1 files changed, 101 insertions, 0 deletions
diff --git a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
index 7308523ad8..d2224a20aa 100644
--- a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
+++ b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
@@ -1733,6 +1733,98 @@ CheckKeyboardConnect (
 }
 
 /**
+   Disable NULL pointer detection
+*/
+VOID
+DisableNullDetection (
+  VOID
+  )
+{
+  EFI_STATUS                            Status;
+  EFI_GCD_MEMORY_SPACE_DESCRIPTOR       Desc;
+
+  if ((PcdGet8 (PcdNullPointerDetectionPropertyMask) & BIT0) == 0) {
+    return;
+  }
+
+  //
+  // Check current capabilities and attributes
+  //
+  Status = gDS->GetMemorySpaceDescriptor (0, &Desc);
+  ASSERT_EFI_ERROR (Status);
+
+  //
+  // Try to add EFI_MEMORY_RP support if necessary
+  //
+  if ((Desc.Capabilities & EFI_MEMORY_RP) == 0) {
+    Desc.Capabilities |= EFI_MEMORY_RP;
+    Status = gDS->SetMemorySpaceCapabilities (0, EFI_PAGES_TO_SIZE(1),
+                                              Desc.Capabilities);
+    ASSERT_EFI_ERROR (Status);
+    if (EFI_ERROR (Status)) {
+      return;
+    }
+  }
+
+  //
+  // Don't bother if EFI_MEMORY_RP is already cleared.
+  //
+  if ((Desc.Attributes & EFI_MEMORY_RP) != 0) {
+    Desc.Attributes &= ~EFI_MEMORY_RP;
+    Status = gDS->SetMemorySpaceAttributes (0, EFI_PAGES_TO_SIZE(1),
+                                            Desc.Attributes);
+    ASSERT_EFI_ERROR (Status);
+  } else {
+    DEBUG ((DEBUG_WARN, "!!! Page 0 is supposed to be disabled !!!\r\n"));
+  }
+}
+
+/**
+   Enable NULL pointer detection
+*/
+VOID
+EnableNullDetection (
+  VOID
+  )
+{
+  EFI_STATUS                            Status;
+  EFI_GCD_MEMORY_SPACE_DESCRIPTOR       Desc;
+
+  if ((PcdGet8 (PcdNullPointerDetectionPropertyMask) & BIT0) == 0) {
+    return;
+  }
+
+  //
+  // Check current capabilities and attributes
+  //
+  Status = gDS->GetMemorySpaceDescriptor (0, &Desc);
+  ASSERT_EFI_ERROR (Status);
+
+  //
+  // Try to add EFI_MEMORY_RP support if necessary
+  //
+  if ((Desc.Capabilities & EFI_MEMORY_RP) == 0) {
+    Desc.Capabilities |= EFI_MEMORY_RP;
+    Status = gDS->SetMemorySpaceCapabilities (0, EFI_PAGES_TO_SIZE(1),
+                                              Desc.Capabilities);
+    ASSERT_EFI_ERROR (Status);
+    if (EFI_ERROR (Status)) {
+      return;
+    }
+  }
+
+  //
+  // Don't bother if EFI_MEMORY_RP is already set.
+  //
+  if ((Desc.Attributes & EFI_MEMORY_RP) == 0) {
+    Desc.Attributes |= EFI_MEMORY_RP;
+    Status = gDS->SetMemorySpaceAttributes (0, EFI_PAGES_TO_SIZE(1),
+                                            Desc.Attributes);
+    ASSERT_EFI_ERROR (Status);
+  }
+}
+
+/**
   Timer event handler: read a series of key stroke from 8042
   and put them into memory key buffer. 
   It is registered as running under TPL_NOTIFY
@@ -1840,6 +1932,11 @@ BiosKeyboardTimerHandler (
 
 
   //
+  // Disable NULL pointer detection temporarily
+  //
+  DisableNullDetection ();
+
+  //
   // Clear the CTRL and ALT BDA flag
   //
   KbFlag1 = *((UINT8 *) (UINTN) 0x417);  // read the STATUS FLAGS 1
@@ -1916,6 +2013,10 @@ BiosKeyboardTimerHandler (
   KbFlag1 &= ~0x0C;                      
   *((UINT8 *) (UINTN) 0x417) = KbFlag1; 
 
+  //
+  // Restore NULL pointer detection
+  //
+  EnableNullDetection ();
   
   //
   // Output EFI input key and shift/toggle state