1 files changed, 51 insertions, 5 deletions
diff --git a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/ArchDebugSupport.c b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/ArchDebugSupport.c
index 52ed647a27..9bd8fca6b6 100644
--- a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/ArchDebugSupport.c
+++ b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/Ia32/ArchDebugSupport.c
@@ -1,7 +1,7 @@
 /** @file
   Supporting functions for IA32 architecture.
 
-  Copyright (c) 2010 - 2012, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2010 - 2013, 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
@@ -39,17 +39,17 @@ InitializeDebugIdt (
   IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) IdtDescriptor.Base;
 
   for (Index = 0; Index < 20; Index ++) {
-    if ((PcdGet32 (PcdExceptionsIgnoredByDebugger) & (1 << Index)) != 0) {
+    if (((PcdGet32 (PcdExceptionsIgnoredByDebugger) & ~(BIT1 | BIT3)) & (1 << Index)) != 0) {
       //
-      // If the exception is masked to be reserved, skip it
+      // If the exception is masked to be reserved except for INT1 and INT3, skip it
       //
       continue;
     }
     InterruptHandler = (UINTN)&Exception0Handle + Index * ExceptionStubHeaderSize;
     IdtEntry[Index].Bits.OffsetLow  = (UINT16)(UINTN)InterruptHandler;
     IdtEntry[Index].Bits.OffsetHigh = (UINT16)((UINTN)InterruptHandler >> 16);
-    IdtEntry[Index].Bits.Selector        = CodeSegment;
-    IdtEntry[Index].Bits.GateType        = IA32_IDT_GATE_TYPE_INTERRUPT_32;
+    IdtEntry[Index].Bits.Selector   = CodeSegment;
+    IdtEntry[Index].Bits.GateType   = IA32_IDT_GATE_TYPE_INTERRUPT_32;
   }
 
   InterruptHandler = (UINTN) &TimerInterruptHandle;
@@ -63,3 +63,49 @@ InitializeDebugIdt (
   //
   AsmWriteCr4 (AsmReadCr4 () | BIT3);
 }
+
+/**
+  Retrieve exception handler from IDT table by ExceptionNum.
+
+  @param[in]  ExceptionNum    Exception number
+ 
+  @return Exception handler
+
+**/
+VOID *
+GetExceptionHandlerInIdtEntry (
+  IN UINTN             ExceptionNum
+  )
+{
+  IA32_IDT_GATE_DESCRIPTOR   *IdtEntry;
+  IA32_DESCRIPTOR            IdtDescriptor;
+
+  AsmReadIdtr (&IdtDescriptor);
+  IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) IdtDescriptor.Base;
+
+  return (VOID *) (((UINTN)IdtEntry[ExceptionNum].Bits.OffsetLow) |
+                  (((UINTN)IdtEntry[ExceptionNum].Bits.OffsetHigh) << 16));
+} 
+
+/**
+  Set exception handler in IDT table by ExceptionNum.
+
+  @param[in]  ExceptionNum      Exception number
+  @param[in]  ExceptionHandler  Exception Handler to be set 
+
+**/
+VOID
+SetExceptionHandlerInIdtEntry (
+  IN UINTN             ExceptionNum,
+  IN VOID              *ExceptionHandler
+  )
+{
+  IA32_IDT_GATE_DESCRIPTOR   *IdtEntry;
+  IA32_DESCRIPTOR            IdtDescriptor;
+
+  AsmReadIdtr (&IdtDescriptor);
+  IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) IdtDescriptor.Base;
+
+  IdtEntry[ExceptionNum].Bits.OffsetLow   = (UINT16)(UINTN)ExceptionHandler;
+  IdtEntry[ExceptionNum].Bits.OffsetHigh  = (UINT16)((UINTN)ExceptionHandler >> 16);
+}