TexFAT Padding Directory Entry

exFAT 1.00 does not define TexFAT Padding directory entry. TexFAT Padding directory entries are only valid in the first cluster of directory and occupy every directory entry of the cluster. The implementations should not move TexFAT Padding directory entries.

Windows CE Access Control Table Directory Entry

exFAT 1.00 does not define Windows CE Access Control Table Directory Entry.

Stream Extension Directory Entry

* GeneralSecondaryFlags

Stream Extension directory entry must immediately follow the File directory entry in the set. It could be only one Stream Extension entry in the set. If NoFatChain flag is set, all allocated clusters are contiguous.

The NameHash field facilitates the purpose of fast file name comparison and is performed on up-cased file name. NameHash verify against a mismatch, however matching hashes cannot guarantee the equality offile names. If name hashes match, a subsequent full name comparison must be performed.

// fileName points to up-cased file name
UNIT16  NameHash(WCHAR *file Name, intnameLength)
{
    UNIT16 hash = 0;
    unsigned char *data = (unsignedchar*) fileName;

    for ( inti = 0; i<nameLenght*2; i++)
        hash = (hash << 15) | (hash >> 1) + data[i];
    return hash;
}

ValidDataLength determines how much actual data written to the file. Implementation shall update this field as data has been written. The data beyond the valid data length is undefined and implementation shall return zeros.