Windows 8 appears to support something that Linux has had for a bit, the Boot(time) Graphics Resource Table (BGRT) included in the ACPI 5 spec. I've been researching ACPI5 and UEFI 2.3.1 a bit since it started showing up.
ACPI Spec (PDF page 180) :
The table is written when the image is drawn on the screen. This should be done after it is expected that any firmware components that may write to the screen are done doing so and it is known that the image is the only thing on the screen. If the boot path is interrupted (e.g. by a key press), the valid bit within the status field should be changed to 0 to indicate to the OS that the current image is invalidated.
This table is only supported on UEFI systems.
There is a tool where you can see if your hardware has this specific ACPI table. It is called Hardware Editor or Hardware Read & Write Utility.
While a system may have the BGRT on the system, so far in my testing, this tool can only see it on a Windows 8 install. A Windows 7 install will still read whatever ACPI tables are there, but some do not show up, including the BGRT. But I am sure you are asking what this is about? Well you know when you boot up Windows 8, you see either the blue Window logo or the Beta fish? Well if the BGRT exists and there is something in it, then that image is shown instead!
So far I have found only 1 board that actually has this table, and it is added with a BIOS update. The Intel DH77EB reveals this capability in the release notes for the 0089 version BIOS:
Here is a link to get this BIOS version.
After updating the board with this BIOS, when Windows booted instead of the normal boot logo, the Intel BIOS splash screen appeared instead! It looked pretty funny. Fortunately, Intel provides a tool called the Intel Integrator Toolkit that lets you modify your BIOS:
Intel Integrator Toolkit 126.96.36.1994
If you use this tool and open the BIO file, you can choose to replace the boot graphics. On a whim, I just put a picture of a cat playing a trumpet in there (centered on black background, BMP file 1024x768) and saved the BIOS. I then updated the BIOS using the F7 method. Afterwards, Windows 8 booted and showed a cat playing a trumpet instead of the smushed Intel splash screen.
So what other ones does this work on? Well Google only had this one result.
Try this in Google yourself, maybe something new will show up:
site:intel.com type:pdf bgrt
This post has been edited by Tripredacus: 20 September 2012 - 08:01 AM
Reason for edit: updated ITK link