IBM started using uEFI on their System x and BladeCenter offerings quite some time ago.  Despite the fact that XenServer does not fully support uEFI, there is a work around that makes it possible to install XenServer on these IBM servers.

Updating the System Configuration

  1. Power on the system and wait until the boot splash screen is displayed, hit “F1″ for Setup
  2. Set the “Legacy Only” boot option by entering the Boot Manager and selecting Add Boot Option
  3. Select Generic Boot Option, then select “Legacy Only”
  4. Back out to the Boot Manger menu and select Change Boot Order
  5. Set “Legacy Only” as the first boot option, then commit the changes
  6. Back out to the main BIOS/uEFI page and select Save Settings

By adding “Legacy Only” to the top of your standard boot options you should now have no problems installing XenServer via PXE or optical media.

For more information about running XenServer on a particular IBM server model, please refer to the XenServer HCL.