The hardware RNG is in the 82802 "Firmware Hub" chip. Specs are at
ftp://download.intel.com/design/chipsets/datashts/29065801.pdf.
Page 9 (of 37):
Intel will provide a Windows* driver to give third party software
access to our RNG for use as a security feature. Also provided will
be a device driver developer kit (DDK) for operating system vendors
who wish to design security drivers for their platform.
Page 26 (of 37):
4.10. Random Number Generator
The Firmware Hub integrates a Random Number Generator (RNG) using
thermal noise generated from inherently random quantum mechanical
properties of silicon. When not generating new random bits the RNG
circuitry will enter a low power state. Intel will provide a binary
software driver to give third party software access to our RNG for
use as a security feature. At this time, the RNG is only to be used
with a system in an OS-present state.
There is no more detail than that in the entire document.
