NDEV               12 file.c         struct devsw devsw[NDEV];
NDEV              441 fs.c               if(ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].read)
NDEV              469 fs.c               if(ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].write)