Method decodeSectorRecord

arch/amiga/decoder.cc:39–75

    }

    void decodeSectorRecord() override
    {
        if (readRaw48() != AMIGA_SECTOR_RECORD)
            return;

        const auto& rawbits = readRawBits(AMIGA_RECORD_SIZE * 16);
        if (rawbits.size() < (AMIGA_RECORD_SIZE * 16))
            return;
        const auto& rawbytes = toBytes(rawbits).slice(0, AMIGA_RECORD_SIZE * 2);
        const auto& bytes = decodeFmMfm(rawbits).slice(0, AMIGA_RECORD_SIZE);

        const uint8_t* ptr = bytes.begin();

        Bytes header = amigaDeinterleave(ptr, 4);
        Bytes recoveryinfo = amigaDeinterleave(ptr, 16);

        _sector->logicalCylinder = header[1] >> 1;
        _sector->logicalHead = header[1] & 1;
        _sector->logicalSector = header[2];

        uint32_t wantedheaderchecksum =
            amigaDeinterleave(ptr, 4).reader().read_be32();
        uint32_t gotheaderchecksum = amigaChecksum(rawbytes.slice(0, 40));
        if (gotheaderchecksum != wantedheaderchecksum)
            return;

        uint32_t wanteddatachecksum =
            amigaDeinterleave(ptr, 4).reader().read_be32();
        uint32_t gotdatachecksum = amigaChecksum(rawbytes.slice(56, 1024));

        Bytes data;
        data.writer().append(amigaDeinterleave(ptr, 512)).append(recoveryinfo);
        _sector->data = data;
        _sector->status = (gotdatachecksum == wanteddatachecksum)
                              ? Sector::OK
                              : Sector::BAD_CHECKSUM;
    }

private:
    const AmigaDecoderProto& _config;