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 *  Copyright (c) 2021, Arm Limited. All rights reserved.<BR>
   6 *
   7 *  SPDX-License-Identifier: BSD-2-Clause-Patent
   8 *
   9 **/
  10
  11 #include <Uefi.h>
  12
  13 #include <Chipset/AArch64.h>
  14 #include <Library/MemoryAllocationLib.h>
  15 #include <Protocol/DebugSupport.h> // for MAX_AARCH64_EXCEPTION
  16
  17 UINTN                   gMaxExceptionNumber = MAX_AARCH64_EXCEPTION;
  18 EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
  19 EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_AARCH64_EXCEPTION + 1] = { 0 };
  20 PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask = ARM_VECTOR_TABLE_ALIGNMENT;
  21 UINTN                   gDebuggerNoHandlerValue = 0; // todo: define for AArch64
  22
  23 #define EL0_STACK_SIZE  EFI_PAGES_TO_SIZE(2)
  24 STATIC UINTN mNewStackBase[EL0_STACK_SIZE / sizeof (UINTN)];
  25
  26 VOID
  27 RegisterEl0Stack (
  28   IN  VOID    *Stack
  29   );
  30
  31 RETURN_STATUS
  32 ArchVectorConfig (
  33   IN  UINTN       VectorBaseAddress
  34   )
  35 {
  36   UINTN             HcrReg;
  37
  38   // Round down sp by 16 bytes alignment
  39   RegisterEl0Stack (
  40     (VOID *)(((UINTN)mNewStackBase + EL0_STACK_SIZE) & ~0xFUL)
  41     );
  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 }