/***************************************************************************** * FullFAT - High Performance, Thread-Safe Embedded FAT File-System * * Copyright (C) 2009 James Walmsley (james@worm.me.uk) * * * * This program is free software: you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation, either version 3 of the License, or * * (at your option) any later version. * * * * This program is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * * GNU General Public License for more details. * * * * You should have received a copy of the GNU General Public License * * along with this program. If not, see . * * * * IMPORTANT NOTICE: * * ================= * * Alternative Licensing is available directly from the Copyright holder, * * (James Walmsley). For more information consult LICENSING.TXT to obtain * * a Commercial license. * * * * See RESTRICTIONS.TXT for extra restrictions on the use of FullFAT. * * * * Removing the above notice is illegal and will invalidate this license. * ***************************************************************************** * See http://worm.me.uk/fullfat for more information. * * Or http://fullfat.googlecode.com/ for latest releases and the wiki. * *****************************************************************************/ /** * @file ff_blk.c * @author James Walmsley * @ingroup BLK * * @defgroup BLK Block Calculater * @brief Handle Block Number conversions * * Helps calculate block numbers. **/ #include "ff_blk.h" /** * @private **/ FF_T_UINT32 FF_getClusterChainNumber(FF_IOMAN *pIoman, FF_T_UINT32 nEntry, FF_T_UINT16 nEntrySize) { FF_PARTITION *pPart = pIoman->pPartition; FF_T_UINT32 clusterChainNumber = nEntry / (pIoman->BlkSize * (pPart->SectorsPerCluster * pPart->BlkFactor) / nEntrySize); return clusterChainNumber; } FF_T_UINT32 FF_getClusterPosition(FF_IOMAN *pIoman, FF_T_UINT32 nEntry, FF_T_UINT16 nEntrySize) { return nEntry % ((pIoman->BlkSize * (pIoman->pPartition->SectorsPerCluster * pIoman->pPartition->BlkFactor)) / nEntrySize); } /** * @private **/ FF_T_UINT32 FF_getMajorBlockNumber(FF_IOMAN *pIoman, FF_T_UINT32 nEntry, FF_T_UINT16 nEntrySize) { FF_PARTITION *pPart = pIoman->pPartition; FF_T_UINT32 relClusterEntry = nEntry % (pIoman->BlkSize * (pPart->SectorsPerCluster * pPart->BlkFactor) / nEntrySize); FF_T_UINT32 majorBlockNumber = relClusterEntry / (pPart->BlkSize / nEntrySize); return majorBlockNumber; } /** * @private **/ FF_T_UINT8 FF_getMinorBlockNumber(FF_IOMAN *pIoman, FF_T_UINT32 nEntry, FF_T_UINT16 nEntrySize) { FF_PARTITION *pPart = pIoman->pPartition; FF_T_UINT32 relClusterEntry = nEntry % (pIoman->BlkSize * (pPart->SectorsPerCluster * pPart->BlkFactor) / nEntrySize); FF_T_UINT16 relmajorBlockEntry = (FF_T_UINT16)(relClusterEntry % (pPart->BlkSize / nEntrySize)); FF_T_UINT8 minorBlockNumber = (FF_T_UINT8) (relmajorBlockEntry / (pIoman->BlkSize / nEntrySize)); return minorBlockNumber; } /** * @private **/ FF_T_UINT32 FF_getMinorBlockEntry(FF_IOMAN *pIoman, FF_T_UINT32 nEntry, FF_T_UINT16 nEntrySize) { FF_PARTITION *pPart = pIoman->pPartition; FF_T_UINT32 relClusterEntry = nEntry % (pIoman->BlkSize * (pPart->SectorsPerCluster * pPart->BlkFactor) / nEntrySize); FF_T_UINT32 relmajorBlockEntry = (FF_T_UINT32)(relClusterEntry % (pPart->BlkSize / nEntrySize)); FF_T_UINT32 minorBlockEntry = (FF_T_UINT32)(relmajorBlockEntry % (pIoman->BlkSize / nEntrySize)); return minorBlockEntry; }