Am Sonntag, den 04.10.2009, 14:31 -0500 schrieb Anthony Liguori:
I don't know enough about EFI, but my concern is that down the road, hardware devices will start to exist that require EFI because they implement EFI modules and not legacy option ROMs. In order to support PCI passthrough of such devices, we will need to provide an EFI capable firmware.
Why? They're initialized at boot time (by the host's EFI firmware, if necessary), and are usable by the OS then.
Look at OpenFirmware, the drivers initialize the hardware and provide just enough support to be able to start an operating system, but as soon as the operating system runs, it takes over as much as possible, as quickly as possible.
For good reasons, as external drivers (no matter if OF or EFI) impose the same flaw as ACPI: Hardware state changes outside the control of the operating system.
Beyond boot loaders and toy kernels, firmware level drivers hurt more than they help. The world changed since the invention of BIOS in CP/M.
Regards, Patrick Georgi