hi , My problem is after I patched the kernel , compile the modules ,there is the message: LD [M] /root/job/fs/yaffs2/yaffs2.o Building modules, stage 2. MODPOST *** Warning: "yaffs_CheckpointOpen" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_EraseBlockInNAND" [/root/job/fs/yaffs2/yaffs2.ko] undefined!*** Warning: "yaffs_InitialiseNAND" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_ReadChunkWithTagsFromNAND" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_WriteChunkWithTagsToNAND" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_CheckpointWrite" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "qsort" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_CheckpointClose" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_CheckpointInvalidateStream" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_CheckpointRead" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_MarkBlockBad" [/root/job/fs/yaffs2/yaffs2.ko] undefined! *** Warning: "yaffs_QueryInitialBlockState" [/root/job/fs/yaffs2/yaffs2.ko] undefined! CC /root/job/fs/yaffs2/yaffs2.mod.o LD [M] /root/job/fs/yaffs2/yaffs2.ko I get the yaffs.ko ,but I canot insmod it : FATAL: Error inserting yaffs (/lib/modules/2.6.16.19/kernel/fs/yaffs2/yaffs.ko): Unknown symbol in module, or unknown parameter (see dmesg) why ? regards.