SourceLevelDebugPkg/Library/PeCoffExtraActionLibDebug/PeCoffExtraActionLib.c

   1 /** @file
   2   PE/Coff Extra Action library instances.
   3
   4   Copyright (c) 2010 - 2012, 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 <Base.h>
  16 #include <Library/PeCoffExtraActionLib.h>
  17 #include <Library/DebugLib.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/IoLib.h>
  20 #include <Library/PcdLib.h>
  21
  22 #include <ImageDebugSupport.h>
  23
  24 #define DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT    1
  25 #define DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3           2
  26
  27 /**
  28   Check if the hardware breakpoint in Drx is enabled by checking the Lx and Gx bit in Dr7.
  29
  30   It assumes that DebugAgent will set both Lx and Gx bit when setting up the hardware breakpoint.
  31
  32
  33   @param  RegisterIndex  Index of Dr register. The value range is from 0 to 3.
  34   @param  Dr7            Value of Dr7 register.
  35
  36   @return TRUE   The hardware breakpoint specified in the Drx is enabled.
  37   @return FALSE  The hardware breakpoint specified in the Drx is disabled.
  38
  39 **/
  40 BOOLEAN
  41 IsDrxEnabled (
  42   IN  UINT8  RegisterIndex,
  43   IN  UINTN  Dr7
  44   )
  45 {
  46   return (BOOLEAN) (((Dr7 >> (RegisterIndex * 2)) & (BIT0 | BIT1)) == (BIT0 | BIT1));
  47 }
  48
  49 /**
  50   Common routine to report the PE/COFF image loading/relocating or unloading event.
  51
  52   If ImageContext is NULL, then ASSERT().
  53
  54   @param  ImageContext  Pointer to the image context structure that describes the
  55                         PE/COFF image.
  56   @param  Signature     IMAGE_LOAD_SIGNATURE or IMAGE_UNLOAD_SIGNATURE.
  57
  58 **/
  59 VOID
  60 PeCoffLoaderExtraActionCommon (
  61   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext,
  62   IN     UINTN                         Signature
  63   )
  64 {
  65   BOOLEAN  InterruptState;
  66   UINTN    Dr0;
  67   UINTN    Dr1;
  68   UINTN    Dr2;
  69   UINTN    Dr3;
  70   UINTN    Dr7;
  71   UINTN    Cr4;
  72   UINTN    NewDr7;
  73   UINT8    LoadImageMethod;
  74   UINT8    DebugAgentStatus;
  75
  76   ASSERT (ImageContext != NULL);
  77
  78   if (ImageContext->PdbPointer != NULL) {
  79     DEBUG((EFI_D_ERROR, "    PDB = %a\n", ImageContext->PdbPointer));
  80   }
  81
  82   //
  83   // Disable interrupts and save the current interrupt state
  84   //
  85   InterruptState = SaveAndDisableInterrupts ();
  86
  87   //
  88   // Save Debug Register State
  89   //
  90   Dr0 = AsmReadDr0 ();
  91   Dr1 = AsmReadDr1 ();
  92   Dr2 = AsmReadDr2 ();
  93   Dr3 = AsmReadDr3 ();
  94   Dr7 = AsmReadDr7 ();
  95   Cr4 = AsmReadCr4 ();
  96
  97   //
  98   // DR0 = Signature
  99   // DR1 = The address of the Null-terminated ASCII string for the PE/COFF image's PDB file name
 100   // DR2 = The pointer to the ImageContext structure
 101   // DR3 = IO_PORT_BREAKPOINT_ADDRESS
 102   // DR7 = Disables all HW breakpoints except for DR3 I/O port access of length 1 byte
 103   // CR4 = Make sure DE(BIT3) is set
 104   //
 105   AsmWriteDr7 (0);
 106   AsmWriteDr0 (Signature);
 107   AsmWriteDr1 ((UINTN) ImageContext->PdbPointer);
 108   AsmWriteDr2 ((UINTN) ImageContext);
 109   AsmWriteDr3 (IO_PORT_BREAKPOINT_ADDRESS);
 110
 111   LoadImageMethod = PcdGet8 (PcdDebugLoadImageMethod);
 112   if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
 113     AsmWriteDr7 (0x20000480);
 114     AsmWriteCr4 (Cr4 | BIT3);
 115     //
 116     // Do an IN from IO_PORT_BREAKPOINT_ADDRESS to generate a HW breakpoint until the port
 117     // returns a read value other than DEBUG_AGENT_IMAGE_WAIT
 118     //
 119     do {
 120       DebugAgentStatus = IoRead8 (IO_PORT_BREAKPOINT_ADDRESS);
 121     } while (DebugAgentStatus == DEBUG_AGENT_IMAGE_WAIT);
 122
 123   } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
 124     //
 125     // Generate a software break point.
 126     //
 127     CpuBreakpoint ();
 128   }
 129
 130   //
 131   // Restore Debug Register State only when Host didn't change it inside exception handler.
 132   // E.g.: User halts the target and sets the HW breakpoint while target is
 133   //       in the above exception handler
 134   //
 135   NewDr7 = AsmReadDr7 ();
 136   if (!IsDrxEnabled (0, NewDr7) && (AsmReadDr0 () == 0 || AsmReadDr0 () == Signature)) {
 137     //
 138     // If user changed Dr3 (by setting HW bp in the above exception handler,
 139     // we will not set Dr0 to 0 in GO/STEP handler because the break cause is not IMAGE_LOAD/_UNLOAD.
 140     //
 141     AsmWriteDr0 (Dr0);
 142   }
 143   if (!IsDrxEnabled (1, NewDr7) && (AsmReadDr1 () == (UINTN) ImageContext->PdbPointer)) {
 144     AsmWriteDr1 (Dr1);
 145   }
 146   if (!IsDrxEnabled (2, NewDr7) && (AsmReadDr2 () == (UINTN) ImageContext)) {
 147     AsmWriteDr2 (Dr2);
 148   }
 149   if (!IsDrxEnabled (3, NewDr7) && (AsmReadDr3 () == IO_PORT_BREAKPOINT_ADDRESS)) {
 150     AsmWriteDr3 (Dr3);
 151   }
 152   if (AsmReadCr4 () == (Cr4 | BIT3)) {
 153     AsmWriteCr4 (Cr4);
 154   }
 155   if (NewDr7 == 0x20000480) {
 156     AsmWriteDr7 (Dr7);
 157   }
 158   //
 159   // Restore the interrupt state
 160   //
 161   SetInterruptState (InterruptState);
 162 }
 163
 164 /**
 165   Performs additional actions after a PE/COFF image has been loaded and relocated.
 166
 167   @param  ImageContext  Pointer to the image context structure that describes the
 168                         PE/COFF image that has already been loaded and relocated.
 169
 170 **/
 171 VOID
 172 EFIAPI
 173 PeCoffLoaderRelocateImageExtraAction (
 174   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 175   )
 176 {
 177   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_LOAD_SIGNATURE);
 178 }
 179
 180 /**
 181   Performs additional actions just before a PE/COFF image is unloaded.  Any resources
 182   that were allocated by PeCoffLoaderRelocateImageExtraAction() must be freed.
 183
 184   @param  ImageContext  Pointer to the image context structure that describes the
 185                         PE/COFF image that is being unloaded.
 186
 187 **/
 188 VOID
 189 EFIAPI
 190 PeCoffLoaderUnloadImageExtraAction (
 191   IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
 192   )
 193 {
 194   PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_UNLOAD_SIGNATURE);
 195 }