/**
* The following function presumes that the block has already been unlocked.
**/
EFI_STATUS
NorFlashUnlockAndEraseSingleBlock (
IN NOR_FLASH_INSTANCE *Instance,
IN UINTN BlockAddress
)
{
EFI_STATUS Status;
UINTN Index;
EFI_TPL OriginalTPL;
// Raise TPL to TPL_HIGH to stop anyone from interrupting us.
OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
Index = 0;
// The block erase might fail a first time (SW bug ?). Retry it ...
do {
// Unlock the block if we have to
Status = NorFlashUnlockSingleBlockIfNecessary (Instance, BlockAddress);
if (!EFI_ERROR(Status)) {
Status = NorFlashEraseSingleBlock (Instance, BlockAddress);
}
Index++;
} while ((Index < NOR_FLASH_ERASE_RETRY) && (Status == EFI_WRITE_PROTECTED));
if (Index == NOR_FLASH_ERASE_RETRY) {
DEBUG((EFI_D_ERROR,"EraseSingleBlock(BlockAddress=0x%08x: Block Locked Error (try to erase %d times)\n", BlockAddress,Index));
}
// Interruptions can resume.
gBS->RestoreTPL (OriginalTPL);
return Status;
}
/**
* This function unlock and erase an entire NOR Flash block.
**/
EFI_STATUS
NorFlashUnlockAndEraseSingleBlock (
IN NOR_FLASH_INSTANCE *Instance,
IN UINTN BlockAddress
)
{
EFI_STATUS Status;
UINTN Index;
EFI_TPL OriginalTPL;
if (!EfiAtRuntime ()) {
// Raise TPL to TPL_HIGH to stop anyone from interrupting us.
OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
} else {
// This initialization is only to prevent the compiler to complain about the
// use of uninitialized variables
OriginalTPL = TPL_HIGH_LEVEL;
}
Index = 0;
// The block erase might fail a first time (SW bug ?). Retry it ...
do {
// Unlock the block if we have to
Status = NorFlashUnlockSingleBlockIfNecessary (Instance, BlockAddress);
if (EFI_ERROR (Status)) {
break;
}
Status = NorFlashEraseSingleBlock (Instance, BlockAddress);
Index++;
} while ((Index < NOR_FLASH_ERASE_RETRY) && (Status == EFI_WRITE_PROTECTED));
if (Index == NOR_FLASH_ERASE_RETRY) {
DEBUG((EFI_D_ERROR,"EraseSingleBlock(BlockAddress=0x%08x: Block Locked Error (try to erase %d times)\n", BlockAddress,Index));
}
if (!EfiAtRuntime ()) {
// Interruptions can resume.
gBS->RestoreTPL (OriginalTPL);
}
return Status;
}
/*
Write a full or portion of a block. It must not span block boundaries; that is,
Offset + *NumBytes <= Instance->Media.BlockSize.
*/
EFI_STATUS
NorFlashWriteSingleBlock (
IN NOR_FLASH_INSTANCE *Instance,
IN EFI_LBA Lba,
IN UINTN Offset,
IN OUT UINTN *NumBytes,
IN UINT8 *Buffer
)
{
EFI_STATUS TempStatus;
UINT32 Tmp;
UINT32 TmpBuf;
UINT32 WordToWrite;
UINT32 Mask;
BOOLEAN DoErase;
UINTN BytesToWrite;
UINTN CurOffset;
UINTN WordAddr;
UINTN BlockSize;
UINTN BlockAddress;
UINTN PrevBlockAddress;
PrevBlockAddress = 0;
if (!Instance->Initialized && Instance->Initialize) {
Instance->Initialize(Instance);
}
DEBUG ((DEBUG_BLKIO, "NorFlashWriteSingleBlock(Parameters: Lba=%ld, Offset=0x%x, *NumBytes=0x%x, Buffer @ 0x%08x)\n", Lba, Offset, *NumBytes, Buffer));
// Detect WriteDisabled state
if (Instance->Media.ReadOnly == TRUE) {
DEBUG ((EFI_D_ERROR, "NorFlashWriteSingleBlock: 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, "NorFlashWriteSingleBlock: 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, "NorFlashWriteSingleBlock: ERROR - EFI_BAD_BUFFER_SIZE: (Offset=0x%x + NumBytes=0x%x) > BlockSize=0x%x\n", Offset, *NumBytes, BlockSize ));
return EFI_BAD_BUFFER_SIZE;
}
// Pick 128bytes as a good start for word operations as opposed to erasing the
// block and writing the data regardless if an erase is really needed.
// It looks like most individual NV variable writes are smaller than 128bytes.
if (*NumBytes <= 128) {
// Check to see if we need to erase before programming the data into NOR.
// If the destination bits are only changing from 1s to 0s we can just write.
// After a block is erased all bits in the block is set to 1.
// If any byte requires us to erase we just give up and rewrite all of it.
DoErase = FALSE;
BytesToWrite = *NumBytes;
CurOffset = Offset;
while (BytesToWrite > 0) {
// Read full word from NOR, splice as required. A word is the smallest
// unit we can write.
TempStatus = NorFlashRead (Instance, Lba, CurOffset & ~(0x3), sizeof(Tmp), &Tmp);
if (EFI_ERROR (TempStatus)) {
return EFI_DEVICE_ERROR;
}
// Physical address of word in NOR to write.
WordAddr = (CurOffset & ~(0x3)) + GET_NOR_BLOCK_ADDRESS (Instance->RegionBaseAddress,
Lba, BlockSize);
// The word of data that is to be written.
TmpBuf = *((UINT32*)(Buffer + (*NumBytes - BytesToWrite)));
// First do word aligned chunks.
if ((CurOffset & 0x3) == 0) {
if (BytesToWrite >= 4) {
// Is the destination still in 'erased' state?
if (~Tmp != 0) {
// Check to see if we are only changing bits to zero.
if ((Tmp ^ TmpBuf) & TmpBuf) {
DoErase = TRUE;
break;
}
}
// Write this word to NOR
WordToWrite = TmpBuf;
CurOffset += sizeof(TmpBuf);
BytesToWrite -= sizeof(TmpBuf);
} else {
// BytesToWrite < 4. Do small writes and left-overs
Mask = ~((~0) << (BytesToWrite * 8));
// Mask out the bytes we want.
TmpBuf &= Mask;
// Is the destination still in 'erased' state?
if ((Tmp & Mask) != Mask) {
// Check to see if we are only changing bits to zero.
if ((Tmp ^ TmpBuf) & TmpBuf) {
DoErase = TRUE;
break;
}
}
// Merge old and new data. Write merged word to NOR
WordToWrite = (Tmp & ~Mask) | TmpBuf;
CurOffset += BytesToWrite;
BytesToWrite = 0;
}
} else {
// Do multiple words, but starting unaligned.
if (BytesToWrite > (4 - (CurOffset & 0x3))) {
Mask = ((~0) << ((CurOffset & 0x3) * 8));
// Mask out the bytes we want.
TmpBuf &= Mask;
// Is the destination still in 'erased' state?
if ((Tmp & Mask) != Mask) {
// Check to see if we are only changing bits to zero.
if ((Tmp ^ TmpBuf) & TmpBuf) {
DoErase = TRUE;
break;
}
}
// Merge old and new data. Write merged word to NOR
WordToWrite = (Tmp & ~Mask) | TmpBuf;
BytesToWrite -= (4 - (CurOffset & 0x3));
CurOffset += (4 - (CurOffset & 0x3));
} else {
// Unaligned and fits in one word.
Mask = (~((~0) << (BytesToWrite * 8))) << ((CurOffset & 0x3) * 8);
// Mask out the bytes we want.
TmpBuf = (TmpBuf << ((CurOffset & 0x3) * 8)) & Mask;
// Is the destination still in 'erased' state?
if ((Tmp & Mask) != Mask) {
// Check to see if we are only changing bits to zero.
if ((Tmp ^ TmpBuf) & TmpBuf) {
DoErase = TRUE;
break;
}
}
// Merge old and new data. Write merged word to NOR
WordToWrite = (Tmp & ~Mask) | TmpBuf;
CurOffset += BytesToWrite;
BytesToWrite = 0;
}
}
//
// Write the word to NOR.
//
BlockAddress = GET_NOR_BLOCK_ADDRESS (Instance->RegionBaseAddress, Lba, BlockSize);
if (BlockAddress != PrevBlockAddress) {
TempStatus = NorFlashUnlockSingleBlockIfNecessary (Instance, BlockAddress);
if (EFI_ERROR (TempStatus)) {
return EFI_DEVICE_ERROR;
}
PrevBlockAddress = BlockAddress;
}
TempStatus = NorFlashWriteSingleWord (Instance, WordAddr, WordToWrite);
if (EFI_ERROR (TempStatus)) {
return EFI_DEVICE_ERROR;
}
}
// Exit if we got here and could write all the data. Otherwise do the
// Erase-Write cycle.
if (!DoErase) {
return EFI_SUCCESS;
}
}
// Check we did get some memory. Buffer is BlockSize.
if (Instance->ShadowBuffer == NULL) {
DEBUG ((EFI_D_ERROR, "FvbWrite: ERROR - Buffer not ready\n"));
return EFI_DEVICE_ERROR;
}
// Read NOR Flash data into shadow buffer
TempStatus = NorFlashReadBlocks (Instance, Lba, BlockSize, Instance->ShadowBuffer);
if (EFI_ERROR (TempStatus)) {
// Return one of the pre-approved error statuses
return EFI_DEVICE_ERROR;
}
// Put the data at the appropriate location inside the buffer area
CopyMem ((VOID*)((UINTN)Instance->ShadowBuffer + Offset), Buffer, *NumBytes);
// Write the modified buffer back to the NorFlash
TempStatus = NorFlashWriteBlocks (Instance, Lba, BlockSize, Instance->ShadowBuffer);
if (EFI_ERROR (TempStatus)) {
// Return one of the pre-approved error statuses
return EFI_DEVICE_ERROR;
}
return EFI_SUCCESS;
}
