feat(fwu): add FWU driver

Implemented FWU metadata load and verification APIs.
Also, exported below APIs to the platform:
1. fwu_init - Load FWU metadata in a structure. Also, set the
	      addresses of updated components in I/O policy
2. fwu_is_trial_run_state - To detect trial run or regular run
			    state

Change-Id: I67eeabb52d9275ac83be635306997b7c353727cd
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

drivers/fwu/fwu.c

+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <common/debug.h>
+#include <common/hw_crc32.h>
+#include <common/tbbr/tbbr_img_def.h>
+#include <drivers/fwu/fwu.h>
+#include <drivers/fwu/fwu_metadata.h>
+#include <drivers/io/io_storage.h>
+
+#include <plat/common/platform.h>
+
+/*
+ * Assert that crc_32 is the first member of fwu_metadata structure.
+ * It avoids accessing data outside of the metadata structure during
+ * CRC32 computation if the crc_32 field gets moved due the structure
+ * member(s) addition in the future.
+ */
+CASSERT((offsetof(struct fwu_metadata, crc_32) == 0),
+	crc_32_must_be_first_member_of_structure);
+
+static struct fwu_metadata metadata;
+static bool is_fwu_initialized;
+
+/*******************************************************************************
+ * Compute CRC32 of the FWU metadata, and check it against the CRC32 value
+ * present in the FWU metadata.
+ *
+ * return -1 on error, otherwise 0
+ ******************************************************************************/
+static int fwu_metadata_crc_check(void)
+{
+	unsigned char *data = (unsigned char *)&metadata;
+
+	uint32_t calc_crc = hw_crc32(0U, data + sizeof(metadata.crc_32),
+				     (sizeof(metadata) -
+				      sizeof(metadata.crc_32)));
+
+	if (metadata.crc_32 != calc_crc) {
+		return -1;
+	}
+
+	return 0;
+}
+
+/*******************************************************************************
+ * Check the sanity of FWU metadata.
+ *
+ * return -1 on error, otherwise 0
+ ******************************************************************************/
+static int fwu_metadata_sanity_check(void)
+{
+	/* ToDo: add more conditions for sanity check */
+	if ((metadata.active_index >= NR_OF_FW_BANKS) ||
+	    (metadata.previous_active_index >= NR_OF_FW_BANKS)) {
+		return -1;
+	}
+
+	return 0;
+}
+
+/*******************************************************************************
+ * Verify and load specified FWU metadata image to local FWU metadata structure.
+ *
+ * @image_id: FWU metadata image id (either FWU_METADATA_IMAGE_ID or
+ *				     BKUP_FWU_METADATA_IMAGE_ID)
+ *
+ * return a negative value on error, otherwise 0
+ ******************************************************************************/
+static int fwu_metadata_load(unsigned int image_id)
+{
+	int result;
+	uintptr_t dev_handle, image_handle, image_spec;
+	size_t bytes_read;
+
+	assert((image_id == FWU_METADATA_IMAGE_ID) ||
+	       (image_id == BKUP_FWU_METADATA_IMAGE_ID));
+
+	result = plat_fwu_set_metadata_image_source(image_id,
+						    &dev_handle,
+						    &image_spec);
+	if (result != 0) {
+		WARN("Failed to set reference to image id=%u (%i)\n",
+		     image_id, result);
+		return result;
+	}
+
+	result = io_open(dev_handle, image_spec, &image_handle);
+	if (result != 0) {
+		WARN("Failed to load image id id=%u (%i)\n",
+		     image_id, result);
+		return result;
+	}
+
+	result = io_read(image_handle, (uintptr_t)&metadata,
+			 sizeof(struct fwu_metadata), &bytes_read);
+
+	if (result != 0) {
+		WARN("Failed to read image id=%u (%i)\n", image_id, result);
+		goto exit;
+	}
+
+	if (sizeof(struct fwu_metadata) != bytes_read) {
+		/* return -1 in case of partial/no read */
+		result = -1;
+		WARN("Read bytes (%zu) instead of expected (%zu) bytes\n",
+		     bytes_read, sizeof(struct fwu_metadata));
+		goto exit;
+	}
+
+	/* sanity check on loaded parameters */
+	result = fwu_metadata_sanity_check();
+	if (result != 0) {
+		WARN("Sanity %s\n", "check failed on FWU metadata");
+		goto exit;
+	}
+
+	/* CRC check on loaded parameters */
+	result = fwu_metadata_crc_check();
+	if (result != 0) {
+		WARN("CRC %s\n", "check failed on FWU metadata");
+	}
+
+exit:
+	(void)io_close(image_handle);
+
+	return result;
+}
+
+/*******************************************************************************
+ * The system runs in the trial run state if any of the images in the active
+ * firmware bank has not been accepted yet.
+ *
+ * Returns true if the system is running in the trial state.
+ ******************************************************************************/
+bool fwu_is_trial_run_state(void)
+{
+	bool trial_run = false;
+
+	assert(is_fwu_initialized == true);
+
+	for (unsigned int i = 0U; i < NR_OF_IMAGES_IN_FW_BANK; i++) {
+		struct fwu_image_entry *entry = &metadata.img_entry[i];
+		struct fwu_image_properties *img_props =
+			&entry->img_props[metadata.active_index];
+		if (img_props->accepted == 0) {
+			trial_run = true;
+			break;
+		}
+	}
+
+	return trial_run;
+}
+
+/*******************************************************************************
+ * Load verified copy of FWU metadata image kept in the platform NV storage
+ * into local FWU metadata structure.
+ * Also, update platform I/O policies with the offset address and length of
+ * firmware-updated images kept in the platform NV storage.
+ ******************************************************************************/
+void fwu_init(void)
+{
+	/* Load FWU metadata which will be used to load the images in the
+	 * active bank as per PSA FWU specification
+	 */
+	int result = fwu_metadata_load(FWU_METADATA_IMAGE_ID);
+
+	if (result != 0) {
+		WARN("loading of FWU-Metadata failed, "
+		     "using Bkup-FWU-Metadata\n");
+
+		result = fwu_metadata_load(BKUP_FWU_METADATA_IMAGE_ID);
+		if (result != 0) {
+			ERROR("loading of Bkup-FWU-Metadata failed\n");
+			panic();
+		}
+	}
+
+	plat_fwu_set_images_source(&metadata);
+
+	is_fwu_initialized = true;
+}

drivers/fwu/fwu.mk

+#
+# Copyright (c) 2021, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+FWU_SRC_DIR	:= drivers/fwu/
+
+FWU_SRCS	:= ${FWU_SRC_DIR}fwu.c
+
+BL2_SOURCES	+= ${FWU_SRCS}

include/drivers/fwu/fwu.h

+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef FWU_H
+#define FWU_H
+
+#include <stdbool.h>
+
+void fwu_init(void);
+bool fwu_is_trial_run_state(void);
+
+#endif /* FWU_H */

include/export/common/tbbr/tbbr_img_def_exp.h

 /*
- * Copyright (c) 2019-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -91,7 +91,17 @@
 /* FW_CONFIG */
 #define FW_CONFIG_ID			U(31)
 
+/*
+ * Primary FWU metadata image ID
+ */
+#define FWU_METADATA_IMAGE_ID		U(32)
+
+/*
+ * Backup FWU metadata image ID
+ */
+#define BKUP_FWU_METADATA_IMAGE_ID	U(33)
+
 /* Max Images */
-#define MAX_IMAGE_IDS			U(32)
+#define MAX_IMAGE_IDS			U(34)
 
 #endif /* ARM_TRUSTED_FIRMWARE_EXPORT_COMMON_TBBR_TBBR_IMG_DEF_EXP_H */