title: First physical core to boot
body: <p>As I was reading through the kernel source code I noticed that a mapping between the physical core id and the virtual core number is being created. This could be because there is some degree of uncertainty in the order in which the cores are brought up.</p>
  
  <p>In a multi-core system, which physical core is the first to boot? Is it <strong><em>always</em></strong> physical core #0? Does this hold for x86, x64, ARM and ARM64?</p>