I find that 0x0800c121 is the entry point of the app using IAR4.0. You can find the following sentences in the map file of the app project:
Program entry at : 0800C121 Relocatable, from module : ?CMAIN .
__program_start 0800C121 Absolute parts (?ABS_ENTRY_MOD) __vector_table (stm32f10x_vector)
Yet the mapping file is different in IAR5.0 . You can not find that sentence. I just set the __APP_Start to __iar_program_start. It did’t work. And we can not set __APP_Start to 0x0800c004, because the reset function is not the main function.