title: What is context in xv6?
body: <p>what is the usage of <code>context</code> in xv6 OS ?
  what is the job of each register in <code>context</code> ?</p>
  
  <pre><code>struct context {
    uint edi;
    uint esi;
    uint ebx;
    uint ebp;
    uint eip;
  };
  </code></pre>