20.16.9.13. Interface ROM BIOS configuration

To specify the ROM BIOS configuration settings, use a management tool to make the following changes to the domain XML:

  ...
  <devices>
    <interface type='network'>
      <source network='default'/>
      <target dev='vnet1'/>
      <rom bar='on' file='/etc/fake/boot.bin'/>
    </interface>
  </devices>
  ...

For hypervisors which support it, you can change how a PCI Network device's ROM is presented to the guest virtual machine. The bar attribute can be set to on or off, and determines whether or not the device's ROM will be visible in the guest virtual machine's memory map. (In PCI documentation, the "rombar" setting controls the presence of the Base Address Register for the ROM). If no rom bar is specified, the qemu default will be used (older versions of qemu used a default of off, while newer qemus have a default of on). The optional file attribute is used to point to a binary file to be presented to the guest virtual machine as the device's ROM BIOS. This can be useful to provide an alternative boot ROM for a network device.