void FF_lockFAT(FF_IOMAN *pIoman) { FF_PendSemaphore(pIoman->pSemaphore); // Use Semaphore to protect FAT modifications. { while((pIoman->Locks & FF_FAT_LOCK)) { FF_ReleaseSemaphore(pIoman->pSemaphore); FF_Yield(); // Keep Releasing and Yielding until we have the Fat protector. FF_PendSemaphore(pIoman->pSemaphore); } pIoman->Locks |= FF_FAT_LOCK; } FF_ReleaseSemaphore(pIoman->pSemaphore); }
static FF_T_SINT32 FF_WriteClusters(FF_FILE *pFile, FF_T_UINT32 Count, FF_T_UINT8 *buffer) { FF_T_UINT32 Sectors; FF_T_UINT32 SequentialClusters = 0; FF_T_UINT32 nItemLBA; FF_T_SINT32 RetVal; while(Count != 0) { if((Count - 1) > 0) { SequentialClusters = FF_GetSequentialClusters(pFile->pIoman, pFile->AddrCurrentCluster, (Count - 1)); } Sectors = (SequentialClusters + 1) * pFile->pIoman->pPartition->SectorsPerCluster; nItemLBA = FF_Cluster2LBA(pFile->pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pFile->pIoman, nItemLBA); do { if(pFile->pIoman->pBlkDevice->fnWriteBlocks) { #ifdef FF_BLKDEV_USES_SEM FF_PendSemaphore(pFile->pIoman->pSemaphore); #endif // Called from FF_Write, sem not claimed RetVal = pFile->pIoman->pBlkDevice->fnWriteBlocks(buffer, nItemLBA, Sectors, pFile->pIoman->pBlkDevice->pParam); #ifdef FF_BLKDEV_USES_SEM FF_ReleaseSemaphore(pFile->pIoman->pSemaphore); #endif if(RetVal == FF_ERR_DRIVER_BUSY) { FF_Yield(); FF_Sleep(FF_DRIVER_BUSY_SLEEP); } } else { RetVal = FF_ERR_DEVICE_DRIVER_FAILED; } }while(RetVal == FF_ERR_DRIVER_BUSY); Count -= (SequentialClusters + 1); pFile->AddrCurrentCluster = FF_TraverseFAT(pFile->pIoman, pFile->AddrCurrentCluster, (SequentialClusters + 1)); pFile->CurrentCluster += (SequentialClusters + 1); buffer += Sectors * pFile->pIoman->BlkSize; SequentialClusters = 0; } return 0; }
FF_BUFFER *FF_GetBuffer(FF_IOMAN *pIoman, FF_T_UINT32 Sector, FF_T_UINT8 Mode) { FF_BUFFER *pBuffer; FF_BUFFER *pBufLRU = NULL; FF_BUFFER *pBufLHITS = NULL; FF_BUFFER *pBufMatch = NULL; FF_T_UINT32 i; while(!pBufMatch) { FF_PendSemaphore(pIoman->pSemaphore); { pBuffer = pIoman->pBuffers; // HT if a perfect match has priority, find that first for(i = 0; i < pIoman->CacheSize; i++, pBuffer++) { pBuffer = (pIoman->pBuffers + i); if(pBuffer->Sector == Sector && pBuffer->Valid == FF_TRUE) { pBufMatch = pBuffer; break; // Why look further if you found a perfect match? } } if(pBufMatch) { // A Match was found process! if(Mode == FF_MODE_READ && pBufMatch->Mode == FF_MODE_READ) { pBufMatch->NumHandles += 1; pBufMatch->Persistance += 1; FF_ReleaseSemaphore(pIoman->pSemaphore); return pBufMatch; } if(pBufMatch->Mode == FF_MODE_WRITE && pBufMatch->NumHandles == 0) { // This buffer has no attached handles. pBufMatch->Mode = Mode; pBufMatch->NumHandles = 1; pBufMatch->Persistance += 1; FF_ReleaseSemaphore(pIoman->pSemaphore); return pBufMatch; } if(pBufMatch->Mode == FF_MODE_READ && Mode == FF_MODE_WRITE && pBufMatch->NumHandles == 0) { pBufMatch->Mode = Mode; pBufMatch->Modified = FF_TRUE; pBufMatch->NumHandles = 1; pBufMatch->Persistance += 1; FF_ReleaseSemaphore(pIoman->pSemaphore); return pBufMatch; } pBufMatch = NULL; // Sector is already in use, keep yielding until its available! } else { pBuffer = pIoman->pBuffers; for(i = 0; i < pIoman->CacheSize; i++, pBuffer++) { if(pBuffer->NumHandles == 0) { pBuffer->LRU += 1; if(!pBufLRU) { pBufLRU = pBuffer; } if(!pBufLHITS) { pBufLHITS = pBuffer; } if(pBuffer->LRU >= pBufLRU->LRU) { if(pBuffer->LRU == pBufLRU->LRU) { if(pBuffer->Persistance > pBufLRU->Persistance) { pBufLRU = pBuffer; } } else { pBufLRU = pBuffer; } } if(pBuffer->Persistance < pBufLHITS->Persistance) { pBufLHITS = pBuffer; } } } if(pBufLRU) { // Process the suitable candidate. if(pBufLRU->Modified == FF_TRUE) { FF_BlockWrite(pIoman, pBufLRU->Sector, 1, pBufLRU->pBuffer); } pBufLRU->Mode = Mode; pBufLRU->Persistance = 1; pBufLRU->LRU = 0; pBufLRU->NumHandles = 1; pBufLRU->Sector = Sector; if(Mode == FF_MODE_WRITE) { pBufLRU->Modified = FF_TRUE; } else { pBufLRU->Modified = FF_FALSE; } FF_BlockRead(pIoman, Sector, 1, pBufLRU->pBuffer); pBufLRU->Valid = FF_TRUE; FF_ReleaseSemaphore(pIoman->pSemaphore); return pBufLRU; } } } FF_ReleaseSemaphore(pIoman->pSemaphore); FF_Yield(); // Better to go asleep to give low-priority task a chance to release buffer(s) } return pBufMatch; // Return the Matched Buffer! }
/** * @public * @brief Equivalent to fread() * * @param pFile FF_FILE object that was created by FF_Open(). * @param ElementSize The size of an element to read. * @param Count The number of elements to read. * @param buffer A pointer to a buffer of adequate size to be filled with the requested data. * * @return Number of bytes read. * **/ FF_T_SINT32 FF_Read(FF_FILE *pFile, FF_T_UINT32 ElementSize, FF_T_UINT32 Count, FF_T_UINT8 *buffer) { FF_T_UINT32 nBytes = ElementSize * Count; FF_T_UINT32 nBytesRead = 0; FF_T_UINT32 nBytesToRead; FF_IOMAN *pIoman; FF_BUFFER *pBuffer; FF_T_UINT32 nRelBlockPos; FF_T_UINT32 nItemLBA; FF_T_SINT32 RetVal = 0; FF_T_UINT16 sSectors; FF_T_UINT32 nRelClusterPos; FF_T_UINT32 nBytesPerCluster; FF_T_UINT32 nClusterDiff; if(!pFile) { return FF_ERR_NULL_POINTER; } if(!(pFile->Mode & FF_MODE_READ)) { return FF_ERR_FILE_NOT_OPENED_IN_READ_MODE; } pIoman = pFile->pIoman; if(pFile->FilePointer == pFile->Filesize) { return 0; } if((pFile->FilePointer + nBytes) > pFile->Filesize) { nBytes = pFile->Filesize - pFile->FilePointer; } nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nRelBlockPos = FF_getMinorBlockEntry(pIoman, pFile->FilePointer, 1); // Get the position within a block. nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); if((nRelBlockPos + nBytes) < pIoman->BlkSize) { // Bytes to read are within a block and less than a block size. pBuffer = FF_GetBuffer(pIoman, nItemLBA, FF_MODE_READ); { memcpy(buffer, (pBuffer->pBuffer + nRelBlockPos), nBytes); } FF_ReleaseBuffer(pIoman, pBuffer); pFile->FilePointer += nBytes; return nBytes; // Return the number of bytes read. } else { //---------- Read (memcpy) to a Sector Boundary if(nRelBlockPos != 0) { // Not on a sector boundary, at this point the LBA is known. nBytesToRead = pIoman->BlkSize - nRelBlockPos; pBuffer = FF_GetBuffer(pIoman, nItemLBA, FF_MODE_READ); { // Here we copy to the sector boudary. memcpy(buffer, (pBuffer->pBuffer + nRelBlockPos), nBytesToRead); } FF_ReleaseBuffer(pIoman, pBuffer); nBytes -= nBytesToRead; nBytesRead += nBytesToRead; pFile->FilePointer += nBytesToRead; buffer += nBytesToRead; } //---------- Read to a Cluster Boundary nRelClusterPos = FF_getClusterPosition(pIoman, pFile->FilePointer, 1); nBytesPerCluster = (pIoman->pPartition->SectorsPerCluster * pIoman->BlkSize); if(nRelClusterPos != 0 && nBytes >= nBytesPerCluster) { // Need to get to cluster boundary nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); sSectors = (FF_T_UINT16) (pIoman->pPartition->SectorsPerCluster - (nRelClusterPos / pIoman->BlkSize)); do { if(pIoman->pBlkDevice->fnReadBlocks) { #ifdef FF_BLKDEV_USES_SEM FF_PendSemaphore(pFile->pIoman->pSemaphore); #endif RetVal = pFile->pIoman->pBlkDevice->fnReadBlocks(buffer, nItemLBA, sSectors, pIoman->pBlkDevice->pParam); #ifdef FF_BLKDEV_USES_SEM FF_ReleaseSemaphore(pFile->pIoman->pSemaphore); #endif } if(RetVal == FF_ERR_DRIVER_BUSY) { FF_Yield(); FF_Sleep(FF_DRIVER_BUSY_SLEEP); } }while(RetVal == FF_ERR_DRIVER_BUSY); nBytesToRead = sSectors * pIoman->BlkSize; nBytes -= nBytesToRead; buffer += nBytesToRead; nBytesRead += nBytesToRead; pFile->FilePointer += nBytesToRead; } //---------- Read Clusters if(nBytes >= nBytesPerCluster) { //----- Thanks to Christopher Clark of DigiPen Institute of Technology in Redmond, US adding this traversal check. nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } //----- End of Contributor fix. FF_ReadClusters(pFile, (nBytes / nBytesPerCluster), buffer); nBytesToRead = (nBytesPerCluster * (nBytes / nBytesPerCluster)); pFile->FilePointer += nBytesToRead; nBytes -= nBytesToRead; buffer += nBytesToRead; nBytesRead += nBytesToRead; } //---------- Read Remaining Blocks if(nBytes >= pIoman->BlkSize) { sSectors = (FF_T_UINT16) (nBytes / pIoman->BlkSize); nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); do { if(pIoman->pBlkDevice->fnReadBlocks) { #ifdef FF_BLKDEV_USES_SEM FF_PendSemaphore(pFile->pIoman->pSemaphore); #endif RetVal = pFile->pIoman->pBlkDevice->fnReadBlocks(buffer, nItemLBA, sSectors, pIoman->pBlkDevice->pParam); #ifdef FF_BLKDEV_USES_SEM FF_ReleaseSemaphore(pFile->pIoman->pSemaphore); #endif } if(RetVal == FF_ERR_DRIVER_BUSY) { FF_Yield(); FF_Sleep(FF_DRIVER_BUSY_SLEEP); } }while(RetVal == FF_ERR_DRIVER_BUSY); nBytesToRead = sSectors * pIoman->BlkSize; pFile->FilePointer += nBytesToRead; nBytes -= nBytesToRead; buffer += nBytesToRead; nBytesRead += nBytesToRead; } //---------- Read (memcpy) Remaining Bytes if(nBytes > 0) { nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); pBuffer = FF_GetBuffer(pIoman, nItemLBA, FF_MODE_READ); { memcpy(buffer, pBuffer->pBuffer, nBytes); } FF_ReleaseBuffer(pIoman, pBuffer); nBytesToRead = nBytes; pFile->FilePointer += nBytesToRead; nBytes -= nBytesToRead; buffer += nBytesToRead; nBytesRead += nBytesToRead; } } return nBytesRead; }
/** * @public * @brief Writes data to a File. * * @param pFile FILE Pointer. * @param ElementSize Size of an Element of Data to be copied. (in bytes). * @param Count Number of Elements of Data to be copied. (ElementSize * Count must not exceed ((2^31)-1) bytes. (2GB). For best performance, multiples of 512 bytes or Cluster sizes are best. * @param buffer Byte-wise buffer containing the data to be written. * * @return **/ FF_T_SINT32 FF_Write(FF_FILE *pFile, FF_T_UINT32 ElementSize, FF_T_UINT32 Count, FF_T_UINT8 *buffer) { FF_T_UINT32 nBytes = ElementSize * Count; FF_T_UINT32 nBytesWritten = 0; FF_T_UINT32 nBytesToWrite; FF_IOMAN *pIoman; FF_BUFFER *pBuffer; FF_T_UINT32 nRelBlockPos; FF_T_UINT32 nItemLBA; FF_T_SINT32 RetVal = 0; FF_T_UINT16 sSectors; FF_T_UINT32 nRelClusterPos; FF_T_UINT32 nBytesPerCluster, nClusterDiff, nClusters; FF_ERROR Error; if(!pFile) { return FF_ERR_NULL_POINTER; } if(!(pFile->Mode & FF_MODE_WRITE)) { return FF_ERR_FILE_NOT_OPENED_IN_WRITE_MODE; } // Make sure a write is after the append point. if((pFile->Mode & FF_MODE_APPEND)) { if(pFile->FilePointer < pFile->Filesize) { FF_Seek(pFile, 0, FF_SEEK_END); } } pIoman = pFile->pIoman; nBytesPerCluster = (pIoman->pPartition->SectorsPerCluster * pIoman->BlkSize); // Extend File for atleast nBytes! // Handle file-space allocation Error = FF_ExtendFile(pFile, pFile->FilePointer + nBytes); if(Error) { return Error; } nRelBlockPos = FF_getMinorBlockEntry(pIoman, pFile->FilePointer, 1); // Get the position within a block. nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster != FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); if((nRelBlockPos + nBytes) < pIoman->BlkSize) { // Bytes to read are within a block and less than a block size. pBuffer = FF_GetBuffer(pIoman, nItemLBA, FF_MODE_WRITE); { memcpy((pBuffer->pBuffer + nRelBlockPos), buffer, nBytes); } FF_ReleaseBuffer(pIoman, pBuffer); pFile->FilePointer += nBytes; nBytesWritten = nBytes; //return nBytes; // Return the number of bytes read. } else { //---------- Write (memcpy) to a Sector Boundary if(nRelBlockPos != 0) { // Not on a sector boundary, at this point the LBA is known. nBytesToWrite = pIoman->BlkSize - nRelBlockPos; pBuffer = FF_GetBuffer(pIoman, nItemLBA, FF_MODE_WRITE); { // Here we copy to the sector boudary. memcpy((pBuffer->pBuffer + nRelBlockPos), buffer, nBytesToWrite); } FF_ReleaseBuffer(pIoman, pBuffer); nBytes -= nBytesToWrite; nBytesWritten += nBytesToWrite; pFile->FilePointer += nBytesToWrite; buffer += nBytesToWrite; } //---------- Write to a Cluster Boundary nRelClusterPos = FF_getClusterPosition(pIoman, pFile->FilePointer, 1); if(nRelClusterPos != 0 && nBytes >= nBytesPerCluster) { // Need to get to cluster boundary nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); sSectors = (FF_T_UINT16) (pIoman->pPartition->SectorsPerCluster - (nRelClusterPos / pIoman->BlkSize)); do { if(pIoman->pBlkDevice->fnWriteBlocks) { #ifdef FF_BLKDEV_USES_SEM FF_PendSemaphore(pFile->pIoman->pSemaphore); #endif RetVal = pFile->pIoman->pBlkDevice->fnWriteBlocks(buffer, nItemLBA, sSectors, pIoman->pBlkDevice->pParam); #ifdef FF_BLKDEV_USES_SEM FF_ReleaseSemaphore(pFile->pIoman->pSemaphore); #endif } if(RetVal == FF_ERR_DRIVER_BUSY) { FF_Yield(); FF_Sleep(FF_DRIVER_BUSY_SLEEP); } }while(RetVal == FF_ERR_DRIVER_BUSY); nBytesToWrite = sSectors * pIoman->BlkSize; nBytes -= nBytesToWrite; buffer += nBytesToWrite; nBytesWritten += nBytesToWrite; pFile->FilePointer += nBytesToWrite; } //---------- Write Clusters if(nBytes >= nBytesPerCluster) { //----- Thanks to Christopher Clark of DigiPen Institute of Technology in Redmond, US adding this traversal check. nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } //----- End of Contributor fix. nClusters = (nBytes / nBytesPerCluster); FF_WriteClusters(pFile, nClusters, buffer); nBytesToWrite = (nBytesPerCluster * nClusters); pFile->FilePointer += nBytesToWrite; nBytes -= nBytesToWrite; buffer += nBytesToWrite; nBytesWritten += nBytesToWrite; } //---------- Write Remaining Blocks if(nBytes >= pIoman->BlkSize) { sSectors = (FF_T_UINT16) (nBytes / pIoman->BlkSize); nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); do { if(pIoman->pBlkDevice->fnWriteBlocks) { #ifdef FF_BLKDEV_USES_SEM FF_PendSemaphore(pFile->pIoman->pSemaphore); #endif RetVal = pFile->pIoman->pBlkDevice->fnWriteBlocks(buffer, nItemLBA, sSectors, pIoman->pBlkDevice->pParam); #ifdef FF_BLKDEV_USES_SEM FF_ReleaseSemaphore(pFile->pIoman->pSemaphore); #endif } if(RetVal == FF_ERR_DRIVER_BUSY) { FF_Yield(); FF_Sleep(FF_DRIVER_BUSY_SLEEP); } }while(RetVal == FF_ERR_DRIVER_BUSY); nBytesToWrite = sSectors * pIoman->BlkSize; pFile->FilePointer += nBytesToWrite; nBytes -= nBytesToWrite; buffer += nBytesToWrite; nBytesWritten += nBytesToWrite; } //---------- Write (memcpy) Remaining Bytes if(nBytes > 0) { nClusterDiff = FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1) - pFile->CurrentCluster; if(nClusterDiff) { if(pFile->CurrentCluster < FF_getClusterChainNumber(pFile->pIoman, pFile->FilePointer, 1)) { pFile->AddrCurrentCluster = FF_TraverseFAT(pIoman, pFile->AddrCurrentCluster, nClusterDiff); pFile->CurrentCluster += nClusterDiff; } } nItemLBA = FF_Cluster2LBA(pIoman, pFile->AddrCurrentCluster); nItemLBA = FF_getRealLBA(pIoman, nItemLBA + FF_getMajorBlockNumber(pIoman, pFile->FilePointer, 1)) + FF_getMinorBlockNumber(pIoman, pFile->FilePointer, 1); pBuffer = FF_GetBuffer(pIoman, nItemLBA, FF_MODE_WRITE); { memcpy(pBuffer->pBuffer, buffer, nBytes); } FF_ReleaseBuffer(pIoman, pBuffer); nBytesToWrite = nBytes; pFile->FilePointer += nBytesToWrite; nBytes -= nBytesToWrite; buffer += nBytesToWrite; nBytesWritten += nBytesToWrite; } } if(pFile->FilePointer > pFile->Filesize) { pFile->Filesize = pFile->FilePointer; } return nBytesWritten; }