Fedora reexamines "trusted boot"

There have been various flaws in Intel chipsets that allow attacks, the most entertaining being an exploit in the BIOS flasher code that would allow you to flash unsigned BIOS images and replace the sinit. I don't believe there are any <em>known</em> flaws in current systems, but http://theinvisiblethings.blogspot.com/search/label/trust... discusses some of the ones that have been found.

So I don't think there's any direct evidence that it's ineffective, merely that history suggests that anything that's never been seriously attacked and which has a track record of holes tends to have more holes that haven't been found yet...