コード例 #1
0
ファイル: ff_ioman.c プロジェクト: BigEd/pyldin
/**
 *	@public
 *	@brief	Mounts the Specified partition, the volume specified by the FF_IOMAN object provided.
 *
 *	The device drivers must adhere to the specification provided by
 *	FF_WRITE_BLOCKS and FF_READ_BLOCKS.
 *
 *	@param	pIoman			FF_IOMAN object.
 *	@param	PartitionNumber	The primary partition number to be mounted. (0 - 3).
 *
 *	@return	0 on success.
 *	@return FF_ERR_NULL_POINTER if a pIoman object wasn't provided.
 *	@return FF_ERR_IOMAN_INVALID_PARTITION_NUM if the partition number is out of range.
 *	@return FF_ERR_IOMAN_NO_MOUNTABLE_PARTITION if no partition was found.
 *	@return FF_ERR_IOMAN_INVALID_FORMAT if the master boot record or partition boot block didn't provide sensible data.
 *	@return FF_ERR_IOMAN_NOT_FAT_FORMATTED if the volume or partition couldn't be determined to be FAT. (@see ff_config.h)
 *
 **/
FF_ERROR FF_MountPartition(FF_IOMAN *pIoman, FF_T_UINT8 PartitionNumber) {
	FF_PARTITION	*pPart;
	FF_BUFFER		*pBuffer = 0;
	FF_ERROR		Error;

	FF_T_UINT8		ucPartitionType;

	int partCount;

	if(!pIoman) {
		return FF_ERR_NULL_POINTER;
	}

	/*if(PartitionNumber > 3) {
		return FF_ERR_IOMAN_INVALID_PARTITION_NUM;
	}*/

	pPart = pIoman->pPartition;

	memset (pIoman->pBuffers, '\0', sizeof(FF_BUFFER) * pIoman->CacheSize);
	memset (pIoman->pCacheMem, '\0', pIoman->BlkSize * pIoman->CacheSize);

	FF_IOMAN_InitBufferDescriptors(pIoman);
	pIoman->FirstFile = 0;

	pBuffer = FF_GetBuffer(pIoman, 0, FF_MODE_READ);
	if(!pBuffer) {
		return FF_ERR_DEVICE_DRIVER_FAILED;
	}

	partCount = FF_PartitionCount (pBuffer->pBuffer);

	pPart->BlkSize = FF_getShort(pBuffer->pBuffer, FF_FAT_BYTES_PER_SECTOR);

	if (partCount == 0) { //(pPart->BlkSize % 512) == 0 && pPart->BlkSize > 0) {
		// Volume is not partitioned (MBR Found)
		pPart->BeginLBA = 0;
	} else {
		
		ucPartitionType = FF_getChar(pBuffer->pBuffer, FF_FAT_PTBL + FF_FAT_PTBL_ID);	// Ensure its not an EFI partition!

		if(ucPartitionType != 0xEE) {

			if(PartitionNumber > 3) {
				FF_ReleaseBuffer(pIoman, pBuffer);
				return FF_ERR_IOMAN_INVALID_PARTITION_NUM;
			}

			// Primary Partitions to deal with!
			pPart->BeginLBA = FF_getLong(pBuffer->pBuffer, FF_FAT_PTBL + FF_FAT_PTBL_LBA + (16 * PartitionNumber));
		}

		FF_ReleaseBuffer(pIoman, pBuffer);

		if(ucPartitionType == 0xEE) {

			pPart->BeginLBA = FF_getLong(pBuffer->pBuffer, FF_FAT_PTBL + FF_FAT_PTBL_LBA);
			Error = FF_GetEfiPartitionEntry(pIoman, PartitionNumber);

			if(Error) {
				return Error;
			}
		}

		if(!pPart->BeginLBA) {
			return FF_ERR_IOMAN_NO_MOUNTABLE_PARTITION;
		}
		// Now we get the Partition sector.
		pBuffer = FF_GetBuffer(pIoman, pPart->BeginLBA, FF_MODE_READ);
		if(!pBuffer) {
			return FF_ERR_DEVICE_DRIVER_FAILED;
		}
		pPart->BlkSize = FF_getShort(pBuffer->pBuffer, FF_FAT_BYTES_PER_SECTOR);
		if((pPart->BlkSize % 512) != 0 || pPart->BlkSize == 0) {
			FF_ReleaseBuffer(pIoman, pBuffer);
			return FF_ERR_IOMAN_INVALID_FORMAT;
		}
	}

	// Assume FAT16, then we'll adjust if its FAT32
	pPart->ReservedSectors = FF_getShort(pBuffer->pBuffer, FF_FAT_RESERVED_SECTORS);
	pPart->FatBeginLBA = pPart->BeginLBA + pPart->ReservedSectors;

	pPart->NumFATS = (FF_T_UINT8) FF_getShort(pBuffer->pBuffer, FF_FAT_NUMBER_OF_FATS);
	pPart->SectorsPerFAT = (FF_T_UINT32) FF_getShort(pBuffer->pBuffer, FF_FAT_16_SECTORS_PER_FAT);

	pPart->SectorsPerCluster = FF_getChar(pBuffer->pBuffer, FF_FAT_SECTORS_PER_CLUS);

	pPart->BlkFactor = (FF_T_UINT8) (pPart->BlkSize / pIoman->BlkSize);    // Set the BlockFactor (How many real-blocks in a fake block!).

	if(pPart->SectorsPerFAT == 0) {	// FAT32
		pPart->SectorsPerFAT	= FF_getLong(pBuffer->pBuffer, FF_FAT_32_SECTORS_PER_FAT);
		pPart->RootDirCluster	= FF_getLong(pBuffer->pBuffer, FF_FAT_ROOT_DIR_CLUSTER);
		pPart->ClusterBeginLBA	= pPart->BeginLBA + pPart->ReservedSectors + (pPart->NumFATS * pPart->SectorsPerFAT);
		pPart->TotalSectors		= (FF_T_UINT32) FF_getShort(pBuffer->pBuffer, FF_FAT_16_TOTAL_SECTORS);
		if(pPart->TotalSectors == 0) {
			pPart->TotalSectors = FF_getLong(pBuffer->pBuffer, FF_FAT_32_TOTAL_SECTORS);
		}
		memcpy (pPart->VolLabel, pBuffer->pBuffer + FF_FAT_32_VOL_LABEL, sizeof pPart->VolLabel);
	} else {	// FAT16
		pPart->ClusterBeginLBA	= pPart->BeginLBA + pPart->ReservedSectors + (pPart->NumFATS * pPart->SectorsPerFAT);
		pPart->TotalSectors		= (FF_T_UINT32) FF_getShort(pBuffer->pBuffer, FF_FAT_16_TOTAL_SECTORS);
		pPart->RootDirCluster	= 1; // 1st Cluster is RootDir!
		if(pPart->TotalSectors == 0) {
			pPart->TotalSectors = FF_getLong(pBuffer->pBuffer, FF_FAT_32_TOTAL_SECTORS);
		}
		memcpy (pPart->VolLabel, pBuffer->pBuffer + FF_FAT_16_VOL_LABEL, sizeof pPart->VolLabel);
	}

	FF_ReleaseBuffer(pIoman, pBuffer);	// Release the buffer finally!

	if(!pPart->BlkSize) {
		return FF_ERR_IOMAN_INVALID_FORMAT;
	}
	
	pPart->RootDirSectors	= ((FF_getShort(pBuffer->pBuffer, FF_FAT_ROOT_ENTRY_COUNT) * 32) + pPart->BlkSize - 1) / pPart->BlkSize;
	pPart->FirstDataSector	= pPart->ClusterBeginLBA + pPart->RootDirSectors;
	pPart->DataSectors		= pPart->TotalSectors - (pPart->ReservedSectors + (pPart->NumFATS * pPart->SectorsPerFAT) + pPart->RootDirSectors);
	
	if(!pPart->SectorsPerCluster) {
		return FF_ERR_IOMAN_INVALID_FORMAT;
	}
	
	pPart->NumClusters		= pPart->DataSectors / pPart->SectorsPerCluster;

	Error = FF_DetermineFatType(pIoman);
	
	if(Error) {
		return Error;
	}

#ifdef FF_MOUNT_FIND_FREE
	pPart->LastFreeCluster	= FF_FindFreeCluster(pIoman);
	pPart->FreeClusterCount = FF_CountFreeClusters(pIoman);
#else
	pPart->LastFreeCluster	= 0;
	pPart->FreeClusterCount = 0;
#endif

	return FF_ERR_NONE;
}
コード例 #2
0
ファイル: ff_file.c プロジェクト: bicepjai/nanos
static FF_ERROR FF_ExtendFile(FF_FILE *pFile, FF_T_UINT32 Size) {
	FF_IOMAN	*pIoman = pFile->pIoman;
	FF_T_UINT32 nBytesPerCluster = pIoman->pPartition->BlkSize * pIoman->pPartition->SectorsPerCluster;
	FF_T_UINT32 nTotalClustersNeeded = Size / nBytesPerCluster;
	FF_T_UINT32 nClusterToExtend; 
	FF_T_UINT32 CurrentCluster, NextCluster;
	FF_T_UINT32	i;
	FF_DIRENT	OriginalEntry;

	if((pFile->Mode & FF_MODE_WRITE) != FF_MODE_WRITE) {
		return FF_ERR_FILE_NOT_OPENED_IN_WRITE_MODE;
	}

	if(pFile->Filesize == 0 && pFile->ObjectCluster == 0) {	// No Allocated clusters.
		// Create a Cluster chain!
		pFile->AddrCurrentCluster = FF_CreateClusterChain(pFile->pIoman);
		if(!FF_GetEntry(pIoman, pFile->DirEntry, pFile->DirCluster, &OriginalEntry)) {
			OriginalEntry.ObjectCluster = pFile->AddrCurrentCluster;
			FF_PutEntry(pIoman, pFile->DirEntry, pFile->DirCluster, &OriginalEntry);
		} else {
			return FF_ERR_FILE_EXTEND_FAILED;
		}
		pFile->ObjectCluster = pFile->AddrCurrentCluster;
		pFile->iChainLength = 1;
		pFile->CurrentCluster = 0;
		pFile->iEndOfChain = pFile->AddrCurrentCluster;
	}
	
	if(Size % nBytesPerCluster) {
		nTotalClustersNeeded += 1;
	}

	if(pFile->iChainLength == 0) {	// First extension requiring the chain length, 
		pFile->iChainLength = FF_GetChainLength(pIoman, pFile->ObjectCluster, &pFile->iEndOfChain);
	}

	nClusterToExtend = (nTotalClustersNeeded - pFile->iChainLength);

	if(nTotalClustersNeeded > pFile->iChainLength) {

		NextCluster = pFile->AddrCurrentCluster;
		FF_lockFAT(pIoman);
		{
			for(i = 0; i <= nClusterToExtend; i++) {
				CurrentCluster = FF_FindEndOfChain(pIoman, NextCluster);
				NextCluster = FF_FindFreeCluster(pIoman);
				if(!NextCluster) {
					FF_unlockFAT(pIoman);
					return FF_ERR_FAT_NO_FREE_CLUSTERS;
				}
				FF_putFatEntry(pIoman, CurrentCluster, NextCluster);
				FF_putFatEntry(pIoman, NextCluster, 0xFFFFFFFF);
			}
			
			pFile->iEndOfChain = FF_FindEndOfChain(pIoman, NextCluster);
		}
		FF_unlockFAT(pIoman);
		
		pFile->iChainLength += i;
		FF_DecreaseFreeClusters(pIoman, i);	// Keep Tab of Numbers for fast FreeSize()
	}

	return FF_ERR_NONE;
}