Hi: I have a board with 512B page size nandflash . I use the yaffs2 source code (because the kernel I choose is 2.6 and the MTD ... ),but I mount flash as yaffs . My problem is after #nandwrite -a -o /dev/mtd0 root.yaffs Writing data to block 0 ioctl(MEMWRITEOOB): Input/output error Data did not fit into device, due to bad blocks : Illegal seek I think there is no bad block in the flash( never write it before ). The root.yaffs is maded by mkyaffsimage ,I think problem is nandwrite OOB info to flash . My step is : # flash_eraseall /dev/mtd0 #mkyaffsimage root root.yaffs #nandwrite -a -o /dev/mtd0 root.yaffs Is there something wrong ? Regards.