diff options
Diffstat (limited to 'MdeModulePkg')
| -rw-r--r-- | MdeModulePkg/Core/Dxe/Mem/Page.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/MdeModulePkg/Core/Dxe/Mem/Page.c b/MdeModulePkg/Core/Dxe/Mem/Page.c index 8a6d35d6e4..90976a1f0f 100644 --- a/MdeModulePkg/Core/Dxe/Mem/Page.c +++ b/MdeModulePkg/Core/Dxe/Mem/Page.c @@ -177,7 +177,20 @@ CoreAddRange ( ASSERT_LOCKED (&gMemoryLock);
DEBUG ((DEBUG_PAGE, "AddRange: %lx-%lx to %d\n", Start, End, Type));
-
+
+ //
+ // If memory of type EfiConventionalMemory is being added that includes the page
+ // starting at address 0, then zero the page starting at address 0. This has
+ // two benifits. It helps find NULL pointer bugs and it also maximizes
+ // compatibility with operating systems that may evaluate memory in this page
+ // for legacy data structures. If memory of any other type is added starting
+ // at address 0, then do not zero the page at address 0 because the page is being
+ // used for other purposes.
+ //
+ if (Type == EfiConventionalMemory && Start == 0 && (End >= EFI_PAGE_SIZE - 1)) {
+ SetMem ((VOID *)(UINTN)Start, EFI_PAGE_SIZE, 0);
+ }
+
//
// Memory map being altered so updated key
//
|