ArmPkg/Drivers/CpuDxe/Exception.c

   1 /** @file
   2
   3   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   4
   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 "CpuDxe.h"
  16
  17 //FIXME: Will not compile on non-ARMv7 builds
  18 #include <Chipset/ArmV7.h>
  19
  20 VOID
  21 ExceptionHandlersStart (
  22   VOID
  23   );
  24
  25 VOID
  26 ExceptionHandlersEnd (
  27   VOID
  28   );
  29
  30 VOID
  31 CommonExceptionEntry (
  32   VOID
  33   );
  34
  35 VOID
  36 AsmCommonExceptionEntry (
  37   VOID
  38   );
  39
  40
  41 EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  42 EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  43
  44
  45
  46 /**
  47   This function registers and enables the handler specified by InterruptHandler for a processor
  48   interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  49   handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  50   The installed handler is called once for each processor interrupt or exception.
  51
  52   @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  53                            are enabled and FALSE if interrupts are disabled.
  54   @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  55                            when a processor interrupt occurs. If this parameter is NULL, then the handler
  56                            will be uninstalled.
  57
  58   @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  59   @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  60                                 previously installed.
  61   @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
  62                                 previously installed.
  63   @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
  64
  65 **/
  66 EFI_STATUS
  67 RegisterInterruptHandler (
  68   IN EFI_EXCEPTION_TYPE             InterruptType,
  69   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
  70   )
  71 {
  72   if (InterruptType > MAX_ARM_EXCEPTION) {
  73     return EFI_UNSUPPORTED;
  74   }
  75
  76   if ((InterruptHandler != NULL) && (gExceptionHandlers[InterruptType] != NULL)) {
  77     return EFI_ALREADY_STARTED;
  78   }
  79
  80   gExceptionHandlers[InterruptType] = InterruptHandler;
  81
  82   return EFI_SUCCESS;
  83 }
  84
  85
  86
  87
  88 VOID
  89 EFIAPI
  90 CommonCExceptionHandler (
  91   IN     EFI_EXCEPTION_TYPE           ExceptionType,
  92   IN OUT EFI_SYSTEM_CONTEXT           SystemContext
  93   )
  94 {
  95
  96   if (ExceptionType <= MAX_ARM_EXCEPTION) {
  97     if (gExceptionHandlers[ExceptionType]) {
  98       gExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
  99       return;
 100     }
 101   } else {
 102     DEBUG ((EFI_D_ERROR, "Unknown exception type %d from %08x\n", ExceptionType, SystemContext.SystemContextArm->PC));
 103     ASSERT (FALSE);
 104   }
 105
 106   if (ExceptionType == EXCEPT_ARM_SOFTWARE_INTERRUPT) {
 107     //
 108     // ARM JTAG debuggers some times use this vector, so it is not an error to get one
 109     //
 110     return;
 111   }
 112
 113   DefaultExceptionHandler (ExceptionType, SystemContext);
 114 }
 115
 116
 117
 118 EFI_STATUS
 119 InitializeExceptions (
 120   IN EFI_CPU_ARCH_PROTOCOL    *Cpu
 121   )
 122 {
 123   EFI_STATUS           Status;
 124   UINTN                Offset;
 125   UINTN                Length;
 126   UINTN                Index;
 127   BOOLEAN              IrqEnabled;
 128   BOOLEAN              FiqEnabled;
 129   EFI_PHYSICAL_ADDRESS Base;
 130   UINT32               *VectorBase;
 131
 132   Status = EFI_SUCCESS;
 133   //
 134   // Disable interrupts
 135   //
 136   Cpu->GetInterruptState (Cpu, &IrqEnabled);
 137   Cpu->DisableInterrupt (Cpu);
 138
 139   //
 140   // EFI does not use the FIQ, but a debugger might so we must disable
 141   // as we take over the exception vectors.
 142   //
 143   FiqEnabled = ArmGetFiqState ();
 144   ArmDisableFiq ();
 145
 146   if (FeaturePcdGet(PcdRelocateVectorTable) == TRUE) {
 147       //
 148       // Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.
 149       //
 150       Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;
 151
 152       //
 153       // Reserve space for the exception handlers
 154       //
 155       Base = (EFI_PHYSICAL_ADDRESS)PcdGet32 (PcdCpuVectorBaseAddress);
 156       VectorBase = (UINT32 *)(UINTN)Base;
 157       Status = gBS->AllocatePages (AllocateAddress, EfiBootServicesCode, EFI_SIZE_TO_PAGES (Length), &Base);
 158       // If the request was for memory that's not in the memory map (which is often the case for 0x00000000
 159       // on embedded systems, for example, we don't want to hang up.  So we'll check here for a status of
 160       // EFI_NOT_FOUND, and continue in that case.
 161       if (EFI_ERROR(Status) && (Status != EFI_NOT_FOUND)) {
 162         ASSERT_EFI_ERROR (Status);
 163       }
 164
 165       // Save existing vector table, in case debugger is already hooked in
 166       CopyMem ((VOID *)gDebuggerExceptionHandlers, (VOID *)VectorBase, sizeof (gDebuggerExceptionHandlers));
 167
 168       // Copy our assembly code into the page that contains the exception vectors.
 169       CopyMem ((VOID *)VectorBase, (VOID *)ExceptionHandlersStart, Length);
 170
 171       //
 172       // Patch in the common Assembly exception handler
 173       //
 174       Offset = (UINTN)CommonExceptionEntry - (UINTN)ExceptionHandlersStart;
 175       *(UINTN *) ((UINT8 *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress) + Offset) = (UINTN)AsmCommonExceptionEntry;
 176
 177       //
 178       // Initialize the C entry points for interrupts
 179       //
 180       for (Index = 0; Index <= MAX_ARM_EXCEPTION; Index++) {
 181         if ((gDebuggerExceptionHandlers[Index] == 0) || (gDebuggerExceptionHandlers[Index] == (VOID *)(UINTN)0xEAFFFFFE)) {
 182           // Exception handler contains branch to vector location (jmp $) so no handler
 183           // NOTE: This code assumes vectors are ARM and not Thumb code
 184           Status = RegisterInterruptHandler (Index, NULL);
 185           ASSERT_EFI_ERROR (Status);
 186         } else {
 187           // If the debugger has alread hooked put its vector back
 188           VectorBase[Index] = (UINT32)(UINTN)gDebuggerExceptionHandlers[Index];
 189         }
 190       }
 191
 192       // Flush Caches since we updated executable stuff
 193       InvalidateInstructionCacheRange ((VOID *)PcdGet32(PcdCpuVectorBaseAddress), Length);
 194
 195       //Note: On ARM processor with the Security Extension, the Vector Table can be located anywhere in the memory.
 196       //      The Vector Base Address Register defines the location
 197       ArmWriteVBar(PcdGet32(PcdCpuVectorBaseAddress));
 198   } else {
 199     // We do not copy the Exception Table at PcdGet32(PcdCpuVectorBaseAddress). We just set Vector Base Address to point into CpuDxe code.
 200     ArmWriteVBar((UINT32)ExceptionHandlersStart);
 201   }
 202
 203   if (FiqEnabled) {
 204     ArmEnableFiq ();
 205   }
 206
 207   if (IrqEnabled) {
 208     //
 209     // Restore interrupt state
 210     //
 211     Status = Cpu->EnableInterrupt (Cpu);
 212   }
 213
 214   return Status;
 215 }