[S] Change in coreboot[main]: security: Allow vboot when INTEL_TXT enabled

[Michał Żygowski (Code Review)]

Attention is currently required from: Christian Walter, Michał Żygowski, Yu-Ping Wu.

Michał Żygowski has uploaded a new patch set (#5) to the change originally created by Filip Lewiński. ( https://review.coreboot.org/c/coreboot/+/82695?usp=email )

The following approvals got outdated and were removed:
Verified+1 by build bot (Jenkins)

Change subject: security: Allow vboot when INTEL_TXT enabled
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security: Allow vboot when INTEL_TXT enabled

INTEL_TXT mandates usage of TPM_MEASURED_BOOT_INIT_BOOTBLOCK, which
is not compatible with VBOOT. This essentially making VBOOT and
INTEL_TXT mutually exclusive, but they do not have to be.

Do not call tpm_setup in bootblock_main if vboot starts in bootblock,
it would only start the TPM slightly faster. Most platforms probably
start vboot in bootblock, so there will be no loss of tpm_setup
state.

If vboot does not start in bootblock and
TPM_MEASURED_BOOT_INIT_BOOTBLOCK is enabled, skip the tpm_setup and
simply initialize the TLCL library.

TEST=Run VP4670 with INTEL_TXT and VBOOT enabled.

Change-Id: I19dc3d910c23fcfd8732465c488f47dd86a96781
Signed-off-by: Michał Żygowski 
---
M src/lib/bootblock.c
M src/security/tpm/Kconfig
M src/security/vboot/tpm_common.c
3 files changed, 19 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/95/82695/5