QuarkPlatformPkg/Acpi/Dxe/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) 2013-2015 Intel Corporation.
   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  OffsetLow;
  26   UINT16  SegmentSelector;
  27   UINT16  Attributes;
  28   UINT16  OffsetHigh;
  29 } INTERRUPT_GATE_DESCRIPTOR;
  30
  31 #define INTERRUPT_GATE_ATTRIBUTE   0x8e00
  32
  33 #pragma pack()
  34 /**
  35   Set a IDT entry for interrupt vector 3 for debug purpose.
  36
  37   @param  AcpiS3Context  a pointer to a structure of ACPI_S3_CONTEXT
  38
  39 **/
  40 VOID
  41 SetIdtEntry (
  42   IN ACPI_S3_CONTEXT     *AcpiS3Context
  43   )
  44 {
  45   INTERRUPT_GATE_DESCRIPTOR                     *IdtEntry;
  46   IA32_DESCRIPTOR                               *IdtDescriptor;
  47   UINTN                                         S3DebugBuffer;
  48
  49   //
  50   // Restore IDT for debug
  51   //
  52   IdtDescriptor = (IA32_DESCRIPTOR *) (UINTN) (AcpiS3Context->IdtrProfile);
  53   IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
  54   S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
  55
  56   IdtEntry->OffsetLow       = (UINT16)S3DebugBuffer;
  57   IdtEntry->SegmentSelector = (UINT16)AsmReadCs ();
  58   IdtEntry->Attributes      = (UINT16)INTERRUPT_GATE_ATTRIBUTE;
  59   IdtEntry->OffsetHigh      = (UINT16)(S3DebugBuffer >> 16);
  60
  61   AsmWriteIdtr (IdtDescriptor);
  62 }
  63