Make these drivers more compatible with a projected Debug Agent Library implementation.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10196 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 21 insertions, 11 deletions

diff --git a/ArmPkg/Drivers/CpuDxe/Exception.c b/ArmPkg/Drivers/CpuDxe/Exception.c
index e313cf3fe9..d99d3d1d01 100644
--- a/ArmPkg/Drivers/CpuDxe/Exception.c
+++ b/ArmPkg/Drivers/CpuDxe/Exception.c
@@ -180,6 +180,7 @@ InitializeExceptions (
   UINTN                Index;

   BOOLEAN              Enabled;

   EFI_PHYSICAL_ADDRESS Base;

+  UINT32               *VectorBase;

 

   //

   // Disable interrupts

@@ -187,16 +188,6 @@ InitializeExceptions (
   Cpu->GetInterruptState (Cpu, &Enabled);

   Cpu->DisableInterrupt (Cpu);

 

-  //

-  // Initialize the C entry points for interrupts

-  //

-  for (Index = 0; Index <= MAX_ARM_EXCEPTION; Index++) {

-    Status = RegisterInterruptHandler (Index, NULL);

-    ASSERT_EFI_ERROR (Status);

-    

-    Status = RegisterDebuggerInterruptHandler (Index, NULL);

-    ASSERT_EFI_ERROR (Status);

-  }

   

   //

   // Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.

@@ -207,6 +198,7 @@ InitializeExceptions (
   // Reserve space for the exception handlers

   //

   Base = (EFI_PHYSICAL_ADDRESS)PcdGet32 (PcdCpuVectorBaseAddress);

+  VectorBase = (UINT32 *)(UINTN)Base;

   Status = gBS->AllocatePages (AllocateAddress, EfiBootServicesCode, EFI_SIZE_TO_PAGES (Length), &Base);

   // If the request was for memory that's not in the memory map (which is often the case for 0x00000000

   // on embedded systems, for example, we don't want to hang up.  So we'll check here for a status of 

@@ -215,7 +207,25 @@ InitializeExceptions (
     ASSERT_EFI_ERROR (Status);

   }

 

-  CopyMem ((VOID *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress), (VOID *)ExceptionHandlersStart, Length);

+  // Save existing vector table, in case debugger is already hooked in

+  CopyMem ((VOID *)gDebuggerExceptionHandlers, (VOID *)VectorBase, sizeof (gDebuggerExceptionHandlers));

+

+  //

+  // Initialize the C entry points for interrupts

+  //

+  for (Index = 0; Index <= MAX_ARM_EXCEPTION; Index++) {

+    Status = RegisterInterruptHandler (Index, NULL);

+    ASSERT_EFI_ERROR (Status);

+    

+    if (VectorBase[Index] == 0xEAFFFFFE) {

+      // Exception handler contains branch to vector location (jmp $) so no handler

+      // NOTE: This code assumes vectors are ARM and not Thumb code

+      gDebuggerExceptionHandlers[Index] = NULL;

+    }

+  }

+

+  // Copy our assembly code into the page that contains the exception vectors. 

+  CopyMem ((VOID *)VectorBase, (VOID *)ExceptionHandlersStart, Length);

 

   //

   // Patch in the common Assembly exception handler