Wrong device for boot due to passthrough pci sata adapter

[Phlogi]

I'm trying to passthrough a pci-e Avago LSI 9211-8i to a freeNAS virtual machine. I got pretty far:
- adapter shows up properly during bios boot
- freeNAS installed properly and can be run as long as the adapter is not passthrough

The LSI adapter messes up the boot order and the SeaBIOS only allows to boot from one of the passthrough devices it seems. Even though I make a boot selection from the f12-menu, it seems to only recognize the 4 passthrough devices:

Any idea? I tried different options for the installed disk: virtio, SATA, etc. but it doesn't make a difference. How can I pass parameter to SeaBios actually? http://www.seabios.org/Runtime_config

 

[Phlogi]

I figured it out: The control config utility allows to disable booting completely (i had to fully restart the hypervisor though to access it):

Credits: https://lime-technology.com/forum/index.php?topic=12767.0