Merge tag 'tpm-master-28012025' of https://source.denx.de/u-boot/custodians/u-boot-tpm

CI: https://source.denx.de/u-boot/custodians/u-boot-tpm/-/pipelines/24375

We have use cases where a previous stage boot loader doesn't have any
TPM drivers. Instead of extending the hardware PCRs it produces an
EventLog that U-Boot later replays on the hardware.

The only real example we have is TF-A, which produces the EventLog using
hashing algorithms created at compile time. This creates a problem to the
TPM since measurements need to extend all active PCR banks. Up to now
we were exiting refusing the extend measurements.

TPMs can be instructed to change their active PCR banks, as long as the
device resets immediately after a reconfiguration. This PR is adding
that functionality. U-Boot can now scan the currently active TPM PCR
banks, the ones it was compiled to support and the ones present in an
EventLog. It the reconfigures the TPM on the fly with the correct algorithms.

2 files changed, 8 insertions, 16 deletions

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index ad0bbdd8a77..d4f6b56afaa 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -438,15 +438,6 @@ config EFI_TCG2_PROTOCOL
 	  Provide a EFI_TCG2_PROTOCOL implementation using the TPM hardware
 	  of the platform.
 
-config EFI_TCG2_PROTOCOL_EVENTLOG_SIZE
-	int "EFI_TCG2_PROTOCOL EventLog size"
-	depends on EFI_TCG2_PROTOCOL
-	default 65536
-	help
-		Define the size of the EventLog for EFI_TCG2_PROTOCOL. Note that
-		this is going to be allocated twice. One for the eventlog it self
-		and one for the configuration table that is required from the spec
-
 config EFI_TCG2_PROTOCOL_MEASURE_DTB
 	bool "Measure DTB with EFI_TCG2_PROTOCOL"
 	depends on EFI_TCG2_PROTOCOL
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index c697b53441a..210a846ebc8 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -112,7 +112,7 @@ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type,
 	/* if ExitBootServices hasn't been called update the normal log */
 	if (!event_log.ebs_called) {
 		if (event_log.truncated ||
-		    event_log.pos + event_size > TPM2_EVENT_LOG_SIZE) {
+		    event_log.pos + event_size > CONFIG_TPM2_EVENT_LOG_SIZE) {
 			event_log.truncated = true;
 			return EFI_VOLUME_FULL;
 		}
@@ -125,7 +125,7 @@ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type,
 		return ret;
 
 	/* if GetEventLog has been called update FinalEventLog as well */
-	if (event_log.final_pos + event_size > TPM2_EVENT_LOG_SIZE)
+	if (event_log.final_pos + event_size > CONFIG_TPM2_EVENT_LOG_SIZE)
 		return EFI_VOLUME_FULL;
 
 	log = (void *)((uintptr_t)event_log.final_buffer + event_log.final_pos);
@@ -823,12 +823,12 @@ static efi_status_t create_final_event(void)
 	 * EFI_TCG2_GET_EVENT_LOGS need to be stored in an instance of an
 	 * EFI_CONFIGURATION_TABLE
 	 */
-	ret = efi_allocate_pool(EFI_ACPI_MEMORY_NVS, TPM2_EVENT_LOG_SIZE,
+	ret = efi_allocate_pool(EFI_ACPI_MEMORY_NVS, CONFIG_TPM2_EVENT_LOG_SIZE,
 				&event_log.final_buffer);
 	if (ret != EFI_SUCCESS)
 		goto out;
 
-	memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE);
+	memset(event_log.final_buffer, 0xff, CONFIG_TPM2_EVENT_LOG_SIZE);
 	final_event = event_log.final_buffer;
 	final_event->number_of_events = 0;
 	final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION;
@@ -914,7 +914,8 @@ static efi_status_t efi_init_event_log(void)
 	if (tcg2_platform_get_tpm2(&dev))
 		return EFI_DEVICE_ERROR;
 
-	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, TPM2_EVENT_LOG_SIZE,
+	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA,
+				CONFIG_TPM2_EVENT_LOG_SIZE,
 				(void **)&event_log.buffer);
 	if (ret != EFI_SUCCESS)
 		return ret;
@@ -923,7 +924,7 @@ static efi_status_t efi_init_event_log(void)
 	 * initialize log area as 0xff so the OS can easily figure out the
 	 * last log entry
 	 */
-	memset(event_log.buffer, 0xff, TPM2_EVENT_LOG_SIZE);
+	memset(event_log.buffer, 0xff, CONFIG_TPM2_EVENT_LOG_SIZE);
 
 	/*
 	 * The log header is defined to be in SHA1 event log entry format.
@@ -940,7 +941,7 @@ static efi_status_t efi_init_event_log(void)
 	 * platforms can use different ways to do so.
 	 */
 	elog.log = event_log.buffer;
-	elog.log_size = TPM2_EVENT_LOG_SIZE;
+	elog.log_size = CONFIG_TPM2_EVENT_LOG_SIZE;
 	rc = tcg2_log_prepare_buffer(dev, &elog, false);
 	if (rc) {
 		ret = (rc == -ENOBUFS) ? EFI_BUFFER_TOO_SMALL : EFI_DEVICE_ERROR;