How to do a call far (x86) to a given 32-bit address?

Answer 1

If memory is flat, i.e., CS has a base of 0 and covers entire 32-bit address space

call <address>

Where address is the 32-bit target address.

EDIT: Ah, I see you have a physical address. I'm presuming this is for a device driver running on Linux. I don't have any experience with the linux kernel, but I'd presume that this physical address isn't mapped 1:1 to a virtual address. You need to get it mapped to a virtual address (sorry, don't know how in Linux), and then call that virtual address.

But this raises the question of what PCI BIOS function you need, going directly to the BIOS outside of the OS is usually the wrong approach.