Driver Development Tools: Windows DDK
Bug Check 0x7F: UNEXPECTED_KERNEL_MODE_TRAP
The UNEXPECTED_KERNEL_MODE_TRAP bug check has a value of 0x0000007F. This indicates that a trap was generated by the Intel CPU and the kernel failed to catch this trap.
This could be either a bound trap (a trap the kernel is not permitted to catch) or a double fault (a fault that occurred while processing an earlier fault, which always results in a system crash).
Parameters
The first parameter displayed on the blue screen specifies the trap number.
Here are some of the most common trap codes:
a.. 0x00000000, or Divide by Zero Error, is caused when a DIV instruction is executed and the divisor is zero. Memory corruption, other hardware problems, or software failures can cause this error.
b.. 0x00000004, or Overflow, occurs when the processor executes a call to an interrupt handler when the overflow (OF) flag is set.
c.. 0x00000005, or Bounds Check Fault, is generated when the processor, while executing a BOUND instruction, finds the operand exceeds the specified limits. A BOUND instruction is used to ensure that a signed array index is within a certain range.
d.. 0x00000006, or Invalid Opcode, is generated when the processor attempts to execute an invalid instruction. This is generally caused when the instruction pointer has become corrupted and is pointing to the wrong location. The most common cause of this is hardware memory corruption.
e.. 0x00000008, or Double Fault, is when an exception occurs while trying to call the handler for a prior exception. Normally, the two exceptions can be handled serially. However, there are several exceptions that cannot be handled serially, and in this situation the processor signals a double fault. There are two common causes of a double fault:
1.. A kernel stack overflow. This occurs when a guard page is hit, and then the kernel tries to push a trap frame. Since there is no stack left, a stack overflow results, causing the double fault. If you suspect this has occurred, use the !thread debugger extension to determine the stack limits, and then use the KB (Display Stack Backtrace) debugger command with a large parameter (for example, kb 100) to display the full stack.
2.. A hardware problem.
The less-common trap codes include:
a.. 0x00000001 — A system-debugger call
b.. 0x00000003 — A debugger breakpoint
c.. 0x00000007 — A hardware coprocessor instruction with no coprocessor present
d.. 0x0000000A — A corrupted Task State Segment
e.. 0x0000000B — An access to a memory segment that was not present
f.. 0x0000000C — An access to memory beyond the limits of a stack
g.. 0x0000000D — An exception not covered by some other exception; a protection fault that pertains to access violations for applications
For other trap numbers, consult an Intel architecture manual.
Cause
Bug check 0x7F usually occurs after the installation of faulty or mismatched hardware (especially memory) or in the event that installed hardware fails.
A double fault can occur when the kernel stack overflows. This can happen if multiple drivers are attached to the same stack. For example, two file system filter drivers can be attached to the same stack and then the file system can recurse back in, overflowing the stack.
Resolving the Problem
Debugging: Always begin with the !analyze debugger extension.
If this is not sufficient, use the KV (Display Stack Backtrace) debugger command.
a.. If KV shows a taskGate, then use the .tss (Display Task State Segment) command on the part before the colon.
b.. If KV shows a trap frame, then use the .trap (Display Trap Frame) command to format the frame.
c.. Otherwise, use the .trap (Display Trap Frame) command on the appropriate frame. (On x86 platforms, this frame is associated with the procedure NT!KiTrap.)
After this, use KV again to display the new stack.
Troubleshooting: If hardware was recently added to the system, remove it to see if the error recurs. If existing hardware has failed, remove or replace the faulty component. Run hardware diagnostics supplied by the system manufacturer, to determine which hardware component has failed. The memory scanner is especially important; faulty or mismatched memory can cause this bug check. For details on these procedures, see the owner’s manual for your computer. Check that all adapter cards in the computer are properly seated. Use an ink eraser or an electrical contact treatment, available at electronics supply stores, to ensure adapter card contacts are clean.
If the error appears on a newly installed system, check the availability of updates for the BIOS, the SCSI controller or network cards. Updates of this kind are typically available on the Web site or BBS of the hardware manufacturer.
Confirm that all hard disks, hard disk controllers, and SCSI adapters are listed on the Microsoft Windows Hardware Compatibility List (HCL).
If the error occurred after the installation of a new or updated device driver, the driver should be removed or replaced. If, under this circumstance, the error occurs during the startup sequence and the system partition is formatted with NTFS, you might be able to use Safe Mode to rename or delete the faulty driver. If the driver is used as part of the system startup process in Safe Mode, you need to start the computer using the Recovery Console in order to access the file. Also try restarting your computer, and press F8 at the character-based menu that displays the operating system choices. At the resulting Windows Advanced Options menu, choose the Last Known Good Configuration option. This option is most effective when only one driver or service is added at a time.
Overclocking (setting the CPU to run at speeds above the rated specification) can cause this error. If this has been done to the computer experiencing the error, return the CPU to the default clock speed setting.
Check the System Log in Event Viewer for additional error messages that might help pinpoint the device or driver that is causing the error. Disabling memory caching of the BIOS might also resolve it.
If you encountered this error while upgrading to a new version of Windows, it might be caused by a device driver, a system service, a virus scanner, or a backup tool that is incompatible with the new version. If possible, remove all third-party device drivers and system services and disable any virus scanners prior to upgrading. Contact the software manufacturer to obtain updates of these tools. Also make sure that you have installed the latest Windows Service Pack.
Finally, if all the above steps fail to resolve the error, take the system motherboard to a repair facility for diagnostic testing. A crack, a scratched trace, or a defective component on the motherboard can also cause this error.
Send feedback on this topic. / Built on Thursday, February 13, 2003
Above from DDK. This is slightly different error number but are the same error. The page for your error says see above page.
Memory Tester
============
http://oca.microsoft.com/en/windiag.asp
If it's not hardware
==============
Type verifier in Start Run, follow the wizard but choose All Drivers. This will slow down your computer and cause more blue screen crashes but will pinpoint what is causing the crash (if the original error message didn't). Once you fix it you rerun verifier and turn it off.
You will be creating a crash dump file in c:\windows\minidump every blue screen.
Then
If you have the XP SP2 Security Update CD
Install symbols from <CD Drive Letter>:\SUPPORT\SYMBOLS
Download
http://www.microsoft.com/whdc/devtools/debugging/installx86.mspx
Load the crash dump file into windbg (File - Load Crash Dump and it's in c:\windows\minidump) and READ WHAT IT SAYS, then
Type
!Analyze -v
into Windbg's command line.
(this will hopefully tell you the faulty component)
If the above is too technical then email the crash dump files to davidc @ mvps.org. Don't send me lots of them. Just the one from your last crash and one from your next crash after you turn verifier on. And only one per mail.
From Help (you want small memory dumps)
==================================
To specify what Windows does if the system stops unexpectedly
You must be logged on as an administrator or a member of the Administrators group in order to complete this procedure. If your computer is connected to a network, network policy settings might also prevent you from completing this procedure.
1.. Open System in Control Panel.
2.. On the Advanced tab, under Startup and Recovery, click Settings.
3.. Under System Failure, select the check boxes that correspond to the actions you want Windows to perform if a Stop error occurs:
a.. Write an event to the system log specifies that event information will be recorded in the system log.
b.. Send an administrative alert specifies that your system administrator will be notified.
c.. Automatically reboot specifies that Windows will automatically restart your computer.
4.. Under Write Debugging Information, choose the type of information you want Windows to record when the system stops unexpectedly:
a.. Small Memory Dump records the smallest amount of information that will help identify the problem. This option requires a paging file of at least 2 MB on the boot volume of your computer and specifies that Windows will create a new file each time the system stops unexpectedly. A history of these files is stored in the directory listed under Small Dump Directory.
b.. Kernel Memory Dump records only kernel memory, which speeds up the process of recording information in a log when the system stops unexpectedly. Depending on the amount of RAM in your computer, you must have 50 MB to 800 MB available for the paging file on the boot volume. The file is stored in the directory listed under Dump File.
c.. Complete Memory Dump records the entire contents of system memory when the system stops unexpectedly. If you choose this option you must have a paging file on the boot volume large enough to hold all of the physical RAM plus one megabyte (MB). The file is stored in the directory listed under Dump File.
Notes
a.. To open System, click Start, click Control Panel, and then double-click System.
b.. You must have at least a 2-MB paging file on the computer's boot volume if you select Write an event to the system log or Send an administrative alert.
c.. If you choose either Kernel Memory Dump or Complete Memory Dump and select the Overwrite any existing file check box, Windows always writes to the same file name. To save individual dump files, clear the Overwrite any existing file check box and change the file name after each Stop error.
d.. You can save some memory if you clear the Write an event to the system log and Send an administrative alert check boxes. The memory saved depends on the computer, but typically about 60 KB to 70 KB are required by these features.
e.. If you contact Microsoft Product Support Services about a Stop error, they might ask for the system-memory dump file generated by the Write Debugging Information option.
Related Topics
--
----------------------------------------------------------
http://www.uscricket.com
Brett Weiss said:
No, no blue screen, just an immediate reboot (no opportunity to save).
The Event Viewer shows the System Error as:
Error code 1000007f, parameter1 00000008, parameter2 80042000, parameter3
00000000, parameter4 00000000.
