbgsettings LOCAL

The LOCAL option is available in Windows 8.0 and Windows Server 2012 and later.

For information on setting up local kernel mode debugging manually, see Setting Up Local Kernel Debugging of a Single Computer Manually.

SERIAL

Specifies that the target machine and the host machine will use a serial connection for debugging. When this option is used, the DEBUGPORT and BAUDRATE parameters should be specified.

BAUDRATE:baud
Specifies the baud rate to use. This parameter is optional. Valid values for baud are 9600, 19200, 38400, 57600, and 115200. The default baud rate is 115200 bps.

DEBUGPORT:port
Specifies the serial port to use as the debugging port. This is an optional setting. The default port is 1 (COM 1).

Example

The following command configures the target computer to use a serial connection for debugging. The command also specifies that the debugging connection will use COM2 and a baud rate of 115,200.

bcdedit /dbgsettings serial debugport:1 baudrate:115200

For more information, see Setting Up Kernel-Mode Debugging over a Serial Cable Manually.

USB

Specifies that the target machine and the host machine will use a USB 2.0 or USB 3.0 connection for debugging. When this option is used, the TARGETNAME parameter must be included as well.

TARGETNAME: targetname
Specifies a string value to use for the target name. Note that TargetName does not have to be the official name of the target computer; it can be any string that you create as long as it meets these restrictions:

  • The string must not contain “debug” anywhere in the TargetName in any combination of upper or lower case. For example if you use “DeBuG” or "DEBUG" anywhere in your targetname, debugging will not work correctly.
  • The only characters in the string are the hyphen (-), the underscore(_), the digits 0 through 9, and the letters A through Z (upper or lower case).
  • The maximum length of the string is 24 characters.

Example

The following command configures the target computer to use USB connection for debugging. The command also specifies a target name that the host computer can use to connect to the target computer.

bcdedit /dbgsettings usb targetname:myTarget

For more information, see:

1394

Important

The 1394 transport is available for use in Windows 10, version 1607 and earlier. It is not available in later versions of Windows. You should transition your projects to other transports, such as KDNET using Ethernet. For more information about that transport, see Setting Up KDNET Network Kernel Debugging Automatically.

Specifies that the target machine and the host machine will use an IEEE 1394 (FireWire) connection for debugging. When this option is used, the CHANNEL parameter can be included as well.

CHANNEL:channel
(Only used when the connection type is 1394.) Specifies the 1394 channel to use. The value for 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. The default value for channel is 0.

For more information, see Setting Up Kernel-Mode Debugging over a 1394 Cable Manually.

General Debugger Settings

/start startpolicy
This option specifies the debugger start policy. The following table shows the options for the startpolicy.

Option Description
ACTIVE Specifies that the kernel debugger is active.
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.

If a start policy is not specified, ACTIVE is the default.

/noumex
Specifies that the kernel debugger ignores user-mode exceptions. By default, the kernel debugger breaks for certain user-mode exceptions, such as STATUS_BREAKPOINT and STATUS_SINGLE_STEP. The /noumex parameter is effective only when there is no user-mode debugger attached to the process.

Comments

The /dbgsettings option configures the debugging settings, but does not enable debugging. You must use the /debug option to enable debugging for a specific boot entry. If there are no debugging settings specified for a particular boot entry, the default debug settings are used.

The default values for the dbgsettings are shown in the following table.

dbgsetting parameter Default value
debugtype Local
debugstart Active
noumex Yes

See also

For information about Windows debugging tools, see Windows Debugging.

For information about setting up and configuring a kernel-mode debugging session, see Setting Up Kernel-Mode Debugging Manually and Setting Up KDNET Network Kernel Debugging Automatically.