If you want to do this right, you do it the way Compaq did with the IBM PC BIOS. One group of engineers analyzes the code, and writes a english text specificat

If you want to do this right, you do it the way Compaq did with the IBM PC BIOS. One group of engineers analyzes the code, and writes a english text specification. A 2nd group (100% disjoint) took that spec and then wrote a compatible BIOS. This survived a legal challenge, but that was in the IP environment of the early '80s, so who knows what would fly now.