dosbox-wii/src/dos/drive_fat.cpp

/*
 *  Copyright (C) 2002-2004  The DOSBox Team
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/* $Id: drive_fat.cpp,v 1.5 2004/09/05 14:23:04 qbix79 Exp $ */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "dosbox.h"
#include "dos_inc.h"
#include "drives.h"
#include "support.h"
#include "cross.h"
#include "bios.h"

#define IMGTYPE_FLOPPY 0
#define IMGTYPE_ISO    1
#define IMGTYPE_HDD	   2

#define FAT12		   0
#define FAT16		   1
#define FAT32		   2

class fatFile : public DOS_File {
public:
	fatFile(const char* name, Bit32u startCluster, Bit32u fileLen, fatDrive *useDrive);
	bool Read(Bit8u * data,Bit16u * size);
	bool Write(Bit8u * data,Bit16u * size);
	bool Seek(Bit32u * pos,Bit32u type);
	bool Close();
	Bit16u GetInformation(void);
	bool UpdateDateTimeFromHost(void);   
public:
	Bit32u firstCluster;
	Bit32u seekpos;
	Bit32u filelength;
	Bit32u currentSector;
	Bit32u curSectOff;
	Bit8u sectorBuffer[512];
	/* Record of where in the directory structure this file is located */
	Bit32u dirCluster;
	Bit32u dirIndex;

	bool loadedSector;
	fatDrive *myDrive;
private:
	enum { NONE,READ,WRITE } last_action;
	Bit16u info;
};


/* IN - char * filename: Name in regular filename format, e.g. bob.txt */
/* OUT - char * filearray: Name in DOS directory format, eleven char, e.g. bob     txt */
static void convToDirFile(char *filename, char *filearray) {
	Bit32u charidx = 0;
	Bit32u flen;
	int i;
	flen = strlen(filename);
	memset(filearray, 32, 11);
	for(i=0;i<flen;i++) {
		if(charidx >= 11) break;
		if(filename[i] != '.') {
			filearray[charidx] = filename[i];
			charidx++;
		} else {
			charidx = 8;
		}
	}

	

}

fatFile::fatFile(const char* name, Bit32u startCluster, Bit32u fileLen, fatDrive *useDrive) {
	Bit32u seekto = 0;
	firstCluster = startCluster;
	myDrive = useDrive;
	filelength = fileLen;
	loadedSector = false;
	curSectOff = 0;
	seekpos = 0;
	memset(&sectorBuffer[0], 0, sizeof(sectorBuffer));
	
	if(filelength > 0) {
	Seek(&seekto, DOS_SEEK_SET);
	myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
		loadedSector = true;
	}
}

bool fatFile::Read(Bit8u * data, Bit16u *size) {
	Bit16u sizedec, sizecount;
	if(seekpos >= filelength) {
		*size = 0;
		return true;
	}

	sizedec = *size;
	sizecount = 0;
	while(sizedec != 0) {
		if(seekpos >= filelength) {
			*size = sizecount;
			return true; 
		}
		data[sizecount] = sectorBuffer[curSectOff];
		curSectOff++;
		seekpos++;
		if(curSectOff >= myDrive->getSectorSize()) {
			currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
			if(currentSector == 0) {
				/* EOC reached before EOF */
				LOG_MSG("EOC reached before EOF, seekpos %d, filelen %d", seekpos, filelength);
				*size = sizecount;
				return true;
			}
			curSectOff = 0;
			myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
			LOG_MSG("Reading absolute sector at %d for seekpos %d", currentSector, seekpos);
		}
		--sizedec;
		sizecount++;
	}
	*size =sizecount;
	return true;
}

bool fatFile::Write(Bit8u * data, Bit16u *size) {
	/* TODO: Check for read-only bit */

	direntry tmpentry;
	Bit16u sizedec, sizecount;
	sizedec = *size;
	sizecount = 0;
	while(sizedec != 0) {
		/* Increase filesize if necessary */
		if(seekpos >= filelength) {
			if(filelength == 0) {
				firstCluster = myDrive->getFirstFreeClust();
				myDrive->allocateCluster(firstCluster, 0);
			}
			filelength = seekpos+1;
		}
		sectorBuffer[curSectOff] = data[sizecount];
		curSectOff++;
		seekpos++;
		if(curSectOff >= myDrive->getSectorSize()) {
			if(loadedSector) myDrive->loadedDisk->Write_AbsoluteSector(currentSector, sectorBuffer);

			currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
			if(currentSector == 0) {
				/* EOC reached before EOF - try to increase file allocation */
				myDrive->appendCluster(firstCluster);
				/* Try getting sector again */
				currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
				if(currentSector == 0) {
					/* No can do. lets give up and go home.  We must be out of room */
					goto finalizeWrite;
				
				}
			}
			curSectOff = 0;
			myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);

			loadedSector = true;
		}
		--sizedec;
		sizecount++;
	}

finalizeWrite:
	myDrive->directoryBrowse(dirCluster, &tmpentry, dirIndex);
	tmpentry.entrysize = filelength;
	tmpentry.loFirstClust = firstCluster;
	myDrive->directoryChange(dirCluster, &tmpentry, dirIndex);

	*size =sizecount;
	return true;

}

bool fatFile::Seek(Bit32u *pos, Bit32u type) {
	Bit32s seekto;
	
	switch(type) {
		case DOS_SEEK_SET:
			seekto = (Bit32s)*pos;
			break;
		case DOS_SEEK_CUR:
			/* Is this relative seek signed? */
			seekto = (Bit32s)*pos + (Bit32s)seekpos;
			break;
		case DOS_SEEK_END:
			seekto = (Bit32s)filelength + (Bit32s)*pos;
			break;
	}
	LOG_MSG("Seek to %d with type %d (absolute value %d)", *pos, type, seekto);

	if((Bit32u)seekto > filelength) seekto = (Bit32s)filelength;
	if(seekto<0) seekto = 0;
	seekpos = (Bit32u)seekto;
	currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
	curSectOff = seekpos % myDrive->getSectorSize();
	myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
	*pos = seekpos;
	return true;
}

bool fatFile::Close() {
	/* Flush buffer */
	if (loadedSector) myDrive->loadedDisk->Write_AbsoluteSector(currentSector, sectorBuffer);

	return false;
}

Bit16u fatFile::GetInformation(void) {
	return 0x202;
}

bool fatFile::UpdateDateTimeFromHost(void) {
	return true;
}

Bit32u fatDrive::getClustFirstSect(Bit32u clustNum) {
	return ((clustNum - 2) * bootbuffer.sectorspercluster) + firstDataSector;
}

Bit32u fatDrive::getClusterValue(Bit32u clustNum) {
	Bit32u fatoffset;
	Bit32u fatsectnum;
	Bit32u fatentoff;

	Bit32u clustValue;


	/* Load two sectors at once for FAT12 */
	Bit8u sectbuffer[1024];

	switch(fattype) {
		case FAT12:
			fatoffset = clustNum + (clustNum / 2);
			break;
		case FAT16:
			fatoffset = clustNum * 2;
			break;
		case FAT32:
			fatoffset = clustNum * 4;
			break;
	}
	fatsectnum = bootbuffer.reservedsectors + (fatoffset / bootbuffer.bytespersector) + partSectOff;
	fatentoff = fatoffset % bootbuffer.bytespersector;

	loadedDisk->Read_AbsoluteSector(fatsectnum, &sectbuffer[0]);
	loadedDisk->Read_AbsoluteSector(fatsectnum+1, &sectbuffer[512]);

	switch(fattype) {
		case FAT12:
			clustValue = *((Bit16u *)&sectbuffer[fatentoff]);
			if(clustNum & 0x1) {
				clustValue >>= 4;
			} else {
				clustValue &= 0xfff;
			}
			break;
		case FAT16:
			clustValue = *((Bit16u *)&sectbuffer[fatentoff]);
			break;
		case FAT32:
			clustValue = *((Bit32u *)&sectbuffer[fatentoff]);
			break;
	}

	return clustValue;
}

void fatDrive::setClusterValue(Bit32u clustNum, Bit32u clustValue) {
	Bit32u fatoffset;
	Bit32u fatsectnum;
	Bit32u fatentoff;
	Bit32u tmpValue;


	/* Load two sectors at once for FAT12 */
	Bit8u sectbuffer[1024];

	switch(fattype) {
		case FAT12:
			fatoffset = clustNum + (clustNum / 2);
			break;
		case FAT16:
			fatoffset = clustNum * 2;
			break;
		case FAT32:
			fatoffset = clustNum * 4;
			break;
	}
	fatsectnum = bootbuffer.reservedsectors + (fatoffset / bootbuffer.bytespersector) + partSectOff;
	fatentoff = fatoffset % bootbuffer.bytespersector;

	loadedDisk->Read_AbsoluteSector(fatsectnum, &sectbuffer[0]);
	loadedDisk->Read_AbsoluteSector(fatsectnum+1, &sectbuffer[512]);

	switch(fattype) {
		case FAT12:
			tmpValue = *((Bit16u *)&sectbuffer[fatentoff]);
			if(clustNum & 0x1) {
				clustValue &= 0xfff;
				clustValue <<= 4;
				tmpValue &= 0xf;
				tmpValue |= clustValue;

			} else {
				clustValue &= 0xfff;
				tmpValue &= 0xf000;
				tmpValue |= clustValue;
			}
			*((Bit16u *)&sectbuffer[fatentoff]) = tmpValue;
			break;
		case FAT16:
			*((Bit16u *)&sectbuffer[fatentoff]) = clustValue;
			break;
		case FAT32:
			*((Bit32u *)&sectbuffer[fatentoff]) = clustValue;
			break;
	}
	int fc;
	for(fc=0;fc<bootbuffer.fatcopies;fc++) {
		loadedDisk->Write_AbsoluteSector(fatsectnum + (fc * bootbuffer.sectorsperfat), &sectbuffer[0]);
		loadedDisk->Write_AbsoluteSector(fatsectnum+1+(fc * bootbuffer.sectorsperfat), &sectbuffer[512]);
	}
}

bool fatDrive::getEntryName(char *fullname, char *entname) {
	Bit16u len = strlen(fullname);
	char dirtoken[DOS_PATHLENGTH];
	Bit32u currentClust = 0;

	direntry foundEntry;
	char * findDir;
	char * findFile;
	strcpy(dirtoken,fullname);

	LOG_MSG("Testing for filename %s", fullname);
	findDir = strtok(dirtoken,"\\");
	findFile = findDir;
	while(findDir != NULL) {
		findFile = findDir;
		findDir = strtok(NULL,"\\");
	}
	strcpy(entname, findFile);
	return true;
}

bool fatDrive::getFileDirEntry(char * filename, direntry * useEntry, Bit32u * dirClust, Bit32u * subEntry) {
	Bit16u len = strlen(filename);
	char dirtoken[DOS_PATHLENGTH];
	Bit32u currentClust = 0;

	direntry foundEntry;
	char * findDir;
	char * findFile;
	strcpy(dirtoken,filename);

	/* Skip if testing in root directory */
	if ((len>0) && (filename[len-1]!='\\')) {
		LOG_MSG("Testing for filename %s", filename);
		findDir = strtok(dirtoken,"\\");
		findFile = findDir;
		while(findDir != NULL) {
			imgDTA->SetupSearch(0,DOS_ATTR_DIRECTORY,findDir);
			imgDTA->SetDirID(0);
			
			findFile = findDir;
			if(!FindNextInternal(currentClust, *imgDTA, &foundEntry)) break;
			currentClust = foundEntry.loFirstClust;
			findDir = strtok(NULL,"\\");
		}
	} else {
		/* Set to root directory */
	}

	/* Search found directory for our file */
	imgDTA->SetupSearch(0,0x5,findFile);
	imgDTA->SetDirID(0);
	if(!FindNextInternal(currentClust, *imgDTA, &foundEntry)) return false;
	
	memcpy(useEntry, &foundEntry, sizeof(direntry));
	*dirClust = (Bit32u)currentClust;
	*subEntry = ((Bit32u)imgDTA->GetDirID()-1);
	


	return true;
}

bool fatDrive::getDirClustNum(char *dir, Bit32u *clustNum, bool parDir) {
	Bit16u len = strlen(dir);
	char dirtoken[DOS_PATHLENGTH];
	Bit32u currentClust = 0;
	direntry foundEntry;
	char * findDir;
	strcpy(dirtoken,dir);

	/* Skip if testing for root directory */
	if ((len>0) && (dir[len-1]!='\\')) {
		LOG_MSG("Testing for dir %s", dir);
		findDir = strtok(dirtoken,"\\");
		while(findDir != NULL) {
			imgDTA->SetupSearch(0,DOS_ATTR_DIRECTORY,findDir);
			imgDTA->SetDirID(0);
			findDir = strtok(NULL,"\\");
			if(!parDir) {
			if(!FindNextInternal(currentClust, *imgDTA, &foundEntry)) return false;
			} else {
				if(findDir == NULL) break;
				if(!FindNextInternal(currentClust, *imgDTA, &foundEntry)) return false;
			}
			currentClust = foundEntry.loFirstClust;
			
		}
		*clustNum = currentClust;
		return true;
	} else {
		/* Set to root directory */
		*clustNum = 0;
		return true;
	}
	return false;

}

Bit32u fatDrive::getSectorSize(void) {
	return bootbuffer.bytespersector;
}

Bit32u fatDrive::getAbsoluteSectFromBytePos(Bit32u startClustNum, Bit32u bytePos) {
	return getAbsoluteSectFromChain(startClustNum, bytePos / bootbuffer.bytespersector);
}

Bit32u fatDrive::getAbsoluteSectFromChain(Bit32u startClustNum, Bit32u logicalSector) {
	Bit32s skipClust = logicalSector / bootbuffer.sectorspercluster;
	Bit32u sectClust = logicalSector % bootbuffer.sectorspercluster;

	Bit32u currentClust = startClustNum;
	Bit32u testvalue;

	while(skipClust!=0) {
		bool isEOF = false;
		testvalue = getClusterValue(currentClust);
		switch(fattype) {
			case FAT12:
				if(testvalue >= 0xff8) isEOF = true;
				break;
			case FAT16:
				if(testvalue >= 0xfff8) isEOF = true;
				break;
			case FAT32:
				if(testvalue >= 0xfffffff8) isEOF = true;
				break;
		}
		if((isEOF) && (skipClust>1)) {
			//LOG_MSG("End of cluster chain reached before end of logical sector seek!");
			return 0;
		}
		currentClust = testvalue;
		--skipClust;
	}
	return (getClustFirstSect(currentClust) + sectClust);
}

void fatDrive::deleteClustChain(Bit32u startCluster) {
	Bit32u testvalue;
	Bit32u currentClust = startCluster;
	bool isEOF = false;
	while(!isEOF) {
		testvalue = getClusterValue(currentClust);
		if(testvalue == 0) {
			/* What the crap?  Cluster is already empty - BAIL! */
			break;
		}
		/* Mark cluster as empty */
		setClusterValue(currentClust, 0);
		switch(fattype) {
			case FAT12:
				if(testvalue >= 0xff8) isEOF = true;
				break;
			case FAT16:
				if(testvalue >= 0xfff8) isEOF = true;
				break;
			case FAT32:
				if(testvalue >= 0xfffffff8) isEOF = true;
				break;
		}
		if(isEOF) break;
		currentClust = testvalue;
	}
}

Bit32u fatDrive::appendCluster(Bit32u startCluster) {
	Bit32u testvalue;
	Bit32u currentClust = startCluster;
	bool isEOF = false;
	
	while(!isEOF) {
		testvalue = getClusterValue(currentClust);
		switch(fattype) {
			case FAT12:
				if(testvalue >= 0xff8) isEOF = true;
				break;
			case FAT16:
				if(testvalue >= 0xfff8) isEOF = true;
				break;
			case FAT32:
				if(testvalue >= 0xfffffff8) isEOF = true;
				break;
		}
		if(isEOF) break;
		currentClust = testvalue;
	}

	Bit32u newClust = getFirstFreeClust();
	/* Drive is full */
	if(newClust == 0) return 0;

	if(!allocateCluster(newClust, currentClust)) return 0;

	zeroOutCluster(newClust);

	return newClust;




}

bool fatDrive::allocateCluster(Bit32u useCluster, Bit32u prevCluster) {

	/* Can't allocate cluster #0 */
	if(useCluster == 0) return false;

	if(prevCluster != 0) {
		/* Refuse to allocate cluster if previous cluster value is zero (unallocated) */
		if(!getClusterValue(prevCluster)) return false;

		/* Point cluster to new cluster in chain */
		setClusterValue(prevCluster, useCluster);
	} 

	switch(fattype) {
		case FAT12:
			setClusterValue(useCluster, 0xfff);
			break;
		case FAT16:
			setClusterValue(useCluster, 0xffff);
			break;
		case FAT32:
			setClusterValue(useCluster, 0xffffffff);
			break;
	}
	return true;

}

fatDrive::fatDrive(const char *sysFilename, Bit32u bytesector, Bit32u cylsector, Bit32u headscyl, Bit32u cylinders, Bit32u startSector) {
	FILE *diskfile;
	Bit32u filesize;
	struct partTable mbrData;
	
	if(imgDTASeg == 0) {
		imgDTASeg = DOS_GetMemory(2);
		imgDTAPtr = RealMake(imgDTASeg, 0);
		imgDTA    = new DOS_DTA(imgDTAPtr);
	}

	diskfile = fopen(sysFilename, "rb+");
	if(!diskfile) return;
	fseek(diskfile, 0L, SEEK_END);
	filesize = (Bit32u)ftell(diskfile) / 1024L;

    /* Load disk image */
	loadedDisk = new imageDisk(diskfile, (Bit8u *)sysFilename, filesize, (filesize > 2880));
	if(!loadedDisk) {
		delete this;
		return;
	}

	if(filesize > 2880) {
		/* Set user specified harddrive parameters */
		loadedDisk->Set_Geometry(headscyl, cylinders,cylsector, bytesector);

		loadedDisk->Read_Sector(0,0,1,&mbrData);
		startSector = 63;
		int m;
		for(m=0;m<4;m++) {
			/* Pick the first available partition */
			if(mbrData.pentry[m].partSize != 0x00) {
				LOG_MSG("Using partition %d on drive; skipping %d sectors", m, mbrData.pentry[m].absSectStart);
				startSector = mbrData.pentry[m].absSectStart;
				break;
			}
		}

		partSectOff = startSector;
	} else {
		/* Floppy disks don't have partitions */
		partSectOff = 0;
	}

	loadedDisk->Read_AbsoluteSector(0+partSectOff,&bootbuffer);
	if ((bootbuffer.magic1 != 0x55) || (bootbuffer.magic2 != 0xaa)) {
		/* Not a FAT filesystem */
		delete this;
		return;
	}

	if(!bootbuffer.sectorsperfat) {
		/* FAT32 not implemented yet */
		delete this;
		return;
	}


	/* Determine FAT format, 12, 16 or 32 */

	/* Get size of root dir in sectors */
	/* TODO: Get 32-bit total sector count if needed */
	Bit32u RootDirSectors = ((bootbuffer.rootdirentries * 32) + (bootbuffer.bytespersector - 1)) / bootbuffer.bytespersector;
	Bit32u DataSectors;
	if(bootbuffer.totalsectorcount != 0) {
		DataSectors = bootbuffer.totalsectorcount - (bootbuffer.reservedsectors + (bootbuffer.fatcopies * bootbuffer.sectorsperfat) + RootDirSectors);
	} else {
		DataSectors = bootbuffer.totalsecdword - (bootbuffer.reservedsectors + (bootbuffer.fatcopies * bootbuffer.sectorsperfat) + RootDirSectors);

	}
	CountOfClusters = DataSectors / bootbuffer.sectorspercluster;

	firstDataSector = (bootbuffer.reservedsectors + (bootbuffer.fatcopies * bootbuffer.sectorsperfat) + RootDirSectors) + partSectOff;
	firstRootDirSect = bootbuffer.reservedsectors + (bootbuffer.fatcopies * bootbuffer.sectorsperfat) + partSectOff;

	if(CountOfClusters < 4085) {
		/* Volume is FAT12 */
		LOG_MSG("Mounted FAT volume is FAT12 with %d clusters", CountOfClusters);
		fattype = FAT12;
	} else if (CountOfClusters < 65525) {
		LOG_MSG("Mounted FAT volume is FAT16 with %d clusters", CountOfClusters);
		fattype = FAT16;
	} else {
		LOG_MSG("Mounted FAT volume is FAT32 with %d clusters", CountOfClusters);
		fattype = FAT32;
	}

	/* There is no cluster 0, this means we are in the root directory */
	cwdDirCluster = 0;




}

bool fatDrive::AllocationInfo(Bit16u *_bytes_sector, Bit8u *_sectors_cluster, Bit16u *_total_clusters, Bit16u *_free_clusters) {
	Bit32u hs, cy, sect,sectsize;
	Bit32u countFree = 0;
	int i;
	
	loadedDisk->Get_Geometry(&hs, &cy, &sect, &sectsize);
	*_bytes_sector = (Bit16u)sectsize;
	*_sectors_cluster = bootbuffer.sectorspercluster;
	*_total_clusters = CountOfClusters;
	for(i=0;i<CountOfClusters;i++) if(!getClusterValue(i+2)) countFree++;
	*_free_clusters = countFree;
	
	return true;
}

Bit32u fatDrive::getFirstFreeClust(void) {
	Bit32u i;
	for(i=0;i<CountOfClusters;i++) {
		if(!getClusterValue(i+2)) return (i+2);
	}

	/* No free cluster found */
	return 0;
	
}

bool fatDrive::isRemote(void) {	return false; }

Bit8u fatDrive::GetMediaByte(void) { return loadedDisk->GetBiosType(); }

bool fatDrive::FileCreate(DOS_File **file, char *name, Bit16u attributes) {
	direntry fileEntry;
	Bit32u dirClust, subEntry;
	char dirName[DOS_NAMELENGTH_ASCII];
	char pathName[11];

	/* Check if file already exists */
	if(getFileDirEntry(name, &fileEntry, &dirClust, &subEntry)) return false;

	/* Can we even get the name of the file itself? */
	if(!getEntryName(name, &dirName[0])) return false;
	convToDirFile(&dirName[0], &pathName[0]);

	/* Can we find the base directory? */
	if(!getDirClustNum(name, &dirClust, true)) return false;
	memset(&fileEntry, 0, sizeof(direntry));
	memcpy(&fileEntry.entryname, &pathName[0], 11);
	fileEntry.attrib = attributes;
	addDirectoryEntry(dirClust, fileEntry);

	/* Check if file exists now */
	if(!getFileDirEntry(name, &fileEntry, &dirClust, &subEntry)) return false;

	/* Empty file created, now lets open it */
	/* TODO: check for read-only flag and requested write access */
	*file = new fatFile(name, fileEntry.loFirstClust, fileEntry.entrysize, this);
	((fatFile *)(*file))->dirCluster = dirClust;
	((fatFile *)(*file))->dirIndex = subEntry;
	
	return true;
}

bool fatDrive::FileExists(const char *name) {
	direntry fileEntry;
	Bit32u dummy1, dummy2;
	if(!getFileDirEntry((char *)name, &fileEntry, &dummy1, &dummy2)) return false;
	return true;
}

bool fatDrive::FileOpen(DOS_File **file, char *name, Bit32u flags) {
	direntry fileEntry;
	Bit32u dirClust, subEntry;
	if(!getFileDirEntry(name, &fileEntry, &dirClust, &subEntry)) return false;
	/* TODO: check for read-only flag and requested write access */
	*file = new fatFile(name, fileEntry.loFirstClust, fileEntry.entrysize, this);
	((fatFile *)(*file))->dirCluster = dirClust;
	((fatFile *)(*file))->dirIndex = subEntry;
	
	return true;
}

bool fatDrive::FileStat(const char *name, FileStat_Block *const stat_block) {
	/* TODO: Stub */
	return false;
}

bool fatDrive::FileUnlink(char * name) {
	direntry fileEntry;
	Bit32u dirClust, subEntry;

	if(!getFileDirEntry(name, &fileEntry, &dirClust, &subEntry)) return false;

	fileEntry.entryname[0] = 0xe5;
	directoryChange(dirClust, &fileEntry, subEntry);

	if(fileEntry.loFirstClust != 0) deleteClustChain(fileEntry.loFirstClust);

	return true;
}

bool fatDrive::FindFirst(char *_dir, DOS_DTA &dta,bool fcb_findfirst) {
	direntry dummyClust;
	Bit8u attr;char pattern[DOS_NAMELENGTH_ASCII];
	dta.GetSearchParams(attr,pattern);
	if(attr & DOS_ATTR_VOLUME) //check for root dir or fcb_findfirst
		LOG(LOG_DOSMISC,LOG_WARN)("findfirst for volumelabel used on fatDrive. Unhandled!!!!!");
	if(!getDirClustNum(_dir, &cwdDirCluster, false)) return false;
	dta.SetDirID(0);
	return FindNextInternal(cwdDirCluster, dta, &dummyClust);
}

char* removeTrailingSpaces(char* str)
{
    char* end = str + strlen(str);
    while(*--end == ' ' && end > str);
    *++end = '\0';
    return str;
}

char* removeLeadingSpaces(char* str)
{
    size_t len = strlen(str);
    size_t pos = strspn(str," ");
    memmove(str,str + pos,len - pos + 1);
    return str;
}

char* trimString(char* str)
{
    return removeTrailingSpaces(removeLeadingSpaces(str));
}

bool fatDrive::FindNextInternal(Bit32u dirClustNumber, DOS_DTA &dta, direntry *foundEntry) {
	direntry sectbuf[16]; /* 16 directory entries per sector */
	Bit32u logentsector; /* Logical entry sector */
	Bit32u entryoffset;  /* Index offset within sector */
	Bit32u tmpsector;
	Bit8u attrs;
	Bit16u dirPos;
	char srch_pattern[DOS_NAMELENGTH_ASCII];
	char find_name[DOS_NAMELENGTH_ASCII];
	char extension[4];

	dta.GetSearchParams(attrs, srch_pattern);
	dirPos = dta.GetDirID();

nextfile:
	logentsector = dirPos / 16;
	entryoffset = dirPos % 16;

	if(dirClustNumber==0) {
		loadedDisk->Read_AbsoluteSector(firstRootDirSect+logentsector,sectbuf);
	} else {
		tmpsector = getAbsoluteSectFromChain(dirClustNumber, logentsector);
		/* A zero sector number can't happen */
		if(tmpsector == 0) return false;
		loadedDisk->Read_AbsoluteSector(tmpsector,sectbuf);
	}
	dirPos++;
	dta.SetDirID(dirPos);

	/* Deleted file entry */
	if (sectbuf[entryoffset].entryname[0] == 0xe5) goto nextfile;

	/* End of directory list */
	if (sectbuf[entryoffset].entryname[0] == 0x00) return false;

	memset(find_name,0,DOS_NAMELENGTH_ASCII);
	memset(extension,0,4);
	memcpy(find_name,&sectbuf[entryoffset].entryname[0],8);
	memcpy(extension,&sectbuf[entryoffset].entryname[8],3);
	trimString(&find_name[0]);
	trimString(&extension[0]);
	if(!(sectbuf[entryoffset].attrib & DOS_ATTR_DIRECTORY)) { 
		strcat(find_name, ".");
		strcat(find_name, extension);
	}

	if((attrs & (sectbuf[entryoffset].attrib | 0x21)) == 0)  goto nextfile;
	if(!WildFileCmp(find_name,srch_pattern)) goto nextfile;

	dta.SetResult(find_name, sectbuf[entryoffset].entrysize, sectbuf[entryoffset].crtDate, sectbuf[entryoffset].crtTime, sectbuf[entryoffset].attrib);
	memcpy(foundEntry, &sectbuf[entryoffset], sizeof(direntry));

	return true;

}

bool fatDrive::FindNext(DOS_DTA &dta) {
	direntry dummyClust;

	return FindNextInternal(cwdDirCluster, dta, &dummyClust);
}

bool fatDrive::GetFileAttr(char *name, Bit16u *attr) {
	/* TODO: Stub */
	return false;
}

bool fatDrive::directoryBrowse(Bit32u dirClustNumber, direntry *useEntry, Bit32s entNum) {
	direntry sectbuf[16]; /* 16 directory entries per sector */
	Bit32u logentsector; /* Logical entry sector */
	Bit32u entryoffset;  /* Index offset within sector */
	Bit32u tmpsector;
	Bit8u attrs;
	Bit16u dirPos = 0;
	char srch_pattern[DOS_NAMELENGTH_ASCII];
	char find_name[DOS_NAMELENGTH_ASCII];
	char extension[4];
	
	while(entNum>=0) {
		
		logentsector = dirPos / 16;
		entryoffset = dirPos % 16;

		if(dirClustNumber==0) {
			if(dirPos >= bootbuffer.rootdirentries) return false;
			tmpsector = firstRootDirSect+logentsector;
			loadedDisk->Read_AbsoluteSector(tmpsector,sectbuf);
		} else {
			tmpsector = getAbsoluteSectFromChain(dirClustNumber, logentsector);
			/* A zero sector number can't happen */
			if(tmpsector == 0) return false;
			loadedDisk->Read_AbsoluteSector(tmpsector,sectbuf);
		}
		dirPos++;


		/* End of directory list */
		if (sectbuf[entryoffset].entryname[0] == 0x00) return false;
		--entNum;
	}
	
	memcpy(useEntry, &sectbuf[entryoffset],sizeof(direntry));
	return true;
}

bool fatDrive::directoryChange(Bit32u dirClustNumber, direntry *useEntry, Bit32s entNum) {
	direntry sectbuf[16]; /* 16 directory entries per sector */
	Bit32u logentsector; /* Logical entry sector */
	Bit32u entryoffset;  /* Index offset within sector */
	Bit32u tmpsector = 0;
	Bit8u attrs;
	Bit16u dirPos = 0;
	char srch_pattern[DOS_NAMELENGTH_ASCII];
	char find_name[DOS_NAMELENGTH_ASCII];
	char extension[4];
	
	while(entNum>=0) {
		
		logentsector = dirPos / 16;
		entryoffset = dirPos % 16;

		if(dirClustNumber==0) {
			if(dirPos >= bootbuffer.rootdirentries) return false;
			tmpsector = firstRootDirSect+logentsector;
			loadedDisk->Read_AbsoluteSector(tmpsector,sectbuf);
		} else {
			tmpsector = getAbsoluteSectFromChain(dirClustNumber, logentsector);
			/* A zero sector number can't happen */
			if(tmpsector == 0) return false;
			loadedDisk->Read_AbsoluteSector(tmpsector,sectbuf);
		}
		dirPos++;


		/* End of directory list */
		if (sectbuf[entryoffset].entryname[0] == 0x00) return false;
		--entNum;
	}
	if(tmpsector != 0) {
        memcpy(&sectbuf[entryoffset], useEntry, sizeof(direntry));
		loadedDisk->Write_AbsoluteSector(tmpsector, sectbuf);
        return true;
	} else {
		return false;
	}
}

bool fatDrive::addDirectoryEntry(Bit32u dirClustNumber, direntry useEntry) {
	direntry sectbuf[16]; /* 16 directory entries per sector */
	Bit32u logentsector; /* Logical entry sector */
	Bit32u entryoffset;  /* Index offset within sector */
	Bit32u tmpsector;
	Bit8u attrs;
	Bit16u dirPos = 0;
	char srch_pattern[DOS_NAMELENGTH_ASCII];
	char find_name[DOS_NAMELENGTH_ASCII];
	char extension[4];
	
	while(true) {
		
		logentsector = dirPos / 16;
		entryoffset = dirPos % 16;

		if(dirClustNumber==0) {
			if(dirPos >= bootbuffer.rootdirentries) return false;
			tmpsector = firstRootDirSect+logentsector;
			loadedDisk->Read_AbsoluteSector(tmpsector,sectbuf);
		} else {
			tmpsector = getAbsoluteSectFromChain(dirClustNumber, logentsector);
			/* A zero sector number can't happen - we need to allocate more room for this directory*/
			if(tmpsector == 0) {
				Bit32u newClust;
				newClust = appendCluster(dirClustNumber);
				if(newClust == 0) return false;
				/* Try again to get tmpsector */
				tmpsector = getAbsoluteSectFromChain(dirClustNumber, logentsector);
				if(tmpsector == 0) return false; /* Give up if still can't get more room for directory */
			}
			loadedDisk->Read_AbsoluteSector(tmpsector,sectbuf);
		}
		dirPos++;

		/* Deleted file entry or end of directory list */
		if ((sectbuf[entryoffset].entryname[0] == 0xe5) || (sectbuf[entryoffset].entryname[0] == 0x00)) {
			sectbuf[entryoffset] = useEntry;
			loadedDisk->Write_AbsoluteSector(tmpsector,sectbuf);
			return true;
		}
	}


	return false;
}

void fatDrive::zeroOutCluster(Bit32u clustNumber) {
	Bit8u secBuffer[512];

	memset(&secBuffer[0], 0, 512);

	int i;
	for(i=0;i<bootbuffer.sectorspercluster;i++) {
		loadedDisk->Write_AbsoluteSector(getAbsoluteSectFromChain(clustNumber,i), &secBuffer[0]);
	}

}

bool fatDrive::MakeDir(char *dir) {
	Bit32u dummyClust, dirClust;
	direntry tmpentry;
	char dirName[DOS_NAMELENGTH_ASCII];
	char pathName[11];

	/* Can we even get the name of the directory itself? */
	if(!getEntryName(dir, &dirName[0])) return false;
	convToDirFile(&dirName[0], &pathName[0]);

	/* Fail to make directory if already exists */
	if(getDirClustNum(dir, &dummyClust, false)) return false;

	dummyClust = getFirstFreeClust();
	/* No more space */
	if(dummyClust == 0) return false;
	
	if(!allocateCluster(dummyClust, 0)) return false;

	zeroOutCluster(dummyClust);

	/* Can we find the base directory? */
	if(!getDirClustNum(dir, &dirClust, true)) return false;
	
	/* Add the new directory to the base directory */
	memset(&tmpentry,0, sizeof(direntry));
	memcpy(&tmpentry.entryname, &pathName[0], 11);
	tmpentry.loFirstClust = (Bit16u)(dummyClust & 0xffff);
	tmpentry.hiFirstClust = (Bit16u)(dummyClust >> 16);
	tmpentry.attrib = DOS_ATTR_DIRECTORY;
	addDirectoryEntry(dirClust, tmpentry);

	/* Add the [.] and [..] entries to our new directory*/
	/* [.] entry */
	memset(&tmpentry,0, sizeof(direntry));
	memcpy(&tmpentry.entryname, ".          ", 11);
	tmpentry.loFirstClust = (Bit16u)(dummyClust & 0xffff);
	tmpentry.hiFirstClust = (Bit16u)(dummyClust >> 16);
	tmpentry.attrib = DOS_ATTR_DIRECTORY;
	addDirectoryEntry(dummyClust, tmpentry);

	/* [..] entry */
	memset(&tmpentry,0, sizeof(direntry));
	memcpy(&tmpentry.entryname, "..         ", 11);
	tmpentry.loFirstClust = (Bit16u)(dirClust & 0xffff);
	tmpentry.hiFirstClust = (Bit16u)(dirClust >> 16);
	tmpentry.attrib = DOS_ATTR_DIRECTORY;
	addDirectoryEntry(dummyClust, tmpentry);

	return true;

}

bool fatDrive::RemoveDir(char *dir) {
	Bit32u dummyClust, dirClust;
	direntry tmpentry;
	char dirName[DOS_NAMELENGTH_ASCII];
	char pathName[11];

	/* Can we even get the name of the directory itself? */
	if(!getEntryName(dir, &dirName[0])) return false;
	convToDirFile(&dirName[0], &pathName[0]);

	/* Get directory starting cluster */
	if(!getDirClustNum(dir, &dummyClust, false)) return false;

	/* Can't remove root directory */
	if(dummyClust == 0) return false;

	/* Get parent directory starting cluster */
	if(!getDirClustNum(dir, &dirClust, true)) return false;

	/* Check to make sure directory is empty */
	Bit32u filecount = 0;
	/* Set to 2 to skip first 2 entries, [.] and [..] */
	Bit32s fileidx = 2;
	while(directoryBrowse(dummyClust, &tmpentry, fileidx)) {
		/* Check for non-deleted files */
		if(tmpentry.entryname[0] != 0xe5) filecount++;
		fileidx++;
	}

	/* Return if directory is not empty */
	if(filecount > 0) return false;

	/* Find directory entry in parent directory */
	fileidx = 2;
	bool found = false;
	while(directoryBrowse(dirClust, &tmpentry, fileidx)) {
		if(memcmp(&tmpentry.entryname, &pathName[0], 11) == 0) {
			found = true;
			tmpentry.entryname[0] = 0xe5;
			directoryChange(dirClust, &tmpentry, fileidx);
			deleteClustChain(dummyClust);

			break;
		}
		fileidx++;
	}

	if(!found) return false;

	return true;
}

bool fatDrive::Rename(char *oldname, char*newname) {
	
	return false;
}

bool fatDrive::TestDir(char *dir) {
	Bit32u dummyClust;
	return getDirClustNum(dir, &dummyClust, false);
}