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 Retrieve 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
FtwGetFvbByHandle(IN EFI_HANDLE FvBlockHandle,OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL ** FvBlock)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 Retrieve 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
FtwGetSarProtocol(OUT VOID ** SarProtocol)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
GetFvbCountAndBuffer(OUT UINTN * NumberHandles,OUT EFI_HANDLE ** Buffer)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
FvbNotificationEvent(IN EFI_EVENT Event,IN VOID * Context)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
FaultTolerantWriteInitialize(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)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