Haha, yeah, as Arvika pointed out BCH codes are very simple
Especially when you have built-in decoder in VNR.
Infact in VNR for the end used the whole formula is pretty simple.
Usually codeword = Data area chunk + Spare area chunk + ECC area chunk.
Where DA+SA = payload; ECC = parity.
In BCH element you have several codewords depending on how many DA chunks you have in page.
Payload and parity positions are just relative offsets of each area from 0 which is beginning of page (consider page as vector of bits or in other words horizontal line of bits/bytes as we see in bitmap).
Polynomial is a coefficients of the formula, usually same for one vendor.
Inv/Rotation are specific settings of ECC code (you have to brute force them, usually just 4 combinations of flags which is easy).
We will add one sweeet feature for unknown/new BCH code analysis for the specified (or all!) Galois field with variable boundaries of areas.
Right now the biggest challenge is scrambled parity area but still doable for most of cases.