fat.c

/*! \file fat.c \brief FAT-Functions */

//###########################################################

///  \ingroup singlefat

///  \defgroup FAT FAT-Functions (fat.c)

///  \code #include "fat.h" \endcode

///  \code #include "dos.h" \endcode

///  \par Uebersicht

//###########################################################

// For FAT12, FAT16 and FAT32

// Only for first Partition

// Only for drives with 512 bytes per sector (the most)

//

// Based on a White Paper from MS

// FAT: General Overview of On-Disk Format

// Version 1.03, December 6, 2000

//

// MBR MasterBootRecord

// PC intern 4

// M.Tischer

// Data Becker

//

// 17.09.2007 Removed most #ifdef USE_FATBUFFER. See dos.h.

//            Sourcecode looks much better now.

//

// 11.10.2006 Replaced "% BYTE_PER_SEC" with "& (BYTE_PER_SEC-1)".

//            Typecast variables from "unsigned long" to "unsigned int" before:

//            secoffset = (unsigned int)fatoffset & (BYTE_PER_SEC-1);

//            Use "unsigned int" for indexing arrays. Does not really speed up,

//            but reduces code size ;)

//

// 25.09.2006 Initialize all global variables to zero for better compatibility

//            with other compilers.

//

// Benutzung auf eigene Gefahr !

//

// Use at your own risk !

//

//#########################################################################

// Last change: 17.09.2007

//#########################################################################

// hk@holger-klabunde.de

// http://www.holger-klabunde.de/index.html

//#########################################################################

// Compiler: AVR-GCC 4.1.1

//#########################################################################

//@{

#include <stdlib.h>

#include <string.h>

#include <ctype.h>

#include "dos.h"

#if defined (FAT_DEBUG_SHOW_FAT_INFO) || defined (FAT_DEBUG_RW_HITS) || defined (FAT_DEBUG_CLUSTERS)

 #include "serial.h" //for testing only

 #include "printf.h" //for testing only

#endif

U8 iob[BYTE_PER_SEC];      //file i/o buffer

U32 FirstDataSector=0; 

U32 FirstRootSector=0; 

U32 FATFirstSector=0;  

U8 FATtype=0;         

#ifdef USE_FAT32

 U32 FAT32RootCluster=0;

 U32 endofclusterchain=0; //value for END_OF_CLUSTERCHAIN 

 U32 maxcluster=0;   // last usable cluster+1

 #ifdef FAT_DEBUG_RW_HITS

  U32 FATWRHits=0;

  U32 FATRDHits=0;

 #endif

#else

 U16 endofclusterchain=0; //value for END_OF_CLUSTERCHAIN 

 U16 maxcluster=0;   // last usable cluster+1

 #ifdef FAT_DEBUG_RW_HITS

  U16 FATWRHits=0;

  U16 FATRDHits=0;

 #endif

#endif

U8 iob_status=0;

U32 FATCurrentSector=0;

#ifdef DOS_WRITE

  U8 FATStatus=0; // only for FAT write buffering

#endif

#ifdef USE_FATBUFFER

 U8 fatbuf[BYTE_PER_SEC];   //buffer for FAT sectors

#endif

U8 secPerCluster=0;

#ifdef USE_64k_CLUSTERS

 U32 BytesPerCluster=0;   //bytes per cluster

#else

 U16 BytesPerCluster=0;   //bytes per cluster

#endif

//U32 RootDirSectors=0; // to big !

//U16 RootDirSectors=0;   // maybe U8 is enough.

U8 RootDirSectors=0;   // never saw more then 32 sectors

//############################################################

/*!\brief Decide if we have to write a used fat sector or read a new fat sector

 * \param    newsector Actual sector number

 * \return     Nothing

 */

void UpdateFATBuffer(U32 newsector)

//############################################################

{

#ifdef USE_FATBUFFER

#else

 if(iob_status!=IOB_FAT) // We have to read a FAT sector first if this is true

 {

   ReadFATSector(newsector,iob); //read FAT sector

   #ifdef FAT_DEBUG_RW_HITS

    FATRDHits++;

   #endif

   FATCurrentSector=newsector;

 }

#endif //#ifdef USE_FATBUFFER

 if(newsector!=FATCurrentSector) // do we need to update the FAT buffer ?

  {

#ifdef DOS_WRITE

   if(FATStatus>0)

    {

     WriteFATSector(FATCurrentSector,FAT_IO_BUFFER); // write the old FAT buffer

     #ifdef FAT_DEBUG_RW_HITS

      FATWRHits++;

     #endif

     FATStatus=0; // flag FAT buffer is save

    } 

#endif

   ReadFATSector(newsector,FAT_IO_BUFFER); //read FAT sector

   #ifdef FAT_DEBUG_RW_HITS

    FATRDHits++;

   #endif

   FATCurrentSector=newsector;

  } 

}

//############################################################

/*!\brief Get back next cluster number from fat cluster chain

 * \param    cluster  Actual cluster number

 * \return     Next cluster number

 */

#ifdef USE_FAT32

 U32 GetNextClusterNumber(U32 cluster)

#else

 U16 GetNextClusterNumber(U16 cluster)

#endif

//############################################################

{

#ifdef USE_FAT12

 U16 tmp, secoffset;

 U8 fatoffset;

#endif

 union Convert *cv;

#ifdef FAT_DEBUG_CLUSTERS

 #ifdef USE_FAT32

  printf("GNCN %lu\n",cluster);

 #else

  printf("GNCN %u\n",cluster);

 #endif

#endif

 if(cluster<maxcluster) //we need to check this ;-)

  {

#ifdef USE_FAT12

   if(FATtype==FAT12)

    {

     // FAT12 has 1.5 Bytes per FAT entry

     // FAT12 can only have 4085 clusters. So cluster * 3 is 16 bit 

     tmp = ((U16)cluster * 3) >>1 ; //multiply by 1.5 (rounds down)

     secoffset = (U16)tmp & (BYTE_PER_SEC-1); //we need this for later

     // FAT12 4085 Cluster * 1.5Bytes = 6127.5 Bytes => max 12 FAT sectors

     // FAT sector offset is 8 Bit 

//     fatoffset = (U8)(tmp / BYTE_PER_SEC); //sector offset from FATFirstSector

     fatoffset = (U8)(tmp >> 9); //sector offset from FATFirstSector

     UpdateFATBuffer(FATFirstSector + fatoffset); //read FAT sector

     if(secoffset == (BYTE_PER_SEC-1)) //if this is the case, cluster number is

                                   //on a sector boundary. read the next sector too

      {

       tmp = FAT_IO_BUFFER[BYTE_PER_SEC-1]; //keep first part of cluster number

       UpdateFATBuffer(FATFirstSector + fatoffset +1 ); //read next FAT sector

       tmp += (U16)FAT_IO_BUFFER[0] << 8; //second part of cluster number

      }

     else

      {

       cv=(union Convert *)&FAT_IO_BUFFER[secoffset];

       tmp=cv->ui;

      } 

     if((U8)cluster & 0x01) tmp>>=4; //shift to right position

     else               tmp&=0xFFF; //delete high nibble

     return (tmp);

    }//if(FATtype==FAT12)

#endif //#ifdef USE_FAT12

#ifdef USE_FAT16

   if(FATtype==FAT16)

    {

     //two bytes per FAT entry

//     UpdateFATBuffer(FATFirstSector + ((U32)cluster * 2) / BYTE_PER_SEC);

//     UpdateFATBuffer(FATFirstSector + ((unsigned int)cluster) / (BYTE_PER_SEC/2));

     UpdateFATBuffer(FATFirstSector + (U8)( (U16)cluster >> 8 ));

     // Buffer index is max 511. So in any case we loose upper bits. typecast cluster to U16

//     cv=(union Convert *)&fatbuf[((U32)cluster * 2) % BYTE_PER_SEC];

     cv=(union Convert *)&FAT_IO_BUFFER[((U16)cluster << 1) & (BYTE_PER_SEC-1)];

     return(cv->ui);

    }//if(FATtype==FAT16)

#endif //#ifdef USE_FAT16

#ifdef USE_FAT32

   if(FATtype==FAT32)

    {

     //four bytes per FAT entry

//     UpdateFATBuffer(FATFirstSector + (cluster * 4) / BYTE_PER_SEC);

//     UpdateFATBuffer(FATFirstSector + cluster / (BYTE_PER_SEC/4));

     UpdateFATBuffer(FATFirstSector + ( cluster >> 7 ));

     // Buffer index is max 511. So in any case we loose upper bits. typecast cluster to U16

     cv=(union Convert *)&FAT_IO_BUFFER[((U16)cluster << 2) & (BYTE_PER_SEC-1)];

     return( cv->ul & 0x0FFFFFFF );

    }//if(FATtype==FAT32) 

#endif //#ifdef USE_FAT32

  }

 return DISK_FULL; //return impossible cluster number

}

//###########################################################

/*!\brief Get back number of first sector of cluster

 * \param    cluster  Actual cluster number

 * \return     Sector number

 */

#ifdef USE_FAT32

 U32 GetFirstSectorOfCluster(U32 cluster)

#else

 U32 GetFirstSectorOfCluster(U16 cluster)

#endif

//###########################################################

{

// Komische Sache: Die Schieberei hier bringt bei ATmega32 ca. 200 Byte weniger Code.

// Bei ATmega644 wird der Code dadurch ca. 20 Bytes größer !

 U8 temp;

 U32 templong;

 templong = cluster-2;

 // secPerCluster is always power of two 

 temp = secPerCluster>>1; // don't multiply with 1 ;)

 while(temp)

  {

   templong <<= 1;

   temp >>= 1;

  }

 return (templong + FirstDataSector);

// return (((U32)(cluster - 2) * secPerCluster) + FirstDataSector);

}

#ifdef DOS_WRITE

//###########################################################

/*!\brief Allocate a new cluster in cluster chain

 * \param    currentcluster  Actual cluster number

 * \return     New cluster number or DISK_FULL

 */

#ifdef USE_FAT32

 U32 AllocCluster(U32 currentcluster)

#else

 U16 AllocCluster(U16 currentcluster)

#endif

//###########################################################

{

#ifdef USE_FAT32

 U32 cluster;

#else

 U16 cluster;

#endif

// do this if you want to search from beginning of FAT

// cluster=FindFreeCluster(0); //get next free cluster number

 cluster=FindFreeCluster(currentcluster); // get next free cluster number

 if(cluster!=DISK_FULL && cluster<=maxcluster) // disk full ?

  {

    // insert new cluster number into chain

    // currentcluster=0 means: this is a new cluster chain

    if(currentcluster>0) WriteClusterNumber(currentcluster,cluster);

   // mark end of cluster chain

#ifdef USE_FAT12

   if(FATtype==FAT12) WriteClusterNumber(cluster,0xFFF); 

#endif

#ifdef USE_FAT16

   if(FATtype==FAT16) WriteClusterNumber(cluster,0xFFFF); 

#endif

#ifdef USE_FAT32

   if(FATtype==FAT32) WriteClusterNumber(cluster,0x0FFFFFFF); 

#endif

  }

#ifdef USE_FATBUFFER

#else

   // We should flush the temporary fatbuffer now because next action is

   // filling iob[] with new data !

   if(FATStatus>0)

    {

     WriteFATSector(FATCurrentSector,iob); // write the FAT buffer

     #ifdef FAT_DEBUG_RW_HITS

      FATWRHits++;

     #endif

     FATStatus=0; // flag FAT buffer is save

    } 

#endif

 return cluster;

}

#endif //DOS_WRITE

#ifdef DOS_WRITE

//###########################################################

/*!\brief Find a free cluster in FAT

 * \param    currentcluster  Actual cluster number

 * \return     Number of a free cluster or DISK_FULL

 */

#ifdef USE_FAT32

 U32 FindFreeCluster(U32 currentcluster)

#else

 U16 FindFreeCluster(U16 currentcluster)

#endif

//###########################################################

{

#ifdef USE_FAT32

 U32 cluster;

#else

 U16 cluster;

#endif

 cluster=currentcluster+1; // its a good idea to look here first

                           // maybe we do not need to search the whole FAT

                           // and can speed up free cluster search

                           // if you do not want this call FindFreeCluster(0)

// search til end of FAT

 while(cluster<maxcluster)

  {

   if(GetNextClusterNumber(cluster)==0) break;

   cluster++;

  }

// if we have not found a free cluster til end of FAT

// lets start a new search at beginning of FAT

 if(cluster>=maxcluster)

  {

   cluster=2; // first possible free cluster

   while(cluster<=currentcluster) // search til we come to where we have started

    {

     if(GetNextClusterNumber(cluster)==0) break;

     cluster++;

    }

   if(cluster>=currentcluster) return DISK_FULL; // no free cluster found

  }

 if(cluster>=maxcluster) return DISK_FULL;

 return cluster;

}

#endif //DOS_WRITE

#ifdef DOS_WRITE

//############################################################

/*!\brief Insert a new cluster number into cluster chain

 * \param    cluster  Actual cluster number

 * \param    number  Cluster number to append to cluster chain

 * \return     Nothing til now (0)

 */

#ifdef USE_FAT32

 U8 WriteClusterNumber(U32 cluster, U32 number)

#else

 U8 WriteClusterNumber(U16 cluster, U16 number)

#endif

//############################################################

{

#ifdef USE_FAT12

 U16 tmp, secoffset;

 U8 fatoffset;

 U8 lo,hi;

 U32 sector;

#endif

 U8 *p;

#ifdef FAT_DEBUG_CLUSTERS

#ifdef USE_FAT32

 printf("WCN %lu\n",cluster);

#else

 printf("WCN %u\n",cluster);

#endif

#endif

 if(cluster<maxcluster) //we need to check this ;-)

  {

#ifdef USE_FAT12

   if(FATtype==FAT12)

    {

     //FAT12 has 1.5 Bytes per FAT entry

     // FAT12 can only have 4085 clusters. So cluster * 3 is 16 bit 

     tmp= ((U16)cluster * 3) >>1 ; //multiply by 1.5 (rounds down)

     secoffset = (U16)tmp & (BYTE_PER_SEC-1); //we need this for later

     // FAT12 4085 Cluster * 1.5Bytes = 6127.5 Bytes => max 12 FAT sectors

     // FAT sector offset is 8 Bit 

//     fatoffset = (U8)(tmp / BYTE_PER_SEC); //sector offset from FATFirstSector

     fatoffset = (U8)(tmp >> 9); //sector offset from FATFirstSector

     sector=FATFirstSector + fatoffset;

     tmp=(U16)number;

     if((U8)cluster & 0x01) tmp<<=4; //shift to right position

     lo=(U8)tmp;

     hi=(U8)(tmp>>8);

     UpdateFATBuffer(sector); //read FAT sector

     if(secoffset == (BYTE_PER_SEC-1)) //if this is the case, cluster number is

                                   //on a sector boundary. read the next sector too

      {

       p = &FAT_IO_BUFFER[BYTE_PER_SEC-1]; //keep first part of cluster number

       if((U8)cluster & 0x01)

        {

         *p&=0x0F;

         *p|=lo;

        }

       else *p=lo;

       FATStatus=1; // we have made an entry, so write before next FAT sector read

       UpdateFATBuffer(sector+1); //read FAT sector

       p = &FAT_IO_BUFFER[0]; //second part of cluster number

       if((U8)cluster & 0x01) *p=hi;

       else

        {

         *p&=0xF0;

         *p|=hi;

        }

       FATStatus=1; // we have made an entry, so write before next FAT sector read

      }

     else

      {

       p = &FAT_IO_BUFFER[secoffset];

       if((U8)cluster & 0x01)

        {

         *p&=0x0F;

         *p++|=lo;

         *p=hi;

        } 

       else

        {

         *p++=lo;

         *p&=0xF0;

         *p|=hi;

        } 

       FATStatus=1; // we have made an entry, so write before next FAT sector read

      } 

    }//if(FATtype==FAT12)

#endif

#ifdef USE_FAT16

   if(FATtype==FAT16)

    {

     //two bytes per FAT entry

//     sector=FATFirstSector + ((U32)cluster * 2) / BYTE_PER_SEC;

//     sector=FATFirstSector + ((unsigned int)cluster) / (BYTE_PER_SEC/2);

     UpdateFATBuffer(FATFirstSector + (U8)( (U16)cluster >> 8 ));

     // Buffer index is max 511. So in any case we loose upper bits. typecast cluster to U16

     p = &FAT_IO_BUFFER[((U16)cluster << 1) & (BYTE_PER_SEC-1)];

     *p++ = (U8)(number);

     *p   = (U8)(number >> 8);

     FATStatus=1; // we have made an entry, so write before next FAT sector read

    }// if(FATtype==FAT16)

#endif //#ifdef USE_FAT16

#ifdef USE_FAT32

   if(FATtype==FAT32)

    {

     //four bytes per FAT entry

//     sector=FATFirstSector + (cluster * 4) / BYTE_PER_SEC;

//     sector=FATFirstSector + cluster / (BYTE_PER_SEC/4);

     UpdateFATBuffer(FATFirstSector + ( cluster >> 7 ));

     // Buffer index is max 511. So in any case we loose upper bits. typecast cluster to U16

     p = &FAT_IO_BUFFER[((U16)cluster << 2) & (BYTE_PER_SEC-1)];

     number&=0x0FFFFFFF;

     *p++ = (U8)( number);

     *p++ = (U8)(number >> 8);

     *p++ = (U8)(number >> 16);

     *p   = (U8)(number >> 24);

     FATStatus=1; // we have made an entry, so write before next FAT sector read

    }// if(FATtype==FAT32) 

#endif //#ifdef USE_FAT32

  } // if(cluster<maxcluster) //we need to check this ;-)

 return 0;

}

#endif //DOS_WRITE

//###########################################################

/*!\brief Get drive informations

 * \return     F_OK if successfull, F_ERROR if not

 *

 * This function is most important for the FAT filesystem.

 * Following values will be read out:

 * Type of the FAT filesystem.

 * Number of sectors for the partition (if there is one).

 * Number of clusters of the drive.

 * Where is the rootdirectory. And many more.

 * When using MMC/SD cards, call MMC_IO_Init() BEFORE GetDriveInformation() !

 */

U8 GetDriveInformation(void)

//###########################################################

{

 U8 by;

 U32 DataSec,TotSec;

 U32 bootSecOffset;

 U32 FATSz; // FATSize

 U8 loop;

#ifdef USE_FAT32

  U32 CountofClusters;

#else

//  U16 CountofClusters;  // for standard division

  U32 CountofClusters;    // for shifting division

#endif

 U16  RootEntrys;

 struct MBR *mbr;

 struct BootSec *boot;

 by=IdentifyMedia(); //LaufwerksInformationen holen

 if(by==0)

  {

   FATtype=0; //Unknown FAT type

   bootSecOffset=0; //erstmal

   by=ReadSector(0,iob); //Lese den MBR. Erster Sektor auf der Platte

                       //enthält max. 4 Partitionstabellen mit jeweils 16Bytes

                       //Die erste fängt bei 0x01BE an, und nur die nehme ich !

   //Erstmal checken ob wir nicht schon einen Bootsektor gelesen haben.

   boot=(struct BootSec *)iob;

   loop=0;

   do

    {

     // Jetzt checke ich doch den FAT-String im Bootsektor um den Typ der FAT

     // zu bestimmen. Einen besseren Weg sehe ich im Moment nicht.

     if(   boot->eb.rm.BS_FilSysType[0]=='F'

//        && boot->eb.rm.BS_FilSysType[1]=='A'

//        && boot->eb.rm.BS_FilSysType[2]=='T'

        && boot->eb.rm.BS_FilSysType[3]=='1'  )

      {

       //Wenn ich hier ankomme habe ich entweder FAT12 oder FAT16

#ifdef USE_FAT12

       if(boot->eb.rm.BS_FilSysType[4]=='2') FATtype=FAT12;

#endif

#ifdef USE_FAT16

       if(boot->eb.rm.BS_FilSysType[4]=='6') FATtype=FAT16;

#endif

      }

     else

      {

#ifdef USE_FAT32

       if(   boot->eb.rm32.BS_FilSysType[0]=='F'

//          && boot->eb.rm32.BS_FilSysType[1]=='A'

//          && boot->eb.rm32.BS_FilSysType[2]=='T'

          && boot->eb.rm32.BS_FilSysType[3]=='3'

          && boot->eb.rm32.BS_FilSysType[4]=='2'

         )

        {

         FATtype=FAT32;

        }

       else //war kein Bootsektor, also feststellen wo der liegt

#endif

        {

         mbr=(struct MBR *)iob; //Pointer auf die Partitionstabelle

         bootSecOffset=mbr->part1.bootoffset; //Nur den brauche ich

         by=ReadSector(bootSecOffset,iob);      //read bootsector

         boot=(struct BootSec *)iob;

        } 

      }

     loop++;

    }while(loop<2 && FATtype==0); //Bis zu zwei Versuche den Bootsektor zu lesen

   if(FATtype==0)

    {

#ifdef FAT_DEBUG_SHOW_FAT_INFO

     puts("FAT unknown\n");

#endif

     return F_ERROR; // FAT-Typ nicht erkannt

    }

   secPerCluster=boot->BPB_SecPerClus; //Sectors per Cluster

   RootEntrys=boot->BPB_RootEntCnt;    //32 Byte Root Directory Entrys

   RootDirSectors = (unsigned char)( ((RootEntrys * 32) + (BYTE_PER_SEC - 1)) / BYTE_PER_SEC);

//Number of sectors for FAT

   if(boot->BPB_FATSz16 != 0) FATSz = boot->BPB_FATSz16;

   else FATSz = boot->eb.rm32.BPB_FATSz32; //Für FAT32

   if(boot->BPB_TotSec16 != 0) TotSec = boot->BPB_TotSec16;

   else TotSec = boot->BPB_TotSec32;

   FATFirstSector= bootSecOffset + boot->BPB_RsvdSecCnt;

   FirstRootSector = FATFirstSector + (boot->BPB_NumFATs * FATSz);

//Number of data sectors

   DataSec = TotSec - (boot->BPB_RsvdSecCnt + (boot->BPB_NumFATs * FATSz) + RootDirSectors);

   FirstDataSector = FirstRootSector + RootDirSectors;

//Number of valid clusters

   //CountofClusters = DataSec / secPerCluster;

   U8 temp;

   // secPerCluster is always power of two 

   temp = secPerCluster>>1; // don't divide by 1 ;)

   CountofClusters = DataSec;

   while(temp)

    {

     CountofClusters >>= 1;

     temp >>= 1;

    }

   maxcluster = CountofClusters + 2;

//Note also that the CountofClusters value is exactly that: the count of data clusters

//starting at cluster 2. The maximum valid cluster number for the volume is

//CountofClusters + 1, and the "count of clusters including the two reserved clusters"

// is CountofClusters + 2.

   FirstDirCluster=0; // for FAT12 and FAT16

#ifdef USE_FAT12

   if(FATtype==FAT12)

    {

     endofclusterchain=EOC12;

    } 

#endif

#ifdef USE_FAT16

   if(FATtype==FAT16)

    {

     endofclusterchain=EOC16;

    } 

#endif

#ifdef USE_FAT32

   if(FATtype==FAT32)

    {

     endofclusterchain=EOC32;

     FAT32RootCluster=boot->eb.rm32.BPB_RootClus;

     FirstDirCluster=FAT32RootCluster;

     FirstRootSector=GetFirstSectorOfCluster(FAT32RootCluster);

    }

#endif

  }

 else

  {

   return F_ERROR; // CF gives no answer

  } 

 FileFirstCluster=0;

 FileSize=0;

 FileFlag=0;

 BytesPerCluster=BYTE_PER_SEC * secPerCluster; //bytes per cluster

 FATCurrentSector=FATFirstSector;

// for debugging only

#ifdef FAT_DEBUG_SHOW_FAT_INFO

 if(FATtype==FAT12) puts("FAT12\n");

 if(FATtype==FAT16) puts("FAT16\n");

 if(FATtype==FAT32) puts("FAT32\n");

 printf("bootSecOffset %lu\n",bootSecOffset);

 printf("Reserved Sectors %u\n",boot->BPB_RsvdSecCnt);

 printf("FAT Sectors %lu\n",FATSz);

 printf("Num. of FAT's %u\n",(U16)boot->BPB_NumFATs);

 printf("secPerCluster %u\n",(U16)secPerCluster);

#ifdef USE_64k_CLUSTERS

 printf("BytesPerCluster %lu\n",BytesPerCluster);

#else

 printf("BytesPerCluster %u\n",BytesPerCluster);

#endif

 printf("FATFirstSector %lu\n",FATFirstSector);

 printf("FirstRootSector %lu\n",FirstRootSector);

 printf("RootDirSectors %u\n",(U16)RootDirSectors);

 printf("FirstDataSector %lu\n",FirstDataSector);

 printf("maxsect %lu\n",maxsect);

#ifdef USE_FAT32

 printf("FirstDirCluster %lu\n",FirstDirCluster);

 printf("maxcluster %lu\n",maxcluster);

#else

 printf("FirstDirCluster %u\n",FirstDirCluster);

 printf("maxcluster %u\n",maxcluster);

#endif

#endif //#ifdef FAT_DEBUG_SHOW_FAT_INFO

 #ifdef DOS_WRITE

  FATStatus=0; // nothing to write til here

 #endif

 ReadFATSector(FATCurrentSector,FAT_IO_BUFFER); //read first FAT sector

 return F_OK;

}

#ifndef USE_FATBUFFER

#ifdef DOS_WRITE

//#########################################################################

U8 WriteFATSector(U32 sector, U8 *buf)

//#########################################################################

{

 iob_status=IOB_FAT; // we have to track this

 return WriteSector(sector,buf); //write sector

}

#endif

//#########################################################################

U8 ReadFATSector(U32 sector, U8 *buf)

//#########################################################################

{

 iob_status=IOB_FAT; // we have to track this

 return ReadSector(sector,buf); //read sector

}

#ifdef DOS_WRITE // Better keep this as a function !

//#########################################################################

U8 WriteDirSector(U32 sector, U8 *buf)

//#########################################################################

{

 iob_status=IOB_DIR; // we have to track this

 return WriteSector(sector,buf); //write sector

}

#endif

//#########################################################################

U8 ReadDirSector(U32 sector, U8 *buf)

//#########################################################################

{

 iob_status=IOB_DIR; // we have to track this

 return ReadSector(sector,buf); //read sector

}

#ifdef DOS_WRITE // This has to be a function for Fwrite(), Fclose() !

//#########################################################################

U8 WriteFileSector(U32 sector, U8 *buf)

//#########################################################################

{

 iob_status=IOB_DATA; // we have to track this

 return WriteSector(sector,buf); //write sector

}

#endif

//#########################################################################

U8 ReadFileSector(U32 sector, U8 *buf)

//#########################################################################

{

 iob_status=IOB_DATA; // we have to track this

 return ReadSector(sector,buf); //read sector

}

#endif //#ifndef USE_FATBUFFER

//@}