ArmPkg/Library/ArmExceptionLib/AArch64/AArch64Exception.c

   1 /** @file
   2 *  Exception Handling support specific for AArch64
   3 *
   4 *  Copyright (c) 2016 HP Development Company, L.P.
   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 <Uefi.h>
  17
  18 #include <Chipset/AArch64.h>
  19 #include <Library/MemoryAllocationLib.h>
  20 #include <Protocol/DebugSupport.h> // for MAX_AARCH64_EXCEPTION
  21
  22 UINTN                   gMaxExceptionNumber = MAX_AARCH64_EXCEPTION;
  23 EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
  24 EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
  25 PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask = ARM_VECTOR_TABLE_ALIGNMENT;
  26 UINTN                   gDebuggerNoHandlerValue = 0; // todo: define for AArch64
  27
  28 #define EL0_STACK_PAGES   2
  29
  30 VOID
  31 RegisterEl0Stack (
  32   IN  VOID    *Stack
  33   );
  34
  35 RETURN_STATUS ArchVectorConfig(
  36   IN  UINTN       VectorBaseAddress
  37   )
  38 {
  39   UINTN             HcrReg;
  40   UINT8             *Stack;
  41
  42   Stack = AllocatePages (EL0_STACK_PAGES);
  43   if (Stack == NULL) {
  44     return RETURN_OUT_OF_RESOURCES;
  45   }
  46
  47   RegisterEl0Stack ((UINT8 *)Stack + EFI_PAGES_TO_SIZE (EL0_STACK_PAGES));
  48
  49   if (ArmReadCurrentEL() == AARCH64_EL2) {
  50     HcrReg = ArmReadHcr();
  51
  52     // Trap General Exceptions. All exceptions that would be routed to EL1 are routed to EL2
  53     HcrReg |= ARM_HCR_TGE;
  54
  55     ArmWriteHcr(HcrReg);
  56   }
  57
  58   return RETURN_SUCCESS;
  59 }