[ros-diffs] [fireball] 25537: - Add MempDisablePages() which unmaps non-accessible memory areas from KSEG0 page table.

Author: fireball
Date: Sat Jan 20 00:37:25 2007
New Revision: 25537
URL: http://svn.reactos.org/svn/reactos?rev=25537&view=rev
Log:
- Add MempDisablePages() which unmaps non-accessible memory areas from KSEG0 page table.
Modified:
    branches/winldr/windows/wlmemory.c
Modified: branches/winldr/windows/wlmemory.c
URL:
http://svn.reactos.org/svn/reactos/branches/winldr/windows/wlmemory.c?rev=2…
==============================================================================
--- branches/winldr/windows/wlmemory.c (original)
+++ branches/winldr/windows/wlmemory.c Sat Jan 20 00:37:25 2007
@@ -262,6 +262,56 @@
 }
 VOID
+MempDisablePages()
+{
+       int i;
+
+       //
+       // We need to delete kernel mapping from memory areas which are
+       // marked as Special or Permanent memory (thus non-accessible)
+       //
+
+       for (i=0; i<MadCount; i++)
+       {
+               if (Mad[i].MemoryType == LoaderFirmwarePermanent ||
+                       Mad[i].MemoryType == LoaderSpecialMemory)
+               {
+                       ULONG StartPage, EndPage, Page;
+
+                       StartPage = Mad[i].BasePage;
+                       EndPage = Mad[i].BasePage + Mad[i].PageCount;
+
+                       //
+                       // But, the first megabyte of memory always stays!
+                       // And, to tell the truth, we don't care about what's
higher
+                       // than LOADER_HIGH_ZONE
+                       if (StartPage < 0x100)
+                               StartPage = 0x100;
+
+                       if (EndPage > LOADER_HIGH_ZONE)
+                               EndPage = LOADER_HIGH_ZONE;
+
+
+                       for (Page = StartPage; Page < EndPage; Page++)
+                       {
+                               PHARDWARE_PTE KernelPT;
+                               ULONG Entry = (Page >> 10) + (KSEG0_BASE >>
22);
+
+                               if (PDE[Entry].Valid)
+                               {
+                                       KernelPT =
(PHARDWARE_PTE)(PDE[Entry].PageFrameNumber << MM_PAGE_SHIFT);
+
+                                       KernelPT[Page & 0x3ff].PageFrameNumber = 0;
+                                       KernelPT[Page & 0x3ff].Valid = 0;
+                                       KernelPT[Page & 0x3ff].Write = 0;
+                               }
+                       }
+               }
+       }
+}
+
+
+VOID
 MempAddMemoryBlock(IN OUT PLOADER_PARAMETER_BLOCK LoaderBlock,
                    ULONG BasePage,
                    ULONG PageCount,
@@ -423,6 +473,30 @@
                }
        }
+       // TEMP, DEBUG!
+       // adding special reserved memory zones for vmware workstation
+#if 0
+       {
+               Mad[MadCount].BasePage = 0xfec00;
+               Mad[MadCount].PageCount = 0x10;
+               Mad[MadCount].MemoryType = LoaderSpecialMemory;
+               WinLdrInsertDescriptor(LoaderBlock, &Mad[MadCount]);
+               MadCount++;
+
+               Mad[MadCount].BasePage = 0xfee00;
+               Mad[MadCount].PageCount = 0x1;
+               Mad[MadCount].MemoryType = LoaderSpecialMemory;
+               WinLdrInsertDescriptor(LoaderBlock, &Mad[MadCount]);
+               MadCount++;
+
+               Mad[MadCount].BasePage = 0xfffe0;
+               Mad[MadCount].PageCount = 0x20;
+               Mad[MadCount].MemoryType = LoaderSpecialMemory;
+               WinLdrInsertDescriptor(LoaderBlock, &Mad[MadCount]);
+               MadCount++;
+       }
+#endif
+
        DbgPrint((DPRINT_WINDOWS, "MadCount: %d\n", MadCount));
        WinLdrpDumpMemoryDescriptors(LoaderBlock); //FIXME: Delete!
@@ -453,6 +527,9 @@
        //DbgPrint((DPRINT_WINDOWS, "VideoMemoryBase: 0x%X\n",
VideoMemoryBase));
        Tss = (PKTSS)(KSEG0_BASE | (TssBasePage << MM_PAGE_SHIFT));
+
+       // Unmap what is not needed from kernel page table
+       MempDisablePages();
        // Fill the memory descriptor list and
        //PrepareMemoryDescriptorList();
@@ -655,7 +732,7 @@
        //
        // TSS Selector (0x28)
        //
-       pGdt[5].LimitLow                                = 0x78-1; // 60 dwords
+       pGdt[5].LimitLow                                = 0x78-1; //FIXME: Check this
        pGdt[5].BaseLow = (USHORT)(Tss & 0xffff);
        pGdt[5].HighWord.Bytes.BaseMid = (UCHAR)((Tss >> 16) & 0xff);
        pGdt[5].HighWord.Bytes.Flags1   = 0x89;