force esxi headless

hello,

i am testing gpu passthrough to my vm(s). i have 2 gpus in the host, and i'm able to pass through gpu#1 to the vm. gpu#2 is used by esxi.

now i would like to add a second vm, and pass gpu#2 to it. for this i need to make sure that esxi doesn't use the gpu at boot time.

so essentially, i would like to turn esx into a headless system.

the only thing i found in the docs was this

Detecting a Headless System

"You can set the headless flag in the ACPI FADT table to mark a system as headless"

can someone explain how that is done exactly?