Yes. You must either cook and inject your own ACPI table (taking inspiration from a similar model to save you time), or go with S0 only using a kernel patch. I

Yes. You must either cook and inject your own ACPI table (taking inspiration from a similar model to save you time), or go with S0 only using a kernel patch. I have done some bios and acpi code before on coreboot. It is tough, lots of work and no guaranteed results if you don't have access to the specs (NDA) Anyway I really don't recommend you do that unless you have experience, documentation and time.