MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/IA32/SetIdtEntry.c

   1 /** @file
   2   Set a IDT entry for debug purpose
   3
   4   Set a IDT entry for interrupt vector 3 for debug purpose for IA32 platform
   5
   6 Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
   7
   8 SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11 #include "ScriptExecute.h"
  12
  13 /**
  14   Set a IDT entry for interrupt vector 3 for debug purpose.
  15
  16   @param  AcpiS3Context  a pointer to a structure of ACPI_S3_CONTEXT
  17
  18 **/
  19 VOID
  20 SetIdtEntry (
  21   IN ACPI_S3_CONTEXT  *AcpiS3Context
  22   )
  23 {
  24   IA32_IDT_GATE_DESCRIPTOR  *IdtEntry;
  25   IA32_DESCRIPTOR           *IdtDescriptor;
  26   UINTN                     S3DebugBuffer;
  27   EFI_STATUS                Status;
  28
  29   //
  30   // Restore IDT for debug
  31   //
  32   IdtDescriptor = (IA32_DESCRIPTOR *)(UINTN)(AcpiS3Context->IdtrProfile);
  33   AsmWriteIdtr (IdtDescriptor);
  34
  35   //
  36   // Setup the default CPU exception handlers
  37   //
  38   Status = InitializeCpuExceptionHandlers (NULL);
  39   ASSERT_EFI_ERROR (Status);
  40
  41   DEBUG_CODE_BEGIN ();
  42   //
  43   // Update IDT entry INT3 if the instruction is valid in it
  44   //
  45   S3DebugBuffer = (UINTN)(AcpiS3Context->S3DebugBufferAddress);
  46   if (*(UINTN *)S3DebugBuffer != (UINTN)-1) {
  47     IdtEntry                  = (IA32_IDT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (IA32_IDT_GATE_DESCRIPTOR)));
  48     IdtEntry->Bits.OffsetLow  = (UINT16)S3DebugBuffer;
  49     IdtEntry->Bits.Selector   = (UINT16)AsmReadCs ();
  50     IdtEntry->Bits.Reserved_0 = 0;
  51     IdtEntry->Bits.GateType   = IA32_IDT_GATE_TYPE_INTERRUPT_32;
  52     IdtEntry->Bits.OffsetHigh = (UINT16)(S3DebugBuffer >> 16);
  53   }
  54
  55   DEBUG_CODE_END ();
  56 }