[PATCH v4 0/5] add measurement support

[PATCH v4 0/5] add measurement support

[Masahisa Kojima]

This patch series add the support of measurement
descibed in TCG PC Client PFP spec(Version 1.05 Revision 23).

Eventlog generated with this patch series are tested on
the aarch64 based machine(Socionext Developerbox) and fTPM
running on OP-TEE.
The eventlog result is almost same result as the one
generated by edk2 running on the Devloperbox and Secure96.

This patch series does not cover all measurement requirements
described in TCG spec, the remaining items will be supported
in the future.
Major missing items in TCG PC Client PFP spec:
 1) If the secure boot variables are updated after they are
   initially measured in PCR[7] and before ExitBootServices()
   has completed, the platform MAY be restarted OR the variables
   MUST be remeasured into PCR[7].
 2) SMBIOS structure measurement
 3) "DeployedMode" and "AuditMode" measurement
 4) EV_EFI_GPT_EVENT event
 5) Measurement of U-boot itself. I assume U-boot measurement will be done
    by the former firmware such as trusted firmware.

Masahisa Kojima (5):
  efi_loader: add secure boot variable measurement
  efi_loader: add boot variable measurement
  efi_loader: add ExitBootServices() measurement
  efi_loader: refactor efi_append_scrtm_version()
  efi_loader: add comment for efi_tcg2.h

 include/efi_loader.h          |   5 +
 include/efi_tcg2.h            |  77 +++++++-
 include/tpm-v2.h              |  18 +-
 lib/efi_loader/efi_boottime.c |  25 +++
 lib/efi_loader/efi_tcg2.c     | 356 +++++++++++++++++++++++++++++++++-
 5 files changed, 471 insertions(+), 10 deletions(-)

-- 
2.17.1

[PATCH v4 1/5] efi_loader: add secure boot variable measurement

[Masahisa Kojima]

TCG PC Client PFP spec requires to measure the secure
boot policy before validating the UEFI image.
This commit adds the secure boot variable measurement
of "SecureBoot", "PK", "KEK", "db", "dbx", "dbt", and "dbr".

Note that this implementation assumes that secure boot
variables are pre-configured and not be set/updated in runtime.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
---
Changes in v4:
- remove unnecessary EFIAPI specifier
- modify wrong guid for dbt and dbr

Changes in v3:
- add "dbt" and "dbr" measurement
- accept empty variable measurement for "SecureBoot", "PK",
  "KEK", "db" and "dbx" as TCG2 spec requires
- fix comment format

Changes in v2:
- missing null check for getting variable data
- some minor fix for readability

 include/efi_tcg2.h        |  20 +++++
 lib/efi_loader/efi_tcg2.c | 165 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 185 insertions(+)

diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h
index bcfb98168a..497ba3ce94 100644
--- a/include/efi_tcg2.h
+++ b/include/efi_tcg2.h
@@ -142,6 +142,26 @@ struct efi_tcg2_final_events_table {
 	struct tcg_pcr_event2 event[];
 };
 
+/**
+ * struct tdUEFI_VARIABLE_DATA - event log structure of UEFI variable
+ * @variable_name:		The vendorGUID parameter in the
+ *				GetVariable() API.
+ * @unicode_name_length:	The length in CHAR16 of the Unicode name of
+ *				the variable.
+ * @variable_data_length:	The size of the variable data.
+ * @unicode_name:		The CHAR16 unicode name of the variable
+ *				without NULL-terminator.
+ * @variable_data:		The data parameter of the efi variable
+ *				in the GetVariable() API.
+ */
+struct efi_tcg2_uefi_variable_data {
+	efi_guid_t variable_name;
+	u64 unicode_name_length;
+	u64 variable_data_length;
+	u16 unicode_name[1];
+	u8 variable_data[1];
+};
+
 struct efi_tcg2_protocol {
 	efi_status_t (EFIAPI * get_capability)(struct efi_tcg2_protocol *this,
 					       struct efi_tcg2_boot_service_capability *capability);
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 1319a8b378..db3d6d7586 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -78,6 +78,19 @@ static const struct digest_info hash_algo_list[] = {
 	},
 };
 
+struct variable_info {
+	u16		*name;
+	const efi_guid_t	*guid;
+};
+
+static struct variable_info secure_variables[] = {
+	{L"SecureBoot", &efi_global_variable_guid},
+	{L"PK", &efi_global_variable_guid},
+	{L"KEK", &efi_global_variable_guid},
+	{L"db", &efi_guid_image_security_database},
+	{L"dbx", &efi_guid_image_security_database},
+};
+
 #define MAX_HASH_COUNT ARRAY_SIZE(hash_algo_list)
 
 /**
@@ -1264,6 +1277,39 @@ free_pool:
 	return ret;
 }
 
+/**
+ * tcg2_measure_event() - common function to add event log and extend PCR
+ *
+ * @dev:		TPM device
+ * @pcr_index:		PCR index
+ * @event_type:		type of event added
+ * @size:		event size
+ * @event:		event data
+ *
+ * Return:	status code
+ */
+static efi_status_t
+tcg2_measure_event(struct udevice *dev, u32 pcr_index, u32 event_type,
+		   u32 size, u8 event[])
+{
+	struct tpml_digest_values digest_list;
+	efi_status_t ret;
+
+	ret = tcg2_create_digest(event, size, &digest_list);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list,
+				    size, event);
+
+out:
+	return ret;
+}
+
 /**
  * efi_append_scrtm_version - Append an S-CRTM EV_S_CRTM_VERSION event on the
  *			      eventlog and extend the PCRs
@@ -1294,6 +1340,118 @@ out:
 	return ret;
 }
 
+/**
+ * tcg2_measure_variable() - add variable event log and extend PCR
+ *
+ * @dev:		TPM device
+ * @pcr_index:		PCR index
+ * @event_type:		type of event added
+ * @var_name:		variable name
+ * @guid:		guid
+ * @data_size:		variable data size
+ * @data:		variable data
+ *
+ * Return:	status code
+ */
+static efi_status_t tcg2_measure_variable(struct udevice *dev, u32 pcr_index,
+					  u32 event_type, u16 *var_name,
+					  const efi_guid_t *guid,
+					  efi_uintn_t data_size, u8 *data)
+{
+	u32 event_size;
+	efi_status_t ret;
+	struct efi_tcg2_uefi_variable_data *event;
+
+	event_size = sizeof(event->variable_name) +
+		     sizeof(event->unicode_name_length) +
+		     sizeof(event->variable_data_length) +
+		     (u16_strlen(var_name) * sizeof(u16)) + data_size;
+	event = malloc(event_size);
+	if (!event)
+		return EFI_OUT_OF_RESOURCES;
+
+	guidcpy(&event->variable_name, guid);
+	event->unicode_name_length = u16_strlen(var_name);
+	event->variable_data_length = data_size;
+	memcpy(event->unicode_name, var_name,
+	       (event->unicode_name_length * sizeof(u16)));
+	if (data) {
+		memcpy((u16 *)event->unicode_name + event->unicode_name_length,
+		       data, data_size);
+	}
+	ret = tcg2_measure_event(dev, pcr_index, event_type, event_size,
+				 (u8 *)event);
+	free(event);
+	return ret;
+}
+
+/**
+ * tcg2_measure_secure_boot_variable() - measure secure boot variables
+ *
+ * @dev:	TPM device
+ *
+ * Return:	status code
+ */
+static efi_status_t tcg2_measure_secure_boot_variable(struct udevice *dev)
+{
+	u8 *data;
+	efi_uintn_t data_size;
+	u32 count, i;
+	efi_status_t ret;
+
+	count = ARRAY_SIZE(secure_variables);
+	for (i = 0; i < count; i++) {
+		/*
+		 * According to the TCG2 PC Client PFP spec, "SecureBoot",
+		 * "PK", "KEK", "db" and "dbx" variables must be measured
+		 * even if they are empty.
+		 */
+		data = efi_get_var(secure_variables[i].name,
+				   secure_variables[i].guid,
+				   &data_size);
+
+		ret = tcg2_measure_variable(dev, 7,
+					    EV_EFI_VARIABLE_DRIVER_CONFIG,
+					    secure_variables[i].name,
+					    secure_variables[i].guid,
+					    data_size, data);
+		free(data);
+		if (ret != EFI_SUCCESS)
+			goto error;
+	}
+
+	/*
+	 * TCG2 PC Client PFP spec says "dbt" and "dbr" are
+	 * measured if present and not empty.
+	 */
+	data = efi_get_var(L"dbt",
+			   &efi_guid_image_security_database,
+			   &data_size);
+	if (data) {
+		ret = tcg2_measure_variable(dev, 7,
+					    EV_EFI_VARIABLE_DRIVER_CONFIG,
+					    L"dbt",
+					    &efi_guid_image_security_database,
+					    data_size, data);
+		free(data);
+	}
+
+	data = efi_get_var(L"dbr",
+			   &efi_guid_image_security_database,
+			   &data_size);
+	if (data) {
+		ret = tcg2_measure_variable(dev, 7,
+					    EV_EFI_VARIABLE_DRIVER_CONFIG,
+					    L"dbr",
+					    &efi_guid_image_security_database,
+					    data_size, data);
+		free(data);
+	}
+
+error:
+	return ret;
+}
+
 /**
  * efi_tcg2_register() - register EFI_TCG2_PROTOCOL
  *
@@ -1328,6 +1486,13 @@ efi_status_t efi_tcg2_register(void)
 		tcg2_uninit();
 		goto fail;
 	}
+
+	ret = tcg2_measure_secure_boot_variable(dev);
+	if (ret != EFI_SUCCESS) {
+		tcg2_uninit();
+		goto fail;
+	}
+
 	return ret;
 
 fail:
-- 
2.17.1

[PATCH v4 2/5] efi_loader: add boot variable measurement

[Masahisa Kojima]

TCG PC Client PFP spec requires to measure "Boot####"
and "BootOrder" variables, EV_SEPARATOR event prior
to the Ready to Boot invocation.
Since u-boot does not implement Ready to Boot event,
these measurements are performed when efi_start_image() is called.

TCG spec also requires to measure "Calling EFI Application from
Boot Option" for each boot attempt, and "Returning from EFI
Application from Boot Option" if a boot device returns control
back to the Boot Manager.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
---
Changes in v4:
- remove unnecessary EFIAPI specifier

Changes in v3:
- modify log output

Changes in v2:
- use efi_create_indexed_name() for "Boot####" variable

 include/efi_loader.h          |   4 ++
 include/tpm-v2.h              |  18 ++++-
 lib/efi_loader/efi_boottime.c |  20 ++++++
 lib/efi_loader/efi_tcg2.c     | 121 ++++++++++++++++++++++++++++++++++
 4 files changed, 162 insertions(+), 1 deletion(-)

diff --git a/include/efi_loader.h b/include/efi_loader.h
index a120d94431..6f61e9faac 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -499,6 +499,10 @@ efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size);
 efi_status_t efi_init_variables(void);
 /* Notify ExitBootServices() is called */
 void efi_variables_boot_exit_notify(void);
+/* Measure efi application invocation */
+efi_status_t efi_tcg2_measure_efi_app_invocation(void);
+/* Measure efi application exit */
+efi_status_t efi_tcg2_measure_efi_app_exit(void);
 /* Called by bootefi to initialize root node */
 efi_status_t efi_root_node_register(void);
 /* Called by bootefi to initialize runtime */
diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 247b386967..325c73006e 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -73,7 +73,7 @@ struct udevice;
 /*
  * event types, cf.
  * "TCG PC Client Platform Firmware Profile Specification", Family "2.0"
- * rev 1.04, June 3, 2019
+ * Level 00 Version 1.05 Revision 23, May 7, 2021
  */
 #define EV_EFI_EVENT_BASE			((u32)0x80000000)
 #define EV_EFI_VARIABLE_DRIVER_CONFIG		((u32)0x80000001)
@@ -85,8 +85,24 @@ struct udevice;
 #define EV_EFI_ACTION				((u32)0x80000007)
 #define EV_EFI_PLATFORM_FIRMWARE_BLOB		((u32)0x80000008)
 #define EV_EFI_HANDOFF_TABLES			((u32)0x80000009)
+#define EV_EFI_PLATFORM_FIRMWARE_BLOB2		((u32)0x8000000A)
+#define EV_EFI_HANDOFF_TABLES2			((u32)0x8000000B)
+#define EV_EFI_VARIABLE_BOOT2			((u32)0x8000000C)
 #define EV_EFI_HCRTM_EVENT			((u32)0x80000010)
 #define EV_EFI_VARIABLE_AUTHORITY		((u32)0x800000E0)
+#define EV_EFI_SPDM_FIRMWARE_BLOB		((u32)0x800000E1)
+#define EV_EFI_SPDM_FIRMWARE_CONFIG		((u32)0x800000E2)
+
+#define EFI_CALLING_EFI_APPLICATION         \
+	"Calling EFI Application from Boot Option"
+#define EFI_RETURNING_FROM_EFI_APPLICATION  \
+	"Returning from EFI Application from Boot Option"
+#define EFI_EXIT_BOOT_SERVICES_INVOCATION   \
+	"Exit Boot Services Invocation"
+#define EFI_EXIT_BOOT_SERVICES_FAILED       \
+	"Exit Boot Services Returned with Failure"
+#define EFI_EXIT_BOOT_SERVICES_SUCCEEDED    \
+	"Exit Boot Services Returned with Success"
 
 /* TPMS_TAGGED_PROPERTY Structure */
 struct tpms_tagged_property {
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 0b98e91813..13ab139222 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -2994,6 +2994,16 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
 	image_obj->exit_status = &exit_status;
 	image_obj->exit_jmp = &exit_jmp;
 
+	if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
+		if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
+			ret = efi_tcg2_measure_efi_app_invocation();
+			if (ret != EFI_SUCCESS) {
+				log_warning("tcg2 measurement fails(0x%lx)\n",
+					    ret);
+			}
+		}
+	}
+
 	/* call the image! */
 	if (setjmp(&exit_jmp)) {
 		/*
@@ -3252,6 +3262,16 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
 	    exit_status != EFI_SUCCESS)
 		efi_delete_image(image_obj, loaded_image_protocol);
 
+	if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
+		if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
+			ret = efi_tcg2_measure_efi_app_exit();
+			if (ret != EFI_SUCCESS) {
+				log_warning("tcg2 measurement fails(0x%lx)\n",
+					    ret);
+			}
+		}
+	}
+
 	/* Make sure entry/exit counts for EFI world cross-overs match */
 	EFI_EXIT(exit_status);
 
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index db3d6d7586..ed71337780 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -35,6 +35,7 @@ struct event_log_buffer {
 };
 
 static struct event_log_buffer event_log;
+static bool tcg2_efi_app_invoked;
 /*
  * When requesting TPM2_CAP_TPM_PROPERTIES the value is on a standard offset.
  * Since the current tpm2_get_capability() response buffers starts at
@@ -1385,6 +1386,126 @@ static efi_status_t tcg2_measure_variable(struct udevice *dev, u32 pcr_index,
 	return ret;
 }
 
+/**
+ * tcg2_measure_boot_variable() - measure boot variables
+ *
+ * @dev:	TPM device
+ *
+ * Return:	status code
+ */
+static efi_status_t tcg2_measure_boot_variable(struct udevice *dev)
+{
+	u16 *boot_order;
+	u16 *boot_index;
+	u16 var_name[] = L"BootOrder";
+	u16 boot_name[] = L"Boot####";
+	u8 *bootvar;
+	efi_uintn_t var_data_size;
+	u32 count, i;
+	efi_status_t ret;
+
+	boot_order = efi_get_var(var_name, &efi_global_variable_guid,
+				 &var_data_size);
+	if (!boot_order) {
+		ret = EFI_NOT_FOUND;
+		goto error;
+	}
+
+	ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2, var_name,
+				    &efi_global_variable_guid, var_data_size,
+				    (u8 *)boot_order);
+	if (ret != EFI_SUCCESS)
+		goto error;
+
+	count = var_data_size / sizeof(*boot_order);
+	boot_index = boot_order;
+	for (i = 0; i < count; i++) {
+		efi_create_indexed_name(boot_name, sizeof(boot_name),
+					"Boot", *boot_index++);
+
+		bootvar = efi_get_var(boot_name, &efi_global_variable_guid,
+				      &var_data_size);
+
+		if (!bootvar) {
+			log_info("%ls not found\n", boot_name);
+			continue;
+		}
+
+		ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2,
+					    boot_name,
+					    &efi_global_variable_guid,
+					    var_data_size, bootvar);
+		free(bootvar);
+		if (ret != EFI_SUCCESS)
+			goto error;
+	}
+
+error:
+	free(boot_order);
+	return ret;
+}
+
+/**
+ * efi_tcg2_measure_efi_app_invocation() - measure efi app invocation
+ *
+ * Return:	status code
+ */
+efi_status_t efi_tcg2_measure_efi_app_invocation(void)
+{
+	efi_status_t ret;
+	u32 pcr_index;
+	struct udevice *dev;
+	u32 event = 0;
+
+	if (tcg2_efi_app_invoked)
+		return EFI_SUCCESS;
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		return ret;
+
+	ret = tcg2_measure_boot_variable(dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_measure_event(dev, 4, EV_EFI_ACTION,
+				 strlen(EFI_CALLING_EFI_APPLICATION),
+				 (u8 *)EFI_CALLING_EFI_APPLICATION);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	for (pcr_index = 0; pcr_index <= 7; pcr_index++) {
+		ret = tcg2_measure_event(dev, pcr_index, EV_SEPARATOR,
+					 sizeof(event), (u8 *)&event);
+		if (ret != EFI_SUCCESS)
+			goto out;
+	}
+
+	tcg2_efi_app_invoked = true;
+out:
+	return ret;
+}
+
+/**
+ * efi_tcg2_measure_efi_app_exit() - measure efi app exit
+ *
+ * Return:	status code
+ */
+efi_status_t efi_tcg2_measure_efi_app_exit(void)
+{
+	efi_status_t ret;
+	struct udevice *dev;
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		return ret;
+
+	ret = tcg2_measure_event(dev, 4, EV_EFI_ACTION,
+				 strlen(EFI_RETURNING_FROM_EFI_APPLICATION),
+				 (u8 *)EFI_RETURNING_FROM_EFI_APPLICATION);
+	return ret;
+}
+
 /**
  * tcg2_measure_secure_boot_variable() - measure secure boot variables
  *
-- 
2.17.1

[PATCH v4 3/5] efi_loader: add ExitBootServices() measurement

[Masahisa Kojima]

TCG PC Client PFP spec requires to measure
"Exit Boot Services Invocation" if ExitBootServices() is invoked.
Depending upon the return code from the ExitBootServices() call,
"Exit Boot Services Returned with Success" or "Exit Boot Services
Returned with Failure" is also measured.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
---
Changes in v4:
- remove unnecessary EFIAPI specifier

Changes in v2:
- use strlen instead of sizeof, event log for EV_EFI_ACTION string

  shall not include NUL terminator
 include/efi_loader.h          |  1 +
 lib/efi_loader/efi_boottime.c |  5 +++
 lib/efi_loader/efi_tcg2.c     | 70 +++++++++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+)

diff --git a/include/efi_loader.h b/include/efi_loader.h
index 6f61e9faac..32cb8d0f1e 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -499,6 +499,7 @@ efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size);
 efi_status_t efi_init_variables(void);
 /* Notify ExitBootServices() is called */
 void efi_variables_boot_exit_notify(void);
+efi_status_t efi_tcg2_notify_exit_boot_services_failed(void);
 /* Measure efi application invocation */
 efi_status_t efi_tcg2_measure_efi_app_invocation(void);
 /* Measure efi application exit */
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 13ab139222..b818cbb540 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -2182,6 +2182,11 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
 	efi_set_watchdog(0);
 	WATCHDOG_RESET();
 out:
+	if (ret != EFI_SUCCESS) {
+		if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL))
+			efi_tcg2_notify_exit_boot_services_failed();
+	}
+
 	return EFI_EXIT(ret);
 }
 
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index ed71337780..8557fce1da 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -1506,6 +1506,67 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void)
 	return ret;
 }
 
+/**
+ * efi_tcg2_notify_exit_boot_services() - ExitBootService callback
+ *
+ * @event:	callback event
+ * @context:	callback context
+ */
+static void
+efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
+{
+	efi_status_t ret;
+	struct udevice *dev;
+
+	EFI_ENTRY("%p, %p", event, context);
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
+				 strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
+				 (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
+				 strlen(EFI_EXIT_BOOT_SERVICES_SUCCEEDED),
+				 (u8 *)EFI_EXIT_BOOT_SERVICES_SUCCEEDED);
+
+out:
+	EFI_EXIT(ret);
+}
+
+/**
+ * efi_tcg2_notify_exit_boot_services_failed()
+ *  - notify ExitBootServices() is failed
+ *
+ * Return:	status code
+ */
+efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
+{
+	struct udevice *dev;
+	efi_status_t ret;
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
+				 strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
+				 (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
+				 strlen(EFI_EXIT_BOOT_SERVICES_FAILED),
+				 (u8 *)EFI_EXIT_BOOT_SERVICES_FAILED);
+
+out:
+	return ret;
+}
+
 /**
  * tcg2_measure_secure_boot_variable() - measure secure boot variables
  *
@@ -1584,6 +1645,7 @@ efi_status_t efi_tcg2_register(void)
 {
 	efi_status_t ret = EFI_SUCCESS;
 	struct udevice *dev;
+	struct efi_event *event;
 
 	ret = platform_get_tpm2_device(&dev);
 	if (ret != EFI_SUCCESS) {
@@ -1608,6 +1670,14 @@ efi_status_t efi_tcg2_register(void)
 		goto fail;
 	}
 
+	ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
+			       efi_tcg2_notify_exit_boot_services, NULL,
+			       NULL, &event);
+	if (ret != EFI_SUCCESS) {
+		tcg2_uninit();
+		goto fail;
+	}
+
 	ret = tcg2_measure_secure_boot_variable(dev);
 	if (ret != EFI_SUCCESS) {
 		tcg2_uninit();
-- 
2.17.1

Re: [PATCH v4 3/5] efi_loader: add ExitBootServices() measurement

[Heinrich Schuchardt]

On 8/13/21 9:12 AM, Masahisa Kojima wrote:
> TCG PC Client PFP spec requires to measure
> "Exit Boot Services Invocation" if ExitBootServices() is invoked.
> Depending upon the return code from the ExitBootServices() call,
> "Exit Boot Services Returned with Success" or "Exit Boot Services
> Returned with Failure" is also measured.
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
> ---
> Changes in v4:
> - remove unnecessary EFIAPI specifier
>
> Changes in v2:
> - use strlen instead of sizeof, event log for EV_EFI_ACTION string
>
>    shall not include NUL terminator
>   include/efi_loader.h          |  1 +
>   lib/efi_loader/efi_boottime.c |  5 +++
>   lib/efi_loader/efi_tcg2.c     | 70 +++++++++++++++++++++++++++++++++++
>   3 files changed, 76 insertions(+)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 6f61e9faac..32cb8d0f1e 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -499,6 +499,7 @@ efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size);
>   efi_status_t efi_init_variables(void);
>   /* Notify ExitBootServices() is called */
>   void efi_variables_boot_exit_notify(void);
> +efi_status_t efi_tcg2_notify_exit_boot_services_failed(void);
>   /* Measure efi application invocation */
>   efi_status_t efi_tcg2_measure_efi_app_invocation(void);
>   /* Measure efi application exit */
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 13ab139222..b818cbb540 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -2182,6 +2182,11 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
>   	efi_set_watchdog(0);
>   	WATCHDOG_RESET();
>   out:
> +	if (ret != EFI_SUCCESS) {
> +		if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL))

There is not need to check ret if the configuration is not enabled.

I make 'if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL))' the first check when
merging.

Best regards

Heinrich

> +			efi_tcg2_notify_exit_boot_services_failed();
> +	}
> +
>   	return EFI_EXIT(ret);
>   }
>
> diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> index ed71337780..8557fce1da 100644
> --- a/lib/efi_loader/efi_tcg2.c
> +++ b/lib/efi_loader/efi_tcg2.c
> @@ -1506,6 +1506,67 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void)
>   	return ret;
>   }
>
> +/**
> + * efi_tcg2_notify_exit_boot_services() - ExitBootService callback
> + *
> + * @event:	callback event
> + * @context:	callback context
> + */
> +static void
> +efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
> +{
> +	efi_status_t ret;
> +	struct udevice *dev;
> +
> +	EFI_ENTRY("%p, %p", event, context);
> +
> +	ret = platform_get_tpm2_device(&dev);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_SUCCEEDED),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_SUCCEEDED);
> +
> +out:
> +	EFI_EXIT(ret);
> +}
> +
> +/**
> + * efi_tcg2_notify_exit_boot_services_failed()
> + *  - notify ExitBootServices() is failed
> + *
> + * Return:	status code
> + */
> +efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
> +{
> +	struct udevice *dev;
> +	efi_status_t ret;
> +
> +	ret = platform_get_tpm2_device(&dev);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_FAILED),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_FAILED);
> +
> +out:
> +	return ret;
> +}
> +
>   /**
>    * tcg2_measure_secure_boot_variable() - measure secure boot variables
>    *
> @@ -1584,6 +1645,7 @@ efi_status_t efi_tcg2_register(void)
>   {
>   	efi_status_t ret = EFI_SUCCESS;
>   	struct udevice *dev;
> +	struct efi_event *event;
>
>   	ret = platform_get_tpm2_device(&dev);
>   	if (ret != EFI_SUCCESS) {
> @@ -1608,6 +1670,14 @@ efi_status_t efi_tcg2_register(void)
>   		goto fail;
>   	}
>
> +	ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
> +			       efi_tcg2_notify_exit_boot_services, NULL,
> +			       NULL, &event);
> +	if (ret != EFI_SUCCESS) {
> +		tcg2_uninit();
> +		goto fail;
> +	}
> +
>   	ret = tcg2_measure_secure_boot_variable(dev);
>   	if (ret != EFI_SUCCESS) {
>   		tcg2_uninit();
>

Re: [PATCH v4 3/5] efi_loader: add ExitBootServices() measurement

[Heinrich Schuchardt]

On 8/13/21 9:12 AM, Masahisa Kojima wrote:
> TCG PC Client PFP spec requires to measure
> "Exit Boot Services Invocation" if ExitBootServices() is invoked.
> Depending upon the return code from the ExitBootServices() call,
> "Exit Boot Services Returned with Success" or "Exit Boot Services
> Returned with Failure" is also measured.
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
> ---
> Changes in v4:
> - remove unnecessary EFIAPI specifier
>
> Changes in v2:
> - use strlen instead of sizeof, event log for EV_EFI_ACTION string
>
>    shall not include NUL terminator
>   include/efi_loader.h          |  1 +
>   lib/efi_loader/efi_boottime.c |  5 +++
>   lib/efi_loader/efi_tcg2.c     | 70 +++++++++++++++++++++++++++++++++++
>   3 files changed, 76 insertions(+)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 6f61e9faac..32cb8d0f1e 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -499,6 +499,7 @@ efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size);
>   efi_status_t efi_init_variables(void);
>   /* Notify ExitBootServices() is called */
>   void efi_variables_boot_exit_notify(void);
> +efi_status_t efi_tcg2_notify_exit_boot_services_failed(void);
>   /* Measure efi application invocation */
>   efi_status_t efi_tcg2_measure_efi_app_invocation(void);
>   /* Measure efi application exit */
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 13ab139222..b818cbb540 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -2182,6 +2182,11 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
>   	efi_set_watchdog(0);
>   	WATCHDOG_RESET();
>   out:
> +	if (ret != EFI_SUCCESS) {
> +		if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL))
> +			efi_tcg2_notify_exit_boot_services_failed();
> +	}
> +
>   	return EFI_EXIT(ret);
>   }
>
> diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> index ed71337780..8557fce1da 100644
> --- a/lib/efi_loader/efi_tcg2.c
> +++ b/lib/efi_loader/efi_tcg2.c
> @@ -1506,6 +1506,67 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void)
>   	return ret;
>   }
>
> +/**
> + * efi_tcg2_notify_exit_boot_services() - ExitBootService callback
> + *
> + * @event:	callback event
> + * @context:	callback context
> + */
> +static void

Event notification functions must be of return type void EFIAPI to match
the ABI used by the x86_64 in the UEFI API.

I will fix this when merging.

Best regards

Heinrich

> +efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
> +{
> +	efi_status_t ret;
> +	struct udevice *dev;
> +
> +	EFI_ENTRY("%p, %p", event, context);
> +
> +	ret = platform_get_tpm2_device(&dev);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_SUCCEEDED),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_SUCCEEDED);
> +
> +out:
> +	EFI_EXIT(ret);
> +}
> +
> +/**
> + * efi_tcg2_notify_exit_boot_services_failed()
> + *  - notify ExitBootServices() is failed
> + *
> + * Return:	status code
> + */
> +efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
> +{
> +	struct udevice *dev;
> +	efi_status_t ret;
> +
> +	ret = platform_get_tpm2_device(&dev);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> +				 strlen(EFI_EXIT_BOOT_SERVICES_FAILED),
> +				 (u8 *)EFI_EXIT_BOOT_SERVICES_FAILED);
> +
> +out:
> +	return ret;
> +}
> +
>   /**
>    * tcg2_measure_secure_boot_variable() - measure secure boot variables
>    *
> @@ -1584,6 +1645,7 @@ efi_status_t efi_tcg2_register(void)
>   {
>   	efi_status_t ret = EFI_SUCCESS;
>   	struct udevice *dev;
> +	struct efi_event *event;
>
>   	ret = platform_get_tpm2_device(&dev);
>   	if (ret != EFI_SUCCESS) {
> @@ -1608,6 +1670,14 @@ efi_status_t efi_tcg2_register(void)
>   		goto fail;
>   	}
>
> +	ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
> +			       efi_tcg2_notify_exit_boot_services, NULL,
> +			       NULL, &event);
> +	if (ret != EFI_SUCCESS) {
> +		tcg2_uninit();
> +		goto fail;
> +	}
> +
>   	ret = tcg2_measure_secure_boot_variable(dev);
>   	if (ret != EFI_SUCCESS) {
>   		tcg2_uninit();
>

Re: [PATCH v4 3/5] efi_loader: add ExitBootServices() measurement

[Masahisa Kojima]

On Sat, 14 Aug 2021 at 18:06, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>
> On 8/13/21 9:12 AM, Masahisa Kojima wrote:
> > TCG PC Client PFP spec requires to measure
> > "Exit Boot Services Invocation" if ExitBootServices() is invoked.
> > Depending upon the return code from the ExitBootServices() call,
> > "Exit Boot Services Returned with Success" or "Exit Boot Services
> > Returned with Failure" is also measured.
> >
> > Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
> > ---
> > Changes in v4:
> > - remove unnecessary EFIAPI specifier
> >
> > Changes in v2:
> > - use strlen instead of sizeof, event log for EV_EFI_ACTION string
> >
> >    shall not include NUL terminator
> >   include/efi_loader.h          |  1 +
> >   lib/efi_loader/efi_boottime.c |  5 +++
> >   lib/efi_loader/efi_tcg2.c     | 70 +++++++++++++++++++++++++++++++++++
> >   3 files changed, 76 insertions(+)
> >
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index 6f61e9faac..32cb8d0f1e 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -499,6 +499,7 @@ efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size);
> >   efi_status_t efi_init_variables(void);
> >   /* Notify ExitBootServices() is called */
> >   void efi_variables_boot_exit_notify(void);
> > +efi_status_t efi_tcg2_notify_exit_boot_services_failed(void);
> >   /* Measure efi application invocation */
> >   efi_status_t efi_tcg2_measure_efi_app_invocation(void);
> >   /* Measure efi application exit */
> > diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> > index 13ab139222..b818cbb540 100644
> > --- a/lib/efi_loader/efi_boottime.c
> > +++ b/lib/efi_loader/efi_boottime.c
> > @@ -2182,6 +2182,11 @@ static efi_status_t EFIAPI efi_exit_boot_services(efi_handle_t image_handle,
> >       efi_set_watchdog(0);
> >       WATCHDOG_RESET();
> >   out:
> > +     if (ret != EFI_SUCCESS) {
> > +             if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL))
> > +                     efi_tcg2_notify_exit_boot_services_failed();
> > +     }
> > +
> >       return EFI_EXIT(ret);
> >   }
> >
> > diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> > index ed71337780..8557fce1da 100644
> > --- a/lib/efi_loader/efi_tcg2.c
> > +++ b/lib/efi_loader/efi_tcg2.c
> > @@ -1506,6 +1506,67 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void)
> >       return ret;
> >   }
> >
> > +/**
> > + * efi_tcg2_notify_exit_boot_services() - ExitBootService callback
> > + *
> > + * @event:   callback event
> > + * @context: callback context
> > + */
> > +static void
>
> Event notification functions must be of return type void EFIAPI to match
> the ABI used by the x86_64 in the UEFI API.
>
> I will fix this when merging.

Hi Heinrich,

Thank you for your fix and merging.

Regards,
Masahisa Kojima

>
> Best regards
>
> Heinrich
>
> > +efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
> > +{
> > +     efi_status_t ret;
> > +     struct udevice *dev;
> > +
> > +     EFI_ENTRY("%p, %p", event, context);
> > +
> > +     ret = platform_get_tpm2_device(&dev);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> > +                              strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
> > +                              (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> > +                              strlen(EFI_EXIT_BOOT_SERVICES_SUCCEEDED),
> > +                              (u8 *)EFI_EXIT_BOOT_SERVICES_SUCCEEDED);
> > +
> > +out:
> > +     EFI_EXIT(ret);
> > +}
> > +
> > +/**
> > + * efi_tcg2_notify_exit_boot_services_failed()
> > + *  - notify ExitBootServices() is failed
> > + *
> > + * Return:   status code
> > + */
> > +efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
> > +{
> > +     struct udevice *dev;
> > +     efi_status_t ret;
> > +
> > +     ret = platform_get_tpm2_device(&dev);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> > +                              strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
> > +                              (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     ret = tcg2_measure_event(dev, 5, EV_EFI_ACTION,
> > +                              strlen(EFI_EXIT_BOOT_SERVICES_FAILED),
> > +                              (u8 *)EFI_EXIT_BOOT_SERVICES_FAILED);
> > +
> > +out:
> > +     return ret;
> > +}
> > +
> >   /**
> >    * tcg2_measure_secure_boot_variable() - measure secure boot variables
> >    *
> > @@ -1584,6 +1645,7 @@ efi_status_t efi_tcg2_register(void)
> >   {
> >       efi_status_t ret = EFI_SUCCESS;
> >       struct udevice *dev;
> > +     struct efi_event *event;
> >
> >       ret = platform_get_tpm2_device(&dev);
> >       if (ret != EFI_SUCCESS) {
> > @@ -1608,6 +1670,14 @@ efi_status_t efi_tcg2_register(void)
> >               goto fail;
> >       }
> >
> > +     ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
> > +                            efi_tcg2_notify_exit_boot_services, NULL,
> > +                            NULL, &event);
> > +     if (ret != EFI_SUCCESS) {
> > +             tcg2_uninit();
> > +             goto fail;
> > +     }
> > +
> >       ret = tcg2_measure_secure_boot_variable(dev);
> >       if (ret != EFI_SUCCESS) {
> >               tcg2_uninit();
> >
>

[PATCH v4 4/5] efi_loader: refactor efi_append_scrtm_version()

[Masahisa Kojima]

Refactor efi_append_scrtm_version() to use common
function for adding eventlog and extending PCR.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
---

(no changes since v1)


 lib/efi_loader/efi_tcg2.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 8557fce1da..2d03809e85 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -1321,23 +1321,11 @@ out:
  */
 static efi_status_t efi_append_scrtm_version(struct udevice *dev)
 {
-	struct tpml_digest_values digest_list;
 	u8 ver[] = U_BOOT_VERSION_STRING;
-	const int pcr_index = 0;
 	efi_status_t ret;
 
-	ret = tcg2_create_digest(ver, sizeof(ver), &digest_list);
-	if (ret != EFI_SUCCESS)
-		goto out;
+	ret = tcg2_measure_event(dev, 0, EV_S_CRTM_VERSION, sizeof(ver), ver);
 
-	ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
-	if (ret != EFI_SUCCESS)
-		goto out;
-
-	ret = tcg2_agile_log_append(pcr_index, EV_S_CRTM_VERSION, &digest_list,
-				    sizeof(ver), ver);
-
-out:
 	return ret;
 }
 
-- 
2.17.1

[PATCH v4 5/5] efi_loader: add comment for efi_tcg2.h

[Masahisa Kojima]

This commit adds the comment of the TCG Specification
efi_tcg2.h file refers, and comment for the structure.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
---

(no change since v3)

Changes in v3:
- update comment format

Changes in v2:
- newly create commit from v2

 include/efi_tcg2.h | 57 +++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 54 insertions(+), 3 deletions(-)

diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h
index 497ba3ce94..b6b958da51 100644
--- a/include/efi_tcg2.h
+++ b/include/efi_tcg2.h
@@ -3,6 +3,13 @@
  * Defines data structures and APIs that allow an OS to interact with UEFI
  * firmware to query information about the device
  *
+ * This file refers the following TCG specification.
+ *  - TCG PC Client Platform Firmware Profile Specification
+ *    https://trustedcomputinggroup.org/resource/pc-client-specific-platform-firmware-profile-specification/
+ *
+ *  - TCG EFI Protocol Specification
+ *    https://trustedcomputinggroup.org/resource/tcg-efi-protocol-specification/
+ *
  * Copyright (c) 2020, Linaro Limited
  */
 
@@ -36,11 +43,23 @@ typedef u32 efi_tcg_event_log_bitmap;
 typedef u32 efi_tcg_event_log_format;
 typedef u32 efi_tcg_event_algorithm_bitmap;
 
+/**
+ * struct tdEFI_TCG2_VERSION - structure of EFI TCG2 version
+ * @major:	major version
+ * @minor:	minor version
+ */
 struct efi_tcg2_version {
 	u8 major;
 	u8 minor;
 };
 
+/**
+ * struct tdEFI_TCG2_EVENT_HEADER - structure of EFI TCG2 event header
+ * @header_size:	size of the event header
+ * @header_version:	header version
+ * @pcr_index:		index of the PCR that is extended
+ * @event_type:		type of the event that is extended
+ */
 struct efi_tcg2_event_header {
 	u32 header_size;
 	u16 header_version;
@@ -48,12 +67,27 @@ struct efi_tcg2_event_header {
 	u32 event_type;
 } __packed;
 
+/**
+ * struct tdEFI_TCG2_EVENT - structure of EFI TCG2 event
+ * @size:	total size of the event including the size component, the header
+ *		and the event data
+ * @header:	event header
+ * @event:	event to add
+ */
 struct efi_tcg2_event {
 	u32 size;
 	struct efi_tcg2_event_header header;
 	u8 event[];
 } __packed;
 
+/**
+ * struct tdUEFI_IMAGE_LOAD_EVENT - structure of PE/COFF image measurement
+ * @image_location_in_memory:	image address
+ * @image_length_in_memory:	image size
+ * @image_link_time_address:	image link time address
+ * @length_of_device_path:	devive path size
+ * @device_path:		device path
+ */
 struct uefi_image_load_event {
 	efi_physical_addr_t image_location_in_memory;
 	u64 image_length_in_memory;
@@ -62,6 +96,23 @@ struct uefi_image_load_event {
 	struct efi_device_path device_path[];
 };
 
+/**
+ * struct tdEFI_TCG2_BOOT_SERVICE_CAPABILITY - protocol capability information
+ * @size:			allocated size of the structure
+ * @structure_version:		version of this structure
+ * @protocol_version:		version of the EFI TCG2 protocol.
+ * @hash_algorithm_bitmap:	supported hash algorithms
+ * @supported_event_logs:	bitmap of supported event log formats
+ * @tpm_present_flag:		false = TPM not present
+ * @max_command_size:		max size (in bytes) of a command
+ *				that can be sent to the TPM
+ * @max_response_size:		max size (in bytes) of a response that
+ *				can be provided by the TPM
+ * @manufacturer_id:		4-byte Vendor ID
+ * @number_of_pcr_banks:	maximum number of PCR banks
+ * @active_pcr_banks:		bitmap of currently active
+ *				PCR banks (hashing algorithms).
+ */
 struct efi_tcg2_boot_service_capability {
 	u8 size;
 	struct efi_tcg2_version structure_version;
@@ -86,7 +137,7 @@ struct efi_tcg2_boot_service_capability {
 #define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2 2
 
 /**
- *  struct TCG_EfiSpecIdEventAlgorithmSize
+ *  struct TCG_EfiSpecIdEventAlgorithmSize - hashing algorithm information
  *
  *  @algorithm_id:	algorithm defined in enum tpm2_algorithms
  *  @digest_size:	size of the algorithm
@@ -97,7 +148,7 @@ struct tcg_efi_spec_id_event_algorithm_size {
 } __packed;
 
 /**
- * struct TCG_EfiSpecIDEventStruct
+ * struct TCG_EfiSpecIDEventStruct - content of the event log header
  *
  * @signature:			signature, set to Spec ID Event03
  * @platform_class:		class defined in TCG ACPI Specification
@@ -130,7 +181,7 @@ struct tcg_efi_spec_id_event {
 } __packed;
 
 /**
- * struct tdEFI_TCG2_FINAL_EVENTS_TABLE
+ * struct tdEFI_TCG2_FINAL_EVENTS_TABLE - log entries after Get Event Log
  * @version:		version number for this structure
  * @number_of_events:	number of events recorded after invocation of
  *			GetEventLog()
-- 
2.17.1