firmware-update | System76 Firmware Update Utility

currently I try to implement the CRC32 check algorithm from IO-Link for IODD files in Java [1]. In IO-Link each sensor is described with an IODD xml file [2]. The file contains a stamp tag with a crc code. My problem here is that the algorithm uses only unsigned integers and Java does not uses this type of types. Is there still a way to implement that?

I also use JetBrains dotPeek program to decompile the IODDChecker (latest Version). The CRC-Logic is in the file clsCRC.cs. At the end of the file I found the method "CRC32" which calculates the CRC. The problem is that they use other integers (unsigned integers) for the lookup-table. An interesting fact is that the algorithm in the IODD checker (crc32_octetwise) is slightly different from the one described in the specification.

Hope you can help me :)

What I tested:

• Java CRC32 from zip
• Guava UnsignedInteger
• BigInteger
• long instead of int

Procedure:

1. Program read the IODD as String/byte array
2. Remove the CRC value from Stamp-Tag from the String/byte array
3. Create CRC32 from string/byte array
4. In the test IODD you can find the CRC 1195433981 which should be equal to the output of the algorithm

Algorithms:
There are two algorithms. The first one is bitwise and the second one is octetwise and uses an lookup-table which you can find here [2].