/**
The GetBlockSize() function retrieves the size of the requested
block. It also returns the number of additional blocks with
the identical size. The GetBlockSize() function is used to
retrieve the block map (see EFI_FIRMWARE_VOLUME_HEADER).
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
@param Lba Indicates the block for which to return the size.
@param BlockSize Pointer to a caller-allocated UINTN in which
the size of the block is returned.
@param NumberOfBlocks Pointer to a caller-allocated UINTN in
which the number of consecutive blocks,
starting with Lba, is returned. All
blocks in this range have a size of
BlockSize.
@retval EFI_SUCCESS The firmware volume base address was returned.
@retval EFI_INVALID_PARAMETER The requested LBA is out of range.
**/
EFI_STATUS
EFIAPI
FvbGetBlockSize (
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
IN EFI_LBA Lba,
OUT UINTN *BlockSize,
OUT UINTN *NumberOfBlocks
)
{
EFI_STATUS Status;
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS(This);
DEBUG ((DEBUG_BLKIO, "FvbGetBlockSize(Lba=%ld, BlockSize=0x%x, LastBlock=%ld)\n", Lba, Instance->Media.BlockSize, Instance->Media.LastBlock));
if (Lba > Instance->Media.LastBlock) {
DEBUG ((EFI_D_ERROR, "FvbGetBlockSize: ERROR - Parameter LBA %ld is beyond the last Lba (%ld).\n", Lba, Instance->Media.LastBlock));
Status = EFI_INVALID_PARAMETER;
} else {
// This is easy because in this platform each NorFlash device has equal sized blocks.
*BlockSize = (UINTN) Instance->Media.BlockSize;
*NumberOfBlocks = (UINTN) (Instance->Media.LastBlock - Lba + 1);
DEBUG ((DEBUG_BLKIO, "FvbGetBlockSize: *BlockSize=0x%x, *NumberOfBlocks=0x%x.\n", *BlockSize, *NumberOfBlocks));
Status = EFI_SUCCESS;
}
return Status;
}
/**
Reads the specified number of bytes into a buffer from the specified block.
The Read() function reads the requested number of bytes from the
requested block and stores them in the provided buffer.
Implementations should be mindful that the firmware volume
might be in the ReadDisabled state. If it is in this state,
the Read() function must return the status code
EFI_ACCESS_DENIED without modifying the contents of the
buffer. The Read() function must also prevent spanning block
boundaries. If a read is requested that would span a block
boundary, the read must read up to the boundary but not
beyond. The output parameter NumBytes must be set to correctly
indicate the number of bytes actually read. The caller must be
aware that a read may be partially completed.
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
@param Lba The starting logical block index from which to read.
@param Offset Offset into the block at which to begin reading.
@param NumBytes Pointer to a UINTN.
At entry, *NumBytes contains the total size of the buffer.
At exit, *NumBytes contains the total number of bytes read.
@param Buffer Pointer to a caller-allocated buffer that will be used
to hold the data that is read.
@retval EFI_SUCCESS The firmware volume was read successfully, and contents are
in Buffer.
@retval EFI_BAD_BUFFER_SIZE Read attempted across an LBA boundary.
On output, NumBytes contains the total number of bytes
returned in Buffer.
@retval EFI_ACCESS_DENIED The firmware volume is in the ReadDisabled state.
@retval EFI_DEVICE_ERROR The block device is not functioning correctly and could not be read.
**/
EFI_STATUS
EFIAPI
FvbRead (
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
IN EFI_LBA Lba,
IN UINTN Offset,
IN OUT UINTN *NumBytes,
IN OUT UINT8 *Buffer
)
{
EFI_STATUS TempStatus;
UINTN BlockSize;
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS(This);
DEBUG ((DEBUG_BLKIO, "FvbRead(Parameters: Lba=%ld, Offset=0x%x, *NumBytes=0x%x, Buffer @ 0x%08x)\n", Instance->StartLba + Lba, Offset, *NumBytes, Buffer));
TempStatus = EFI_SUCCESS;
// Cache the block size to avoid de-referencing pointers all the time
BlockSize = Instance->Media.BlockSize;
DEBUG ((DEBUG_BLKIO, "FvbRead: Check if (Offset=0x%x + NumBytes=0x%x) <= BlockSize=0x%x\n", Offset, *NumBytes, BlockSize ));
// The read must not span block boundaries.
// We need to check each variable individually because adding two large values together overflows.
if ((Offset >= BlockSize) ||
(*NumBytes > BlockSize) ||
((Offset + *NumBytes) > BlockSize)) {
DEBUG ((EFI_D_ERROR, "FvbRead: ERROR - EFI_BAD_BUFFER_SIZE: (Offset=0x%x + NumBytes=0x%x) > BlockSize=0x%x\n", Offset, *NumBytes, BlockSize ));
return EFI_BAD_BUFFER_SIZE;
}
// We must have some bytes to read
if (*NumBytes == 0) {
return EFI_BAD_BUFFER_SIZE;
}
// Decide if we are doing full block reads or not.
if (*NumBytes % BlockSize != 0) {
TempStatus = NorFlashRead (Instance, Instance->StartLba + Lba, Offset, *NumBytes, Buffer);
if (EFI_ERROR (TempStatus)) {
return EFI_DEVICE_ERROR;
}
} else {
// Read NOR Flash data into shadow buffer
TempStatus = NorFlashReadBlocks (Instance, Instance->StartLba + Lba, BlockSize, Buffer);
if (EFI_ERROR (TempStatus)) {
// Return one of the pre-approved error statuses
return EFI_DEVICE_ERROR;
}
}
return EFI_SUCCESS;
}
/**
Writes the specified number of bytes from the input buffer to the block.
The Write() function writes the specified number of bytes from
the provided buffer to the specified block and offset. If the
firmware volume is sticky write, the caller must ensure that
all the bits of the specified range to write are in the
EFI_FVB_ERASE_POLARITY state before calling the Write()
function, or else the result will be unpredictable. This
unpredictability arises because, for a sticky-write firmware
volume, a write may negate a bit in the EFI_FVB_ERASE_POLARITY
state but cannot flip it back again. Before calling the
Write() function, it is recommended for the caller to first call
the EraseBlocks() function to erase the specified block to
write. A block erase cycle will transition bits from the
(NOT)EFI_FVB_ERASE_POLARITY state back to the
EFI_FVB_ERASE_POLARITY state. Implementations should be
mindful that the firmware volume might be in the WriteDisabled
state. If it is in this state, the Write() function must
return the status code EFI_ACCESS_DENIED without modifying the
contents of the firmware volume. The Write() function must
also prevent spanning block boundaries. If a write is
requested that spans a block boundary, the write must store up
to the boundary but not beyond. The output parameter NumBytes
must be set to correctly indicate the number of bytes actually
written. The caller must be aware that a write may be
partially completed. All writes, partial or otherwise, must be
fully flushed to the hardware before the Write() service
returns.
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
@param Lba The starting logical block index to write to.
@param Offset Offset into the block at which to begin writing.
@param NumBytes The pointer to a UINTN.
At entry, *NumBytes contains the total size of the buffer.
At exit, *NumBytes contains the total number of bytes actually written.
@param Buffer The pointer to a caller-allocated buffer that contains the source for the write.
@retval EFI_SUCCESS The firmware volume was written successfully.
@retval EFI_BAD_BUFFER_SIZE The write was attempted across an LBA boundary.
On output, NumBytes contains the total number of bytes
actually written.
@retval EFI_ACCESS_DENIED The firmware volume is in the WriteDisabled state.
@retval EFI_DEVICE_ERROR The block device is malfunctioning and could not be written.
**/
EFI_STATUS
EFIAPI
FvbWrite (
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
IN EFI_LBA Lba,
IN UINTN Offset,
IN OUT UINTN *NumBytes,
IN UINT8 *Buffer
)
{
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS (This);
return NorFlashWriteSingleBlock (Instance, Instance->StartLba + Lba, Offset, NumBytes, Buffer);
}
/**
The GetPhysicalAddress() function retrieves the base address of
a memory-mapped firmware volume. This function should be called
only for memory-mapped firmware volumes.
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
@param Address Pointer to a caller-allocated
EFI_PHYSICAL_ADDRESS that, on successful
return from GetPhysicalAddress(), contains the
base address of the firmware volume.
@retval EFI_SUCCESS The firmware volume base address was returned.
@retval EFI_NOT_SUPPORTED The firmware volume is not memory mapped.
**/
EFI_STATUS
EFIAPI
FvbGetPhysicalAddress (
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
OUT EFI_PHYSICAL_ADDRESS *Address
)
{
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS(This);
DEBUG ((DEBUG_BLKIO, "FvbGetPhysicalAddress(BaseAddress=0x%08x)\n", Instance->RegionBaseAddress));
ASSERT(Address != NULL);
*Address = PcdGet32 (PcdFlashNvStorageVariableBase);
return EFI_SUCCESS;
}
/**
The GetAttributes() function retrieves the attributes and
current settings of the block.
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
@param Attributes Pointer to EFI_FVB_ATTRIBUTES_2 in which the attributes and
current settings are returned.
Type EFI_FVB_ATTRIBUTES_2 is defined in EFI_FIRMWARE_VOLUME_HEADER.
@retval EFI_SUCCESS The firmware volume attributes were returned.
**/
EFI_STATUS
EFIAPI
FvbGetAttributes(
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
OUT EFI_FVB_ATTRIBUTES_2 *Attributes
)
{
EFI_FVB_ATTRIBUTES_2 FlashFvbAttributes;
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS(This);
FlashFvbAttributes = (EFI_FVB_ATTRIBUTES_2) (
EFI_FVB2_READ_ENABLED_CAP | // Reads may be enabled
EFI_FVB2_READ_STATUS | // Reads are currently enabled
EFI_FVB2_STICKY_WRITE | // A block erase is required to flip bits into EFI_FVB2_ERASE_POLARITY
EFI_FVB2_MEMORY_MAPPED | // It is memory mapped
EFI_FVB2_ERASE_POLARITY // After erasure all bits take this value (i.e. '1')
);
// Check if it is write protected
if (Instance->Media.ReadOnly != TRUE) {
FlashFvbAttributes = FlashFvbAttributes |
EFI_FVB2_WRITE_STATUS | // Writes are currently enabled
EFI_FVB2_WRITE_ENABLED_CAP; // Writes may be enabled
}
*Attributes = FlashFvbAttributes;
DEBUG ((DEBUG_BLKIO, "FvbGetAttributes(0x%X)\n", *Attributes));
return EFI_SUCCESS;
}
/**
Erases and initialises a firmware volume block.
The EraseBlocks() function erases one or more blocks as denoted
by the variable argument list. The entire parameter list of
blocks must be verified before erasing any blocks. If a block is
requested that does not exist within the associated firmware
volume (it has a larger index than the last block of the
firmware volume), the EraseBlocks() function must return the
status code EFI_INVALID_PARAMETER without modifying the contents
of the firmware volume. Implementations should be mindful that
the firmware volume might be in the WriteDisabled state. If it
is in this state, the EraseBlocks() function must return the
status code EFI_ACCESS_DENIED without modifying the contents of
the firmware volume. All calls to EraseBlocks() must be fully
flushed to the hardware before the EraseBlocks() service
returns.
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL
instance.
@param ... The variable argument list is a list of tuples.
Each tuple describes a range of LBAs to erase
and consists of the following:
- An EFI_LBA that indicates the starting LBA
- A UINTN that indicates the number of blocks to erase.
The list is terminated with an EFI_LBA_LIST_TERMINATOR.
For example, the following indicates that two ranges of blocks
(5-7 and 10-11) are to be erased:
EraseBlocks (This, 5, 3, 10, 2, EFI_LBA_LIST_TERMINATOR);
@retval EFI_SUCCESS The erase request successfully completed.
@retval EFI_ACCESS_DENIED The firmware volume is in the WriteDisabled state.
@retval EFI_DEVICE_ERROR The block device is not functioning correctly and could not be written.
The firmware device may have been partially erased.
@retval EFI_INVALID_PARAMETER One or more of the LBAs listed in the variable argument list do
not exist in the firmware volume.
**/
EFI_STATUS
EFIAPI
FvbEraseBlocks (
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
...
)
{
EFI_STATUS Status;
VA_LIST Args;
UINTN BlockAddress; // Physical address of Lba to erase
EFI_LBA StartingLba; // Lba from which we start erasing
UINTN NumOfLba; // Number of Lba blocks to erase
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS(This);
DEBUG ((DEBUG_BLKIO, "FvbEraseBlocks()\n"));
Status = EFI_SUCCESS;
// Detect WriteDisabled state
if (Instance->Media.ReadOnly == TRUE) {
// Firmware volume is in WriteDisabled state
DEBUG ((EFI_D_ERROR, "FvbEraseBlocks: ERROR - Device is in WriteDisabled state.\n"));
return EFI_ACCESS_DENIED;
}
// Before erasing, check the entire list of parameters to ensure all specified blocks are valid
VA_START (Args, This);
do {
// Get the Lba from which we start erasing
StartingLba = VA_ARG (Args, EFI_LBA);
// Have we reached the end of the list?
if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
//Exit the while loop
break;
}
// How many Lba blocks are we requested to erase?
NumOfLba = VA_ARG (Args, UINT32);
// All blocks must be within range
DEBUG ((DEBUG_BLKIO, "FvbEraseBlocks: Check if: ( StartingLba=%ld + NumOfLba=%d - 1 ) > LastBlock=%ld.\n", Instance->StartLba + StartingLba, NumOfLba, Instance->Media.LastBlock));
if ((NumOfLba == 0) || ((Instance->StartLba + StartingLba + NumOfLba - 1) > Instance->Media.LastBlock)) {
VA_END (Args);
DEBUG ((EFI_D_ERROR, "FvbEraseBlocks: ERROR - Lba range goes past the last Lba.\n"));
Status = EFI_INVALID_PARAMETER;
goto EXIT;
}
} while (TRUE);
VA_END (Args);
//
// To get here, all must be ok, so start erasing
//
VA_START (Args, This);
do {
// Get the Lba from which we start erasing
StartingLba = VA_ARG (Args, EFI_LBA);
// Have we reached the end of the list?
if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
// Exit the while loop
break;
}
// How many Lba blocks are we requested to erase?
NumOfLba = VA_ARG (Args, UINT32);
// Go through each one and erase it
while (NumOfLba > 0) {
// Get the physical address of Lba to erase
BlockAddress = GET_NOR_BLOCK_ADDRESS (
Instance->RegionBaseAddress,
Instance->StartLba + StartingLba,
Instance->Media.BlockSize
);
// Erase it
DEBUG ((DEBUG_BLKIO, "FvbEraseBlocks: Erasing Lba=%ld @ 0x%08x.\n", Instance->StartLba + StartingLba, BlockAddress));
Status = NorFlashUnlockAndEraseSingleBlock (Instance, BlockAddress);
if (EFI_ERROR(Status)) {
VA_END (Args);
Status = EFI_DEVICE_ERROR;
goto EXIT;
}
// Move to the next Lba
StartingLba++;
NumOfLba--;
}
} while (TRUE);
VA_END (Args);
EXIT:
return Status;
}
/**
Writes the specified number of bytes from the input buffer to the block.
The Write() function writes the specified number of bytes from
the provided buffer to the specified block and offset. If the
firmware volume is sticky write, the caller must ensure that
all the bits of the specified range to write are in the
EFI_FVB_ERASE_POLARITY state before calling the Write()
function, or else the result will be unpredictable. This
unpredictability arises because, for a sticky-write firmware
volume, a write may negate a bit in the EFI_FVB_ERASE_POLARITY
state but cannot flip it back again. Before calling the
Write() function, it is recommended for the caller to first call
the EraseBlocks() function to erase the specified block to
write. A block erase cycle will transition bits from the
(NOT)EFI_FVB_ERASE_POLARITY state back to the
EFI_FVB_ERASE_POLARITY state. Implementations should be
mindful that the firmware volume might be in the WriteDisabled
state. If it is in this state, the Write() function must
return the status code EFI_ACCESS_DENIED without modifying the
contents of the firmware volume. The Write() function must
also prevent spanning block boundaries. If a write is
requested that spans a block boundary, the write must store up
to the boundary but not beyond. The output parameter NumBytes
must be set to correctly indicate the number of bytes actually
written. The caller must be aware that a write may be
partially completed. All writes, partial or otherwise, must be
fully flushed to the hardware before the Write() service
returns.
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
@param Lba The starting logical block index to write to.
@param Offset Offset into the block at which to begin writing.
@param NumBytes The pointer to a UINTN.
At entry, *NumBytes contains the total size of the buffer.
At exit, *NumBytes contains the total number of bytes actually written.
@param Buffer The pointer to a caller-allocated buffer that contains the source for the write.
@retval EFI_SUCCESS The firmware volume was written successfully.
@retval EFI_BAD_BUFFER_SIZE The write was attempted across an LBA boundary.
On output, NumBytes contains the total number of bytes
actually written.
@retval EFI_ACCESS_DENIED The firmware volume is in the WriteDisabled state.
@retval EFI_DEVICE_ERROR The block device is malfunctioning and could not be written.
**/
EFI_STATUS
EFIAPI
FvbWrite (
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
IN EFI_LBA Lba,
IN UINTN Offset,
IN OUT UINTN *NumBytes,
IN UINT8 *Buffer
)
{
EFI_STATUS Status;
EFI_STATUS TempStatus;
UINTN BlockSize;
UINT8 *BlockBuffer;
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS(This);
if (!Instance->Initialized && Instance->Initialize) {
Instance->Initialize(Instance);
}
DEBUG ((DEBUG_BLKIO, "FvbWrite(Parameters: Lba=%ld, Offset=0x%x, *NumBytes=0x%x, Buffer @ 0x%08x)\n", Instance->StartLba + Lba, Offset, *NumBytes, Buffer));
Status = EFI_SUCCESS;
TempStatus = Status;
// Detect WriteDisabled state
if (Instance->Media.ReadOnly == TRUE) {
DEBUG ((EFI_D_ERROR, "FvbWrite: ERROR - Can not write: Device is in WriteDisabled state.\n"));
// It is in WriteDisabled state, return an error right away
return EFI_ACCESS_DENIED;
}
// Cache the block size to avoid de-referencing pointers all the time
BlockSize = Instance->Media.BlockSize;
// The write must not span block boundaries.
// We need to check each variable individually because adding two large values together overflows.
if ( ( Offset >= BlockSize ) ||
( *NumBytes > BlockSize ) ||
( (Offset + *NumBytes) > BlockSize ) ) {
DEBUG ((EFI_D_ERROR, "FvbWrite: ERROR - EFI_BAD_BUFFER_SIZE: (Offset=0x%x + NumBytes=0x%x) > BlockSize=0x%x\n", Offset, *NumBytes, BlockSize ));
return EFI_BAD_BUFFER_SIZE;
}
// We must have some bytes to write
if (*NumBytes == 0) {
DEBUG ((EFI_D_ERROR, "FvbWrite: ERROR - EFI_BAD_BUFFER_SIZE: (Offset=0x%x + NumBytes=0x%x) > BlockSize=0x%x\n", Offset, *NumBytes, BlockSize ));
return EFI_BAD_BUFFER_SIZE;
}
// Allocate runtime memory to read in the NOR Flash data.
// Since the intention is to use this with Variable Services and since these are runtime,
// allocate the memory from the runtime pool.
BlockBuffer = AllocateRuntimePool (BlockSize);
// Check we did get some memory
if( BlockBuffer == NULL ) {
DEBUG ((EFI_D_ERROR, "FvbWrite: ERROR - Can not allocate BlockBuffer @ 0x%08x.\n", BlockBuffer));
return EFI_DEVICE_ERROR;
}
// Read NOR Flash data into shadow buffer
TempStatus = NorFlashReadBlocks (Instance, Instance->StartLba + Lba, BlockSize, BlockBuffer);
if (EFI_ERROR (TempStatus)) {
// Return one of the pre-approved error statuses
Status = EFI_DEVICE_ERROR;
goto FREE_MEMORY;
}
// Put the data at the appropriate location inside the buffer area
CopyMem((BlockBuffer + Offset), Buffer, *NumBytes);
// Write the modified buffer back to the NorFlash
Status = NorFlashWriteBlocks (Instance, Instance->StartLba + Lba, BlockSize, BlockBuffer);
if (EFI_ERROR (TempStatus)) {
// Return one of the pre-approved error statuses
Status = EFI_DEVICE_ERROR;
goto FREE_MEMORY;
}
FREE_MEMORY:
FreePool(BlockBuffer);
return Status;
}
/**
Reads the specified number of bytes into a buffer from the specified block.
The Read() function reads the requested number of bytes from the
requested block and stores them in the provided buffer.
Implementations should be mindful that the firmware volume
might be in the ReadDisabled state. If it is in this state,
the Read() function must return the status code
EFI_ACCESS_DENIED without modifying the contents of the
buffer. The Read() function must also prevent spanning block
boundaries. If a read is requested that would span a block
boundary, the read must read up to the boundary but not
beyond. The output parameter NumBytes must be set to correctly
indicate the number of bytes actually read. The caller must be
aware that a read may be partially completed.
@param This Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
@param Lba The starting logical block index from which to read.
@param Offset Offset into the block at which to begin reading.
@param NumBytes Pointer to a UINTN.
At entry, *NumBytes contains the total size of the buffer.
At exit, *NumBytes contains the total number of bytes read.
@param Buffer Pointer to a caller-allocated buffer that will be used
to hold the data that is read.
@retval EFI_SUCCESS The firmware volume was read successfully, and contents are
in Buffer.
@retval EFI_BAD_BUFFER_SIZE Read attempted across an LBA boundary.
On output, NumBytes contains the total number of bytes
returned in Buffer.
@retval EFI_ACCESS_DENIED The firmware volume is in the ReadDisabled state.
@retval EFI_DEVICE_ERROR The block device is not functioning correctly and could not be read.
**/
EFI_STATUS
EFIAPI
FvbRead (
IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL *This,
IN EFI_LBA Lba,
IN UINTN Offset,
IN OUT UINTN *NumBytes,
IN OUT UINT8 *Buffer
)
{
EFI_STATUS Status;
EFI_STATUS TempStatus;
UINTN BlockSize;
UINT8 *BlockBuffer;
NOR_FLASH_INSTANCE *Instance;
Instance = INSTANCE_FROM_FVB_THIS(This);
DEBUG ((DEBUG_BLKIO, "FvbRead(Parameters: Lba=%ld, Offset=0x%x, *NumBytes=0x%x, Buffer @ 0x%08x)\n", Instance->StartLba + Lba, Offset, *NumBytes, Buffer));
if (!Instance->Initialized && Instance->Initialize) {
Instance->Initialize(Instance);
}
Status = EFI_SUCCESS;
TempStatus = Status;
// Cache the block size to avoid de-referencing pointers all the time
BlockSize = Instance->Media.BlockSize;
DEBUG ((DEBUG_BLKIO, "FvbRead: Check if (Offset=0x%x + NumBytes=0x%x) <= BlockSize=0x%x\n", Offset, *NumBytes, BlockSize ));
// The read must not span block boundaries.
// We need to check each variable individually because adding two large values together overflows.
if ((Offset >= BlockSize) ||
(*NumBytes > BlockSize) ||
((Offset + *NumBytes) > BlockSize)) {
DEBUG ((EFI_D_ERROR, "FvbRead: ERROR - EFI_BAD_BUFFER_SIZE: (Offset=0x%x + NumBytes=0x%x) > BlockSize=0x%x\n", Offset, *NumBytes, BlockSize ));
return EFI_BAD_BUFFER_SIZE;
}
// We must have some bytes to read
if (*NumBytes == 0) {
return EFI_BAD_BUFFER_SIZE;
}
// FixMe: Allow an arbitrary number of bytes to be read out, not just a multiple of block size.
// Allocate runtime memory to read in the NOR Flash data. Variable Services are runtime.
BlockBuffer = AllocateRuntimePool (BlockSize);
// Check if the memory allocation was successful
if (BlockBuffer == NULL) {
DEBUG ((EFI_D_ERROR, "FvbRead: ERROR - Could not allocate BlockBuffer @ 0x%08x.\n", BlockBuffer));
return EFI_DEVICE_ERROR;
}
// Read NOR Flash data into shadow buffer
TempStatus = NorFlashReadBlocks (Instance, Instance->StartLba + Lba, BlockSize, BlockBuffer);
if (EFI_ERROR (TempStatus)) {
// Return one of the pre-approved error statuses
Status = EFI_DEVICE_ERROR;
goto FREE_MEMORY;
}
// Put the data at the appropriate location inside the buffer area
DEBUG ((DEBUG_BLKIO, "FvbRead: CopyMem( Dst=0x%08x, Src=0x%08x, Size=0x%x ).\n", Buffer, BlockBuffer + Offset, *NumBytes));
CopyMem(Buffer, BlockBuffer + Offset, *NumBytes);
FREE_MEMORY:
FreePool(BlockBuffer);
return Status;
}
