title: Add Static Library to Contiki Makefile. File Format Not Recognized
body: <p>I have a simple contiki project, and have linked it with a simple static library created with eclipse project located in a separated directory.This is my makefile. </p>
  
  <pre><code>CONTIKI_PROJECT = hello-eclipse
  all: $(CONTIKI_PROJECT)
  LIBINCLUDE = /home/farissyariati/Software/Contiki/contiki-2.7/contiki-projects/ContikiExampleStaticLib/
  CFLAGS += -I$(LIBINCLUDE)
  PROJECT_LIBRARIES += /home/farissyariati/Software/Contiki/contiki-2.7/contiki-projects/ContikiExampleStaticLib/Release/libContikiExampleStaticLib.a
  
  CONTIKI = ../..
  include $(CONTIKI)/Makefile.include
  </code></pre>
  
  <p>And this is my c file. </p>
  
  <pre><code>#include "contiki.h"
  #include "calculate.h"
  #include &lt;stdio.h&gt;
  
  PROCESS(hello_eclipse_process, "Hello Eclipse Process");
  AUTOSTART_PROCESSES(&amp;hello_eclipse_process);
  
  PROCESS_THREAD(hello_eclipse_process, ev, data){
      PROCESS_BEGIN();
      int x = add_something(1, 2);
      printf("Hello Eclipse %d\n", x);
      PROCESS_END();
  }
  </code></pre>
  
  <p>After trying several way to link my static library with makefile, I successfully build it on my eclipse, but when I build it in my cooja to add a new mote, the cooja inform me something like this</p>
  
  <pre><code>/home/farissyariati/Software/Contiki/contiki-2.7/contiki-projects/ContikiExampleStaticLib/Release/libContikiExampleStaticLib.a: could not read symbols: File format not recognized
  collect2: ld returned 1 exit status
  make: *** [hello-eclipse.z1] Error 1
  rm obj_z1/contiki-z1-main.o hello-eclipse.co
  Process returned error code 2
  </code></pre>
  
  <p>How can I fix it? I have dealt with it for a week. 
  Any help will be very appreciated. </p>