[mirror_edk2.git] / MdeModulePkg / Universal / FirmwareVolume / FaultTolerantWriteDxe / Ia32 / Ia32FtwMisc.c

/** @file\r
  \r
  Ia32 platform related code to support FtwLite.\r
  \r
Copyright (c) 2006 - 2008, Intel Corporation                                                         \r
All rights reserved. This program and the accompanying materials                          \r
are licensed and made available under the terms and conditions of the BSD License         \r
which accompanies this distribution.  The full text of the license may be found at        \r
http://opensource.org/licenses/bsd-license.php                                            \r
                                                                                          \r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     \r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
\r
**/\r
\r
\r
#include <FtwLite.h>\r
\r
//\r
// MACROs for boot block update\r
//\r
#define BOOT_BLOCK_BASE 0xFFFF0000\r
\r
//\r
// (LPC -- D31:F0)\r
//\r
#define LPC_BUS_NUMBER    0x00\r
#define LPC_DEVICE_NUMBER 0x1F\r
#define LPC_IF            0xF0\r
//\r
// Top swap\r
//\r
#define GEN_STATUS    0xD4\r
#define TOP_SWAP_BIT  (1 << 13)\r
\r
STATIC\r
UINT32\r
ReadPciRegister (\r
  IN UINT32                 Offset\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Read PCI register value.\r
\r
Arguments:\r
\r
  Offset  - Offset of the register\r
\r
Returns:\r
\r
  The value.\r
\r
--*/\r
{\r
  EFI_STATUS                      Status;\r
  UINT32                          Value;\r
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *PciRootBridgeIo;\r
\r
  Value   = 0;\r
  Status  = gBS->LocateProtocol (&gEfiPciRootBridgeIoProtocolGuid, NULL, (VOID **) &PciRootBridgeIo);\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((EFI_D_ERROR, "FtwLite: Locate PCI root bridge io protocol - %r", Status));\r
    return 0;\r
  }\r
\r
  Status = PciRootBridgeIo->Pci.Read (\r
                                  PciRootBridgeIo,\r
                                  EfiPciWidthUint32,\r
                                  EFI_PCI_ADDRESS (\r
                                    LPC_BUS_NUMBER,\r
                                    LPC_DEVICE_NUMBER,\r
                                    LPC_IF,\r
                                    Offset\r
                                    ),\r
                                  1,\r
                                  &Value\r
                                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return Value;\r
}\r
\r
STATIC\r
EFI_STATUS\r
GetSwapState (\r
  IN EFI_FTW_LITE_DEVICE    *FtwLiteDevice,\r
  OUT BOOLEAN               *SwapState\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Get swap state\r
\r
Arguments:\r
\r
  FtwLiteDevice - Calling context\r
  SwapState     - Swap state\r
\r
Returns:\r
\r
  EFI_SUCCESS - State successfully got\r
\r
--*/\r
{\r
  //\r
  // Top swap status is 13 bit\r
  //\r
  *SwapState = (BOOLEAN) ((ReadPciRegister (GEN_STATUS) & TOP_SWAP_BIT) != 0);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
STATIC\r
EFI_STATUS\r
SetSwapState (\r
  IN EFI_FTW_LITE_DEVICE    *FtwLiteDevice,\r
  IN  BOOLEAN               TopSwap\r
  )\r
/*++\r
\r
Routine Description:\r
    Set swap state.\r
\r
Arguments:\r
    FtwLiteDevice  - Indicates a pointer to the calling context.  \r
    TopSwap        - New swap state\r
\r
Returns:\r
    EFI_SUCCESS   - The function completed successfully\r
\r
Note:\r
    the Top-Swap bit (bit 13, D31: F0, Offset D4h). Note that\r
    software will not be able to clear the Top-Swap bit until the system is\r
    rebooted without GNT[A]# being pulled down.\r
\r
--*/\r
{\r
  UINT32                          GenStatus;\r
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *PciRootBridgeIo;\r
  EFI_STATUS                      Status;\r
\r
  //\r
  // Top-Swap bit (bit 13, D31: F0, Offset D4h)\r
  //\r
  GenStatus = ReadPciRegister (GEN_STATUS);\r
\r
  //\r
  // Set 13 bit, according to input NewSwapState\r
  //\r
  if (TopSwap) {\r
    GenStatus |= TOP_SWAP_BIT;\r
  } else {\r
    GenStatus &= ~TOP_SWAP_BIT;\r
  }\r
\r
  Status = gBS->LocateProtocol (&gEfiPciRootBridgeIoProtocolGuid, NULL, (VOID **) &PciRootBridgeIo);\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((EFI_D_ERROR, "FtwLite: Locate PCI root bridge io protocol - %r", Status));\r
    return Status;\r
  }\r
  //\r
  // Write back the GenStatus register\r
  //\r
  Status = PciRootBridgeIo->Pci.Write (\r
                                  PciRootBridgeIo,\r
                                  EfiPciWidthUint32,\r
                                  EFI_PCI_ADDRESS (\r
                                    LPC_BUS_NUMBER,\r
                                    LPC_DEVICE_NUMBER,\r
                                    LPC_IF,\r
                                    GEN_STATUS\r
                                    ),\r
                                  1,\r
                                  &GenStatus\r
                                  );\r
\r
  DEBUG_CODE_BEGIN ();\r
    if (TopSwap) {\r
      DEBUG ((EFI_D_ERROR, "SAR: Set top swap\n"));\r
    } else {\r
      DEBUG ((EFI_D_ERROR, "SAR: Clear top swap\n"));\r
    }\r
  DEBUG_CODE_END ();\r
\r
  return EFI_SUCCESS;\r
}\r
\r
BOOLEAN\r
IsBootBlock (\r
  EFI_FTW_LITE_DEVICE                 *FtwLiteDevice,\r
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvBlock,\r
  EFI_LBA                             Lba\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Check whether the block is a boot block.\r
\r
Arguments:\r
\r
  FtwLiteDevice - Calling context\r
  FvBlock       - Fvb protocol instance\r
  Lba           - Lba value\r
\r
Returns:\r
\r
  Is a boot block or not\r
\r
--*/\r
{\r
  EFI_STATUS                          Status;\r
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *BootFvb;\r
\r
  Status = GetFvbByAddress (BOOT_BLOCK_BASE, &BootFvb);\r
  if (EFI_ERROR (Status)) {\r
    return FALSE;\r
  }\r
  //\r
  // Compare the Fvb\r
  //\r
  return (BOOLEAN) (FvBlock == BootFvb);\r
}\r
\r
EFI_STATUS\r
FlushSpareBlockToBootBlock (\r
  EFI_FTW_LITE_DEVICE      *FtwLiteDevice\r
  )\r
/*++\r
\r
Routine Description:\r
    Copy the content of spare block to a boot block. Size is FTW_BLOCK_SIZE.\r
    Spare block is accessed by FTW backup FVB protocol interface. LBA is \r
    FtwLiteDevice->FtwSpareLba.\r
    Boot block is accessed by BootFvb protocol interface. LBA is 0.\r
\r
Arguments:\r
    FtwLiteDevice  - The private data of FTW_LITE driver\r
\r
Returns:\r
    EFI_SUCCESS              - Spare block content is copied to boot block\r
    EFI_INVALID_PARAMETER    - Input parameter error\r
    EFI_OUT_OF_RESOURCES     - Allocate memory error\r
    EFI_ABORTED              - The function could not complete successfully\r
\r
Notes:\r
    FTW will do extra work on boot block update.\r
    FTW should depend on a protocol of EFI_ADDRESS_RANGE_SWAP_PROTOCOL, \r
    which is produced by a chipset driver.\r
\r
    FTW updating boot block steps:\r
    1. Erase top swap block (0xFFFE-0xFFFEFFFF) and write data to it ready\r
    2. Read data from top swap block to memory buffer\r
    3. SetSwapState(EFI_SWAPPED)\r
    4. Erasing boot block (0xFFFF-0xFFFFFFFF)\r
    5. Programming boot block until the boot block is ok.\r
    6. SetSwapState(UNSWAPPED)\r
\r
    Notes:\r
     1. Since the SwapState bit is saved in CMOS, FTW can restore and continue \r
     even in the scenario of power failure.\r
     2. FTW shall not allow to update boot block when battery state is error.\r
\r
--*/\r
{\r
  EFI_STATUS                          Status;\r
  UINTN                               Length;\r
  UINT8                               *Buffer;\r
  UINTN                               Count;\r
  UINT8                               *Ptr;\r
  UINTN                               Index;\r
  BOOLEAN                             TopSwap;\r
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *BootFvb;\r
  EFI_LBA                             BootLba;\r
\r
  //\r
  // Allocate a memory buffer\r
  //\r
  Length  = FtwLiteDevice->SpareAreaLength;\r
  Buffer  = AllocatePool (Length);\r
  if (Buffer == NULL) {\r
  }\r
  //\r
  // Get TopSwap bit state\r
  //\r
  Status = GetSwapState (FtwLiteDevice, &TopSwap);\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((EFI_D_ERROR, "FtwLite: Get Top Swapped status - %r\n", Status));\r
    FreePool (Buffer);\r
    return EFI_ABORTED;\r
  }\r
\r
  if (TopSwap) {\r
    //\r
    // Get FVB of current boot block\r
    //\r
    Status = GetFvbByAddress (FtwLiteDevice->SpareAreaAddress + FTW_BLOCK_SIZE, &BootFvb);\r
    if (EFI_ERROR (Status)) {\r
      FreePool (Buffer);\r
      return Status;\r
    }\r
    //\r
    // Read data from current boot block\r
    //\r
    BootLba = 0;\r
    Ptr     = Buffer;\r
    for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {\r
      Count = FtwLiteDevice->SizeOfSpareBlock;\r
      Status = BootFvb->Read (\r
                          BootFvb,\r
                          BootLba + Index,\r
                          0,\r
                          &Count,\r
                          Ptr\r
                          );\r
      if (EFI_ERROR (Status)) {\r
        FreePool (Buffer);\r
        return Status;\r
      }\r
\r
      Ptr += Count;\r
    }\r
\r
  } else {\r
    //\r
    // Read data from spare block\r
    //\r
    Ptr = Buffer;\r
    for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {\r
      Count = FtwLiteDevice->SizeOfSpareBlock;\r
      Status = FtwLiteDevice->FtwBackupFvb->Read (\r
                                              FtwLiteDevice->FtwBackupFvb,\r
                                              FtwLiteDevice->FtwSpareLba + Index,\r
                                              0,\r
                                              &Count,\r
                                              Ptr\r
                                              );\r
      if (EFI_ERROR (Status)) {\r
        FreePool (Buffer);\r
        return Status;\r
      }\r
\r
      Ptr += Count;\r
    }\r
    //\r
    // Set TopSwap bit\r
    //\r
    Status = SetSwapState (FtwLiteDevice, TRUE);\r
    DEBUG ((EFI_D_ERROR, "FtwLite: Set Swap State - %r\n", Status));\r
    ASSERT_EFI_ERROR (Status);\r
  }\r
  //\r
  // Erase boot block. After setting TopSwap bit, it's spare block now!\r
  //\r
  Status = FtwEraseSpareBlock (FtwLiteDevice);\r
  if (EFI_ERROR (Status)) {\r
    FreePool (Buffer);\r
    return EFI_ABORTED;\r
  }\r
  //\r
  // Write memory buffer to currenet spare block\r
  //\r
  Ptr = Buffer;\r
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {\r
    Count = FtwLiteDevice->SizeOfSpareBlock;\r
    Status = FtwLiteDevice->FtwBackupFvb->Write (\r
                                            FtwLiteDevice->FtwBackupFvb,\r
                                            FtwLiteDevice->FtwSpareLba + Index,\r
                                            0,\r
                                            &Count,\r
                                            Ptr\r
                                            );\r
    if (EFI_ERROR (Status)) {\r
      DEBUG ((EFI_D_FTW_LITE, "FtwLite: FVB Write boot block - %r\n", Status));\r
      FreePool (Buffer);\r
      return Status;\r
    }\r
\r
    Ptr += Count;\r
  }\r
\r
  FreePool (Buffer);\r
\r
  //\r
  // Clear TopSwap bit\r
  //\r
  Status = SetSwapState (FtwLiteDevice, FALSE);\r
  DEBUG ((EFI_D_ERROR, "FtwLite: Clear Swap State - %r\n", Status));\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return EFI_SUCCESS;\r
}\r
Commit	Line	Data
6cc9ca32 LG	1	/** @file\r
	2	\r
	3	Ia32 platform related code to support FtwLite.\r
	4	\r
	5	Copyright (c) 2006 - 2008, Intel Corporation \r
d7dec593	6	All rights reserved. This program and the accompanying materials \r
	7	are licensed and made available under the terms and conditions of the BSD License \r
	8	which accompanies this distribution. The full text of the license may be found at \r
	9	http://opensource.org/licenses/bsd-license.php \r
	10	\r
	11	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
	12	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
	13	\r
6cc9ca32	14	**/\r
d7dec593	15	\r
	16	\r
	17	#include <FtwLite.h>\r
	18	\r
	19	//\r
	20	// MACROs for boot block update\r
	21	//\r
	22	#define BOOT_BLOCK_BASE 0xFFFF0000\r
	23	\r
	24	//\r
	25	// (LPC -- D31:F0)\r
	26	//\r
	27	#define LPC_BUS_NUMBER 0x00\r
	28	#define LPC_DEVICE_NUMBER 0x1F\r
	29	#define LPC_IF 0xF0\r
	30	//\r
	31	// Top swap\r
	32	//\r
	33	#define GEN_STATUS 0xD4\r
	34	#define TOP_SWAP_BIT (1 << 13)\r
	35	\r
	36	STATIC\r
	37	UINT32\r
	38	ReadPciRegister (\r
	39	IN UINT32 Offset\r
	40	)\r
	41	/*++\r
	42	\r
	43	Routine Description:\r
	44	\r
	45	Read PCI register value.\r
	46	\r
	47	Arguments:\r
	48	\r
	49	Offset - Offset of the register\r
	50	\r
	51	Returns:\r
	52	\r
	53	The value.\r
	54	\r
	55	--*/\r
	56	{\r
	57	EFI_STATUS Status;\r
	58	UINT32 Value;\r
	59	EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *PciRootBridgeIo;\r
	60	\r
	61	Value = 0;\r
	62	Status = gBS->LocateProtocol (&gEfiPciRootBridgeIoProtocolGuid, NULL, (VOID **) &PciRootBridgeIo);\r
	63	if (EFI_ERROR (Status)) {\r
	64	DEBUG ((EFI_D_ERROR, "FtwLite: Locate PCI root bridge io protocol - %r", Status));\r
	65	return 0;\r
	66	}\r
	67	\r
	68	Status = PciRootBridgeIo->Pci.Read (\r
	69	PciRootBridgeIo,\r
	70	EfiPciWidthUint32,\r
	71	EFI_PCI_ADDRESS (\r
	72	LPC_BUS_NUMBER,\r
	73	LPC_DEVICE_NUMBER,\r
	74	LPC_IF,\r
	75	Offset\r
	76	),\r
	77	1,\r
	78	&Value\r
79	);\r
80	ASSERT_EFI_ERROR (Status);\r
81	\r
82	return Value;\r
83	}\r
84	\r
85	STATIC\r
86	EFI_STATUS\r
87	GetSwapState (\r
88	IN EFI_FTW_LITE_DEVICE *FtwLiteDevice,\r
89	OUT BOOLEAN *SwapState\r
90	)\r
91	/*++\r
92	\r
93	Routine Description:\r
94	\r
95	Get swap state\r
96	\r
97	Arguments:\r
98	\r
99	FtwLiteDevice - Calling context\r
100	SwapState - Swap state\r
101	\r
102	Returns:\r
103	\r
104	EFI_SUCCESS - State successfully got\r
105	\r
106	--*/\r
107	{\r
108	//\r
109	// Top swap status is 13 bit\r
110	//\r
111	*SwapState = (BOOLEAN) ((ReadPciRegister (GEN_STATUS) & TOP_SWAP_BIT) != 0);\r
112	\r
113	return EFI_SUCCESS;\r
114	}\r
115	\r
116	STATIC\r
117	EFI_STATUS\r
118	SetSwapState (\r
119	IN EFI_FTW_LITE_DEVICE *FtwLiteDevice,\r
120	IN BOOLEAN TopSwap\r
121	)\r
122	/*++\r
123	\r
124	Routine Description:\r
125	Set swap state.\r
126	\r
127	Arguments:\r
128	FtwLiteDevice - Indicates a pointer to the calling context. \r
129	TopSwap - New swap state\r
130	\r
131	Returns:\r
132	EFI_SUCCESS - The function completed successfully\r
133	\r
134	Note:\r
135	the Top-Swap bit (bit 13, D31: F0, Offset D4h). Note that\r
136	software will not be able to clear the Top-Swap bit until the system is\r
137	rebooted without GNT[A]# being pulled down.\r
138	\r
139	--*/\r
140	{\r
141	UINT32 GenStatus;\r
142	EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *PciRootBridgeIo;\r
143	EFI_STATUS Status;\r
144	\r
145	//\r
146	// Top-Swap bit (bit 13, D31: F0, Offset D4h)\r
147	//\r
148	GenStatus = ReadPciRegister (GEN_STATUS);\r
149	\r
150	//\r
151	// Set 13 bit, according to input NewSwapState\r
152	//\r
153	if (TopSwap) {\r
154	GenStatus \|= TOP_SWAP_BIT;\r
155	} else {\r
156	GenStatus &= ~TOP_SWAP_BIT;\r
157	}\r
158	\r
159	Status = gBS->LocateProtocol (&gEfiPciRootBridgeIoProtocolGuid, NULL, (VOID **) &PciRootBridgeIo);\r
160	if (EFI_ERROR (Status)) {\r
161	DEBUG ((EFI_D_ERROR, "FtwLite: Locate PCI root bridge io protocol - %r", Status));\r
162	return Status;\r
163	}\r
164	//\r
165	// Write back the GenStatus register\r
166	//\r
167	Status = PciRootBridgeIo->Pci.Write (\r
168	PciRootBridgeIo,\r
169	EfiPciWidthUint32,\r
170	EFI_PCI_ADDRESS (\r
171	LPC_BUS_NUMBER,\r
172	LPC_DEVICE_NUMBER,\r
173	LPC_IF,\r
174	GEN_STATUS\r
175	),\r
176	1,\r
177	&GenStatus\r
178	);\r
179	\r
180	DEBUG_CODE_BEGIN ();\r
181	if (TopSwap) {\r
182	DEBUG ((EFI_D_ERROR, "SAR: Set top swap\n"));\r
183	} else {\r
184	DEBUG ((EFI_D_ERROR, "SAR: Clear top swap\n"));\r
185	}\r
186	DEBUG_CODE_END ();\r
187	\r
188	return EFI_SUCCESS;\r
189	}\r
190	\r
191	BOOLEAN\r
192	IsBootBlock (\r
193	EFI_FTW_LITE_DEVICE *FtwLiteDevice,\r
194	EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL *FvBlock,\r
195	EFI_LBA Lba\r
196	)\r
197	/*++\r
198	\r
199	Routine Description:\r
200	\r
201	Check whether the block is a boot block.\r
202	\r
203	Arguments:\r
204	\r
205	FtwLiteDevice - Calling context\r
206	FvBlock - Fvb protocol instance\r
207	Lba - Lba value\r
208	\r
209	Returns:\r
210	\r
211	Is a boot block or not\r
212	\r
213	--*/\r
214	{\r
215	EFI_STATUS Status;\r
216	EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL *BootFvb;\r
217	\r
218	Status = GetFvbByAddress (BOOT_BLOCK_BASE, &BootFvb);\r
219	if (EFI_ERROR (Status)) {\r
220	return FALSE;\r
221	}\r
222	//\r
223	// Compare the Fvb\r
224	//\r
225	return (BOOLEAN) (FvBlock == BootFvb);\r
226	}\r
227	\r
228	EFI_STATUS\r
229	FlushSpareBlockToBootBlock (\r
230	EFI_FTW_LITE_DEVICE *FtwLiteDevice\r
231	)\r
232	/*++\r
233	\r
234	Routine Description:\r
235	Copy the content of spare block to a boot block. Size is FTW_BLOCK_SIZE.\r
236	Spare block is accessed by FTW backup FVB protocol interface. LBA is \r
237	FtwLiteDevice->FtwSpareLba.\r
238	Boot block is accessed by BootFvb protocol interface. LBA is 0.\r
239	\r
240	Arguments:\r
241	FtwLiteDevice - The private data of FTW_LITE driver\r
242	\r
243	Returns:\r
244	EFI_SUCCESS - Spare block content is copied to boot block\r
245	EFI_INVALID_PARAMETER - Input parameter error\r
246	EFI_OUT_OF_RESOURCES - Allocate memory error\r
247	EFI_ABORTED - The function could not complete successfully\r
248	\r
249	Notes:\r
250	FTW will do extra work on boot block update.\r
251	FTW should depend on a protocol of EFI_ADDRESS_RANGE_SWAP_PROTOCOL, \r
252	which is produced by a chipset driver.\r
253	\r
254	FTW updating boot block steps:\r
255	1. Erase top swap block (0xFFFE-0xFFFEFFFF) and write data to it ready\r
256	2. Read data from top swap block to memory buffer\r
257	3. SetSwapState(EFI_SWAPPED)\r
258	4. Erasing boot block (0xFFFF-0xFFFFFFFF)\r
259	5. Programming boot block until the boot block is ok.\r
260	6. SetSwapState(UNSWAPPED)\r
261	\r
262	Notes:\r
263	1. Since the SwapState bit is saved in CMOS, FTW can restore and continue \r
264	even in the scenario of power failure.\r
265	2. FTW shall not allow to update boot block when battery state is error.\r
266	\r
267	--*/\r
268	{\r
269	EFI_STATUS Status;\r
270	UINTN Length;\r
271	UINT8 *Buffer;\r
272	UINTN Count;\r
273	UINT8 *Ptr;\r
274	UINTN Index;\r
275	BOOLEAN TopSwap;\r
276	EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL *BootFvb;\r
277	EFI_LBA BootLba;\r
278	\r
279	//\r
280	// Allocate a memory buffer\r
281	//\r
282	Length = FtwLiteDevice->SpareAreaLength;\r
283	Buffer = AllocatePool (Length);\r
284	if (Buffer == NULL) {\r
285	}\r
286	//\r
287	// Get TopSwap bit state\r
288	//\r
289	Status = GetSwapState (FtwLiteDevice, &TopSwap);\r
290	if (EFI_ERROR (Status)) {\r
291	DEBUG ((EFI_D_ERROR, "FtwLite: Get Top Swapped status - %r\n", Status));\r
292	FreePool (Buffer);\r
293	return EFI_ABORTED;\r
294	}\r
295	\r
296	if (TopSwap) {\r
297	//\r
298	// Get FVB of current boot block\r
299	//\r
300	Status = GetFvbByAddress (FtwLiteDevice->SpareAreaAddress + FTW_BLOCK_SIZE, &BootFvb);\r
301	if (EFI_ERROR (Status)) {\r
302	FreePool (Buffer);\r
303	return Status;\r
304	}\r
305	//\r
306	// Read data from current boot block\r
307	//\r
308	BootLba = 0;\r
309	Ptr = Buffer;\r
310	for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {\r
311	Count = FtwLiteDevice->SizeOfSpareBlock;\r
312	Status = BootFvb->Read (\r
313	BootFvb,\r
314	BootLba + Index,\r
315	0,\r
316	&Count,\r
317	Ptr\r
318	);\r
319	if (EFI_ERROR (Status)) {\r
320	FreePool (Buffer);\r
321	return Status;\r
322	}\r
323	\r
324	Ptr += Count;\r
325	}\r
326	\r
327	} else {\r
328	//\r
329	// Read data from spare block\r
330	//\r
331	Ptr = Buffer;\r
332	for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {\r
333	Count = FtwLiteDevice->SizeOfSpareBlock;\r
334	Status = FtwLiteDevice->FtwBackupFvb->Read (\r
335	FtwLiteDevice->FtwBackupFvb,\r
336	FtwLiteDevice->FtwSpareLba + Index,\r
337	0,\r
338	&Count,\r
339	Ptr\r
340	);\r
341	if (EFI_ERROR (Status)) {\r
342	FreePool (Buffer);\r
343	return Status;\r
344	}\r
345	\r
346	Ptr += Count;\r
347	}\r
348	//\r
349	// Set TopSwap bit\r
350	//\r
351	Status = SetSwapState (FtwLiteDevice, TRUE);\r
352	DEBUG ((EFI_D_ERROR, "FtwLite: Set Swap State - %r\n", Status));\r
353	ASSERT_EFI_ERROR (Status);\r
354	}\r
355	//\r
356	// Erase boot block. After setting TopSwap bit, it's spare block now!\r
357	//\r
358	Status = FtwEraseSpareBlock (FtwLiteDevice);\r
359	if (EFI_ERROR (Status)) {\r
360	FreePool (Buffer);\r
361	return EFI_ABORTED;\r
362	}\r
363	//\r
364	// Write memory buffer to currenet spare block\r
365	//\r
366	Ptr = Buffer;\r
367	for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {\r
368	Count = FtwLiteDevice->SizeOfSpareBlock;\r
369	Status = FtwLiteDevice->FtwBackupFvb->Write (\r
370	FtwLiteDevice->FtwBackupFvb,\r
371	FtwLiteDevice->FtwSpareLba + Index,\r
372	0,\r
373	&Count,\r
374	Ptr\r
375	);\r
376	if (EFI_ERROR (Status)) {\r
377	DEBUG ((EFI_D_FTW_LITE, "FtwLite: FVB Write boot block - %r\n", Status));\r
378	FreePool (Buffer);\r
379	return Status;\r
380	}\r
381	\r
382	Ptr += Count;\r
383	}\r
384	\r
385	FreePool (Buffer);\r
386	\r
387	//\r
388	// Clear TopSwap bit\r
389	//\r
390	Status = SetSwapState (FtwLiteDevice, FALSE);\r
391	DEBUG ((EFI_D_ERROR, "FtwLite: Clear Swap State - %r\n", Status));\r
392	ASSERT_EFI_ERROR (Status);\r
393	\r
394	return EFI_SUCCESS;\r
395	}\r