关于keil软件的问题！

好好学习-2049864

 .\UART.axf: Warning: L6373W: libattrs.map file not found in System Library directory D:\Program Files\ARM\ADSv1_2\LIB\armlib\. Library selection may be impaired.
.\UART.axf: Warning: L6310W: Unable to find ARM libraries.
.\UART.axf: Error: L6411E: No compatible library exists with a definition of startup symbol __main.
Not enough information to list image symbols.
Not enough information to list the image map.
Finished: 2 information, 2 warning and 1 error messages.
".\UART.axf" - 1 Error(s), 3 Warning(s).
Target not created

这个问题怎么解决？谢谢