mount-encrypted: expprt nvram contents to tmpfs

Export the NVRAM contents to tmpfs (/tmp) for use during boot without
incurring the cost of repeated trips through the TPM.

Signed-off-by: Will Drewry <wad@chromium.org>

BUG=chromium-os:37367
TEST=builds, boots, emits lockbox.nvram which validates using in-progress lockbox-cache
BRANCH=none
Change-Id: I8b1103f4bd22bd75e98a7617a571bdb3a06d2914
Previous-Reviewed-on: https://gerrit.chromium.org/gerrit/41433
Commit-Queue: Will Drewry <wad@chromium.org>
(cherry picked from commit 265e2f78dd46845253b683ca8367483c31ba3f4a)
Reviewed-on: https://gerrit.chromium.org/gerrit/42114
Commit-Queue: Mattias Nissler <mnissler@chromium.org>
Reviewed-by: Mattias Nissler <mnissler@chromium.org>
Tested-by: Mattias Nissler <mnissler@chromium.org>
1 file changed