ArmPkg/Drivers/CpuDxe/Exception.c

   1 /** @file
   2
   3   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   4   Portions Copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.<BR>
   5
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include "CpuDxe.h"
  17 #include <Library/CpuExceptionHandlerLib.h>
  18 #include <Guid/VectorHandoffTable.h>
  19
  20 EFI_STATUS
  21 InitializeExceptions (
  22   IN EFI_CPU_ARCH_PROTOCOL    *Cpu
  23   ) {
  24   EFI_STATUS                      Status;
  25   EFI_VECTOR_HANDOFF_INFO         *VectorInfoList;
  26   EFI_VECTOR_HANDOFF_INFO         *VectorInfo;
  27   BOOLEAN                         IrqEnabled;
  28   BOOLEAN                         FiqEnabled;
  29
  30   VectorInfo = (EFI_VECTOR_HANDOFF_INFO *)NULL;
  31   Status = EfiGetSystemConfigurationTable(&gEfiVectorHandoffTableGuid, (VOID **)&VectorInfoList);
  32   if (Status == EFI_SUCCESS && VectorInfoList != NULL) {
  33     VectorInfo = VectorInfoList;
  34   }
  35
  36   // intialize the CpuExceptionHandlerLib so we take over the exception vector table from the DXE Core
  37   InitializeCpuExceptionHandlers(VectorInfo);
  38
  39   Status = EFI_SUCCESS;
  40
  41   //
  42   // Disable interrupts
  43   //
  44   Cpu->GetInterruptState (Cpu, &IrqEnabled);
  45   Cpu->DisableInterrupt (Cpu);
  46
  47   //
  48   // EFI does not use the FIQ, but a debugger might so we must disable
  49   // as we take over the exception vectors.
  50   //
  51   FiqEnabled = ArmGetFiqState ();
  52   ArmDisableFiq ();
  53
  54   if (FiqEnabled) {
  55     ArmEnableFiq ();
  56   }
  57
  58   if (IrqEnabled) {
  59     //
  60     // Restore interrupt state
  61     //
  62     Status = Cpu->EnableInterrupt (Cpu);
  63   }
  64
  65   //
  66   // On a DEBUG build, unmask SErrors so they are delivered right away rather
  67   // than when the OS unmasks them. This gives us a better chance of figuring
  68   // out the cause.
  69   //
  70   DEBUG_CODE (
  71     ArmEnableAsynchronousAbort ();
  72   );
  73
  74   return Status;
  75 }
  76
  77 /**
  78 This function registers and enables the handler specified by InterruptHandler for a processor
  79 interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  80 handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  81 The installed handler is called once for each processor interrupt or exception.
  82
  83 @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  84 are enabled and FALSE if interrupts are disabled.
  85 @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  86 when a processor interrupt occurs. If this parameter is NULL, then the handler
  87 will be uninstalled.
  88
  89 @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  90 @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  91 previously installed.
  92 @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
  93 previously installed.
  94 @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
  95
  96 **/
  97 EFI_STATUS
  98 RegisterInterruptHandler(
  99   IN EFI_EXCEPTION_TYPE             InterruptType,
 100   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
 101   ) {
 102   // pass down to CpuExceptionHandlerLib
 103   return (EFI_STATUS)RegisterCpuInterruptHandler(InterruptType, InterruptHandler);
 104 }