diff mbox series

[v2,5/8] tpm: Move TCG functions into a separate file

Message ID 20240623114838.14639-6-ilias.apalodimas@linaro.org
State Accepted
Commit a56037a461b54d9f17b8cd82bfe9543a159c0c2f
Headers show
Series The great TCG deduplication saga | expand

Commit Message

Ilias Apalodimas June 23, 2024, 11:48 a.m. UTC
The previous patch is moving the TPM TCG headers in their own file for
a cleaner API. Move the functions in their own file as well.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
 include/tpm-v2.h   | 190 -------------
 include/tpm_tcg2.h | 189 ++++++++++++
 lib/Makefile       |   2 +
 lib/tpm-v2.c       | 675 +------------------------------------------
 lib/tpm_tcg2.c     | 695 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 887 insertions(+), 864 deletions(-)
 create mode 100644 lib/tpm_tcg2.c
diff mbox series

Patch

diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 38d79207e321..fc7c58204e58 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -399,188 +399,6 @@  enum {
 	HR_NV_INDEX		= TPM_HT_NV_INDEX << HR_SHIFT,
 };
 
-/**
- * struct tcg2_event_log - Container for managing the platform event log
- *
- * @log:		Address of the log
- * @log_position:	Current entry position
- * @log_size:		Log space available
- * @found:		Boolean indicating if an existing log was discovered
- */
-struct tcg2_event_log {
-	u8 *log;
-	u32 log_position;
-	u32 log_size;
-	bool found;
-};
-
-/**
- * Create a list of digests of the supported PCR banks for a given input data
- *
- * @dev		TPM device
- * @input	Data
- * @length	Length of the data to calculate the digest
- * @digest_list	List of digests to fill in
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
-		       struct tpml_digest_values *digest_list);
-
-/**
- * Get the event size of the specified digests
- *
- * @digest_list	List of digests for the event
- *
- * Return: Size in bytes of the event
- */
-u32 tcg2_event_get_size(struct tpml_digest_values *digest_list);
-
-/**
- * tcg2_get_active_pcr_banks
- *
- * @dev			TPM device
- * @active_pcr_banks	Bitmask of PCR algorithms supported
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks);
-
-/**
- * tcg2_log_append - Append an event to an event log
- *
- * @pcr_index	Index of the PCR
- * @event_type	Type of event
- * @digest_list List of digests to add
- * @size	Size of event
- * @event	Event data
- * @log		Log buffer to append the event to
- */
-void tcg2_log_append(u32 pcr_index, u32 event_type,
-		     struct tpml_digest_values *digest_list, u32 size,
-		     const u8 *event, u8 *log);
-
-/**
- * Extend the PCR with specified digests
- *
- * @dev		TPM device
- * @pcr_index	Index of the PCR
- * @digest_list	List of digests to extend
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index,
-		    struct tpml_digest_values *digest_list);
-
-/**
- * Read the PCR into a list of digests
- *
- * @dev		TPM device
- * @pcr_index	Index of the PCR
- * @digest_list	List of digests to extend
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_pcr_read(struct udevice *dev, u32 pcr_index,
-		  struct tpml_digest_values *digest_list);
-
-/**
- * Measure data into the TPM PCRs and the platform event log.
- *
- * @dev		TPM device
- * @log		Platform event log
- * @pcr_index	Index of the PCR
- * @size	Size of the data or 0 for event only
- * @data	Pointer to the data or NULL for event only
- * @event_type	Event log type
- * @event_size	Size of the event
- * @event	Pointer to the event
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog,
-		      u32 pcr_index, u32 size, const u8 *data, u32 event_type,
-		      u32 event_size, const u8 *event);
-
-#define tcg2_measure_event(dev, elog, pcr_index, event_type, size, event) \
-	tcg2_measure_data(dev, elog, pcr_index, 0, NULL, event_type, size, \
-			  event)
-
-/**
- * Prepare the event log buffer. This function tries to discover an existing
- * event log in memory from a previous bootloader stage. If such a log exists
- * and the PCRs are not extended, the log is "replayed" to extend the PCRs.
- * If no log is discovered, create the log header.
- *
- * @dev			TPM device
- * @elog		Platform event log. The log pointer and log_size
- *			members must be initialized to either 0 or to a valid
- *			memory region, in which case any existing log
- *			discovered will be copied to the specified memory
- *			region.
- * @ignore_existing_log	Boolean to indicate whether or not to ignore an
- *			existing platform log in memory
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog,
-			    bool ignore_existing_log);
-
-/**
- * Begin measurements.
- *
- * @dev			TPM device
- * @elog		Platform event log. The log pointer and log_size
- *			members must be initialized to either 0 or to a valid
- *			memory region, in which case any existing log
- *			discovered will be copied to the specified memory
- *			region.
- * @ignore_existing_log Boolean to indicate whether or not to ignore an
- *			existing platform log in memory
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog,
-			  bool ignore_existing_log);
-
-/**
- * Stop measurements and record separator events.
- *
- * @dev		TPM device
- * @elog	Platform event log
- * @error	Boolean to indicate whether an error ocurred or not
- */
-void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog,
-			   bool error);
-
-/**
- * Get the platform event log address and size.
- *
- * @dev		TPM device
- * @addr	Address of the log
- * @size	Size of the log
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size);
-
-/**
- * Get the first TPM2 device found.
- *
- * @dev		TPM device
- *
- * Return: zero on success, negative errno otherwise
- */
-int tcg2_platform_get_tpm2(struct udevice **dev);
-
-/**
- * Platform-specific function for handling TPM startup errors
- *
- * @dev		TPM device
- * @rc		The TPM response code
- */
-void tcg2_platform_startup_error(struct udevice *dev, int rc);
-
 /**
  * Issue a TPM2_Startup command.
  *
@@ -897,12 +715,4 @@  enum tpm2_algorithms tpm2_name_to_algorithm(const char *name);
  */
 const char *tpm2_algorithm_name(enum tpm2_algorithms);
 
-/**
- * tpm2_algorithm_to_mask() - Get a TCG hash mask for algorithm
- *
- * @hash_alg: TCG defined algorithm
- * Return: TCG hashing algorithm bitmaps (or 0 if algo not supported)
- */
-u32 tpm2_algorithm_to_mask(enum tpm2_algorithms);
-
 #endif /* __TPM_V2_H */
diff --git a/include/tpm_tcg2.h b/include/tpm_tcg2.h
index 581ff6f24a4c..4e4ea1e8067d 100644
--- a/include/tpm_tcg2.h
+++ b/include/tpm_tcg2.h
@@ -142,5 +142,194 @@  struct tcg_efi_spec_id_event {
 #define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2 2
 #define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 0
 #define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2 2
+/**
+ * struct tcg2_event_log - Container for managing the platform event log
+ *
+ * @log:		Address of the log
+ * @log_position:	Current entry position
+ * @log_size:		Log space available
+ * @found:		Boolean indicating if an existing log was discovered
+ */
+struct tcg2_event_log {
+	u8 *log;
+	u32 log_position;
+	u32 log_size;
+	bool found;
+};
+
+/**
+ * Create a list of digests of the supported PCR banks for a given input data
+ *
+ * @dev		TPM device
+ * @input	Data
+ * @length	Length of the data to calculate the digest
+ * @digest_list	List of digests to fill in
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
+		       struct tpml_digest_values *digest_list);
+
+/**
+ * Get the event size of the specified digests
+ *
+ * @digest_list	List of digests for the event
+ *
+ * Return: Size in bytes of the event
+ */
+u32 tcg2_event_get_size(struct tpml_digest_values *digest_list);
+
+/**
+ * tcg2_get_active_pcr_banks
+ *
+ * @dev			TPM device
+ * @active_pcr_banks	Bitmask of PCR algorithms supported
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks);
+
+/**
+ * tcg2_log_append - Append an event to an event log
+ *
+ * @pcr_index	Index of the PCR
+ * @event_type	Type of event
+ * @digest_list List of digests to add
+ * @size	Size of event
+ * @event	Event data
+ * @log		Log buffer to append the event to
+ */
+void tcg2_log_append(u32 pcr_index, u32 event_type,
+		     struct tpml_digest_values *digest_list, u32 size,
+		     const u8 *event, u8 *log);
+
+/**
+ * Extend the PCR with specified digests
+ *
+ * @dev		TPM device
+ * @pcr_index	Index of the PCR
+ * @digest_list	List of digests to extend
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index,
+		    struct tpml_digest_values *digest_list);
+
+/**
+ * Read the PCR into a list of digests
+ *
+ * @dev		TPM device
+ * @pcr_index	Index of the PCR
+ * @digest_list	List of digests to extend
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_pcr_read(struct udevice *dev, u32 pcr_index,
+		  struct tpml_digest_values *digest_list);
+
+/**
+ * Measure data into the TPM PCRs and the platform event log.
+ *
+ * @dev		TPM device
+ * @log		Platform event log
+ * @pcr_index	Index of the PCR
+ * @size	Size of the data or 0 for event only
+ * @data	Pointer to the data or NULL for event only
+ * @event_type	Event log type
+ * @event_size	Size of the event
+ * @event	Pointer to the event
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog,
+		      u32 pcr_index, u32 size, const u8 *data, u32 event_type,
+		      u32 event_size, const u8 *event);
+
+#define tcg2_measure_event(dev, elog, pcr_index, event_type, size, event) \
+	tcg2_measure_data(dev, elog, pcr_index, 0, NULL, event_type, size, \
+			  event)
+
+/**
+ * Prepare the event log buffer. This function tries to discover an existing
+ * event log in memory from a previous bootloader stage. If such a log exists
+ * and the PCRs are not extended, the log is "replayed" to extend the PCRs.
+ * If no log is discovered, create the log header.
+ *
+ * @dev			TPM device
+ * @elog		Platform event log. The log pointer and log_size
+ *			members must be initialized to either 0 or to a valid
+ *			memory region, in which case any existing log
+ *			discovered will be copied to the specified memory
+ *			region.
+ * @ignore_existing_log	Boolean to indicate whether or not to ignore an
+ *			existing platform log in memory
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog,
+			    bool ignore_existing_log);
+
+/**
+ * Begin measurements.
+ *
+ * @dev			TPM device
+ * @elog		Platform event log. The log pointer and log_size
+ *			members must be initialized to either 0 or to a valid
+ *			memory region, in which case any existing log
+ *			discovered will be copied to the specified memory
+ *			region.
+ * @ignore_existing_log Boolean to indicate whether or not to ignore an
+ *			existing platform log in memory
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog,
+			  bool ignore_existing_log);
+
+/**
+ * Stop measurements and record separator events.
+ *
+ * @dev		TPM device
+ * @elog	Platform event log
+ * @error	Boolean to indicate whether an error ocurred or not
+ */
+void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog,
+			   bool error);
+
+/**
+ * Get the platform event log address and size.
+ *
+ * @dev		TPM device
+ * @addr	Address of the log
+ * @size	Size of the log
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size);
+
+/**
+ * Get the first TPM2 device found.
+ *
+ * @dev		TPM device
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tcg2_platform_get_tpm2(struct udevice **dev);
+
+/**
+ * Platform-specific function for handling TPM startup errors
+ *
+ * @dev		TPM device
+ * @rc		The TPM response code
+ */
+void tcg2_platform_startup_error(struct udevice *dev, int rc);
+
+/**
+ * tcg2_algorithm_to_mask() - Get a TCG hash mask for algorithm
+ *
+ * @hash_alg: TCG defined algorithm
+ * Return: TCG hashing algorithm bitmaps (or 0 if algo not supported)
+ */
+u32 tcg2_algorithm_to_mask(enum tpm2_algorithms);
 
 #endif /* __TPM_TCG_V2_H */
diff --git a/lib/Makefile b/lib/Makefile
index 2a76acf100d0..e389ad014f89 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -61,6 +61,8 @@  ifeq ($(CONFIG_$(SPL_TPL_)TPM),y)
 obj-$(CONFIG_TPM) += tpm_api.o
 obj-$(CONFIG_TPM_V1) += tpm-v1.o
 obj-$(CONFIG_TPM_V2) += tpm-v2.o
+obj-$(CONFIG_EFI_TCG2_PROTOCOL) += tpm_tcg2.o
+obj-$(CONFIG_MEASURED_BOOT) += tpm_tcg2.o
 endif
 
 obj-$(CONFIG_$(SPL_TPL_)CRC8) += crc8.o
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index c3832bb7f767..62ab804b4b38 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -23,668 +23,6 @@ 
 
 #include "tpm-utils.h"
 
-int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks)
-{
-	u32 supported = 0;
-	u32 pcr_banks = 0;
-	u32 active = 0;
-	int rc;
-
-	rc = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks);
-	if (rc)
-		return rc;
-
-	*active_pcr_banks = active;
-
-	return 0;
-}
-
-u32 tcg2_event_get_size(struct tpml_digest_values *digest_list)
-{
-	u32 len;
-	size_t i;
-
-	len = offsetof(struct tcg_pcr_event2, digests);
-	len += offsetof(struct tpml_digest_values, digests);
-	for (i = 0; i < digest_list->count; ++i) {
-		u16 l = tpm2_algorithm_to_len(digest_list->digests[i].hash_alg);
-
-		if (!l)
-			continue;
-
-		len += l + offsetof(struct tpmt_ha, digest);
-	}
-	len += sizeof(u32);
-
-	return len;
-}
-
-int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
-		       struct tpml_digest_values *digest_list)
-{
-	u8 final[sizeof(union tpmu_ha)];
-	sha256_context ctx_256;
-	sha512_context ctx_512;
-	sha1_context ctx;
-	u32 active;
-	size_t i;
-	u32 len;
-	int rc;
-
-	rc = tcg2_get_active_pcr_banks(dev, &active);
-	if (rc)
-		return rc;
-
-	digest_list->count = 0;
-	for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
-		if (!(active & hash_algo_list[i].hash_mask))
-			continue;
-
-		switch (hash_algo_list[i].hash_alg) {
-		case TPM2_ALG_SHA1:
-			sha1_starts(&ctx);
-			sha1_update(&ctx, input, length);
-			sha1_finish(&ctx, final);
-			len = TPM2_SHA1_DIGEST_SIZE;
-			break;
-		case TPM2_ALG_SHA256:
-			sha256_starts(&ctx_256);
-			sha256_update(&ctx_256, input, length);
-			sha256_finish(&ctx_256, final);
-			len = TPM2_SHA256_DIGEST_SIZE;
-			break;
-		case TPM2_ALG_SHA384:
-			sha384_starts(&ctx_512);
-			sha384_update(&ctx_512, input, length);
-			sha384_finish(&ctx_512, final);
-			len = TPM2_SHA384_DIGEST_SIZE;
-			break;
-		case TPM2_ALG_SHA512:
-			sha512_starts(&ctx_512);
-			sha512_update(&ctx_512, input, length);
-			sha512_finish(&ctx_512, final);
-			len = TPM2_SHA512_DIGEST_SIZE;
-			break;
-		default:
-			printf("%s: unsupported algorithm %x\n", __func__,
-			       hash_algo_list[i].hash_alg);
-			continue;
-		}
-
-		digest_list->digests[digest_list->count].hash_alg =
-			hash_algo_list[i].hash_alg;
-		memcpy(&digest_list->digests[digest_list->count].digest, final,
-		       len);
-		digest_list->count++;
-	}
-
-	return 0;
-}
-
-void tcg2_log_append(u32 pcr_index, u32 event_type,
-		     struct tpml_digest_values *digest_list, u32 size,
-		     const u8 *event, u8 *log)
-{
-	size_t len;
-	size_t pos;
-	u32 i;
-
-	pos = offsetof(struct tcg_pcr_event2, pcr_index);
-	put_unaligned_le32(pcr_index, log);
-	pos = offsetof(struct tcg_pcr_event2, event_type);
-	put_unaligned_le32(event_type, log + pos);
-	pos = offsetof(struct tcg_pcr_event2, digests) +
-		offsetof(struct tpml_digest_values, count);
-	put_unaligned_le32(digest_list->count, log + pos);
-
-	pos = offsetof(struct tcg_pcr_event2, digests) +
-		offsetof(struct tpml_digest_values, digests);
-	for (i = 0; i < digest_list->count; ++i) {
-		u16 hash_alg = digest_list->digests[i].hash_alg;
-
-		len = tpm2_algorithm_to_len(hash_alg);
-		if (!len)
-			continue;
-
-		pos += offsetof(struct tpmt_ha, hash_alg);
-		put_unaligned_le16(hash_alg, log + pos);
-		pos += offsetof(struct tpmt_ha, digest);
-		memcpy(log + pos, (u8 *)&digest_list->digests[i].digest, len);
-		pos += len;
-	}
-
-	put_unaligned_le32(size, log + pos);
-	pos += sizeof(u32);
-	memcpy(log + pos, event, size);
-}
-
-static int tcg2_log_append_check(struct tcg2_event_log *elog, u32 pcr_index,
-				 u32 event_type,
-				 struct tpml_digest_values *digest_list,
-				 u32 size, const u8 *event)
-{
-	u32 event_size;
-	u8 *log;
-
-	event_size = size + tcg2_event_get_size(digest_list);
-	if (elog->log_position + event_size > elog->log_size) {
-		printf("%s: log too large: %u + %u > %u\n", __func__,
-		       elog->log_position, event_size, elog->log_size);
-		return -ENOBUFS;
-	}
-
-	log = elog->log + elog->log_position;
-	elog->log_position += event_size;
-
-	tcg2_log_append(pcr_index, event_type, digest_list, size, event, log);
-
-	return 0;
-}
-
-static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog)
-{
-	struct tcg_efi_spec_id_event *ev;
-	struct tcg_pcr_event *log;
-	u32 event_size;
-	u32 count = 0;
-	u32 log_size;
-	u32 active;
-	size_t i;
-	u16 len;
-	int rc;
-
-	rc = tcg2_get_active_pcr_banks(dev, &active);
-	if (rc)
-		return rc;
-
-	event_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes);
-	for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
-		if (!(active & hash_algo_list[i].hash_mask))
-			continue;
-
-		switch (hash_algo_list[i].hash_alg) {
-		case TPM2_ALG_SHA1:
-		case TPM2_ALG_SHA256:
-		case TPM2_ALG_SHA384:
-		case TPM2_ALG_SHA512:
-			count++;
-			break;
-		default:
-			continue;
-		}
-	}
-
-	event_size += 1 +
-		(sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count);
-	log_size = offsetof(struct tcg_pcr_event, event) + event_size;
-
-	if (log_size > elog->log_size) {
-		printf("%s: log too large: %u > %u\n", __func__, log_size,
-		       elog->log_size);
-		return -ENOBUFS;
-	}
-
-	log = (struct tcg_pcr_event *)elog->log;
-	put_unaligned_le32(0, &log->pcr_index);
-	put_unaligned_le32(EV_NO_ACTION, &log->event_type);
-	memset(&log->digest, 0, sizeof(log->digest));
-	put_unaligned_le32(event_size, &log->event_size);
-
-	ev = (struct tcg_efi_spec_id_event *)log->event;
-	strlcpy((char *)ev->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
-		sizeof(ev->signature));
-	put_unaligned_le32(0, &ev->platform_class);
-	ev->spec_version_minor = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2;
-	ev->spec_version_major = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2;
-	ev->spec_errata = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2;
-	ev->uintn_size = sizeof(size_t) / sizeof(u32);
-	put_unaligned_le32(count, &ev->number_of_algorithms);
-
-	count = 0;
-	for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
-		if (!(active & hash_algo_list[i].hash_mask))
-			continue;
-
-		len = hash_algo_list[i].hash_len;
-		if (!len)
-			continue;
-
-		put_unaligned_le16(hash_algo_list[i].hash_alg,
-				   &ev->digest_sizes[count].algorithm_id);
-		put_unaligned_le16(len, &ev->digest_sizes[count].digest_size);
-		count++;
-	}
-
-	*((u8 *)ev + (event_size - 1)) = 0;
-	elog->log_position = log_size;
-
-	return 0;
-}
-
-static int tcg2_replay_eventlog(struct tcg2_event_log *elog,
-				struct udevice *dev,
-				struct tpml_digest_values *digest_list,
-				u32 log_position)
-{
-	const u32 offset = offsetof(struct tcg_pcr_event2, digests) +
-		offsetof(struct tpml_digest_values, digests);
-	u32 event_size;
-	u32 count;
-	u16 algo;
-	u32 pcr;
-	u32 pos;
-	u16 len;
-	u8 *log;
-	int rc;
-	u32 i;
-
-	while (log_position + offset < elog->log_size) {
-		log = elog->log + log_position;
-
-		pos = offsetof(struct tcg_pcr_event2, pcr_index);
-		pcr = get_unaligned_le32(log + pos);
-		pos = offsetof(struct tcg_pcr_event2, event_type);
-		if (!get_unaligned_le32(log + pos))
-			return 0;
-
-		pos = offsetof(struct tcg_pcr_event2, digests) +
-			offsetof(struct tpml_digest_values, count);
-		count = get_unaligned_le32(log + pos);
-		if (count > ARRAY_SIZE(hash_algo_list) ||
-		    (digest_list->count && digest_list->count != count))
-			return 0;
-
-		pos = offsetof(struct tcg_pcr_event2, digests) +
-			offsetof(struct tpml_digest_values, digests);
-		for (i = 0; i < count; ++i) {
-			pos += offsetof(struct tpmt_ha, hash_alg);
-			if (log_position + pos + sizeof(u16) >= elog->log_size)
-				return 0;
-
-			algo = get_unaligned_le16(log + pos);
-			pos += offsetof(struct tpmt_ha, digest);
-			switch (algo) {
-			case TPM2_ALG_SHA1:
-			case TPM2_ALG_SHA256:
-			case TPM2_ALG_SHA384:
-			case TPM2_ALG_SHA512:
-				len = tpm2_algorithm_to_len(algo);
-				break;
-			default:
-				return 0;
-			}
-
-			if (digest_list->count) {
-				if (algo != digest_list->digests[i].hash_alg ||
-				    log_position + pos + len >= elog->log_size)
-					return 0;
-
-				memcpy(digest_list->digests[i].digest.sha512,
-				       log + pos, len);
-			}
-
-			pos += len;
-		}
-
-		if (log_position + pos + sizeof(u32) >= elog->log_size)
-			return 0;
-
-		event_size = get_unaligned_le32(log + pos);
-		pos += event_size + sizeof(u32);
-		if (log_position + pos > elog->log_size)
-			return 0;
-
-		if (digest_list->count) {
-			rc = tcg2_pcr_extend(dev, pcr, digest_list);
-			if (rc)
-				return rc;
-		}
-
-		log_position += pos;
-	}
-
-	elog->log_position = log_position;
-	elog->found = true;
-	return 0;
-}
-
-static int tcg2_log_parse(struct udevice *dev, struct tcg2_event_log *elog)
-{
-	struct tpml_digest_values digest_list;
-	struct tcg_efi_spec_id_event *event;
-	struct tcg_pcr_event *log;
-	u32 log_active;
-	u32 calc_size;
-	u32 active;
-	u32 count;
-	u32 evsz;
-	u32 mask;
-	u16 algo;
-	u16 len;
-	int rc;
-	u32 i;
-	u16 j;
-
-	if (elog->log_size <= offsetof(struct tcg_pcr_event, event))
-		return 0;
-
-	log = (struct tcg_pcr_event *)elog->log;
-	if (get_unaligned_le32(&log->pcr_index) != 0 ||
-	    get_unaligned_le32(&log->event_type) != EV_NO_ACTION)
-		return 0;
-
-	for (i = 0; i < sizeof(log->digest); i++) {
-		if (log->digest[i])
-			return 0;
-	}
-
-	evsz = get_unaligned_le32(&log->event_size);
-	if (evsz < offsetof(struct tcg_efi_spec_id_event, digest_sizes) ||
-	    evsz + offsetof(struct tcg_pcr_event, event) > elog->log_size)
-		return 0;
-
-	event = (struct tcg_efi_spec_id_event *)log->event;
-	if (memcmp(event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
-		   sizeof(TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03)))
-		return 0;
-
-	if (event->spec_version_minor != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 ||
-	    event->spec_version_major != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2)
-		return 0;
-
-	count = get_unaligned_le32(&event->number_of_algorithms);
-	if (count > ARRAY_SIZE(hash_algo_list))
-		return 0;
-
-	calc_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
-		(sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count) +
-		1;
-	if (evsz != calc_size)
-		return 0;
-
-	rc = tcg2_get_active_pcr_banks(dev, &active);
-	if (rc)
-		return rc;
-
-	digest_list.count = 0;
-	log_active = 0;
-
-	for (i = 0; i < count; ++i) {
-		algo = get_unaligned_le16(&event->digest_sizes[i].algorithm_id);
-		mask = tpm2_algorithm_to_mask(algo);
-
-		if (!(active & mask))
-			return 0;
-
-		switch (algo) {
-		case TPM2_ALG_SHA1:
-		case TPM2_ALG_SHA256:
-		case TPM2_ALG_SHA384:
-		case TPM2_ALG_SHA512:
-			len = get_unaligned_le16(&event->digest_sizes[i].digest_size);
-			if (tpm2_algorithm_to_len(algo) != len)
-				return 0;
-			digest_list.digests[digest_list.count++].hash_alg = algo;
-			break;
-		default:
-			return 0;
-		}
-
-		log_active |= mask;
-	}
-
-	/* Ensure the previous firmware extended all the PCRs. */
-	if (log_active != active)
-		return 0;
-
-	/* Read PCR0 to check if previous firmware extended the PCRs or not. */
-	rc = tcg2_pcr_read(dev, 0, &digest_list);
-	if (rc)
-		return rc;
-
-	for (i = 0; i < digest_list.count; ++i) {
-		len = tpm2_algorithm_to_len(digest_list.digests[i].hash_alg);
-		for (j = 0; j < len; ++j) {
-			if (digest_list.digests[i].digest.sha512[j])
-				break;
-		}
-
-		/* PCR is non-zero; it has been extended, so skip extending. */
-		if (j != len) {
-			digest_list.count = 0;
-			break;
-		}
-	}
-
-	return tcg2_replay_eventlog(elog, dev, &digest_list,
-				    offsetof(struct tcg_pcr_event, event) +
-				    evsz);
-}
-
-int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index,
-		    struct tpml_digest_values *digest_list)
-{
-	u32 rc;
-	u32 i;
-
-	for (i = 0; i < digest_list->count; i++) {
-		u32 alg = digest_list->digests[i].hash_alg;
-
-		rc = tpm2_pcr_extend(dev, pcr_index, alg,
-				     (u8 *)&digest_list->digests[i].digest,
-				     tpm2_algorithm_to_len(alg));
-		if (rc) {
-			printf("%s: error pcr:%u alg:%08x\n", __func__,
-			       pcr_index, alg);
-			return rc;
-		}
-	}
-
-	return 0;
-}
-
-int tcg2_pcr_read(struct udevice *dev, u32 pcr_index,
-		  struct tpml_digest_values *digest_list)
-{
-	struct tpm_chip_priv *priv;
-	u32 rc;
-	u32 i;
-
-	priv = dev_get_uclass_priv(dev);
-	if (!priv)
-		return -ENODEV;
-
-	for (i = 0; i < digest_list->count; i++) {
-		u32 alg = digest_list->digests[i].hash_alg;
-		u8 *digest = (u8 *)&digest_list->digests[i].digest;
-
-		rc = tpm2_pcr_read(dev, pcr_index, priv->pcr_select_min, alg,
-				   digest, tpm2_algorithm_to_len(alg), NULL);
-		if (rc) {
-			printf("%s: error pcr:%u alg:%08x\n", __func__,
-			       pcr_index, alg);
-			return rc;
-		}
-	}
-
-	return 0;
-}
-
-int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog,
-		      u32 pcr_index, u32 size, const u8 *data, u32 event_type,
-		      u32 event_size, const u8 *event)
-{
-	struct tpml_digest_values digest_list;
-	int rc;
-
-	if (data)
-		rc = tcg2_create_digest(dev, data, size, &digest_list);
-	else
-		rc = tcg2_create_digest(dev, event, event_size, &digest_list);
-	if (rc)
-		return rc;
-
-	rc = tcg2_pcr_extend(dev, pcr_index, &digest_list);
-	if (rc)
-		return rc;
-
-	return tcg2_log_append_check(elog, pcr_index, event_type, &digest_list,
-				     event_size, event);
-}
-
-int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog,
-			    bool ignore_existing_log)
-{
-	struct tcg2_event_log log;
-	int rc;
-
-	elog->log_position = 0;
-	elog->found = false;
-
-	rc = tcg2_platform_get_log(dev, (void **)&log.log, &log.log_size);
-	if (!rc) {
-		log.log_position = 0;
-		log.found = false;
-
-		if (!ignore_existing_log) {
-			rc = tcg2_log_parse(dev, &log);
-			if (rc)
-				return rc;
-		}
-
-		if (elog->log_size) {
-			if (log.found) {
-				if (elog->log_size < log.log_position)
-					return -ENOBUFS;
-
-				/*
-				 * Copy the discovered log into the user buffer
-				 * if there's enough space.
-				 */
-				memcpy(elog->log, log.log, log.log_position);
-			}
-
-			unmap_physmem(log.log, MAP_NOCACHE);
-		} else {
-			elog->log = log.log;
-			elog->log_size = log.log_size;
-		}
-
-		elog->log_position = log.log_position;
-		elog->found = log.found;
-	}
-
-	/*
-	 * Initialize the log buffer if no log was discovered and the buffer is
-	 * valid. User's can pass in their own buffer as a fallback if no
-	 * memory region is found.
-	 */
-	if (!elog->found && elog->log_size)
-		rc = tcg2_log_init(dev, elog);
-
-	return rc;
-}
-
-int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog,
-			  bool ignore_existing_log)
-{
-	int rc;
-
-	rc = tcg2_platform_get_tpm2(dev);
-	if (rc)
-		return rc;
-
-	rc = tpm_auto_start(*dev);
-	if (rc)
-		return rc;
-
-	rc = tcg2_log_prepare_buffer(*dev, elog, ignore_existing_log);
-	if (rc) {
-		tcg2_measurement_term(*dev, elog, true);
-		return rc;
-	}
-
-	rc = tcg2_measure_event(*dev, elog, 0, EV_S_CRTM_VERSION,
-				strlen(version_string) + 1,
-				(u8 *)version_string);
-	if (rc) {
-		tcg2_measurement_term(*dev, elog, true);
-		return rc;
-	}
-
-	return 0;
-}
-
-void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog,
-			   bool error)
-{
-	u32 event = error ? 0x1 : 0xffffffff;
-	int i;
-
-	for (i = 0; i < 8; ++i)
-		tcg2_measure_event(dev, elog, i, EV_SEPARATOR, sizeof(event),
-				   (const u8 *)&event);
-
-	if (elog->log)
-		unmap_physmem(elog->log, MAP_NOCACHE);
-}
-
-__weak int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size)
-{
-	const __be32 *addr_prop;
-	const __be32 *size_prop;
-	int asize;
-	int ssize;
-
-	*addr = NULL;
-	*size = 0;
-
-	addr_prop = dev_read_prop(dev, "tpm_event_log_addr", &asize);
-	if (!addr_prop)
-		addr_prop = dev_read_prop(dev, "linux,sml-base", &asize);
-
-	size_prop = dev_read_prop(dev, "tpm_event_log_size", &ssize);
-	if (!size_prop)
-		size_prop = dev_read_prop(dev, "linux,sml-size", &ssize);
-
-	if (addr_prop && size_prop) {
-		u64 a = of_read_number(addr_prop, asize / sizeof(__be32));
-		u64 s = of_read_number(size_prop, ssize / sizeof(__be32));
-
-		*addr = map_physmem(a, s, MAP_NOCACHE);
-		*size = (u32)s;
-	} else {
-		struct ofnode_phandle_args args;
-		phys_addr_t a;
-		fdt_size_t s;
-
-		if (dev_read_phandle_with_args(dev, "memory-region", NULL, 0,
-					       0, &args))
-			return -ENODEV;
-
-		a = ofnode_get_addr_size(args.node, "reg", &s);
-		if (a == FDT_ADDR_T_NONE)
-			return -ENOMEM;
-
-		*addr = map_physmem(a, s, MAP_NOCACHE);
-		*size = (u32)s;
-	}
-
-	return 0;
-}
-
-__weak int tcg2_platform_get_tpm2(struct udevice **dev)
-{
-	for_each_tpm_device(*dev) {
-		if (tpm_get_version(*dev) == TPM_V2)
-			return 0;
-	}
-
-	return -ENODEV;
-}
-
-__weak void tcg2_platform_startup_error(struct udevice *dev, int rc) {}
-
 u32 tpm2_startup(struct udevice *dev, enum tpm2_startup_types mode)
 {
 	const u8 command_v2[12] = {
@@ -1141,7 +479,7 @@  int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr,
 	}
 
 	for (i = 0; i < pcrs.count; i++) {
-		u32 hash_mask = tpm2_algorithm_to_mask(pcrs.selection[i].hash);
+		u32 hash_mask = tcg2_algorithm_to_mask(pcrs.selection[i].hash);
 
 		if (hash_mask) {
 			*supported_pcr |= hash_mask;
@@ -1567,14 +905,3 @@  const char *tpm2_algorithm_name(enum tpm2_algorithms algo)
 	return "";
 }
 
-u32 tpm2_algorithm_to_mask(enum tpm2_algorithms algo)
-{
-	size_t i;
-
-	for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
-		if (hash_algo_list[i].hash_alg == algo)
-			return hash_algo_list[i].hash_mask;
-	}
-
-	return 0;
-}
diff --git a/lib/tpm_tcg2.c b/lib/tpm_tcg2.c
new file mode 100644
index 000000000000..91b9612fd3f6
--- /dev/null
+++ b/lib/tpm_tcg2.c
@@ -0,0 +1,695 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2023 Linaro Limited
+ */
+
+#include <dm.h>
+#include <dm/of_access.h>
+#include <tpm_api.h>
+#include <tpm-common.h>
+#include <tpm-v2.h>
+#include <tpm_tcg2.h>
+#include <u-boot/sha1.h>
+#include <u-boot/sha256.h>
+#include <u-boot/sha512.h>
+#include <version_string.h>
+#include <asm/io.h>
+#include <linux/bitops.h>
+#include <linux/unaligned/be_byteshift.h>
+#include <linux/unaligned/generic.h>
+#include <linux/unaligned/le_byteshift.h>
+#include "tpm-utils.h"
+
+int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks)
+{
+	u32 supported = 0;
+	u32 pcr_banks = 0;
+	u32 active = 0;
+	int rc;
+
+	rc = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks);
+	if (rc)
+		return rc;
+
+	*active_pcr_banks = active;
+
+	return 0;
+}
+
+u32 tcg2_event_get_size(struct tpml_digest_values *digest_list)
+{
+	u32 len;
+	size_t i;
+
+	len = offsetof(struct tcg_pcr_event2, digests);
+	len += offsetof(struct tpml_digest_values, digests);
+	for (i = 0; i < digest_list->count; ++i) {
+		u16 l = tpm2_algorithm_to_len(digest_list->digests[i].hash_alg);
+
+		if (!l)
+			continue;
+
+		len += l + offsetof(struct tpmt_ha, digest);
+	}
+	len += sizeof(u32);
+
+	return len;
+}
+
+int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
+		       struct tpml_digest_values *digest_list)
+{
+	u8 final[sizeof(union tpmu_ha)];
+	sha256_context ctx_256;
+	sha512_context ctx_512;
+	sha1_context ctx;
+	u32 active;
+	size_t i;
+	u32 len;
+	int rc;
+
+	rc = tcg2_get_active_pcr_banks(dev, &active);
+	if (rc)
+		return rc;
+
+	digest_list->count = 0;
+	for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
+		if (!(active & hash_algo_list[i].hash_mask))
+			continue;
+
+		switch (hash_algo_list[i].hash_alg) {
+		case TPM2_ALG_SHA1:
+			sha1_starts(&ctx);
+			sha1_update(&ctx, input, length);
+			sha1_finish(&ctx, final);
+			len = TPM2_SHA1_DIGEST_SIZE;
+			break;
+		case TPM2_ALG_SHA256:
+			sha256_starts(&ctx_256);
+			sha256_update(&ctx_256, input, length);
+			sha256_finish(&ctx_256, final);
+			len = TPM2_SHA256_DIGEST_SIZE;
+			break;
+		case TPM2_ALG_SHA384:
+			sha384_starts(&ctx_512);
+			sha384_update(&ctx_512, input, length);
+			sha384_finish(&ctx_512, final);
+			len = TPM2_SHA384_DIGEST_SIZE;
+			break;
+		case TPM2_ALG_SHA512:
+			sha512_starts(&ctx_512);
+			sha512_update(&ctx_512, input, length);
+			sha512_finish(&ctx_512, final);
+			len = TPM2_SHA512_DIGEST_SIZE;
+			break;
+		default:
+			printf("%s: unsupported algorithm %x\n", __func__,
+			       hash_algo_list[i].hash_alg);
+			continue;
+		}
+
+		digest_list->digests[digest_list->count].hash_alg =
+			hash_algo_list[i].hash_alg;
+		memcpy(&digest_list->digests[digest_list->count].digest, final,
+		       len);
+		digest_list->count++;
+	}
+
+	return 0;
+}
+
+void tcg2_log_append(u32 pcr_index, u32 event_type,
+		     struct tpml_digest_values *digest_list, u32 size,
+		     const u8 *event, u8 *log)
+{
+	size_t len;
+	size_t pos;
+	u32 i;
+
+	pos = offsetof(struct tcg_pcr_event2, pcr_index);
+	put_unaligned_le32(pcr_index, log);
+	pos = offsetof(struct tcg_pcr_event2, event_type);
+	put_unaligned_le32(event_type, log + pos);
+	pos = offsetof(struct tcg_pcr_event2, digests) +
+		offsetof(struct tpml_digest_values, count);
+	put_unaligned_le32(digest_list->count, log + pos);
+
+	pos = offsetof(struct tcg_pcr_event2, digests) +
+		offsetof(struct tpml_digest_values, digests);
+	for (i = 0; i < digest_list->count; ++i) {
+		u16 hash_alg = digest_list->digests[i].hash_alg;
+
+		len = tpm2_algorithm_to_len(hash_alg);
+		if (!len)
+			continue;
+
+		pos += offsetof(struct tpmt_ha, hash_alg);
+		put_unaligned_le16(hash_alg, log + pos);
+		pos += offsetof(struct tpmt_ha, digest);
+		memcpy(log + pos, (u8 *)&digest_list->digests[i].digest, len);
+		pos += len;
+	}
+
+	put_unaligned_le32(size, log + pos);
+	pos += sizeof(u32);
+	memcpy(log + pos, event, size);
+}
+
+static int tcg2_log_append_check(struct tcg2_event_log *elog, u32 pcr_index,
+				 u32 event_type,
+				 struct tpml_digest_values *digest_list,
+				 u32 size, const u8 *event)
+{
+	u32 event_size;
+	u8 *log;
+
+	event_size = size + tcg2_event_get_size(digest_list);
+	if (elog->log_position + event_size > elog->log_size) {
+		printf("%s: log too large: %u + %u > %u\n", __func__,
+		       elog->log_position, event_size, elog->log_size);
+		return -ENOBUFS;
+	}
+
+	log = elog->log + elog->log_position;
+	elog->log_position += event_size;
+
+	tcg2_log_append(pcr_index, event_type, digest_list, size, event, log);
+
+	return 0;
+}
+
+static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog)
+{
+	struct tcg_efi_spec_id_event *ev;
+	struct tcg_pcr_event *log;
+	u32 event_size;
+	u32 count = 0;
+	u32 log_size;
+	u32 active;
+	size_t i;
+	u16 len;
+	int rc;
+
+	rc = tcg2_get_active_pcr_banks(dev, &active);
+	if (rc)
+		return rc;
+
+	event_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes);
+	for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
+		if (!(active & hash_algo_list[i].hash_mask))
+			continue;
+
+		switch (hash_algo_list[i].hash_alg) {
+		case TPM2_ALG_SHA1:
+		case TPM2_ALG_SHA256:
+		case TPM2_ALG_SHA384:
+		case TPM2_ALG_SHA512:
+			count++;
+			break;
+		default:
+			continue;
+		}
+	}
+
+	event_size += 1 +
+		(sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count);
+	log_size = offsetof(struct tcg_pcr_event, event) + event_size;
+
+	if (log_size > elog->log_size) {
+		printf("%s: log too large: %u > %u\n", __func__, log_size,
+		       elog->log_size);
+		return -ENOBUFS;
+	}
+
+	log = (struct tcg_pcr_event *)elog->log;
+	put_unaligned_le32(0, &log->pcr_index);
+	put_unaligned_le32(EV_NO_ACTION, &log->event_type);
+	memset(&log->digest, 0, sizeof(log->digest));
+	put_unaligned_le32(event_size, &log->event_size);
+
+	ev = (struct tcg_efi_spec_id_event *)log->event;
+	strlcpy((char *)ev->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
+		sizeof(ev->signature));
+	put_unaligned_le32(0, &ev->platform_class);
+	ev->spec_version_minor = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2;
+	ev->spec_version_major = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2;
+	ev->spec_errata = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2;
+	ev->uintn_size = sizeof(size_t) / sizeof(u32);
+	put_unaligned_le32(count, &ev->number_of_algorithms);
+
+	count = 0;
+	for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
+		if (!(active & hash_algo_list[i].hash_mask))
+			continue;
+
+		len = hash_algo_list[i].hash_len;
+		if (!len)
+			continue;
+
+		put_unaligned_le16(hash_algo_list[i].hash_alg,
+				   &ev->digest_sizes[count].algorithm_id);
+		put_unaligned_le16(len, &ev->digest_sizes[count].digest_size);
+		count++;
+	}
+
+	*((u8 *)ev + (event_size - 1)) = 0;
+	elog->log_position = log_size;
+
+	return 0;
+}
+
+static int tcg2_replay_eventlog(struct tcg2_event_log *elog,
+				struct udevice *dev,
+				struct tpml_digest_values *digest_list,
+				u32 log_position)
+{
+	const u32 offset = offsetof(struct tcg_pcr_event2, digests) +
+		offsetof(struct tpml_digest_values, digests);
+	u32 event_size;
+	u32 count;
+	u16 algo;
+	u32 pcr;
+	u32 pos;
+	u16 len;
+	u8 *log;
+	int rc;
+	u32 i;
+
+	while (log_position + offset < elog->log_size) {
+		log = elog->log + log_position;
+
+		pos = offsetof(struct tcg_pcr_event2, pcr_index);
+		pcr = get_unaligned_le32(log + pos);
+		pos = offsetof(struct tcg_pcr_event2, event_type);
+		if (!get_unaligned_le32(log + pos))
+			return 0;
+
+		pos = offsetof(struct tcg_pcr_event2, digests) +
+			offsetof(struct tpml_digest_values, count);
+		count = get_unaligned_le32(log + pos);
+		if (count > ARRAY_SIZE(hash_algo_list) ||
+		    (digest_list->count && digest_list->count != count))
+			return 0;
+
+		pos = offsetof(struct tcg_pcr_event2, digests) +
+			offsetof(struct tpml_digest_values, digests);
+		for (i = 0; i < count; ++i) {
+			pos += offsetof(struct tpmt_ha, hash_alg);
+			if (log_position + pos + sizeof(u16) >= elog->log_size)
+				return 0;
+
+			algo = get_unaligned_le16(log + pos);
+			pos += offsetof(struct tpmt_ha, digest);
+			switch (algo) {
+			case TPM2_ALG_SHA1:
+			case TPM2_ALG_SHA256:
+			case TPM2_ALG_SHA384:
+			case TPM2_ALG_SHA512:
+				len = tpm2_algorithm_to_len(algo);
+				break;
+			default:
+				return 0;
+			}
+
+			if (digest_list->count) {
+				if (algo != digest_list->digests[i].hash_alg ||
+				    log_position + pos + len >= elog->log_size)
+					return 0;
+
+				memcpy(digest_list->digests[i].digest.sha512,
+				       log + pos, len);
+			}
+
+			pos += len;
+		}
+
+		if (log_position + pos + sizeof(u32) >= elog->log_size)
+			return 0;
+
+		event_size = get_unaligned_le32(log + pos);
+		pos += event_size + sizeof(u32);
+		if (log_position + pos > elog->log_size)
+			return 0;
+
+		if (digest_list->count) {
+			rc = tcg2_pcr_extend(dev, pcr, digest_list);
+			if (rc)
+				return rc;
+		}
+
+		log_position += pos;
+	}
+
+	elog->log_position = log_position;
+	elog->found = true;
+	return 0;
+}
+
+static int tcg2_log_parse(struct udevice *dev, struct tcg2_event_log *elog)
+{
+	struct tpml_digest_values digest_list;
+	struct tcg_efi_spec_id_event *event;
+	struct tcg_pcr_event *log;
+	u32 log_active;
+	u32 calc_size;
+	u32 active;
+	u32 count;
+	u32 evsz;
+	u32 mask;
+	u16 algo;
+	u16 len;
+	int rc;
+	u32 i;
+	u16 j;
+
+	if (elog->log_size <= offsetof(struct tcg_pcr_event, event))
+		return 0;
+
+	log = (struct tcg_pcr_event *)elog->log;
+	if (get_unaligned_le32(&log->pcr_index) != 0 ||
+	    get_unaligned_le32(&log->event_type) != EV_NO_ACTION)
+		return 0;
+
+	for (i = 0; i < sizeof(log->digest); i++) {
+		if (log->digest[i])
+			return 0;
+	}
+
+	evsz = get_unaligned_le32(&log->event_size);
+	if (evsz < offsetof(struct tcg_efi_spec_id_event, digest_sizes) ||
+	    evsz + offsetof(struct tcg_pcr_event, event) > elog->log_size)
+		return 0;
+
+	event = (struct tcg_efi_spec_id_event *)log->event;
+	if (memcmp(event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03,
+		   sizeof(TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03)))
+		return 0;
+
+	if (event->spec_version_minor != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 ||
+	    event->spec_version_major != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2)
+		return 0;
+
+	count = get_unaligned_le32(&event->number_of_algorithms);
+	if (count > ARRAY_SIZE(hash_algo_list))
+		return 0;
+
+	calc_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
+		(sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count) +
+		1;
+	if (evsz != calc_size)
+		return 0;
+
+	rc = tcg2_get_active_pcr_banks(dev, &active);
+	if (rc)
+		return rc;
+
+	digest_list.count = 0;
+	log_active = 0;
+
+	for (i = 0; i < count; ++i) {
+		algo = get_unaligned_le16(&event->digest_sizes[i].algorithm_id);
+		mask = tcg2_algorithm_to_mask(algo);
+
+		if (!(active & mask))
+			return 0;
+
+		switch (algo) {
+		case TPM2_ALG_SHA1:
+		case TPM2_ALG_SHA256:
+		case TPM2_ALG_SHA384:
+		case TPM2_ALG_SHA512:
+			len = get_unaligned_le16(&event->digest_sizes[i].digest_size);
+			if (tpm2_algorithm_to_len(algo) != len)
+				return 0;
+			digest_list.digests[digest_list.count++].hash_alg = algo;
+			break;
+		default:
+			return 0;
+		}
+
+		log_active |= mask;
+	}
+
+	/* Ensure the previous firmware extended all the PCRs. */
+	if (log_active != active)
+		return 0;
+
+	/* Read PCR0 to check if previous firmware extended the PCRs or not. */
+	rc = tcg2_pcr_read(dev, 0, &digest_list);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < digest_list.count; ++i) {
+		len = tpm2_algorithm_to_len(digest_list.digests[i].hash_alg);
+		for (j = 0; j < len; ++j) {
+			if (digest_list.digests[i].digest.sha512[j])
+				break;
+		}
+
+		/* PCR is non-zero; it has been extended, so skip extending. */
+		if (j != len) {
+			digest_list.count = 0;
+			break;
+		}
+	}
+
+	return tcg2_replay_eventlog(elog, dev, &digest_list,
+				    offsetof(struct tcg_pcr_event, event) +
+				    evsz);
+}
+
+int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index,
+		    struct tpml_digest_values *digest_list)
+{
+	u32 rc;
+	u32 i;
+
+	for (i = 0; i < digest_list->count; i++) {
+		u32 alg = digest_list->digests[i].hash_alg;
+
+		rc = tpm2_pcr_extend(dev, pcr_index, alg,
+				     (u8 *)&digest_list->digests[i].digest,
+				     tpm2_algorithm_to_len(alg));
+		if (rc) {
+			printf("%s: error pcr:%u alg:%08x\n", __func__,
+			       pcr_index, alg);
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+int tcg2_pcr_read(struct udevice *dev, u32 pcr_index,
+		  struct tpml_digest_values *digest_list)
+{
+	struct tpm_chip_priv *priv;
+	u32 rc;
+	u32 i;
+
+	priv = dev_get_uclass_priv(dev);
+	if (!priv)
+		return -ENODEV;
+
+	for (i = 0; i < digest_list->count; i++) {
+		u32 alg = digest_list->digests[i].hash_alg;
+		u8 *digest = (u8 *)&digest_list->digests[i].digest;
+
+		rc = tpm2_pcr_read(dev, pcr_index, priv->pcr_select_min, alg,
+				   digest, tpm2_algorithm_to_len(alg), NULL);
+		if (rc) {
+			printf("%s: error pcr:%u alg:%08x\n", __func__,
+			       pcr_index, alg);
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog,
+		      u32 pcr_index, u32 size, const u8 *data, u32 event_type,
+		      u32 event_size, const u8 *event)
+{
+	struct tpml_digest_values digest_list;
+	int rc;
+
+	if (data)
+		rc = tcg2_create_digest(dev, data, size, &digest_list);
+	else
+		rc = tcg2_create_digest(dev, event, event_size, &digest_list);
+	if (rc)
+		return rc;
+
+	rc = tcg2_pcr_extend(dev, pcr_index, &digest_list);
+	if (rc)
+		return rc;
+
+	return tcg2_log_append_check(elog, pcr_index, event_type, &digest_list,
+				     event_size, event);
+}
+
+int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog,
+			    bool ignore_existing_log)
+{
+	struct tcg2_event_log log;
+	int rc;
+
+	elog->log_position = 0;
+	elog->found = false;
+
+	rc = tcg2_platform_get_log(dev, (void **)&log.log, &log.log_size);
+	if (!rc) {
+		log.log_position = 0;
+		log.found = false;
+
+		if (!ignore_existing_log) {
+			rc = tcg2_log_parse(dev, &log);
+			if (rc)
+				return rc;
+		}
+
+		if (elog->log_size) {
+			if (log.found) {
+				if (elog->log_size < log.log_position)
+					return -ENOBUFS;
+
+				/*
+				 * Copy the discovered log into the user buffer
+				 * if there's enough space.
+				 */
+				memcpy(elog->log, log.log, log.log_position);
+			}
+
+			unmap_physmem(log.log, MAP_NOCACHE);
+		} else {
+			elog->log = log.log;
+			elog->log_size = log.log_size;
+		}
+
+		elog->log_position = log.log_position;
+		elog->found = log.found;
+	}
+
+	/*
+	 * Initialize the log buffer if no log was discovered and the buffer is
+	 * valid. User's can pass in their own buffer as a fallback if no
+	 * memory region is found.
+	 */
+	if (!elog->found && elog->log_size)
+		rc = tcg2_log_init(dev, elog);
+
+	return rc;
+}
+
+int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog,
+			  bool ignore_existing_log)
+{
+	int rc;
+
+	rc = tcg2_platform_get_tpm2(dev);
+	if (rc)
+		return rc;
+
+	rc = tpm_auto_start(*dev);
+	if (rc)
+		return rc;
+
+	rc = tcg2_log_prepare_buffer(*dev, elog, ignore_existing_log);
+	if (rc) {
+		tcg2_measurement_term(*dev, elog, true);
+		return rc;
+	}
+
+	rc = tcg2_measure_event(*dev, elog, 0, EV_S_CRTM_VERSION,
+				strlen(version_string) + 1,
+				(u8 *)version_string);
+	if (rc) {
+		tcg2_measurement_term(*dev, elog, true);
+		return rc;
+	}
+
+	return 0;
+}
+
+void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog,
+			   bool error)
+{
+	u32 event = error ? 0x1 : 0xffffffff;
+	int i;
+
+	for (i = 0; i < 8; ++i)
+		tcg2_measure_event(dev, elog, i, EV_SEPARATOR, sizeof(event),
+				   (const u8 *)&event);
+
+	if (elog->log)
+		unmap_physmem(elog->log, MAP_NOCACHE);
+}
+
+__weak int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size)
+{
+	const __be32 *addr_prop;
+	const __be32 *size_prop;
+	int asize;
+	int ssize;
+
+	*addr = NULL;
+	*size = 0;
+
+	addr_prop = dev_read_prop(dev, "tpm_event_log_addr", &asize);
+	if (!addr_prop)
+		addr_prop = dev_read_prop(dev, "linux,sml-base", &asize);
+
+	size_prop = dev_read_prop(dev, "tpm_event_log_size", &ssize);
+	if (!size_prop)
+		size_prop = dev_read_prop(dev, "linux,sml-size", &ssize);
+
+	if (addr_prop && size_prop) {
+		u64 a = of_read_number(addr_prop, asize / sizeof(__be32));
+		u64 s = of_read_number(size_prop, ssize / sizeof(__be32));
+
+		*addr = map_physmem(a, s, MAP_NOCACHE);
+		*size = (u32)s;
+	} else {
+		struct ofnode_phandle_args args;
+		phys_addr_t a;
+		fdt_size_t s;
+
+		if (dev_read_phandle_with_args(dev, "memory-region", NULL, 0,
+					       0, &args))
+			return -ENODEV;
+
+		a = ofnode_get_addr_size(args.node, "reg", &s);
+		if (a == FDT_ADDR_T_NONE)
+			return -ENOMEM;
+
+		*addr = map_physmem(a, s, MAP_NOCACHE);
+		*size = (u32)s;
+	}
+
+	return 0;
+}
+
+__weak int tcg2_platform_get_tpm2(struct udevice **dev)
+{
+	for_each_tpm_device(*dev) {
+		if (tpm_get_version(*dev) == TPM_V2)
+			return 0;
+	}
+
+	return -ENODEV;
+}
+
+u32 tcg2_algorithm_to_mask(enum tpm2_algorithms algo)
+{
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
+		if (hash_algo_list[i].hash_alg == algo)
+			return hash_algo_list[i].hash_mask;
+	}
+
+	return 0;
+}
+
+__weak void tcg2_platform_startup_error(struct udevice *dev, int rc) {}