I have a question about assigning PCI BAR resource.

In OliveHill, internal graphics(bus 0, dev 1, func 0)'s BAR0 (base address register) is 0xe000000c. This is Graphic Memory Base Address.

I want to change this value to 0xc000000c. I have to do 2 things:

1) alloc resource at 0xc0000000 whose length is 512M

2) write the address value to internal graphics(bus 0, dev 1, func 0)'s BAR0

for 1), maybe I can alloc resource when reading resource.

but I don't know how to deal with 2). It seems that, BAR's resources are assigned by device's ops->set_resources() function. But I can't find this function.

My question is

1) when internal graphics(bus 0, dev 1, func 0)'s BAR0 is set to 0xe0000000? How can I change it?

2) How does coreboot alloc resources on 0xe0000000? I also can't find it.

This is a general question: how does coreboot assign PCI device's BAR resource?