int nval_del(struct yaffs_dev *dev, char *xb, int xb_size, const YCHAR * name);
int nval_set(struct yaffs_dev *dev,
char *xb, int xb_size, const YCHAR * name, const char *buf,
int nval_del(struct yaffs_dev *dev, char *xb, int xb_size, const YCHAR * name);
int nval_set(struct yaffs_dev *dev,
char *xb, int xb_size, const YCHAR * name, const char *buf,