Hi, The previous yaffs i tried was not cvs version incidentally. I build the cvs version and it cracks up in errors UPD include/linux/compile.h CC init/version.o LD init/built-in.o LD .tmp_vmlinux1 fs/built-in.o(.text+0x4e640): In function `yaffs_internal_read_super_mtd': fs/yaffs/yaffs_fs.c:1499: undefined reference to `nandmtd_WriteChunkToNAND' fs/built-in.o(.text+0x4e644):fs/yaffs/yaffs_fs.c:1499: undefined reference to `nandmtd_ReadChunkFromNAND' fs/built-in.o(.text+0x4e648):fs/yaffs/yaffs_fs.c:1499: undefined reference to `nandmtd_EraseBlockInNAND' fs/built-in.o(.text+0x4e64c):fs/yaffs/yaffs_fs.c:1499: undefined reference to `nandmtd_InitialiseNAND' make: *** [.tmp_vmlinux1] Error 1 Any clues ?? A grep of my driver/mtd/nand does not show any such functions ? And do nandwrite and nandtest actually work on 512 page mtd devices ? If anyone has a working build , please provide me a link . regards