AMI's take on the Trusted Computing BIOS

WE'VE NOW HAD a chance to look at the white paper American Megatrends Inc (AMI) sent us yesterday on its BIOS which supports the Trusted Computing Platform Alliance.

As the letter we published earlier today points out, AMI is a member of the TCPA but it claims that it has produced the BIOS in response to other industry players - they'll need the BIOS support to deliver their cunning plans.

We welcome AMI's openness in both approaching us and providing the following information in the white paper.

AMI says in the document that the BIOS plays a minimal but important role in a TCPA enabled system. It loads the vendor specific TPM driver, records info that verifies the integrity of the BIOS and pre-boot process, and give a run time software interface to the TOP, which the OS uses for so-called "trusted applications".

There is, in fact, something of an overhead during boot time, as we feared. AMI says in the white paper that the additional authentication steps increase the boot time by around five seconds. But it claims that doesn't mean a significant booting overhead because AMI BIOS 8 has faster boot speeds anyway.

AMIBIOS 8 uses an "emodule" which separates the hardware support from the technology support and this concept can be combined with the Visual E-BIOS development environment for Microsoft Window.

The core TCPA component contains code which is common to all TCPA systems and that uses hooks/tables in the chipset and board components to access the chipset and the board's related features.

There are both 32-bit and 16-bit code components in AMI's TCPA code.

While AMI is a member of the TCPA -- like many other third party companies - what we're really interested in is the steering committee of this group, which seems to be accountable to no-one but itself, and the members of which are as nebulous as Scotch Mist. µ