/****************************************************************************
* _f_updatefileentry
* Updated a file directory entry or removes the entry
* and the fat chain belonging to it.
***************************************************************************/
static unsigned char _f_updatefileentry ( int remove )
{
F_DIRENTRY * de;
unsigned short date;
unsigned short time;
de = (F_DIRENTRY *)( gl_sector + sizeof( F_DIRENTRY ) * gl_file.dirpos.pos );
if ( _f_readglsector( gl_file.dirpos.sector ) || remove )
{
_f_setdecluster( de, 0 );
_f_setlong( &de->filesize, 0 );
(void)_f_writeglsector( (unsigned long)-1 );
(void)_f_removechain( gl_file.startcluster );
return F_ERR_WRITE;
}
_f_setdecluster( de, gl_file.startcluster );
_f_setlong( &de->filesize, gl_file.filesize );
f_igettimedate( &time, &date );
_f_setword( &de->cdate, date ); /*if there is realtime clock then creation date could be set from*/
_f_setword( &de->ctime, time ); /*if there is realtime clock then creation time could be set from*/
if ( gl_volume.mediatype == F_FAT32_MEDIA )
{
_f_setword( &de->lastaccessdate, date ); /*if there is realtime clock then creation date could be set from*/
}
return _f_writeglsector( (unsigned long)-1 );
} /* _f_updatefileentry */
/****************************************************************************
*
* _f_readbootrecord
*
* read boot record from a volume, it detects if there is MBR on the media
*
* RETURNS
*
* error code or zero if successful
*
***************************************************************************/
static unsigned char _f_readbootrecord ( void )
{
unsigned char ret;
unsigned char * ptr = (unsigned char *)gl_sector;
unsigned long maxcluster, _n;
unsigned long first_sector = 0;
gl_volume.mediatype = F_UNKNOWN_MEDIA;
ret = _f_readglsector( 0 );
if ( ret )
{
return ret;
}
if ( ( ptr[0x1fe] != 0x55 ) || ( ptr[0x1ff] != 0xaa ) )
{
return F_ERR_NOTFORMATTED; /*??*/
}
if ( ( ptr[0] != 0xeb ) && ( ptr[0] != 0xe9 ) )
{
first_sector = _f_getlong( &ptr[0x08 + 0x1be] ); /*start sector for 1st partioon*/
ret = _f_readglsector( first_sector );
if ( ret )
{
return ret;
}
if ( ( ptr[0x1fe] != 0x55 ) || ( ptr[0x1ff] != 0xaa ) )
{
return F_ERR_NOTFORMATTED; /*??*/
}
if ( ( ptr[0] != 0xeb ) && ( ptr[0] != 0xe9 ) )
{
return F_ERR_NOTFORMATTED; /*??*/
}
}
ptr += 11;
if ( _f_getword( ptr ) != F_SECTOR_SIZE )
{
return F_ERR_NOTSUPPSECTORSIZE;
}
ptr += 2;
gl_volume.bootrecord.sector_per_cluster = *ptr++;
gl_volume.firstfat.sector = _f_getword( ptr );
ptr += 2;
gl_volume.bootrecord.number_of_FATs = *ptr++;
gl_volume.root.num = _f_getword( ptr );
ptr += 2;
gl_volume.root.num *= sizeof( F_DIRENTRY );
gl_volume.root.num /= F_SECTOR_SIZE;
maxcluster = _f_getword( ptr );
ptr += 2;
gl_volume.bootrecord.media_descriptor = *ptr++;
gl_volume.firstfat.num = _f_getword( ptr );
ptr += 6;
_n = _f_getlong( ptr );
ptr += 4;
if ( _n < first_sector )
{
_n = first_sector;
}
gl_volume.firstfat.sector += _n;
if ( !maxcluster )
{
maxcluster = _f_getlong( ptr );
}
ptr += 4;
if ( gl_volume.firstfat.num )
{
gl_volume.root.sector = gl_volume.firstfat.sector + ( gl_volume.firstfat.num * gl_volume.bootrecord.number_of_FATs );
gl_volume._tdata.sector = gl_volume.root.sector + gl_volume.root.num;
gl_volume._tdata.num = 0;
ptr += 3;
}
else
{
gl_volume.firstfat.num = _f_getlong( ptr );
ptr += 8;
gl_volume._tdata.sector = gl_volume.firstfat.sector;
gl_volume._tdata.sector += gl_volume.firstfat.num * gl_volume.bootrecord.number_of_FATs;
gl_volume._tdata.num = 0;
gl_volume.bootrecord.rootcluster = _f_getlong( ptr );
ptr += 23;
gl_volume.root.num = gl_volume.bootrecord.sector_per_cluster;
gl_volume.root.sector = ( ( gl_volume.bootrecord.rootcluster - 2 ) * gl_volume.root.num ) + gl_volume._tdata.sector;
}
gl_volume.bootrecord.serial_number = _f_getlong( ptr );
maxcluster -= gl_volume._tdata.sector;
maxcluster += _n;
gl_volume.maxcluster = maxcluster / gl_volume.bootrecord.sector_per_cluster;
if ( gl_volume.maxcluster < ( F_CLUSTER_RESERVED & 0xfff ) )
{
gl_volume.mediatype = F_FAT12_MEDIA;
}
else if ( gl_volume.maxcluster < ( F_CLUSTER_RESERVED & 0xffff ) )
{
gl_volume.mediatype = F_FAT16_MEDIA;
}
else
{
gl_volume.mediatype = F_FAT32_MEDIA;
}
if ( gl_volume.bootrecord.media_descriptor != 0xf8 ) /*fixdrive*/
{
if ( gl_volume.bootrecord.media_descriptor != 0xf0 ) /*removable*/
{
return F_ERR_NOTFORMATTED; /*??*/
}
}
return F_NO_ERROR;
} /* _f_readbootrecord */
