3 files changed, 53 insertions, 10 deletions

diff --git a/src/lib/tpm2_marshaling.c b/src/lib/tpm2_marshaling.c
index 6d4d622d91..52dac9c553 100644
--- a/src/lib/tpm2_marshaling.c
+++ b/src/lib/tpm2_marshaling.c
@@ -394,20 +394,16 @@ static void marshal_cr50_vendor_command(void **buffer, void *command_body,
 			size_t *buffer_space)
 {
 	uint16_t *sub_command;
-
-	/* Ensure at least the sub command can fit in the body and there's
-	   valid pointer. Could be reading past the buffer... */
-	if (command_body == NULL || *buffer_space < sizeof(uint16_t)) {
-		*buffer_space = 0;
-		return;
-	}
-
 	sub_command = command_body;
 
 	switch (*sub_command) {
 	case TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS:
 		marshal_u16(buffer, *sub_command, buffer_space);
 		break;
+	case TPM2_CR50_SUB_CMD_TURN_UPDATE_ON:
+		marshal_u16(buffer, sub_command[0], buffer_space);
+		marshal_u16(buffer, sub_command[1], buffer_space);
+		break;
 	default:
 		/* Unsupported subcommand. */
 		printk(BIOS_WARNING, "Unsupported cr50 subcommand: 0x%04x\n",
@@ -596,6 +592,25 @@ static void unmarshal_nv_read(void **buffer, int *size,
 	*size = 0;
 }
 
+static void unmarshal_vendor_command(void **buffer, int *size,
+				     struct vendor_command_response *vcr)
+{
+	vcr->vc_subcommand = unmarshal_u16(buffer, size);
+
+	switch (vcr->vc_subcommand) {
+	case TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS:
+		break;
+	case TPM2_CR50_SUB_CMD_TURN_UPDATE_ON:
+		vcr->num_restored_headers = unmarshal_u8(buffer, size);
+		break;
+	default:
+		printk(BIOS_ERR,
+		       "%s:%d - unsupported vendor command %#04x!\n",
+		       __func__, __LINE__, vcr->vc_subcommand);
+		break;
+	}
+}
+
 struct tpm2_response *tpm_unmarshal_response(TPM_CC command,
 					     void *response_body,
 					     size_t in_size)
@@ -648,8 +663,8 @@ struct tpm2_response *tpm_unmarshal_response(TPM_CC command,
 		break;
 
 	case TPM2_CR50_VENDOR_COMMAND:
-		/* Assume no other data returned for the time being. */
-		cr_size = 0;
+		unmarshal_vendor_command(&response_body, &cr_size,
+					 &tpm2_resp->vcr);
 		break;
 
 	default:
diff --git a/src/lib/tpm2_tlcl.c b/src/lib/tpm2_tlcl.c
index 967612ad20..1118afb1df 100644
--- a/src/lib/tpm2_tlcl.c
+++ b/src/lib/tpm2_tlcl.c
@@ -406,3 +406,22 @@ uint32_t tlcl_cr50_enable_nvcommits(void)
 	}
 	return TPM_SUCCESS;
 }
+
+uint32_t tlcl_cr50_enable_update(uint16_t timeout_ms,
+				 uint8_t *num_restored_headers)
+{
+	struct tpm2_response *response;
+	uint16_t command_body[] = {
+		TPM2_CR50_SUB_CMD_TURN_UPDATE_ON, timeout_ms
+	};
+
+	printk(BIOS_INFO, "Checking cr50 for pending updates\n");
+
+	response = tpm_process_command(TPM2_CR50_VENDOR_COMMAND, command_body);
+
+	if (!response || response->hdr.tpm_code)
+		return TPM_E_INTERNAL_INCONSISTENCY;
+
+	*num_restored_headers = response->vcr.num_restored_headers;
+	return TPM_SUCCESS;
+}
diff --git a/src/lib/tpm2_tlcl_structures.h b/src/lib/tpm2_tlcl_structures.h
index ec5b674701..2d6164b1b7 100644
--- a/src/lib/tpm2_tlcl_structures.h
+++ b/src/lib/tpm2_tlcl_structures.h
@@ -78,6 +78,7 @@ struct tpm_header {
    knowledge of all commands. */
 #define TPM2_CR50_VENDOR_COMMAND ((TPM_CC)(TPM_CC_VENDOR_BIT_MASK | 0))
 #define  TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS (21)
+#define  TPM2_CR50_SUB_CMD_TURN_UPDATE_ON (24)
 
 /* Startup values. */
 #define TPM_SU_CLEAR 0
@@ -279,6 +280,13 @@ struct nv_read_response {
 	TPM2B_MAX_NV_BUFFER buffer;
 };
 
+struct vendor_command_response {
+	uint16_t vc_subcommand;
+	union {
+		uint8_t num_restored_headers;
+	};
+};
+
 struct tpm2_session_attrs {
 	uint8_t continueSession : 1;
 	uint8_t auditExclusive  : 1;
@@ -311,6 +319,7 @@ struct tpm2_response {
 		struct get_cap_response gc;
 		struct nv_read_response nvr;
 		struct tpm2_session_header def_space;
+		struct vendor_command_response vcr;
 	};
 };