[SOLVED] on gcc compiler, i have a source code which has obect file i.e., .o file already generated need to generate executable in .bin format help.

i have following error while generating the executables.
/usr/bin/ld: a9gprs.o: Relocations in generic ELF (EM: 40)
a9gprs.o: error adding symbols: File in wrong format
collect2: error: ld returned 1 exit status
and i have following content in my obj folder.
a9gprs.o cpu_comp.o gpio.o modbus.o stm32f0xx_exti.o stm32f0xx_misc.o stm32f0xx_spi.o stm32f0xx_wwdg.o uart.o
assert.o cpu.o hooks.o startup_stm32f0xx.o stm32f0xx_flash.o stm32f0xx_pwr.o stm32f0xx_syscfg.o syscalls.o
boot.o delay.o led.o stm32f0xx_dbgmcu.o stm32f0xx_gpio.o stm32f0xx_rcc.o stm32f0xx_tim.o system_stm32f0xx.o
com.o _exit.o main.o stm32f0xx_dma.o stm32f0xx_i2c.o stm32f0xx_rtc.o stm32f0xx_usart.o timer.o
please tell me the command to execute them.

Execute what?

From the message, it appears that you have a faulty .o file and need to check your source code for that item and recompile after fixing things, but that is just a first guess based on the error message. What we KNOW from that message is that the .o file is not correct.