title: How does x86 assigns interrupt number for PCI device in Linux?
body: <p>My understanding is BIOS or EFI detects the hardware during bootup and determines interrupt number, then passes it to Linux once kernel is up and running. And based on my research the lower the interrupt number the higher its priority. </p>
  
  <p>My question is how does BIOS/EFI decide which hardware should have high priority over another? Is it something that is configurable or is hardcoded by BIOS/EFI?</p>