int yflash_ReadChunkWithTagsFromNAND(struct yaffs_dev *dev,int nand_chunk, u8 *data, struct yaffs_ext_tags *tags);
int yflash_InitialiseNAND(struct yaffs_dev *dev);
int yflash_MarkNANDBlockBad(struct yaffs_dev *dev, int block_no);
int yflash_ReadChunkWithTagsFromNAND(struct yaffs_dev *dev,int nand_chunk, u8 *data, struct yaffs_ext_tags *tags);
int yflash_InitialiseNAND(struct yaffs_dev *dev);
int yflash_MarkNANDBlockBad(struct yaffs_dev *dev, int block_no);