Undefined symbol main (referred from entry9a.o).

Compiler error ：
Error: L6218E: Undefined symbol main (referred from entry9a.o).
Error: L6218E: Undefined symbol main (referred from rtentry2.o).
Analyze possible causes ：
1. If main Error writing function , hold main Write mian, There will be

Error: L6218E: Undefined symbol main (referred from rtentry2.o). Just change it back ;

2. If... Is not taken into account when the project is established main.c Or write main Function file is added to the project file , Will appear ：

Error: L6218E: Undefined symbol main (referred from entry9a.o). Add the file to the project file

3. Not written main Function also appears .

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