Hi Charles, Here is Diego from Harman, I have some doubts about yaffs2 img and hope can get some support from you. As we know we can use the mkyaffs2image to build a yaffs2 image file and then write to the nand partition directly. Now I want to clear the head format of the yaffs2 image file. I think the mkyaffs2image should add some contents like size or crc to the head but I am not sure. And how the mechanism of mkyaffs2image tool, I am also confused. Br Diego Sr Software System Engineer China R&D Center, Harman International 26-27F, Innov Tower, Block A, No.1801 Hongmei Road, Xuhui District, Shanghai, 200233, P.R. China Phone: +86 21 23064500 Mobile: +86 13761729112 Email: Yujie.Ding@harman.com