title: In Kernel makefile $(call cmd, tags) what is the cmd here refers to?
body: <p>In Kernel Makefile i found the code like below:</p>
  
  <pre><code>ctags CTAGS CSCOPE: $(HEADERS) $(SOURCES) 
  
  $(ETAGS) $(ETAGSFALGS) $(HEADERS) $(SOURCES)
  
  $(call cmd, ctags)
  </code></pre>
  
  <p>Also, where can i find the Macro or function ?</p>