[U-Boot] Support for Intel i7 2nd GEneration processors

[Graeme Russ]

Hi Flash,

Note: I have no experience with (U)EFI
On Tue, Aug 30, 2011 at 3:35 PM, Flash K <bootloader99 at yahoo.com> wrote:
> Hi Graeme,
> I was checking out other alternatives to BIOS. I came across EFI , a new
> technology that seems to replace the BIOS in the near future. However I am
> still not clear as to where EFI fits in the booting process. They say that
> EFI cannot replace the BIOS but plans to do so in the near future.

(U)EFI cannot replace BIOS because most OS's still depend on BIOS to boot.
BIOS provides a standard way for an OS to do some fundamental operations
in real-mode (the mode the x86 CPU boots into) before the OS's switches to
protected mode (and hence can no longer use BIOS). After the switch to
protected mode, the OS's drivers interface directly to the hardware. Some
of these fundamental operations include determining memory size and loading
the core OS components from the hard drive

> FAQs at http://www.uefi.org/about/
> Intel also says that they are providing support for some motherboards. So is
> UEFI meant for use with the existing BIOS or with a custom developed BIOS
> from Uboot/Coreboot? Some information online also says that UEFI can be used
> as a payload for Coreboot. The entire thing is a little confusing. I am not
> able to understand where UEFI fits in with the BIOIS?

I suppose you could call (U)EFI a 'bootloader' of sorts. I theory, you could
write an (U)EFI for a motherboard and have it do everything BIOS currently
does (provided you knew all the ins-and-outs of the hardware components). I
gather that (U)EFI is far more extensible than coreboot or U-Boot - But it
is also a lot bigger (I have heard numbers up to 2MB - U-Boot is <256kB).
I gather that the size is due to a single (U)EFI image being able to cater
for multiple hardware configurations - Each U-Boot image is tailored to a
very specific hardware configuration (or very limited set thereof)

As a coreboot payload, I think coreboot does some low-level init of the
motherboard hardware (SDRAM for example) and then passes control onto
(U)EFI

So until Linux and Windows support (U)EFI and stop supporting BIOS, (U)EFI
is not going to replace BIOS

Regards,

Graeme