ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c

   1 /** @file
   2   Default exception handler
   3
   4   Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   5   Copyright (c) 2012, ARM Ltd. All rights reserved.<BR>
   6
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #include <Uefi.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/DebugLib.h>
  20 #include <Library/PeCoffGetEntryPointLib.h>
  21 #include <Library/PrintLib.h>
  22 #include <Library/ArmDisassemblerLib.h>
  23 #include <Library/SerialPortLib.h>
  24
  25 #include <Guid/DebugImageInfoTable.h>
  26
  27 #include <Protocol/DebugSupport.h>
  28 #include <Library/DefaultExceptionHandlerLib.h>
  29
  30 //
  31 // The number of elements in a CHAR8 array, including the terminating NUL, that
  32 // is meant to hold the string rendering of the CPSR.
  33 //
  34 #define CPSR_STRING_SIZE 32
  35
  36 typedef struct {
  37   UINT32  BIT;
  38   CHAR8   Char;
  39 } CPSR_CHAR;
  40
  41 CHAR8 *
  42 GetImageName (
  43   IN  UINTN  FaultAddress,
  44   OUT UINTN  *ImageBase,
  45   OUT UINTN  *PeCoffSizeOfHeaders
  46   );
  47
  48 /**
  49   Convert the Current Program Status Register (CPSR) to a string. The string is
  50   a defacto standard in the ARM world.
  51
  52   It is possible to add extra bits by adding them to CpsrChar array.
  53
  54   @param  Cpsr         ARM CPSR register value
  55   @param  ReturnStr    CPSR_STRING_SIZE byte string that contains string
  56                        version of CPSR
  57
  58 **/
  59 VOID
  60 CpsrString (
  61   IN  UINT32  Cpsr,
  62   OUT CHAR8   *ReturnStr
  63   )
  64 {
  65   UINTN     Index;
  66   CHAR8*    Str;
  67   CHAR8*    ModeStr;
  68   CPSR_CHAR CpsrChar[] = {
  69     { 31, 'n' },
  70     { 30, 'z' },
  71     { 29, 'c' },
  72     { 28, 'v' },
  73
  74     { 9,  'e' },
  75     { 8,  'a' },
  76     { 7,  'i' },
  77     { 6,  'f' },
  78     { 5,  't' },
  79     { 0,  '?' }
  80   };
  81
  82   Str = ReturnStr;
  83
  84   for (Index = 0; CpsrChar[Index].BIT != 0; Index++, Str++) {
  85     *Str = CpsrChar[Index].Char;
  86     if ((Cpsr & (1 << CpsrChar[Index].BIT)) != 0) {
  87       // Concert to upper case if bit is set
  88       *Str &= ~0x20;
  89     }
  90   }
  91
  92   *Str++ = '_';
  93   *Str = '\0';
  94
  95   switch (Cpsr & 0x1f) {
  96   case 0x10:
  97     ModeStr = "usr";
  98     break;
  99   case 0x011:
 100     ModeStr = "fiq";
 101     break;
 102   case 0x12:
 103     ModeStr = "irq";
 104     break;
 105   case 0x13:
 106     ModeStr = "svc";
 107     break;
 108   case 0x16:
 109     ModeStr = "mon";
 110     break;
 111   case 0x17:
 112     ModeStr = "abt";
 113     break;
 114   case 0x1b:
 115     ModeStr = "und";
 116     break;
 117   case 0x1f:
 118     ModeStr = "sys";
 119     break;
 120
 121   default:
 122     ModeStr = "???";
 123     break;
 124   }
 125
 126   //
 127   // See the interface contract in the leading comment block.
 128   //
 129   AsciiStrCatS (Str, CPSR_STRING_SIZE - (Str - ReturnStr), ModeStr);
 130 }
 131
 132 CHAR8 *
 133 FaultStatusToString (
 134   IN  UINT32  Status
 135   )
 136 {
 137   CHAR8 *FaultSource;
 138
 139   switch (Status) {
 140     case 0x01: FaultSource = "Alignment fault"; break;
 141     case 0x02: FaultSource = "Debug event fault"; break;
 142     case 0x03: FaultSource = "Access Flag fault on Section"; break;
 143     case 0x04: FaultSource = "Cache maintenance operation fault[2]"; break;
 144     case 0x05: FaultSource = "Translation fault on Section"; break;
 145     case 0x06: FaultSource = "Access Flag fault on Page"; break;
 146     case 0x07: FaultSource = "Translation fault on Page"; break;
 147     case 0x08: FaultSource = "Precise External Abort"; break;
 148     case 0x09: FaultSource = "Domain fault on Section"; break;
 149     case 0x0b: FaultSource = "Domain fault on Page"; break;
 150     case 0x0c: FaultSource = "External abort on translation, first level"; break;
 151     case 0x0d: FaultSource = "Permission fault on Section"; break;
 152     case 0x0e: FaultSource = "External abort on translation, second level"; break;
 153     case 0x0f: FaultSource = "Permission fault on Page"; break;
 154     case 0x16: FaultSource = "Imprecise External Abort"; break;
 155     default:   FaultSource = "No function"; break;
 156     }
 157
 158   return FaultSource;
 159 }
 160
 161 STATIC CHAR8 *gExceptionTypeString[] = {
 162   "Reset",
 163   "Undefined OpCode",
 164   "SVC",
 165   "Prefetch Abort",
 166   "Data Abort",
 167   "Undefined",
 168   "IRQ",
 169   "FIQ"
 170 };
 171
 172 /**
 173   This is the default action to take on an unexpected exception
 174
 175   Since this is exception context don't do anything crazy like try to allcoate memory.
 176
 177   @param  ExceptionType    Type of the exception
 178   @param  SystemContext    Register state at the time of the Exception
 179
 180
 181 **/
 182 VOID
 183 DefaultExceptionHandler (
 184   IN     EFI_EXCEPTION_TYPE           ExceptionType,
 185   IN OUT EFI_SYSTEM_CONTEXT           SystemContext
 186   )
 187 {
 188   CHAR8     Buffer[100];
 189   UINTN     CharCount;
 190   UINT32    DfsrStatus;
 191   UINT32    IfsrStatus;
 192   BOOLEAN   DfsrWrite;
 193   UINT32    PcAdjust = 0;
 194
 195   CharCount = AsciiSPrint (Buffer,sizeof (Buffer),"\n%a Exception PC at 0x%08x  CPSR 0x%08x ",
 196          gExceptionTypeString[ExceptionType], SystemContext.SystemContextArm->PC, SystemContext.SystemContextArm->CPSR);
 197   SerialPortWrite ((UINT8 *) Buffer, CharCount);
 198
 199   DEBUG_CODE_BEGIN ();
 200     CHAR8   *Pdb;
 201     UINT32  ImageBase;
 202     UINT32  PeCoffSizeOfHeader;
 203     UINT32  Offset;
 204     CHAR8   CpsrStr[CPSR_STRING_SIZE];  // char per bit. Lower 5-bits are mode
 205                                         // that is a 3 char string
 206     CHAR8   Buffer[80];
 207     UINT8   *DisAsm;
 208     UINT32  ItBlock;
 209
 210     CpsrString (SystemContext.SystemContextArm->CPSR, CpsrStr);
 211     DEBUG ((EFI_D_ERROR, "%a\n", CpsrStr));
 212
 213     Pdb = GetImageName (SystemContext.SystemContextArm->PC, &ImageBase, &PeCoffSizeOfHeader);
 214     Offset = SystemContext.SystemContextArm->PC - ImageBase;
 215     if (Pdb != NULL) {
 216       DEBUG ((EFI_D_ERROR, "%a\n", Pdb));
 217
 218       //
 219       // A PE/COFF image loads its headers into memory so the headers are
 220       // included in the linked addresses. ELF and Mach-O images do not
 221       // include the headers so the first byte of the image is usually
 222       // text (code). If you look at link maps from ELF or Mach-O images
 223       // you need to subtract out the size of the PE/COFF header to get
 224       // get the offset that matches the link map.
 225       //
 226       DEBUG ((EFI_D_ERROR, "loaded at 0x%08x (PE/COFF offset) 0x%x (ELF or Mach-O offset) 0x%x", ImageBase, Offset, Offset - PeCoffSizeOfHeader));
 227
 228       // If we come from an image it is safe to show the instruction. We know it should not fault
 229       DisAsm = (UINT8 *)(UINTN)SystemContext.SystemContextArm->PC;
 230       ItBlock = 0;
 231       DisassembleInstruction (&DisAsm, (SystemContext.SystemContextArm->CPSR & BIT5) == BIT5, TRUE, &ItBlock, Buffer, sizeof (Buffer));
 232       DEBUG ((EFI_D_ERROR, "\n%a", Buffer));
 233
 234       switch (ExceptionType) {
 235       case EXCEPT_ARM_UNDEFINED_INSTRUCTION:
 236       case EXCEPT_ARM_SOFTWARE_INTERRUPT:
 237       case EXCEPT_ARM_PREFETCH_ABORT:
 238       case EXCEPT_ARM_DATA_ABORT:
 239         // advance PC past the faulting instruction
 240         PcAdjust = (UINTN)DisAsm - SystemContext.SystemContextArm->PC;
 241         break;
 242
 243       default:
 244         break;
 245       }
 246
 247     }
 248   DEBUG_CODE_END ();
 249   DEBUG ((EFI_D_ERROR, "\n  R0 0x%08x   R1 0x%08x   R2 0x%08x   R3 0x%08x\n", SystemContext.SystemContextArm->R0, SystemContext.SystemContextArm->R1, SystemContext.SystemContextArm->R2, SystemContext.SystemContextArm->R3));
 250   DEBUG ((EFI_D_ERROR, "  R4 0x%08x   R5 0x%08x   R6 0x%08x   R7 0x%08x\n", SystemContext.SystemContextArm->R4, SystemContext.SystemContextArm->R5, SystemContext.SystemContextArm->R6, SystemContext.SystemContextArm->R7));
 251   DEBUG ((EFI_D_ERROR, "  R8 0x%08x   R9 0x%08x  R10 0x%08x  R11 0x%08x\n", SystemContext.SystemContextArm->R8, SystemContext.SystemContextArm->R9, SystemContext.SystemContextArm->R10, SystemContext.SystemContextArm->R11));
 252   DEBUG ((EFI_D_ERROR, " R12 0x%08x   SP 0x%08x   LR 0x%08x   PC 0x%08x\n", SystemContext.SystemContextArm->R12, SystemContext.SystemContextArm->SP, SystemContext.SystemContextArm->LR, SystemContext.SystemContextArm->PC));
 253   DEBUG ((EFI_D_ERROR, "DFSR 0x%08x DFAR 0x%08x IFSR 0x%08x IFAR 0x%08x\n", SystemContext.SystemContextArm->DFSR, SystemContext.SystemContextArm->DFAR, SystemContext.SystemContextArm->IFSR, SystemContext.SystemContextArm->IFAR));
 254
 255   // Bit10 is Status[4] Bit3:0 is Status[3:0]
 256   DfsrStatus = (SystemContext.SystemContextArm->DFSR & 0xf) | ((SystemContext.SystemContextArm->DFSR >> 6) & 0x10);
 257   DfsrWrite = (SystemContext.SystemContextArm->DFSR & BIT11) != 0;
 258   if (DfsrStatus != 0x00) {
 259     DEBUG ((EFI_D_ERROR, " %a: %a 0x%08x\n", FaultStatusToString (DfsrStatus), DfsrWrite ? "write to" : "read from", SystemContext.SystemContextArm->DFAR));
 260   }
 261
 262   IfsrStatus = (SystemContext.SystemContextArm->IFSR & 0xf) | ((SystemContext.SystemContextArm->IFSR >> 6) & 0x10);
 263   if (IfsrStatus != 0) {
 264     DEBUG ((EFI_D_ERROR, " Instruction %a at 0x%08x\n", FaultStatusToString (SystemContext.SystemContextArm->IFSR & 0xf), SystemContext.SystemContextArm->IFAR));
 265   }
 266
 267   DEBUG ((EFI_D_ERROR, "\n"));
 268   ASSERT (FALSE);
 269
 270   CpuDeadLoop ();   // may return if executing under a debugger
 271
 272   // Clear the error registers that we have already displayed incase some one wants to keep going
 273   SystemContext.SystemContextArm->DFSR = 0;
 274   SystemContext.SystemContextArm->IFSR = 0;
 275
 276   // If some one is stepping past the exception handler adjust the PC to point to the next instruction
 277   SystemContext.SystemContextArm->PC += PcAdjust;
 278 }