MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/X64/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 x64 platform
   5
   6 Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
   7
   8 This program and the accompanying materials
   9 are licensed and made available under the terms and conditions of the BSD License
  10 which accompanies this distribution.  The full text of the license may be found at
  11 http://opensource.org/licenses/bsd-license.php
  12
  13 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16 **/
  17 #include "ScriptExecute.h"
  18 //
  19 // INTERRUPT_GATE_DESCRIPTOR and SetIdtEntry () are used to setup IDT to do debug
  20 //
  21
  22 #pragma pack(1)
  23
  24 typedef struct {
  25   UINT16    Offset15To0;
  26   UINT16    SegmentSelector;
  27   UINT16    Attributes;
  28   UINT16    Offset31To16;
  29   UINT32    Offset63To32;
  30   UINT32    Reserved;
  31 } INTERRUPT_GATE_DESCRIPTOR;
  32
  33 #define INTERRUPT_GATE_ATTRIBUTE   0x8e00
  34
  35 #pragma pack()
  36 /**
  37   Set a IDT entry for interrupt vector 3 for debug purpose.
  38
  39   @param  AcpiS3Context  a pointer to a structure of ACPI_S3_CONTEXT
  40
  41 **/
  42 VOID
  43 SetIdtEntry (
  44   IN ACPI_S3_CONTEXT     *AcpiS3Context
  45   )
  46 {
  47   INTERRUPT_GATE_DESCRIPTOR                     *IdtEntry;
  48   IA32_DESCRIPTOR                               *IdtDescriptor;
  49   UINTN                                         S3DebugBuffer;
  50
  51   //
  52   // Restore IDT for debug
  53   //
  54   IdtDescriptor = (IA32_DESCRIPTOR *) (UINTN) (AcpiS3Context->IdtrProfile);
  55   AsmWriteIdtr (IdtDescriptor);
  56
  57   //
  58   // Setup the default CPU exception handlers
  59   //
  60   SetupCpuExceptionHandlers ();
  61
  62   //
  63   // Update IDT entry INT3
  64   //
  65   IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
  66   S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
  67
  68   IdtEntry->Offset15To0     = (UINT16)S3DebugBuffer;
  69   IdtEntry->SegmentSelector = (UINT16)AsmReadCs ();;
  70   IdtEntry->Attributes      = (UINT16)INTERRUPT_GATE_ATTRIBUTE;
  71   IdtEntry->Offset31To16    = (UINT16)(S3DebugBuffer >> 16);
  72   IdtEntry->Offset63To32    = (UINT32)(S3DebugBuffer >> 32);
  73   IdtEntry->Reserved        = 0;
  74
  75 }
  76