..objmain.axf: Error: L6218E: Undefined symbol SDCardInfo (referred from main.o).
..objmain.axf: Error: L6218E: Undefined symbol SD_EraseTest (referred from main.o).
..objmain.axf: Error: L6218E: Undefined symbol SD_MultiBlockTest (referred from main.o).
..objmain.axf: Error: L6218E: Undefined symbol SD_SingleBlockTest (referred from main.o).
Target not created
这是什么情况,我查了查我对这几个函数声明了,并且添加了头文件,怎么还是错呢,找了一天了快都找不到解决办法,各位大神帮帮我吧