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_SIZE  EFI_PAGES_TO_SIZE(2)
  23 STATIC UINTN mNewStackBase[EL0_STACK_SIZE / sizeof (UINTN)];
  24
  25 VOID
  26 RegisterEl0Stack (
  27   IN  VOID    *Stack
  28   );
  29
  30 RETURN_STATUS ArchVectorConfig(
  31   IN  UINTN       VectorBaseAddress
  32   )
  33 {
  34   UINTN             HcrReg;
  35
  36   // Round down sp by 16 bytes alignment
  37   RegisterEl0Stack (
  38     (VOID *)(((UINTN)mNewStackBase + EL0_STACK_SIZE) & ~0xFUL)
  39     );
  40
  41   if (ArmReadCurrentEL() == AARCH64_EL2) {
  42     HcrReg = ArmReadHcr();
  43
  44     // Trap General Exceptions. All exceptions that would be routed to EL1 are routed to EL2
  45     HcrReg |= ARM_HCR_TGE;
  46
  47     ArmWriteHcr(HcrReg);
  48   }
  49
  50   return RETURN_SUCCESS;
  51 }