tree e64977ddb66f256039463db2e85feb576ef921e6
parent c7a4f74dad2b91bebad608618f3fda434563be74
author Alex Klyubin <klyubin@google.com> 1376684364 -0700
committer Alex Klyubin <klyubin@google.com> 1376956708 -0700

Seed Linux RNG from Hardware RNG at boot during init.

The Linux RNG may have little entropy during boot. As more and more
devices have a Hardware RNG, we mix in 512 bytes from Hardware RNG
(if present) into Linux RNG early during boot (after
wait_for_coldboot_done and before property_service_init actions in
init).

To avoid having to trust the output of Hardware RNG, we do not mix it
into the Linux RNG's primary pool or increase the Linux RNG's entropy
estimates.

Bug: 10362513
Change-Id: I80617f21710400747f5e7533e518d90ea74e2f11