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 *  SPDX-License-Identifier: BSD-2-Clause-Patent
   7 *
   8 **/
   9
  10 #include <Uefi.h>
  11
  12 #include <Chipset/AArch64.h>
  13 #include <Library/MemoryAllocationLib.h>
  14 #include <Protocol/DebugSupport.h> // for MAX_AARCH64_EXCEPTION
  15
  16 UINTN                   gMaxExceptionNumber = MAX_AARCH64_EXCEPTION;
  17 EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
  18 EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
  19 PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask = ARM_VECTOR_TABLE_ALIGNMENT;
  20 UINTN                   gDebuggerNoHandlerValue = 0; // todo: define for AArch64
  21
  22 #define EL0_STACK_PAGES   2
  23
  24 VOID
  25 RegisterEl0Stack (
  26   IN  VOID    *Stack
  27   );
  28
  29 RETURN_STATUS ArchVectorConfig(
  30   IN  UINTN       VectorBaseAddress
  31   )
  32 {
  33   UINTN             HcrReg;
  34   UINT8             *Stack;
  35
  36   Stack = AllocatePages (EL0_STACK_PAGES);
  37   if (Stack == NULL) {
  38     return RETURN_OUT_OF_RESOURCES;
  39   }
  40
  41   RegisterEl0Stack ((UINT8 *)Stack + EFI_PAGES_TO_SIZE (EL0_STACK_PAGES));
  42
  43   if (ArmReadCurrentEL() == AARCH64_EL2) {
  44     HcrReg = ArmReadHcr();
  45
  46     // Trap General Exceptions. All exceptions that would be routed to EL1 are routed to EL2
  47     HcrReg |= ARM_HCR_TGE;
  48
  49     ArmWriteHcr(HcrReg);
  50   }
  51
  52   return RETURN_SUCCESS;
  53 }