ref: 7d7650dffc20c3853eb1acd551c9a02f73751ae3
dir: /sys/src/9/port/nandecc.h/
typedef enum NandEccError { NandEccErrorBad, NandEccErrorGood, NandEccErrorOneBit, NandEccErrorOneBitInEcc, } NandEccError; ulong nandecc(uchar buf[256]); NandEccError nandecccorrect(uchar buf[256], ulong calcecc, ulong *storedecc, int reportbad);