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 - 2010, 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 "FaultTolerantWrite.h"
  55 EFI_EVENT                                 mFvbRegistration = NULL;
  56
  57
  58 /**
  59   Retrive the FVB protocol interface by HANDLE.
  60
  61   @param[in]  FvBlockHandle     The handle of FVB protocol that provides services for
  62                                 reading, writing, and erasing the target block.
  63   @param[out] FvBlock           The interface of FVB protocol
  64
  65   @retval EFI_SUCCESS           The interface information for the specified protocol was returned.
  66   @retval EFI_UNSUPPORTED       The device does not support the FVB protocol.
  67   @retval EFI_INVALID_PARAMETER FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.
  68
  69 **/
  70 EFI_STATUS
  71 FtwGetFvbByHandle (
  72   IN  EFI_HANDLE                          FvBlockHandle,
  73   OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
  74   )
  75 {
  76   //
  77   // To get the FVB protocol interface on the handle
  78   //
  79   return gBS->HandleProtocol (
  80                 FvBlockHandle,
  81                 &gEfiFirmwareVolumeBlockProtocolGuid,
  82                 (VOID **) FvBlock
  83                 );
  84 }
  85
  86 /**
  87   Retrive the Swap Address Range protocol interface.
  88
  89   @param[out] SarProtocol       The interface of SAR protocol
  90
  91   @retval EFI_SUCCESS           The SAR protocol instance was found and returned in SarProtocol.
  92   @retval EFI_NOT_FOUND         The SAR protocol instance was not found.
  93   @retval EFI_INVALID_PARAMETER SarProtocol is NULL.
  94
  95 **/
  96 EFI_STATUS
  97 FtwGetSarProtocol (
  98   OUT VOID                                **SarProtocol
  99   )
 100 {
 101   EFI_STATUS                              Status;
 102
 103   //
 104   // Locate Swap Address Range protocol
 105   //
 106   Status = gBS->LocateProtocol (
 107                   &gEfiSwapAddressRangeProtocolGuid,
 108                   NULL,
 109                   SarProtocol
 110                   );
 111   return Status;
 112 }
 113
 114 /**
 115   Function returns an array of handles that support the FVB protocol
 116   in a buffer allocated from pool.
 117
 118   @param[out]  NumberHandles    The number of handles returned in Buffer.
 119   @param[out]  Buffer           A pointer to the buffer to return the requested
 120                                 array of  handles that support FVB protocol.
 121
 122   @retval EFI_SUCCESS           The array of handles was returned in Buffer, and the number of
 123                                 handles in Buffer was returned in NumberHandles.
 124   @retval EFI_NOT_FOUND         No FVB handle was found.
 125   @retval EFI_OUT_OF_RESOURCES  There is not enough pool memory to store the matching results.
 126   @retval EFI_INVALID_PARAMETER NumberHandles is NULL or Buffer is NULL.
 127
 128 **/
 129 EFI_STATUS
 130 GetFvbCountAndBuffer (
 131   OUT UINTN                               *NumberHandles,
 132   OUT EFI_HANDLE                          **Buffer
 133   )
 134 {
 135   EFI_STATUS                              Status;
 136
 137   //
 138   // Locate all handles of Fvb protocol
 139   //
 140   Status = gBS->LocateHandleBuffer (
 141                   ByProtocol,
 142                   &gEfiFirmwareVolumeBlockProtocolGuid,
 143                   NULL,
 144                   NumberHandles,
 145                   Buffer
 146                   );
 147   return Status;
 148 }
 149
 150
 151 /**
 152   Firmware Volume Block Protocol notification event handler.
 153
 154   @param[in] Event    Event whose notification function is being invoked.
 155   @param[in] Context  Pointer to the notification function's context.
 156
 157 **/
 158 VOID
 159 EFIAPI
 160 FvbNotificationEvent (
 161   IN  EFI_EVENT                           Event,
 162   IN  VOID                                *Context
 163   )
 164 {
 165   EFI_STATUS                              Status;
 166   EFI_FAULT_TOLERANT_WRITE_PROTOCOL       *FtwProtocol;
 167   EFI_FTW_DEVICE                          *FtwDevice;
 168
 169   //
 170   // Just return to avoid install SMM FaultTolerantWriteProtocol again
 171   // if Fault Tolerant Write protocol had been installed.
 172   //
 173   Status = gBS->LocateProtocol (
 174                   &gEfiFaultTolerantWriteProtocolGuid,
 175                   NULL,
 176                   (VOID **) &FtwProtocol
 177                   );
 178   if (!EFI_ERROR (Status)) {
 179     return ;
 180   }
 181
 182   //
 183   // Found proper FVB protocol and initialize FtwDevice for protocol installation
 184   //
 185   FtwDevice = (EFI_FTW_DEVICE *)Context;
 186   Status = InitFtwProtocol (FtwDevice);
 187   if (EFI_ERROR(Status)) {
 188     return ;
 189   }
 190
 191   //
 192   // Install protocol interface
 193   //
 194   Status = gBS->InstallProtocolInterface (
 195                   &FtwDevice->Handle,
 196                   &gEfiFaultTolerantWriteProtocolGuid,
 197                   EFI_NATIVE_INTERFACE,
 198                   &FtwDevice->FtwInstance
 199                   );
 200   ASSERT_EFI_ERROR (Status);
 201
 202   Status = gBS->CloseEvent (Event);
 203   ASSERT_EFI_ERROR (Status);
 204
 205   return;
 206 }
 207
 208
 209 /**
 210   This function is the entry point of the Fault Tolerant Write driver.
 211
 212   @param[in] ImageHandle        A handle for the image that is initializing this driver
 213   @param[in] SystemTable        A pointer to the EFI system table
 214
 215   @retval EFI_SUCCESS           The initialization finished successfully.
 216   @retval EFI_OUT_OF_RESOURCES  Allocate memory error
 217   @retval EFI_INVALID_PARAMETER Workspace or Spare block does not exist
 218
 219 **/
 220 EFI_STATUS
 221 EFIAPI
 222 FaultTolerantWriteInitialize (
 223   IN EFI_HANDLE                           ImageHandle,
 224   IN EFI_SYSTEM_TABLE                     *SystemTable
 225   )
 226 {
 227   EFI_STATUS                              Status;
 228   EFI_FTW_DEVICE                          *FtwDevice;
 229
 230   //
 231   // Allocate private data structure for FTW protocol and do some initialization
 232   //
 233   Status = InitFtwDevice (&FtwDevice);
 234   if (EFI_ERROR(Status)) {
 235     return Status;
 236   }
 237
 238   //
 239   // Register FvbNotificationEvent () notify function.
 240   //
 241   EfiCreateProtocolNotifyEvent (
 242     &gEfiFirmwareVolumeBlockProtocolGuid,
 243     TPL_CALLBACK,
 244     FvbNotificationEvent,
 245     (VOID *)FtwDevice,
 246     &mFvbRegistration
 247     );
 248
 249   return EFI_SUCCESS;
 250 }