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authorArthur Heymans <arthur@aheymans.xyz>2021-03-29 14:23:53 +0200
committerArthur Heymans <arthur@aheymans.xyz>2021-05-06 08:26:41 +0000
commit6f8e9443aa55ad27045fb437fd8df3386d66ba3e (patch)
tree32d21070ab5343979b6f95bae77567d26d6230d6 /src/security/tpm
parent59a621abc70464352eaf540bd6cb896935b9ba72 (diff)
security/tpm: Add option to init TPM in bootblock
When using a hardware assisted root of trust measurement, like Intel TXT/CBnT, the TPM init needs to happen inside the bootblock to form a proper chain of trust. Change-Id: Ifacba5d9ab19b47968b4f2ed5731ded4aac55022 Signed-off-by: Arthur Heymans <arthur@aheymans.xyz> Reviewed-on: https://review.coreboot.org/c/coreboot/+/51923 Reviewed-by: Christian Walter <christian.walter@9elements.com> Reviewed-by: Angel Pons <th3fanbus@gmail.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/security/tpm')
-rw-r--r--src/security/tpm/Kconfig8
-rw-r--r--src/security/tpm/tspi/tspi.c6
2 files changed, 13 insertions, 1 deletions
diff --git a/src/security/tpm/Kconfig b/src/security/tpm/Kconfig
index e1255d1680..13bef06985 100644
--- a/src/security/tpm/Kconfig
+++ b/src/security/tpm/Kconfig
@@ -106,6 +106,14 @@ config TPM_MEASURED_BOOT
help
Enables measured boot (experimental)
+config TPM_MEASURED_BOOT_INIT_BOOTBLOCK
+ bool
+ depends on TPM_MEASURED_BOOT && !VBOOT
+ help
+ Initialize TPM inside the bootblock instead of ramstage. This is
+ useful with some form of hardware assisted root of trust
+ measurement like Intel TXT/CBnT.
+
config TPM_MEASURED_BOOT_RUNTIME_DATA
string "Runtime data whitelist"
default ""
diff --git a/src/security/tpm/tspi/tspi.c b/src/security/tpm/tspi/tspi.c
index 6ef01383ce..7a8e2befdf 100644
--- a/src/security/tpm/tspi/tspi.c
+++ b/src/security/tpm/tspi/tspi.c
@@ -1,5 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-only */
+#include <rules.h>
#include <console/cbmem_console.h>
#include <console/console.h>
#include <security/tpm/tspi/crtm.h>
@@ -104,6 +105,9 @@ static inline int tspi_tpm_is_setup(void)
return vboot_logic_executed();
}
+ if (CONFIG(TPM_MEASURED_BOOT_INIT_BOOTBLOCK))
+ return ENV_BOOTBLOCK ? tpm_is_setup : 1;
+
if (ENV_RAMSTAGE)
return tpm_is_setup;
@@ -180,7 +184,7 @@ uint32_t tpm_setup(int s3flag)
#if CONFIG(TPM1)
result = tpm1_invoke_state_machine();
#endif
- if (CONFIG(TPM_MEASURED_BOOT))
+ if (CONFIG(TPM_MEASURED_BOOT) && !CONFIG(TPM_MEASURED_BOOT_INIT_BOOTBLOCK))
result = tspi_measure_cache_to_pcr();
tpm_is_setup = 1;