About use DS-5  issues

Hi，

     I am writing Bare-metal code for s3c6410 with DS-5,when i  add a empty fuction without static keyword limit to main fuction,i found that the code was does not work,but i add static keyword to limit the empty fuction ,then the code was work.I have no any debug tools,i don't known where is the issues,

  Hope your help, thanks!