ref: 4a120a381652668b7eb9313d9b8ca1835ddccb91
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);