Fix BiosVideo thunk bug about invalid legacy region area.

[mirror_edk2.git] / DuetPkg / BiosVideoThunkDxe / LegacyBiosThunk.c

diff --git a/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c b/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
index e21ab362ef630b70e2d58e38dc842887db75c249..0f02659b6b84eaecb5bbeae8dc0616a67d374885 100644 (file)
--- a/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
+++ b/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
@@ -30,26 +30,25 @@ InitializeBiosIntCaller (
   UINT32                RealModeBufferSize;\r
   UINT32                ExtraStackSize;\r
   EFI_PHYSICAL_ADDRESS  LegacyRegionBase;\r
-  \r
+  UINT32                LegacyRegionSize;\r
   //\r
   // Get LegacyRegion\r
   //\r
   AsmGetThunk16Properties (&RealModeBufferSize, &ExtraStackSize);\r
-\r
+  LegacyRegionSize = (((RealModeBufferSize + ExtraStackSize) / EFI_PAGE_SIZE) + 1) * EFI_PAGE_SIZE;\r
   LegacyRegionBase = 0x100000;\r
   Status = gBS->AllocatePages (\r
                   AllocateMaxAddress,\r
                   EfiACPIMemoryNVS,\r
-                  EFI_SIZE_TO_PAGES(RealModeBufferSize + ExtraStackSize + 200),\r
+                  EFI_SIZE_TO_PAGES(LegacyRegionSize),\r
                   &LegacyRegionBase\r
                   );\r
   ASSERT_EFI_ERROR (Status);\r
   \r
   ThunkContext->RealModeBuffer     = (VOID*)(UINTN)LegacyRegionBase;\r
-  ThunkContext->RealModeBufferSize = EFI_PAGES_TO_SIZE (RealModeBufferSize);\r
-  ThunkContext->ThunkAttributes    = 3;\r
+  ThunkContext->RealModeBufferSize = LegacyRegionSize;\r
+  ThunkContext->ThunkAttributes    = THUNK_ATTRIBUTE_BIG_REAL_MODE|THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15;\r
   AsmPrepareThunk16(ThunkContext);\r
-  \r
 }\r
 \r
 /**\r