[Yaffs] make yaffs2 error

dear all,when I make mkyaffsimgae with arm-linux-gccthe follow error occours,can you give me some suggestions? thanksmkyaffsimage.c:117: warning: 'yaffs_CalcNameSum' defined but not usedarm-linux-gcc -o mkyaffsimage yaffs_ecc.o mkyaffsimage.omkyaffsimage.o: In function `process_directory':mkyaffsimage.c:(.text+0xaac): undefined reference to `__lxstat'mkyaffsimage.o: In function `main':mkyaffsimage.c:(.text+0xeb4): undefined reference to `__xstat'collect2: ld returned 1 exit statusmake: *** [mkyaffsimage] Error 1