ArmPkg/Drivers/CpuDxe/Exception.c

   1 /** @file
   2
   3   Copyright (c) 2008-2009, Apple Inc. All rights reserved.
   4
   5   All rights reserved. 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 "CpuDxe.h"
  16
  17
  18 VOID
  19 ExceptionHandlersStart (
  20   VOID
  21   );
  22
  23 VOID
  24 ExceptionHandlersEnd (
  25   VOID
  26   );
  27
  28 VOID
  29 CommonExceptionEntry (
  30   VOID
  31   );
  32
  33 VOID
  34 AsmCommonExceptionEntry (
  35   VOID
  36   );
  37
  38
  39 EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  40 EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  41
  42
  43
  44 /**
  45   This function registers and enables the handler specified by InterruptHandler for a processor
  46   interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  47   handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  48   The installed handler is called once for each processor interrupt or exception.
  49
  50   @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  51                            are enabled and FALSE if interrupts are disabled.
  52   @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  53                            when a processor interrupt occurs. If this parameter is NULL, then the handler
  54                            will be uninstalled.
  55
  56   @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  57   @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  58                                 previously installed.
  59   @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
  60                                 previously installed.
  61   @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
  62
  63 **/
  64 EFI_STATUS
  65 RegisterInterruptHandler (
  66   IN EFI_EXCEPTION_TYPE             InterruptType,
  67   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
  68   )
  69 {
  70   if (InterruptType > MAX_ARM_EXCEPTION) {
  71     return EFI_UNSUPPORTED;
  72   }
  73
  74   if ((InterruptHandler != NULL) && (gExceptionHandlers[InterruptType] != NULL)) {
  75     return EFI_ALREADY_STARTED;
  76   }
  77
  78   gExceptionHandlers[InterruptType] = InterruptHandler;
  79
  80   return EFI_SUCCESS;
  81 }
  82
  83
  84 /**
  85   This function registers and enables the handler specified by InterruptHandler for a processor
  86   interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  87   handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  88   The installed handler is called once for each processor interrupt or exception.
  89
  90   @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  91                            are enabled and FALSE if interrupts are disabled.
  92   @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  93                            when a processor interrupt occurs. If this parameter is NULL, then the handler
  94                            will be uninstalled.
  95
  96   @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  97   @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  98                                 previously installed.
  99   @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
 100                                 previously installed.
 101   @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
 102
 103 **/
 104 EFI_STATUS
 105 RegisterDebuggerInterruptHandler (
 106   IN EFI_EXCEPTION_TYPE             InterruptType,
 107   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
 108   )
 109 {
 110   if (InterruptType > MAX_ARM_EXCEPTION) {
 111     return EFI_UNSUPPORTED;
 112   }
 113
 114   if ((InterruptHandler != NULL) && (gDebuggerExceptionHandlers[InterruptType] != NULL)) {
 115     return EFI_ALREADY_STARTED;
 116   }
 117
 118   gDebuggerExceptionHandlers[InterruptType] = InterruptHandler;
 119
 120   return EFI_SUCCESS;
 121 }
 122
 123
 124
 125 VOID
 126 EFIAPI
 127 CommonCExceptionHandler (
 128   IN     EFI_EXCEPTION_TYPE           ExceptionType,
 129   IN OUT EFI_SYSTEM_CONTEXT           SystemContext
 130   )
 131 {
 132   BOOLEAN Dispatched = FALSE;
 133
 134
 135   if (ExceptionType <= MAX_ARM_EXCEPTION) {
 136     if (gDebuggerExceptionHandlers[ExceptionType]) {
 137       //
 138       // If DebugSupport hooked the interrupt call the handler. This does not disable
 139       // the normal handler.
 140       //
 141       gDebuggerExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
 142       Dispatched = TRUE;
 143     }
 144     if (gExceptionHandlers[ExceptionType]) {
 145       gExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
 146       Dispatched = TRUE;
 147     }
 148   } else {
 149     DEBUG ((EFI_D_ERROR, "Unknown exception type %d from %08x\n", ExceptionType, SystemContext.SystemContextArm->PC));
 150     ASSERT (FALSE);
 151   }
 152
 153   if (Dispatched) {
 154     //
 155     // We did work so this was an expected ExceptionType
 156     //
 157     return;
 158   }
 159
 160   if (ExceptionType == EXCEPT_ARM_SOFTWARE_INTERRUPT) {
 161     //
 162     // ARM JTAG debuggers some times use this vector, so it is not an error to get one
 163     //
 164     return;
 165   }
 166
 167   DefaultExceptionHandler (ExceptionType, SystemContext);
 168 }
 169
 170
 171
 172 EFI_STATUS
 173 InitializeExceptions (
 174   IN EFI_CPU_ARCH_PROTOCOL    *Cpu
 175   )
 176 {
 177   EFI_STATUS           Status;
 178   UINTN                Offset;
 179   UINTN                Length;
 180   UINTN                Index;
 181   BOOLEAN              Enabled;
 182   EFI_PHYSICAL_ADDRESS Base;
 183   UINT32               *VectorBase;
 184
 185   //
 186   // Disable interrupts
 187   //
 188   Cpu->GetInterruptState (Cpu, &Enabled);
 189   Cpu->DisableInterrupt (Cpu);
 190
 191
 192   //
 193   // Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.
 194   //
 195   Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;
 196
 197   //
 198   // Reserve space for the exception handlers
 199   //
 200   Base = (EFI_PHYSICAL_ADDRESS)PcdGet32 (PcdCpuVectorBaseAddress);
 201   VectorBase = (UINT32 *)(UINTN)Base;
 202   Status = gBS->AllocatePages (AllocateAddress, EfiBootServicesCode, EFI_SIZE_TO_PAGES (Length), &Base);
 203   // If the request was for memory that's not in the memory map (which is often the case for 0x00000000
 204   // on embedded systems, for example, we don't want to hang up.  So we'll check here for a status of
 205   // EFI_NOT_FOUND, and continue in that case.
 206   if (EFI_ERROR(Status) && (Status != EFI_NOT_FOUND)) {
 207     ASSERT_EFI_ERROR (Status);
 208   }
 209
 210   // Save existing vector table, in case debugger is already hooked in
 211   CopyMem ((VOID *)gDebuggerExceptionHandlers, (VOID *)VectorBase, sizeof (gDebuggerExceptionHandlers));
 212
 213   //
 214   // Initialize the C entry points for interrupts
 215   //
 216   for (Index = 0; Index <= MAX_ARM_EXCEPTION; Index++) {
 217     Status = RegisterInterruptHandler (Index, NULL);
 218     ASSERT_EFI_ERROR (Status);
 219
 220     if (VectorBase[Index] == 0xEAFFFFFE) {
 221       // Exception handler contains branch to vector location (jmp $) so no handler
 222       // NOTE: This code assumes vectors are ARM and not Thumb code
 223       gDebuggerExceptionHandlers[Index] = NULL;
 224     }
 225   }
 226
 227   // Copy our assembly code into the page that contains the exception vectors.
 228   CopyMem ((VOID *)VectorBase, (VOID *)ExceptionHandlersStart, Length);
 229
 230   //
 231   // Patch in the common Assembly exception handler
 232   //
 233   Offset = (UINTN)CommonExceptionEntry - (UINTN)ExceptionHandlersStart;
 234   *(UINTN *) ((UINT8 *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress) + Offset) = (UINTN)AsmCommonExceptionEntry;
 235
 236   // Flush Caches since we updated executable stuff
 237   InvalidateInstructionCacheRange ((VOID *)PcdGet32(PcdCpuVectorBaseAddress), Length);
 238
 239   if (Enabled) {
 240     //
 241     // Restore interrupt state
 242     //
 243     Status = Cpu->EnableInterrupt (Cpu);
 244   }
 245
 246   return Status;
 247 }