vboot2: Support reboot requested by secdata
When a TPM goes from the disabled state to the enabled state, it must
reboot after being enabled, before it can be initialized. In vboot1,
TLCL was part of vboot and this was handled internally. In vboot2, the
caller must set a context flag, so that vboot can decide whether to
allow the reboot, or whether to go directly to recovery mode. This
check is necessary to handle the following cases:
1) The device is booting normally, but the TPM needs a reboot. This
should simply reboot, without going to recovery mode.
2) The device is booting in recovery mode, but the TPM needs a reboot.
If this is the first time it asked us, allow the reboot.
3) The TPM asked for a reboot last time, so we did. And it's still
asking. Don't reboot, because that runs the risk that whatever is wrong
won't be fixed next boot either, and we'll get stuck in a reboot loop
that will prevent recovery. Boot into recovery mode.
Add a new NvStorage bit to track whether the TPM requested a reboot on
the previous boot. That's better than what we did in vboot1, where we
used a special recovery request. Vboot1 couldn't track getting stuck in
a reboot loop in normal mode, only in recovery mode. The new code can
catch both.
BUG=chrome-os-partner:45462
BRANCH=ryu
TEST=make runtests
Change-Id: I2ee54af107275ccf64a6cb41132b7a0fc02bb983
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/300572
Tested-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
13 files changed
