title: Objcopy elf to bin file
body: <p>I have STM32F404 board and I am trying to flash it. I am following this <a href="http://www.wolinlabs.com/blog/linux.stm32.discovery.gcc.html" rel="noreferrer">tutorial</a>.</p>
  
  <p>In the project <a href="https://github.com/rowol/stm32_discovery_arm_gcc/blob/master/STM32F4-Discovery_FW_V1.1.0/Project/Peripheral_Examples/TIM_TimeBase/Makefile" rel="noreferrer">Makefile</a></p>
  
  <pre><code>$(PROJ_NAME).elf: $(SRCS)
      $(CC) $(CFLAGS) $^ -o $@ 
      $(OBJCOPY) -O ihex $(PROJ_NAME).elf $(PROJ_NAME).hex
      $(OBJCOPY) -O binary $(PROJ_NAME).elf $(PROJ_NAME).bin
  
  burn: proj
      $(STLINK)/st-flash write $(PROJ_NAME).bin 0x8000000
  </code></pre>
  
  <p>The bin file is generated using <code>OBJCOPY</code>and then flashed using the Make target <code>burn</code></p>
  
  <p>My questions :</p>
  
  <p><strong>Question 1</strong>: What does <code>OBJCOPY=arm-none-eabi-objcopy</code> in this case. I opened the man but I didn't fully undrestand can anyone explain it simply ?</p>
  
  <p><strong>Question 2</strong>: Flashing the bin file gives the expected result (Leds blinking) However the leds are not blinking by flashing the elf file <code>$(STLINK)/st-flash write $(PROJ_NAME).elf 0x8000000</code> so why ?</p>