Hi, I am porting YAFFS for an embedded system. Right now I am writing flash driver. *The flash has 512 B page and no OOB region*. As can be seen from "yaffs_guts.h" the implementer has to provide the following functions to YAFFS: int (*drv_write_chunk_fn) (struct yaffs_dev *dev, int nand_chunk, const u8 *data, int data_len, const u8 *oob, int oob_len); int (*drv_read_chunk_fn) (struct yaffs_dev *dev, int nand_chunk, u8 *data, int data_len, u8 *oob, int oob_len, enum yaffs_ecc_result *ecc_result); int (*drv_erase_fn) (struct yaffs_dev *dev, int block_no); int (*drv_mark_bad_fn) (struct yaffs_dev *dev, int block_no); int (*drv_check_bad_fn) (struct yaffs_dev *dev, int block_no); int (*drv_initialise_fn) (struct yaffs_dev *dev); int (*drv_deinitialise_fn) (struct yaffs_dev *dev); Please, could smbd. explain to me how to implement a write function. Since my flash has no OOB region, should I reserve some place for OOB in the next page or completely ommit writing OOB data. I want to use YAFFS1. Does YAFFS1 require OOB? Should I also implement drv_mark_bad_fn and drv_check_bad_fn functions for YAFFS1 or leave them empty? And is there any compile time option which makes sure that only YAFFS1 functionality is compiled? I have seed in yaffs_dev.param there is option is_yaffs2. So is it sufficient only to set this to 0 to have only YAFFS1 functionality?