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How to Set Up Windows NT Debug Symbols

This article was previously published under Q148659

Windows NT Debug Symbols must be set up if a computer needs to be remotelyor locally debugged. This article provides instructions on how toset up Windows NT Debug Symbols.

Article Contents

  • What Are Symbols
  • Setting Up a Custom Symbol Tree
  • Single Processor vs. Multiprocessor
  • Custom HAL.DLL
  • After the Symbol Tree Is Created

What Are Symbols

Debug Symbol files (symbols) are required to do both kernel and user-modedebugging in Windows NT. Symbols provide a way to resolve global variablesand function names in the loaded executable file.

Symbols are produced by the linker when a program is built. They arestripped out of the retail product and saved in a separate (.DBG) file.This considerably reduces file size which decreases file load time and thusincreases system performance. Symbols represent Function\API names andglobal variables.

The .DBG file contains symbolic information for each file. They can befound on the SUPPORT\DEBUG\<platform>\SYMBOLS directory of the Windows NTinstallation compact disc.

Patched builds such as Service Packs require a special set of symbols, thatis a combination of the base build and the patched symbols.

The SYMBOLS directory is divided up into seven subdirectories, calledExtension Subdirectories (note that many of the symbol files in thesedirectories match USER MODE components of Windows NT):

   COM - symbols for all files ending in .COM go here   CPL - symbols for all files ending in .CPL go here.   DLL - symbols for all files ending in .DLL go here   DRV - symbols for all files ending in .DRV go here   EXE - symbols for all files ending in .EXE go here   SCR - symbols for all files ending in .SCR go here   SYS - symbols for all files ending in .SYS go here.

The symbols must match their respective files. Symbols from a differentbuild give erroneous information. All of the symbol file link dates mustmatch those on the computer being debugged.

Setting Up a Custom Symbol Trees

The Symbol Tree is the subdirectory tree on the host computer whichcontains the symbol files which match the remote computer being debugged.
  1. Create a Subdirectory on the host computer. For example:
  2. Always start with the base Windows NT version number. Copy the following files from the installation compact disc for the appropriate version:
  3. Copy the symbols for the appropriate Service Pack into the custom tree. Service Pack symbols can be found on FTP.MICROSOFT.COM.

    For example, the symbols for Windows NT 3.51 Service Pack 4 can be downloaded from the following location:

    Download the file called SYM_351<X>.EXE where X represents the platform (I for x86, A for Alpha, P for PPC).

    Decompress the files into the symbol tree. For example:
    SYM_351<X>.EXE -d C:\SYMBOLS
  4. Copy any third-party patches, such as the Compaq SSD symbols, to the custom symbol tree. These symbols must be obtained from the third-party vendor.
  5. If Microsoft has supplied unique fixes for your installation, copy the DBG file supplied with the fix into the appropriate subdirectory (for example: SYS, EXE, DLL).
  6. If the computer is a single processor Intel system, the symbol tree is complete. Please see the "After the Symbol Tree is Created" section below.

Single Processor vs. Multiprocessor

Windows NT uses a special kernel for SMP systems. During installation thiskernel is renamed. It is important that the DBF file is renamed fordebugging.

   NTOSKRNL.EXE  NTOSKRNL.DBG  = Single processor   NTKRNLMP.EXE  NTKRNLMP.DBG  = Multiple processors

If the system is a Multi-Processor, do the following:
  1. Change the directory to the DLL component directory. For example:
  2. Rename the uniprocessor kernel to another filename. For example:
  3. Copy the multiprocessor kernel over the uniprocessor kernel. For example:

Custom HAL.DLL

Some hardware platforms require a special Hardware Abstraction Layer (HAL)Driver. Like the Kernel file, the custom HAL is renamed during theinstallation process. Here is a list of common HALs:

HAL files for I386 Computers:

Filename                   Description---------------------------------------------------HAL.DLL                    Standard HAL for Intel systemsHAL486C.DLL                HAL for 486 c step processorHALAPIC.DLL                Uniprocessor version of HALMPS.DLLHALAST.DLL                 HAL for AST SMP systemsHALCBUS.DLL                HAL for Cbus systemsHALMCA.DLL                 HAL for MCA-based systems (PS\2 and others)HALMPS.DLL                 HAL for most Intel multiprocessor systemsHALNCR.DLL                 HAL for NCR SMP computersHALOLI.DLL                 HAL for Olivetti SMP computersHALSP.DLL                  HAL for Compaq SystemproHALWYSE7.DLL               HAL for Wyse7 systemsHAL files for DEC Alpha Computers:Filename                   Description---------------------------------------------------HAL0JENS.DLL               Digital DECpc AXP 150 HALHALALCOR.DLL               Digital AlphaStation 600 FamilyHALAVANT.DLL               Digital AlphaStation 200\400 Family HALHALEB64P.DLL               Digital AlphaPC64 HALHALGAMMP.DLL               Digital AlphaServer 2x00 5\xxx Family HALHALMIKAS.DLL               Digital AlphaServer 1000 Family Uniprocessor HALHALNONME.DLL               Digital AXPpci 33 HALHALQS.DLL                  Digital Multia MultiClient Desktop HALHALSABMP.DLL               Digital AlphaServer 2x00 4\xxx Family HALHAL files for MIPS Computers:Filename                   Description---------------------------------------------------HALACR.DLL                 ACER HALHALDTI.DLL                 DESKStation EvolutionHALDUOMP.DLL               Microsoft-designed dual MP HALHALFXS.DLL                 MTI with a r4000 or r4400HALFXSPC.DLL               MTI with a r4600HALNECMP.DLL               NEC dual MPHALNTP.DLL                 NeTpower FASTseriesHALR98MP.DLL               NEC 4 processor MPHALSNI4X.DLL               Siemens Nixdorf UP and MPHALTYNE.DLL                DESKstation TyneHAL files for PPC Computers:Filename                   Description---------------------------------------------------HALCARO.DLL                HAL for IBM-6070HALEAGLE.DLL               HAL for Motorola PowerStack and Big BendHALFIRE.DLL                Hal for Powerized_ES,                                   Powerized_MX, and                                   Powerized_MX MPHALPOLO.DLL                HAL for IBM-6030HALPPC.DLL                 HAL for IBM-6015HALWOOD.DLL                HAL for IBM-6020

How to Determine Which HAL to Use:

During installation, a text log file is created. This file has a line whichshows which HAL is installed during setup. If the HAL has changed afterthe original Setup, the SETUP.LOG does not reflect the change. To verify,do the following:
  1. Go to %SystemRoot%\REPAIR subdirectory.
  2. Run ATTRIB -R -H -S SETUP.LOG to make the file visible.
  3. Use Notepad to view SETUP.LOG and search for "Hal".
NOTE: This same technique can be useful to verify if a special kernel isalso used.

Copy the HAL into the Symbol Tree:
  1. Change directory to \SYMBOLS\DLL.
  2. Rename HAL.DBG to HAL.X86.
  3. Copy the "Custom HLL.DBG" to HAL.DBG.

After the Symbol Tree Is Created

The symbol tree is now complete. For more information, query on thefollowing word here in the Microsoft Knowledge Base:
3.50 3.51 prodnt debugref

Article ID: 148659 - Last Review: 11/01/2006 06:11:36 - Revision: 3.1

  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 3.51
  • KB148659