1 files changed, 7 insertions, 2 deletions
diff --git a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/X64/ArchDebugSupport.c b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/X64/ArchDebugSupport.c
index 60d3eb8bb3..08cef0154f 100644
--- a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/X64/ArchDebugSupport.c
+++ b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/X64/ArchDebugSupport.c
@@ -1,7 +1,7 @@
 /** @file
   Supporting functions for X64 architecture.
 
-  Copyright (c) 2010 - 2013, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -28,6 +28,7 @@ InitializeDebugIdt (
   IA32_DESCRIPTOR            IdtDescriptor;
   UINTN                      Index;
   UINT16                     CodeSegment;
+  UINT32                     RegEdx;
 
   AsmReadIdtr (&IdtDescriptor);
 
@@ -61,9 +62,13 @@ InitializeDebugIdt (
   IdtEntry[DEBUG_TIMER_VECTOR].Bits.GateType        = IA32_IDT_GATE_TYPE_INTERRUPT_32;
 
   //
+  // If the CPU supports Debug Extensions(CPUID:01 EDX:BIT2), then 
   // Set DE flag in CR4 to enable IO breakpoint
   //
-  AsmWriteCr4 (AsmReadCr4 () | BIT3);
+  AsmCpuid (1, NULL, NULL, NULL, &RegEdx);
+  if ((RegEdx & BIT2) != 0) {
+    AsmWriteCr4 (AsmReadCr4 () | BIT3);
+  }
 }
 
 /**