int MultipleFatCheck(RDWRHandle handle)
{
unsigned short sectorsperfat = GetSectorsPerFat(handle);
unsigned char numberoffats = GetNumberOfFats(handle);
unsigned long bytesinfat = GetBytesInFat(handle), compared = 0, rest;
SECTOR fat1start = GetFatStart(handle), fat2start = fat1start, i, j;
char buffer1[BYTESPERSECTOR];
char buffer2[BYTESPERSECTOR];
if ((sectorsperfat == 0) || (numberoffats == 0) || (fat1start == 0) ||
(bytesinfat == 0))
return FAIL; /* Not succeeded. */
if (numberoffats == 1) return TRUE; /* Succeeded when only one fat? */
rest = bytesinfat % BYTESPERSECTOR;
for (i = 0; i < numberoffats - 1; i++)
{
fat2start += sectorsperfat;
for (j = 0; j < sectorsperfat; j++)
{
if (ReadSectors(handle, 1, fat1start + j, buffer1) == -1)
return FAIL;
if (ReadSectors(handle, 1, fat2start + j, buffer2) == -1)
return FAIL;
if (compared == bytesinfat - rest)
{
if (memcmp(buffer1, buffer2, (int) rest) != 0)
return FALSE;
compared = 0;
}
else
{
if (memcmp(buffer1, buffer2, BYTESPERSECTOR) != 0)
return FALSE;
compared += BYTESPERSECTOR;
}
}
}
return TRUE;
}
SECTOR GetDirectoryStart(RDWRHandle handle)
{
unsigned short reserved;
unsigned char fats;
unsigned long SectorsPerFat;
if (handle->dirbegin == 0)
{
reserved = GetReservedSectors(handle);
if (reserved == 0) RETURN_FTEERR(FALSE);
fats = GetNumberOfFats(handle);
if (fats == 0) RETURN_FTEERR(FALSE);
SectorsPerFat = GetSectorsPerFat(handle);
if (SectorsPerFat == 0) RETURN_FTEERR(FALSE);
handle->dirbegin = (SECTOR) reserved + ((SECTOR)fats * SectorsPerFat);
}
return handle->dirbegin;
}
