编译时出错，求助各位大侠！

小熊在线

编译时，报错，报错信息如下：
Build started: Project: Ksec_FreeRTOS
*** Using Compiler 'V5.06 update 6 (build 750)', folder: 'C:\Program Files\Keil_v5\ARM\ARMCC\Bin'
Build target 'FreeFRTOS'
linking...
.\Objects\Ksec_FreeRTOS.axf: Error: L6218E: Undefined symbol vTaskSwitchContext (referred from port.o).
.\Objects\Ksec_FreeRTOS.axf: Error: L6218E: Undefined symbol listSET_LIST_ITEM_OWNER (referred from task.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 2 error messages.
".\Objects\Ksec_FreeRTOS.axf" - 2 Error(s), 0 Warning(s).
Target not created.
Build Time Elapsed:  00:00:01


求助各位高手，这是什么原因呀？

Grit

vTaskSwitchContext listSET_LIST_ITEM_OWNER
这两个函数找不到定义