MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c

   1 /** @file
   2
   3   This is a simple fault tolerant write driver.
   4
   5   This boot service protocol only provides fault tolerant write capability for
   6   block devices.  The protocol has internal non-volatile intermediate storage
   7   of the data and private information. It should be able to recover
   8   automatically from a critical fault, such as power failure.
   9
  10   The implementation uses an FTW (Fault Tolerant Write) Work Space.
  11   This work space is a memory copy of the work space on the Working Block,
  12   the size of the work space is the FTW_WORK_SPACE_SIZE bytes.
  13
  14   The work space stores each write record as EFI_FTW_RECORD structure.
  15   The spare block stores the write buffer before write to the target block.
  16
  17   The write record has three states to specify the different phase of write operation.
  18   1) WRITE_ALLOCATED is that the record is allocated in write space.
  19      The information of write operation is stored in write record structure.
  20   2) SPARE_COMPLETED is that the data from write buffer is writed into the spare block as the backup.
  21   3) WRITE_COMPLETED is that the data is copied from the spare block to the target block.
  22
  23   This driver operates the data as the whole size of spare block.
  24   It first read the SpareAreaLength data from the target block into the spare memory buffer.
  25   Then copy the write buffer data into the spare memory buffer.
  26   Then write the spare memory buffer into the spare block.
  27   Final copy the data from the spare block to the target block.
  28
  29   To make this drive work well, the following conditions must be satisfied:
  30   1. The write NumBytes data must be fit within Spare area.
  31      Offset + NumBytes <= SpareAreaLength
  32   2. The whole flash range has the same block size.
  33   3. Working block is an area which contains working space in its last block and has the same size as spare block.
  34   4. Working Block area must be in the single one Firmware Volume Block range which FVB protocol is produced on.
  35   5. Spare area must be in the single one Firmware Volume Block range which FVB protocol is produced on.
  36   6. Any write data area (SpareAreaLength Area) which the data will be written into must be
  37      in the single one Firmware Volume Block range which FVB protocol is produced on.
  38   7. If write data area (such as Variable range) is enlarged, the spare area range must be enlarged.
  39      The spare area must be enough large to store the write data before write them into the target range.
  40   If one of them is not satisfied, FtwWrite may fail.
  41   Usually, Spare area only takes one block. That's SpareAreaLength = BlockSize, NumberOfSpareBlock = 1.
  42
  43 Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  44 SPDX-License-Identifier: BSD-2-Clause-Patent
  45
  46 **/
  47
  48 #include <Library/UefiBootServicesTableLib.h>
  49 #include "FaultTolerantWrite.h"
  50 EFI_EVENT                                 mFvbRegistration = NULL;
  51
  52
  53 /**
  54   Retrieve the FVB protocol interface by HANDLE.
  55
  56   @param[in]  FvBlockHandle     The handle of FVB protocol that provides services for
  57                                 reading, writing, and erasing the target block.
  58   @param[out] FvBlock           The interface of FVB protocol
  59
  60   @retval EFI_SUCCESS           The interface information for the specified protocol was returned.
  61   @retval EFI_UNSUPPORTED       The device does not support the FVB protocol.
  62   @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.
  63
  64 **/
  65 EFI_STATUS
  66 FtwGetFvbByHandle (
  67   IN  EFI_HANDLE                          FvBlockHandle,
  68   OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
  69   )
  70 {
  71   //
  72   // To get the FVB protocol interface on the handle
  73   //
  74   return gBS->HandleProtocol (
  75                 FvBlockHandle,
  76                 &gEfiFirmwareVolumeBlockProtocolGuid,
  77                 (VOID **) FvBlock
  78                 );
  79 }
  80
  81 /**
  82   Retrieve the Swap Address Range protocol interface.
  83
  84   @param[out] SarProtocol       The interface of SAR protocol
  85
  86   @retval EFI_SUCCESS           The SAR protocol instance was found and returned in SarProtocol.
  87   @retval EFI_NOT_FOUND         The SAR protocol instance was not found.
  88   @retval EFI_INVALID_PARAMETER SarProtocol is NULL.
  89
  90 **/
  91 EFI_STATUS
  92 FtwGetSarProtocol (
  93   OUT VOID                                **SarProtocol
  94   )
  95 {
  96   EFI_STATUS                              Status;
  97
  98   //
  99   // Locate Swap Address Range protocol
 100   //
 101   Status = gBS->LocateProtocol (
 102                   &gEfiSwapAddressRangeProtocolGuid,
 103                   NULL,
 104                   SarProtocol
 105                   );
 106   return Status;
 107 }
 108
 109 /**
 110   Function returns an array of handles that support the FVB protocol
 111   in a buffer allocated from pool.
 112
 113   @param[out]  NumberHandles    The number of handles returned in Buffer.
 114   @param[out]  Buffer           A pointer to the buffer to return the requested
 115                                 array of  handles that support FVB protocol.
 116
 117   @retval EFI_SUCCESS           The array of handles was returned in Buffer, and the number of
 118                                 handles in Buffer was returned in NumberHandles.
 119   @retval EFI_NOT_FOUND         No FVB handle was found.
 120   @retval EFI_OUT_OF_RESOURCES  There is not enough pool memory to store the matching results.
 121   @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL.
 122
 123 **/
 124 EFI_STATUS
 125 GetFvbCountAndBuffer (
 126   OUT UINTN                               *NumberHandles,
 127   OUT EFI_HANDLE                          **Buffer
 128   )
 129 {
 130   EFI_STATUS                              Status;
 131
 132   //
 133   // Locate all handles of Fvb protocol
 134   //
 135   Status = gBS->LocateHandleBuffer (
 136                   ByProtocol,
 137                   &gEfiFirmwareVolumeBlockProtocolGuid,
 138                   NULL,
 139                   NumberHandles,
 140                   Buffer
 141                   );
 142   return Status;
 143 }
 144
 145
 146 /**
 147   Firmware Volume Block Protocol notification event handler.
 148
 149   @param[in] Event    Event whose notification function is being invoked.
 150   @param[in] Context  Pointer to the notification function's context.
 151
 152 **/
 153 VOID
 154 EFIAPI
 155 FvbNotificationEvent (
 156   IN  EFI_EVENT                           Event,
 157   IN  VOID                                *Context
 158   )
 159 {
 160   EFI_STATUS                              Status;
 161   EFI_FAULT_TOLERANT_WRITE_PROTOCOL       *FtwProtocol;
 162   EFI_FTW_DEVICE                          *FtwDevice;
 163
 164   //
 165   // Just return to avoid installing FaultTolerantWriteProtocol again
 166   // if Fault Tolerant Write protocol has been installed.
 167   //
 168   Status = gBS->LocateProtocol (
 169                   &gEfiFaultTolerantWriteProtocolGuid,
 170                   NULL,
 171                   (VOID **) &FtwProtocol
 172                   );
 173   if (!EFI_ERROR (Status)) {
 174     return ;
 175   }
 176
 177   //
 178   // Found proper FVB protocol and initialize FtwDevice for protocol installation
 179   //
 180   FtwDevice = (EFI_FTW_DEVICE *)Context;
 181   Status = InitFtwProtocol (FtwDevice);
 182   if (EFI_ERROR(Status)) {
 183     return ;
 184   }
 185
 186   //
 187   // Install protocol interface
 188   //
 189   Status = gBS->InstallProtocolInterface (
 190                   &FtwDevice->Handle,
 191                   &gEfiFaultTolerantWriteProtocolGuid,
 192                   EFI_NATIVE_INTERFACE,
 193                   &FtwDevice->FtwInstance
 194                   );
 195   ASSERT_EFI_ERROR (Status);
 196
 197   Status = gBS->CloseEvent (Event);
 198   ASSERT_EFI_ERROR (Status);
 199
 200   return;
 201 }
 202
 203
 204 /**
 205   This function is the entry point of the Fault Tolerant Write driver.
 206
 207   @param[in] ImageHandle        A handle for the image that is initializing this driver
 208   @param[in] SystemTable        A pointer to the EFI system table
 209
 210   @retval EFI_SUCCESS           The initialization finished successfully.
 211   @retval EFI_OUT_OF_RESOURCES  Allocate memory error
 212   @retval EFI_INVALID_PARAMETER Workspace or Spare block does not exist
 213
 214 **/
 215 EFI_STATUS
 216 EFIAPI
 217 FaultTolerantWriteInitialize (
 218   IN EFI_HANDLE                           ImageHandle,
 219   IN EFI_SYSTEM_TABLE                     *SystemTable
 220   )
 221 {
 222   EFI_STATUS                              Status;
 223   EFI_FTW_DEVICE                          *FtwDevice;
 224
 225   FtwDevice = NULL;
 226
 227   //
 228   // Allocate private data structure for FTW protocol and do some initialization
 229   //
 230   Status = InitFtwDevice (&FtwDevice);
 231   if (EFI_ERROR(Status)) {
 232     return Status;
 233   }
 234
 235   //
 236   // Register FvbNotificationEvent () notify function.
 237   //
 238   EfiCreateProtocolNotifyEvent (
 239     &gEfiFirmwareVolumeBlockProtocolGuid,
 240     TPL_CALLBACK,
 241     FvbNotificationEvent,
 242     (VOID *)FtwDevice,
 243     &mFvbRegistration
 244     );
 245
 246   return EFI_SUCCESS;
 247 }
 248
 249 /**
 250   Internal implementation of CRC32. Depending on the execution context
 251   (traditional SMM or DXE vs standalone MM), this function is implemented
 252   via a call to the CalculateCrc32 () boot service, or via a library
 253   call.
 254
 255   If Buffer is NULL, then ASSERT().
 256   If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
 257
 258   @param[in]  Buffer       A pointer to the buffer on which the 32-bit CRC is to be computed.
 259   @param[in]  Length       The number of bytes in the buffer Data.
 260
 261   @retval Crc32            The 32-bit CRC was computed for the data buffer.
 262
 263 **/
 264 UINT32
 265 FtwCalculateCrc32 (
 266   IN  VOID                         *Buffer,
 267   IN  UINTN                        Length
 268   )
 269 {
 270   EFI_STATUS    Status;
 271   UINT32        ReturnValue;
 272
 273   Status = gBS->CalculateCrc32 (Buffer, Length, &ReturnValue);
 274   ASSERT_EFI_ERROR (Status);
 275
 276   return ReturnValue;
 277 }