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#ifndef CHECKSUM_P_H
#define CHECKSUM_P_H

// Copied from qbytearray.cpp
// Modified to initialise the crc with 0x6363 instead of 0xffff and to not invert the final result.
static const quint16 crc_tbl[16] = {
    0x0000, 0x1081, 0x2102, 0x3183,
    0x4204, 0x5285, 0x6306, 0x7387,
    0x8408, 0x9489, 0xa50a, 0xb58b,
    0xc60c, 0xd68d, 0xe70e, 0xf78f
};

quint16 qNfcChecksum(const char *data, uint len)
{
    register quint16 crc = 0x6363;
    uchar c;
    const uchar *p = reinterpret_cast<const uchar *>(data);
    while (len--) {
        c = *p++;
        crc = ((crc >> 4) & 0x0fff) ^ crc_tbl[((crc ^ c) & 15)];
        c >>= 4;
        crc = ((crc >> 4) & 0x0fff) ^ crc_tbl[((crc ^ c) & 15)];
    }
    return crc;
}

#endif // CHECKSUM_P_H
