ref: 53f2b41ec64895a1d8bcebeeb7824c59e854eb13
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);