title: How does the CPU know where to look for a given physical memory address?
body: <p>If I understand correctly, whenever a CPU is turned on it jumps to a manufacturer hardwired default physical memory address and starts executing the binary code present there. Naturally in a PC the default location maps to the ROM containing the BIOS.</p>
  
  <p>Suppose I have a system with RAM installed as well, how does the CPU know that it is supposed to search for that specific address in the ROM chip containing the BIOS and not RAM's address?</p>
  
  <p>Do the manufacturers of the Motherboard and the RAM have some standard or contract where they agree that the memory addresses of their hardware will never overlap?</p>