Fix BiosVideo thunk bug about invalid legacy region area.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8099 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 5 insertions, 6 deletions

diff --git a/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c b/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
index e21ab362ef..0f02659b6b 100644
--- a/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
+++ b/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
@@ -30,26 +30,25 @@ InitializeBiosIntCaller (
   UINT32                RealModeBufferSize;

   UINT32                ExtraStackSize;

   EFI_PHYSICAL_ADDRESS  LegacyRegionBase;

-  

+  UINT32                LegacyRegionSize;

   //

   // Get LegacyRegion

   //

   AsmGetThunk16Properties (&RealModeBufferSize, &ExtraStackSize);

-

+  LegacyRegionSize = (((RealModeBufferSize + ExtraStackSize) / EFI_PAGE_SIZE) + 1) * EFI_PAGE_SIZE;

   LegacyRegionBase = 0x100000;

   Status = gBS->AllocatePages (

                   AllocateMaxAddress,

                   EfiACPIMemoryNVS,

-                  EFI_SIZE_TO_PAGES(RealModeBufferSize + ExtraStackSize + 200),

+                  EFI_SIZE_TO_PAGES(LegacyRegionSize),

                   &LegacyRegionBase

                   );

   ASSERT_EFI_ERROR (Status);

   

   ThunkContext->RealModeBuffer     = (VOID*)(UINTN)LegacyRegionBase;

-  ThunkContext->RealModeBufferSize = EFI_PAGES_TO_SIZE (RealModeBufferSize);

-  ThunkContext->ThunkAttributes    = 3;

+  ThunkContext->RealModeBufferSize = LegacyRegionSize;

+  ThunkContext->ThunkAttributes    = THUNK_ATTRIBUTE_BIG_REAL_MODE|THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15;

   AsmPrepareThunk16(ThunkContext);

-  

 }

 

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