KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q208005: FIX: Page Table Initialization Missing in x86 OAL

Article: Q208005
Product(s): Microsoft C Compiler
Version(s): WINDOWS:
Operating System(s): 
Keyword(s): kbETK kbVC500
Last Modified: 04-MAY-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows CE Embedded Toolkit for Visual C++ 5.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

An x86-based implementation of the Windows CE operating system does not boot
when a custom physical memory layout is used.

CAUSE
=====

The Windows CE x86 OAL code supplied in the Windows CE Embedded Toolkit for
Visual C++ 5.0 lacks an OEM customizable routine to preset entries into the page
table. This prevents the OEM from building a proper initial virtual memory
address space during system initialization.

RESOLUTION
==========

To correct this problem, the Windows CE kernel component NK.LIB has been updated
to call a new OAL function, OEMInitPageTable(). A new OAL sample file has been
added (Oeminit.asm) to implement this new OAL function. By modifying the
OEMInitPageTable() function an OEM can properly build the initial page table to
match the physical memory layout of the platform.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug has been corrected in the Windows CE 2.1
Enhancement Pack for the Embedded Toolkit, and is also available as a patch for
Windows CE 2.0 from Microsoft Developer support.

MORE INFORMATION
================

The Windows CE x86 kernel contains an initial page table that maps memory
resources for a x86 development platform. This page table may not be appropriate
for all other x86 platform implementations.

Flash memory, additional DRAM, and ROM address space may not be a part of the
built-in page table and will cause the system to halt when the switch from
physical addressing to virtual addressing takes place.

Additional query words: wceoem

======================================================================
Keywords          : kbETK kbVC500 
Technology        : kbAudDeveloper kbWinCEETKSearch kbWinCESearch kbWinCEETKVC500
Version           : WINDOWS:
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.