SourceLevelDebugPkg/Library/DebugAgent/SmmDebugAgent/SmmDebugAgentLib.c

   1 /** @file
   2   Debug Agent library implementition.
   3
   4   Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "SmmDebugAgentLib.h"
  16
  17 DEBUG_AGENT_MAILBOX         *mMailboxPointer = NULL;
  18 DEBUG_AGENT_MAILBOX         mLocalMailbox;
  19 UINTN                       mSavedDebugRegisters[6];
  20 CONST BOOLEAN               MultiProcessorDebugSupport = FALSE;
  21
  22
  23 /**
  24   Get Debug Agent Mailbox pointer.
  25
  26   @return Mailbox pointer.
  27
  28 **/
  29 DEBUG_AGENT_MAILBOX *
  30 GetMailboxPointer (
  31   VOID
  32   )
  33 {
  34   return mMailboxPointer;
  35 }
  36
  37 /**
  38   Get debug port handle.
  39
  40   @return Debug port handle.
  41
  42 **/
  43 DEBUG_PORT_HANDLE
  44 GetDebugPortHandle (
  45   VOID
  46   )
  47 {
  48   return (DEBUG_PORT_HANDLE) (UINTN)(mMailboxPointer->DebugPortHandle);
  49 }
  50
  51 /**
  52   Store debug register when SMI exit.
  53
  54 **/
  55 VOID
  56 SaveDebugRegister (
  57   VOID
  58   )
  59 {
  60   mSavedDebugRegisters[0] = AsmReadDr0 ();
  61   mSavedDebugRegisters[1] = AsmReadDr1 ();
  62   mSavedDebugRegisters[2] = AsmReadDr2 ();
  63   mSavedDebugRegisters[3] = AsmReadDr3 ();
  64   mSavedDebugRegisters[4] = AsmReadDr6 ();
  65   mSavedDebugRegisters[5] = AsmReadDr7 ();
  66 }
  67
  68 /**
  69   Restore debug register when SMI exit.
  70
  71 **/
  72 VOID
  73 RestoreDebugRegister (
  74   VOID
  75   )
  76 {
  77   AsmWriteDr7 (0);
  78   AsmWriteDr0 (mSavedDebugRegisters[0]);
  79   AsmWriteDr1 (mSavedDebugRegisters[1]);
  80   AsmWriteDr2 (mSavedDebugRegisters[2]);
  81   AsmWriteDr3 (mSavedDebugRegisters[3]);
  82   AsmWriteDr6 (mSavedDebugRegisters[4]);
  83   AsmWriteDr7 (mSavedDebugRegisters[5]);
  84 }
  85
  86 /**
  87   Initialize debug agent.
  88
  89   This function is used to set up debug enviroment for source level debug
  90   in SMM code.
  91
  92   If InitFlag is DEBUG_AGENT_INIT_SMM, it will overirde IDT table entries
  93   and initialize debug port. It will get debug agent Mailbox from GUIDed HOB,
  94   it it exists, debug agent wiil copied it into the local Mailbox in SMM space.
  95   it will overirde IDT table entries and initialize debug port. Context will be
  96   NULL.
  97   If InitFlag is DEBUG_AGENT_INIT_ENTER_SMI, debug agent will save Debug
  98   Registers and get local Mailbox in SMM space. Context will be NULL.
  99   If InitFlag is DEBUG_AGENT_INIT_EXIT_SMI, debug agent will restore Debug
 100   Registers. Context will be NULL.
 101
 102   @param[in] InitFlag     Init flag is used to decide initialize process.
 103   @param[in] Context      Context needed according to InitFlag.
 104   @param[in] Function     Continue function called by debug agent library; it was
 105                           optional.
 106
 107 **/
 108 VOID
 109 EFIAPI
 110 InitializeDebugAgent (
 111   IN UINT32                InitFlag,
 112   IN VOID                  *Context, OPTIONAL
 113   IN DEBUG_AGENT_CONTINUE  Function  OPTIONAL
 114   )
 115 {
 116   EFI_STATUS               Status;
 117   UINT64                   DebugPortHandle;
 118
 119   switch (InitFlag) {
 120   case DEBUG_AGENT_INIT_SMM:
 121     Status = EfiGetSystemConfigurationTable (&gEfiDebugAgentGuid, (VOID **) &mMailboxPointer);
 122     if (EFI_ERROR (Status) || mMailboxPointer == NULL) {
 123       ZeroMem (&mLocalMailbox, sizeof (DEBUG_AGENT_MAILBOX));
 124       mMailboxPointer = &mLocalMailbox;
 125     }
 126
 127     break;
 128
 129   case DEBUG_AGENT_INIT_ENTER_SMI:
 130     SaveDebugRegister ();
 131     InitializeDebugIdt ();
 132
 133     if (mMailboxPointer != NULL) {
 134       //
 135       // Initialize debug communication port
 136       //
 137       DebugPortHandle = (UINT64) (UINTN)DebugPortInitialize ((DEBUG_PORT_HANDLE) (UINTN)mMailboxPointer->DebugPortHandle, NULL);
 138       mMailboxPointer->DebugPortHandle = DebugPortHandle;
 139
 140       if (mMailboxPointer->DebugFlag.Bits.BreakOnNextSmi == 1) {
 141         //
 142         // If SMM entry break is set, SMM code will be break at here.
 143         //
 144         CpuBreakpoint ();
 145       }
 146     }
 147     break;
 148
 149   case DEBUG_AGENT_INIT_EXIT_SMI:
 150     RestoreDebugRegister ();
 151     break;
 152   }
 153 }
 154