feat(fwu_metadata): add FWU metadata header and build options

Added a firmware update metadata structure as per section 4.1
in the specification document[1].

Also, added the build options used in defining the firmware
update metadata structure.

[1]: https://developer.arm.com/documentation/den0118/a/

Change-Id: I8f43264a46fde777ceae7fd2a5bb0326f1711928
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/Makefile b/Makefile
index 4dbc2be..edc0d49 100644
--- a/Makefile
+++ b/Makefile
@@ -967,6 +967,8 @@
         ARM_ARCH_MINOR \
         BRANCH_PROTECTION \
         FW_ENC_STATUS \
+        NR_OF_FW_BANKS \
+        NR_OF_IMAGES_IN_FW_BANK \
 )))
 
 ifdef KEY_SIZE
@@ -1054,6 +1056,8 @@
         USE_SP804_TIMER \
         ENABLE_FEAT_RNG \
         ENABLE_FEAT_SB \
+        NR_OF_FW_BANKS \
+        NR_OF_IMAGES_IN_FW_BANK \
 )))
 
 ifeq (${SANITIZE_UB},trap)
diff --git a/include/drivers/fwu/fwu_metadata.h b/include/drivers/fwu/fwu_metadata.h
new file mode 100644
index 0000000..2e88de5
--- /dev/null
+++ b/include/drivers/fwu/fwu_metadata.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * FWU metadata information as per the specification section 4.1:
+ * https://developer.arm.com/documentation/den0118/a/
+ *
+ */
+
+#ifndef FWU_METADATA_H
+#define FWU_METADATA_H
+
+#include <stdint.h>
+#include <tools_share/uuid.h>
+
+/* Properties of image in a bank */
+struct fwu_image_properties {
+
+	/* UUID of the image in this bank */
+	uuid_t img_uuid;
+
+	/* [0]: bit describing the image acceptance status –
+	 *      1 means the image is accepted
+	 * [31:1]: MBZ
+	 */
+	uint32_t accepted;
+
+	/* reserved (MBZ) */
+	uint32_t reserved;
+
+} __packed;
+
+/* Image entry information */
+struct fwu_image_entry {
+
+	/* UUID identifying the image type */
+	uuid_t img_type_uuid;
+
+	/* UUID of the storage volume where the image is located */
+	uuid_t location_uuid;
+
+	/* Properties of images with img_type_uuid in the different FW banks */
+	struct fwu_image_properties img_props[NR_OF_FW_BANKS];
+
+} __packed;
+
+/*
+ * FWU metadata filled by the updater and consumed by TF-A for
+ * various purposes as below:
+ * 1. Get active FW bank.
+ * 2. Rollback to previous working FW bank.
+ * 3. Get properties of all images present in all banks.
+ */
+struct fwu_metadata {
+
+	/* Metadata CRC value */
+	uint32_t crc_32;
+
+	/* Metadata version */
+	uint32_t version;
+
+	/* Bank index with which device boots */
+	uint32_t active_index;
+
+	/* Previous bank index with which device booted successfully */
+	uint32_t previous_active_index;
+
+	/* Image entry information */
+	struct fwu_image_entry img_entry[NR_OF_IMAGES_IN_FW_BANK];
+
+} __packed;
+
+#endif /* FWU_METADATA_H */
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index b2d1ee2..53d9605 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -344,3 +344,11 @@
 
 # Build option to use the SP804 timer instead of the generic one
 USE_SP804_TIMER			:= 0
+
+# Build option to define number of firmware banks, used in firmware update
+# metadata structure.
+NR_OF_FW_BANKS			:= 2
+
+# Build option to define number of images in firmware bank, used in firmware
+# update metadata structure.
+NR_OF_IMAGES_IN_FW_BANK		:= 1