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
  19 GLOBAL_REMOVE_IF_UNREFERENCED DEBUG_AGENT_MAILBOX         mLocalMailbox;
  20
  21 GLOBAL_REMOVE_IF_UNREFERENCED UINTN    mSavedDebugRegisters[6];
  22
  23 CONST BOOLEAN                    MultiProcessorDebugSupport = FALSE;
  24
  25
  26 /**
  27   Get Debug Agent Mailbox pointer.
  28
  29   @return Mailbox pointer.
  30
  31 **/
  32 DEBUG_AGENT_MAILBOX *
  33 GetMailboxPointer (
  34   VOID
  35   )
  36 {
  37   return mMailboxPointer;
  38 }
  39
  40 /**
  41   Get debug port handle.
  42
  43   @return Debug port handle.
  44
  45 **/
  46 DEBUG_PORT_HANDLE
  47 GetDebugPortHandle (
  48   VOID
  49   )
  50 {
  51   return (DEBUG_PORT_HANDLE) (UINTN)(mMailboxPointer->DebugPortHandle);
  52 }
  53
  54 /**
  55   Store debug register when SMI exit.
  56
  57 **/
  58 VOID
  59 SaveDebugRegister (
  60   VOID
  61   )
  62 {
  63   mSavedDebugRegisters[0] = AsmReadDr0 ();
  64   mSavedDebugRegisters[1] = AsmReadDr1 ();
  65   mSavedDebugRegisters[2] = AsmReadDr2 ();
  66   mSavedDebugRegisters[3] = AsmReadDr3 ();
  67   mSavedDebugRegisters[4] = AsmReadDr6 ();
  68   mSavedDebugRegisters[5] = AsmReadDr7 ();
  69 }
  70
  71 /**
  72   Restore debug register when SMI exit.
  73
  74 **/
  75 VOID
  76 RestoreDebugRegister (
  77   VOID
  78   )
  79 {
  80   AsmWriteDr7 (0);
  81   AsmWriteDr0 (mSavedDebugRegisters[0]);
  82   AsmWriteDr1 (mSavedDebugRegisters[1]);
  83   AsmWriteDr2 (mSavedDebugRegisters[2]);
  84   AsmWriteDr3 (mSavedDebugRegisters[3]);
  85   AsmWriteDr6 (mSavedDebugRegisters[4]);
  86   AsmWriteDr7 (mSavedDebugRegisters[5]);
  87 }
  88
  89 /**
  90   Initialize debug agent.
  91
  92   This function is used to set up debug enviroment for source level debug
  93   in SMM code.
  94
  95   If InitFlag is DEBUG_AGENT_INIT_SMM, it will overirde IDT table entries
  96   and initialize debug port. It will get debug agent Mailbox from GUIDed HOB,
  97   it it exists, debug agent wiil copied it into the local Mailbox in SMM space.
  98   it will overirde IDT table entries and initialize debug port. Context will be
  99   NULL.
 100   If InitFlag is DEBUG_AGENT_INIT_ENTER_SMI, debug agent will save Debug
 101   Registers and get local Mailbox in SMM space. Context will be NULL.
 102   If InitFlag is DEBUG_AGENT_INIT_EXIT_SMI, debug agent will restore Debug
 103   Registers. Context will be NULL.
 104
 105   @param[in] InitFlag     Init flag is used to decide initialize process.
 106   @param[in] Context      Context needed according to InitFlag.
 107   @param[in] Function     Continue function called by debug agent library; it was
 108                           optional.
 109
 110 **/
 111 VOID
 112 EFIAPI
 113 InitializeDebugAgent (
 114   IN UINT32                InitFlag,
 115   IN VOID                  *Context, OPTIONAL
 116   IN DEBUG_AGENT_CONTINUE  Function  OPTIONAL
 117   )
 118 {
 119   EFI_STATUS               Status;
 120   UINT64                   DebugPortHandle;
 121
 122   switch (InitFlag) {
 123   case DEBUG_AGENT_INIT_SMM:
 124     Status = EfiGetSystemConfigurationTable (&gEfiDebugAgentGuid, (VOID **) &mMailboxPointer);
 125     if (EFI_ERROR (Status) || mMailboxPointer == NULL) {
 126       ZeroMem (&mLocalMailbox, sizeof (DEBUG_AGENT_MAILBOX));
 127       mMailboxPointer = &mLocalMailbox;
 128     }
 129
 130     break;
 131
 132   case DEBUG_AGENT_INIT_ENTER_SMI:
 133     SaveDebugRegister ();
 134     InitializeDebugIdt ();
 135
 136     if (mMailboxPointer != NULL) {
 137       //
 138       // Initialize debug communication port
 139       //
 140       DebugPortHandle = (UINT64) (UINTN)DebugPortInitialize ((DEBUG_PORT_HANDLE) (UINTN)mMailboxPointer->DebugPortHandle, NULL);
 141       mMailboxPointer->DebugPortHandle = DebugPortHandle;
 142
 143       if (mMailboxPointer->DebugFlag.Bits.BreakOnNextSmi == 1) {
 144         //
 145         // If SMM entry break is set, SMM code will be break at here.
 146         //
 147         CpuBreakpoint ();
 148       }
 149     }
 150     break;
 151
 152   case DEBUG_AGENT_INIT_EXIT_SMI:
 153     RestoreDebugRegister ();
 154     break;
 155   }
 156 }
 157