MDK编译报错Error: L6218E: Undefined symbol SystemInit (referred from startup_stm32f10x_md.0)

使用keil编译程序时，出现如下错误

.\Objects\STM32_MD.axf: Error: L6218E: Undefined symbol SystemInit (referred from startup_stm32f10x_md.o).
Not enough information to list image symbols.
Not enough information to list load addresses in the image map.
Finished: 2 information, 0 warning and 1 error messages.
“.\Objects\STM32_MD.axf” - 1 Error(s), 0 Warning(s).
Target not created.

问题：缺失对SystemInit的定义

解决：增加一行代码对SystemInit的定义

#include "stm32f10x.h"
int main(void)
{
while(1);
}
void SystemInit(void)
{}