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 - 2014, 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 installing FaultTolerantWriteProtocol again 171 // if Fault Tolerant Write protocol has 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 FtwDevice = NULL; 231 232 // 233 // Allocate private data structure for FTW protocol and do some initialization 234 // 235 Status = InitFtwDevice (&FtwDevice); 236 if (EFI_ERROR(Status)) { 237 return Status; 238 } 239 240 // 241 // Register FvbNotificationEvent () notify function. 242 // 243 EfiCreateProtocolNotifyEvent ( 244 &gEfiFirmwareVolumeBlockProtocolGuid, 245 TPL_CALLBACK, 246 FvbNotificationEvent, 247 (VOID *)FtwDevice, 248 &mFvbRegistration 249 ); 250 251 return EFI_SUCCESS; 252 } 253
