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 This program and the accompanying materials
  45 are licensed and made available under the terms and conditions of the BSD License
  46 which accompanies this distribution.  The full text of the license may be found at
  47 http://opensource.org/licenses/bsd-license.php
  48
  49 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  50 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  51
  52 **/
  53
  54 #include <Library/UefiBootServicesTableLib.h>
  55 #include "FaultTolerantWrite.h"
  56 EFI_EVENT                                 mFvbRegistration = NULL;
  57
  58
  59 /**
  60   Retrieve the FVB protocol interface by HANDLE.
  61
  62   @param[in]  FvBlockHandle     The handle of FVB protocol that provides services for
  63                                 reading, writing, and erasing the target block.
  64   @param[out] FvBlock           The interface of FVB protocol
  65
  66   @retval EFI_SUCCESS           The interface information for the specified protocol was returned.
  67   @retval EFI_UNSUPPORTED       The device does not support the FVB protocol.
  68   @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.
  69
  70 **/
  71 EFI_STATUS
  72 FtwGetFvbByHandle (
  73   IN  EFI_HANDLE                          FvBlockHandle,
  74   OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
  75   )
  76 {
  77   //
  78   // To get the FVB protocol interface on the handle
  79   //
  80   return gBS->HandleProtocol (
  81                 FvBlockHandle,
  82                 &gEfiFirmwareVolumeBlockProtocolGuid,
  83                 (VOID **) FvBlock
  84                 );
  85 }
  86
  87 /**
  88   Retrieve the Swap Address Range protocol interface.
  89
  90   @param[out] SarProtocol       The interface of SAR protocol
  91
  92   @retval EFI_SUCCESS           The SAR protocol instance was found and returned in SarProtocol.
  93   @retval EFI_NOT_FOUND         The SAR protocol instance was not found.
  94   @retval EFI_INVALID_PARAMETER SarProtocol is NULL.
  95
  96 **/
  97 EFI_STATUS
  98 FtwGetSarProtocol (
  99   OUT VOID                                **SarProtocol
 100   )
 101 {
 102   EFI_STATUS                              Status;
 103
 104   //
 105   // Locate Swap Address Range protocol
 106   //
 107   Status = gBS->LocateProtocol (
 108                   &gEfiSwapAddressRangeProtocolGuid,
 109                   NULL,
 110                   SarProtocol
 111                   );
 112   return Status;
 113 }
 114
 115 /**
 116   Function returns an array of handles that support the FVB protocol
 117   in a buffer allocated from pool.
 118
 119   @param[out]  NumberHandles    The number of handles returned in Buffer.
 120   @param[out]  Buffer           A pointer to the buffer to return the requested
 121                                 array of  handles that support FVB protocol.
 122
 123   @retval EFI_SUCCESS           The array of handles was returned in Buffer, and the number of
 124                                 handles in Buffer was returned in NumberHandles.
 125   @retval EFI_NOT_FOUND         No FVB handle was found.
 126   @retval EFI_OUT_OF_RESOURCES  There is not enough pool memory to store the matching results.
 127   @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL.
 128
 129 **/
 130 EFI_STATUS
 131 GetFvbCountAndBuffer (
 132   OUT UINTN                               *NumberHandles,
 133   OUT EFI_HANDLE                          **Buffer
 134   )
 135 {
 136   EFI_STATUS                              Status;
 137
 138   //
 139   // Locate all handles of Fvb protocol
 140   //
 141   Status = gBS->LocateHandleBuffer (
 142                   ByProtocol,
 143                   &gEfiFirmwareVolumeBlockProtocolGuid,
 144                   NULL,
 145                   NumberHandles,
 146                   Buffer
 147                   );
 148   return Status;
 149 }
 150
 151
 152 /**
 153   Firmware Volume Block Protocol notification event handler.
 154
 155   @param[in] Event    Event whose notification function is being invoked.
 156   @param[in] Context  Pointer to the notification function's context.
 157
 158 **/
 159 VOID
 160 EFIAPI
 161 FvbNotificationEvent (
 162   IN  EFI_EVENT                           Event,
 163   IN  VOID                                *Context
 164   )
 165 {
 166   EFI_STATUS                              Status;
 167   EFI_FAULT_TOLERANT_WRITE_PROTOCOL       *FtwProtocol;
 168   EFI_FTW_DEVICE                          *FtwDevice;
 169
 170   //
 171   // Just return to avoid installing FaultTolerantWriteProtocol again
 172   // if Fault Tolerant Write protocol has been installed.
 173   //
 174   Status = gBS->LocateProtocol (
 175                   &gEfiFaultTolerantWriteProtocolGuid,
 176                   NULL,
 177                   (VOID **) &FtwProtocol
 178                   );
 179   if (!EFI_ERROR (Status)) {
 180     return ;
 181   }
 182
 183   //
 184   // Found proper FVB protocol and initialize FtwDevice for protocol installation
 185   //
 186   FtwDevice = (EFI_FTW_DEVICE *)Context;
 187   Status = InitFtwProtocol (FtwDevice);
 188   if (EFI_ERROR(Status)) {
 189     return ;
 190   }
 191
 192   //
 193   // Install protocol interface
 194   //
 195   Status = gBS->InstallProtocolInterface (
 196                   &FtwDevice->Handle,
 197                   &gEfiFaultTolerantWriteProtocolGuid,
 198                   EFI_NATIVE_INTERFACE,
 199                   &FtwDevice->FtwInstance
 200                   );
 201   ASSERT_EFI_ERROR (Status);
 202
 203   Status = gBS->CloseEvent (Event);
 204   ASSERT_EFI_ERROR (Status);
 205
 206   return;
 207 }
 208
 209
 210 /**
 211   This function is the entry point of the Fault Tolerant Write driver.
 212
 213   @param[in] ImageHandle        A handle for the image that is initializing this driver
 214   @param[in] SystemTable        A pointer to the EFI system table
 215
 216   @retval EFI_SUCCESS           The initialization finished successfully.
 217   @retval EFI_OUT_OF_RESOURCES  Allocate memory error
 218   @retval EFI_INVALID_PARAMETER Workspace or Spare block does not exist
 219
 220 **/
 221 EFI_STATUS
 222 EFIAPI
 223 FaultTolerantWriteInitialize (
 224   IN EFI_HANDLE                           ImageHandle,
 225   IN EFI_SYSTEM_TABLE                     *SystemTable
 226   )
 227 {
 228   EFI_STATUS                              Status;
 229   EFI_FTW_DEVICE                          *FtwDevice;
 230
 231   FtwDevice = NULL;
 232
 233   //
 234   // Allocate private data structure for FTW protocol and do some initialization
 235   //
 236   Status = InitFtwDevice (&FtwDevice);
 237   if (EFI_ERROR(Status)) {
 238     return Status;
 239   }
 240
 241   //
 242   // Register FvbNotificationEvent () notify function.
 243   //
 244   EfiCreateProtocolNotifyEvent (
 245     &gEfiFirmwareVolumeBlockProtocolGuid,
 246     TPL_CALLBACK,
 247     FvbNotificationEvent,
 248     (VOID *)FtwDevice,
 249     &mFvbRegistration
 250     );
 251
 252   return EFI_SUCCESS;
 253 }
 254
 255 /**
 256   Internal implementation of CRC32. Depending on the execution context
 257   (traditional SMM or DXE vs standalone MM), this function is implemented
 258   via a call to the CalculateCrc32 () boot service, or via a library
 259   call.
 260
 261   If Buffer is NULL, then ASSERT().
 262   If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
 263
 264   @param[in]  Buffer       A pointer to the buffer on which the 32-bit CRC is to be computed.
 265   @param[in]  Length       The number of bytes in the buffer Data.
 266
 267   @retval Crc32            The 32-bit CRC was computed for the data buffer.
 268
 269 **/
 270 UINT32
 271 FtwCalculateCrc32 (
 272   IN  VOID                         *Buffer,
 273   IN  UINTN                        Length
 274   )
 275 {
 276   EFI_STATUS    Status;
 277   UINT32        ReturnValue;
 278
 279   Status = gBS->CalculateCrc32 (Buffer, Length, &ReturnValue);
 280   ASSERT_EFI_ERROR (Status);
 281
 282   return ReturnValue;
 283 }