报错如下：
Build target 'STM32F429I-Discovery'
linking...
STM32F429I-DiscoverySTM32F429I-Discovery.axf: Error: L6218E: Undefined symbol HAL_RTCEx_BKUPWrite (referred from main.o).
STM32F429I-DiscoverySTM32F429I-Discovery.axf: Error: L6218E: Undefined symbol HAL_RTC_GetDate (referred from main.o).
STM32F429I-DiscoverySTM32F429I-Discovery.axf: Error: L6218E: Undefined symbol HAL_RTC_GetTime (referred from main.o).
STM32F429I-DiscoverySTM32F429I-Discovery.axf: Error: L6218E: Undefined symbol HAL_RTC_Init (referred from main.o).
STM32F429I-DiscoverySTM32F429I-Discovery.axf: Error: L6218E: Undefined symbol HAL_RTC_SetDate (referred from main.o).
STM32F429I-DiscoverySTM32F429I-Discovery.axf: Error: L6218E: Undefined symbol HAL_RTC_SetTime (referred from main.o).
"STM32F429I-DiscoverySTM32F429I-Discovery.axf" - 6 Errors, 0 Warning(s).
Target not created

请问各位这是什么原因呢？我把路径都改成英文后也还是不可以的