lib/fwu_updates/fwu.c - filogic/uboot - Gitiles

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2022, Linaro Limited
  */

 #include <dm.h>
 #include <efi.h>
 #include <efi_loader.h>
 #include <efi_variable.h>
 #include <event.h>
 #include <fwu.h>
 #include <fwu_mdata.h>
 #include <malloc.h>

 #include <linux/errno.h>
 #include <linux/types.h>

 #include <u-boot/crc.h>

 static struct fwu_mdata g_mdata; /* = {0} makes uninit crc32 always invalid */
 static struct udevice *g_dev;
 static u8 in_trial;
 static u8 boottime_check;

 enum {
 	IMAGE_ACCEPT_SET = 1,
 	IMAGE_ACCEPT_CLEAR,
 };

 enum {
 	PRIMARY_PART = 1,
 	SECONDARY_PART,
 	BOTH_PARTS,
 };

 static int trial_counter_update(u16 *trial_state_ctr)
 {
 	bool delete;
 	u32 var_attr;
 	efi_status_t status;
 	efi_uintn_t var_size;

 	delete = !trial_state_ctr ? true : false;
 	var_size = !trial_state_ctr ? 0 : (efi_uintn_t)sizeof(*trial_state_ctr);
 	var_attr = !trial_state_ctr ? 0 : EFI_VARIABLE_NON_VOLATILE |
 		EFI_VARIABLE_BOOTSERVICE_ACCESS;
 	status = efi_set_variable_int(u"TrialStateCtr",
 				      &efi_global_variable_guid,
 				      var_attr,
 				      var_size, trial_state_ctr, false);

 	if ((delete && (status != EFI_NOT_FOUND &&
 			status != EFI_SUCCESS)) ||
 	    (!delete && status != EFI_SUCCESS))
 		return -1;

 	return 0;
 }

 static int trial_counter_read(u16 *trial_state_ctr)
 {
 	efi_status_t status;
 	efi_uintn_t var_size;

 	var_size = (efi_uintn_t)sizeof(trial_state_ctr);
 	status = efi_get_variable_int(u"TrialStateCtr",
 				      &efi_global_variable_guid,
 				      NULL,
 				      &var_size, trial_state_ctr,
 				      NULL);
 	if (status != EFI_SUCCESS) {
 		log_err("Unable to read TrialStateCtr variable\n");
 		return -1;
 	}

 	return 0;
 }

 static int fwu_trial_count_update(void)
 {
 	int ret;
 	u16 trial_state_ctr;

 	ret = trial_counter_read(&trial_state_ctr);
 	if (ret) {
 		log_debug("Unable to read trial_state_ctr\n");
 		goto out;
 	}

 	++trial_state_ctr;
 	if (trial_state_ctr > CONFIG_FWU_TRIAL_STATE_CNT) {
 		log_info("Trial State count exceeded. Revert back to previous_active_index\n");
 		ret = fwu_revert_boot_index();
 		if (ret)
 			log_err("Unable to revert active_index\n");
 		ret = 1;
 	} else {
 		log_info("Trial State count: attempt %d out of %d\n",
 			 trial_state_ctr, CONFIG_FWU_TRIAL_STATE_CNT);
 		ret = trial_counter_update(&trial_state_ctr);
 		if (ret)
 			log_err("Unable to increment TrialStateCtr variable\n");
 	}

 out:
 	return ret;
 }

 static int in_trial_state(struct fwu_mdata *mdata)
 {
 	u32 i, active_bank;
 	struct fwu_image_entry *img_entry;
 	struct fwu_image_bank_info *img_bank_info;

 	active_bank = mdata->active_index;
 	img_entry = &mdata->img_entry[0];
 	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
 		img_bank_info = &img_entry[i].img_bank_info[active_bank];
 		if (!img_bank_info->accepted) {
 			log_info("System booting in Trial State\n");
 			return 1;
 		}
 	}

 	return 0;
 }

 static int fwu_get_image_type_id(u8 *image_index, efi_guid_t *image_type_id)
 {
 	u8 index;
 	int i;
 	struct efi_fw_image *image;

 	index = *image_index;
 	image = update_info.images;
 	for (i = 0; i < update_info.num_images; i++) {
 		if (index == image[i].image_index) {
 			guidcpy(image_type_id, &image[i].image_type_id);
 			return 0;
 		}
 	}

 	return -ENOENT;
 }

 /**
  * fwu_sync_mdata() - Update given meta-data partition(s) with the copy provided
  * @mdata: FWU metadata structure
  * @part: Bitmask of FWU metadata partitions to be written to
  *
  * Return: 0 if OK, -ve on error
  */
 static int fwu_sync_mdata(struct fwu_mdata *mdata, int part)
 {
 	void *buf = &mdata->version;
 	int err;

 	if (part == BOTH_PARTS) {
 		err = fwu_sync_mdata(mdata, SECONDARY_PART);
 		if (err)
 			return err;
 		part = PRIMARY_PART;
 	}

 	/*
 	 * Calculate the crc32 for the updated FWU metadata
 	 * and put the updated value in the FWU metadata crc32
 	 * field
 	 */
 	mdata->crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));

 	err = fwu_write_mdata(g_dev, mdata, part == PRIMARY_PART);
 	if (err) {
 		log_err("Unable to write %s mdata\n",
 			part == PRIMARY_PART ?  "primary" : "secondary");
 		return err;
 	}

 	/* update the cached copy of meta-data */
 	memcpy(&g_mdata, mdata, sizeof(struct fwu_mdata));

 	return 0;
 }

 static inline int mdata_crc_check(struct fwu_mdata *mdata)
 {
 	void *buf = &mdata->version;
 	u32 calc_crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));

 	return calc_crc32 == mdata->crc32 ? 0 : -EINVAL;
 }

 /**
  * fwu_get_mdata() - Read, verify and return the FWU metadata
  * @mdata: Output FWU metadata read or NULL
  *
  * Read both the metadata copies from the storage media, verify their checksum,
  * and ascertain that both copies match. If one of the copies has gone bad,
  * restore it from the good copy.
  *
  * Return: 0 if OK, -ve on error
  */
 int fwu_get_mdata(struct fwu_mdata *mdata)
 {
 	int err;
 	bool parts_ok[2] = { false };
 	struct fwu_mdata s, *parts_mdata[2];

 	parts_mdata[0] = &g_mdata;
 	parts_mdata[1] = &s;

 	/* if mdata already read and ready */
 	err = mdata_crc_check(parts_mdata[0]);
 	if (!err)
 		goto ret_mdata;
 	/* else read, verify and, if needed, fix mdata */

 	for (int i = 0; i < 2; i++) {
 		parts_ok[i] = false;
 		err = fwu_read_mdata(g_dev, parts_mdata[i], !i);
 		if (!err) {
 			err = mdata_crc_check(parts_mdata[i]);
 			if (!err)
 				parts_ok[i] = true;
 			else
 				log_debug("mdata : %s crc32 failed\n", i ? "secondary" : "primary");
 		}
 	}

 	if (parts_ok[0] && parts_ok[1]) {
 		/*
 		 * Before returning, check that both the
 		 * FWU metadata copies are the same.
 		 */
 		err = memcmp(parts_mdata[0], parts_mdata[1], sizeof(struct fwu_mdata));
 		if (!err)
 			goto ret_mdata;

 		/*
 		 * If not, populate the secondary partition from the
 		 * primary partition copy.
 		 */
 		log_info("Both FWU metadata copies are valid but do not match.");
 		log_info(" Restoring the secondary partition from the primary\n");
 		parts_ok[1] = false;
 	}

 	for (int i = 0; i < 2; i++) {
 		if (parts_ok[i])
 			continue;

 		memcpy(parts_mdata[i], parts_mdata[1 - i], sizeof(struct fwu_mdata));
 		err = fwu_sync_mdata(parts_mdata[i], i ? SECONDARY_PART : PRIMARY_PART);
 		if (err) {
 			log_debug("mdata : %s write failed\n", i ? "secondary" : "primary");
 			return err;
 		}
 	}

 ret_mdata:
 	if (!err && mdata)
 		memcpy(mdata, parts_mdata[0], sizeof(struct fwu_mdata));

 	return err;
 }

 /**
  * fwu_get_active_index() - Get active_index from the FWU metadata
  * @active_idx: active_index value to be read
  *
  * Read the active_index field from the FWU metadata and place it in
  * the variable pointed to be the function argument.
  *
  * Return: 0 if OK, -ve on error
  *
  */
 int fwu_get_active_index(uint *active_idx)
 {
 	int ret = 0;
 	struct fwu_mdata *mdata = &g_mdata;

 	/*
 	 * Found the FWU metadata partition, now read the active_index
 	 * value
 	 */
 	*active_idx = mdata->active_index;
 	if (*active_idx >= CONFIG_FWU_NUM_BANKS) {
 		log_debug("Active index value read is incorrect\n");
 		ret = -EINVAL;
 	}

 	return ret;
 }

 /**
  * fwu_set_active_index() - Set active_index in the FWU metadata
  * @active_idx: active_index value to be set
  *
  * Update the active_index field in the FWU metadata
  *
  * Return: 0 if OK, -ve on error
  *
  */
 int fwu_set_active_index(uint active_idx)
 {
 	int ret;
 	struct fwu_mdata *mdata = &g_mdata;

 	if (active_idx >= CONFIG_FWU_NUM_BANKS) {
 		log_debug("Invalid active index value\n");
 		return -EINVAL;
 	}

 	/*
 	 * Update the active index and previous_active_index fields
 	 * in the FWU metadata
 	 */
 	mdata->previous_active_index = mdata->active_index;
 	mdata->active_index = active_idx;

 	/*
 	 * Now write this updated FWU metadata to both the
 	 * FWU metadata partitions
 	 */
 	ret = fwu_sync_mdata(mdata, BOTH_PARTS);
 	if (ret) {
 		log_debug("Failed to update FWU metadata partitions\n");
 		ret = -EIO;
 	}

 	return ret;
 }

 /**
  * fwu_get_image_index() - Get the Image Index to be used for capsule update
  * @image_index: The Image Index for the image
  *
  * The FWU multi bank update feature computes the value of image_index at
  * runtime, based on the bank to which the image needs to be written to.
  * Derive the image_index value for the image.
  *
  * Currently, the capsule update driver uses the DFU framework for
  * the updates. This function gets the DFU alt number which is to
  * be used as the Image Index
  *
  * Return: 0 if OK, -ve on error
  *
  */
 int fwu_get_image_index(u8 *image_index)
 {
 	int ret, i;
 	u8 alt_num;
 	uint update_bank;
 	efi_guid_t *image_guid, image_type_id;
 	struct fwu_mdata *mdata = &g_mdata;
 	struct fwu_image_entry *img_entry;
 	struct fwu_image_bank_info *img_bank_info;

 	ret = fwu_plat_get_update_index(&update_bank);
 	if (ret) {
 		log_debug("Failed to get the FWU update bank\n");
 		goto out;
 	}

 	ret = fwu_get_image_type_id(image_index, &image_type_id);
 	if (ret) {
 		log_debug("Unable to get image_type_id for image_index %u\n",
 			  *image_index);
 		goto out;
 	}

 	ret = -EINVAL;
 	/*
 	 * The FWU metadata has been read. Now get the image_uuid for the
 	 * image with the update_bank.
 	 */
 	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
 		if (!guidcmp(&image_type_id,
 			     &mdata->img_entry[i].image_type_uuid)) {
 			img_entry = &mdata->img_entry[i];
 			img_bank_info = &img_entry->img_bank_info[update_bank];
 			image_guid = &img_bank_info->image_uuid;
 			ret = fwu_plat_get_alt_num(g_dev, image_guid, &alt_num);
 			if (ret) {
 				log_debug("alt_num not found for partition with GUID %pUs\n",
 					  image_guid);
 			} else {
 				log_debug("alt_num %d for partition %pUs\n",
 					  alt_num, image_guid);
 				*image_index = alt_num + 1;
 			}

 			goto out;
 		}
 	}

 	log_err("Partition with the image type %pUs not found\n",
 		&image_type_id);

 out:
 	return ret;
 }

 /**
  * fwu_revert_boot_index() - Revert the active index in the FWU metadata
  *
  * Revert the active_index value in the FWU metadata, by swapping the values
  * of active_index and previous_active_index in both copies of the
  * FWU metadata.
  *
  * Return: 0 if OK, -ve on error
  *
  */
 int fwu_revert_boot_index(void)
 {
 	int ret;
 	u32 cur_active_index;
 	struct fwu_mdata *mdata = &g_mdata;

 	/*
 	 * Swap the active index and previous_active_index fields
 	 * in the FWU metadata
 	 */
 	cur_active_index = mdata->active_index;
 	mdata->active_index = mdata->previous_active_index;
 	mdata->previous_active_index = cur_active_index;

 	/*
 	 * Now write this updated FWU metadata to both the
 	 * FWU metadata partitions
 	 */
 	ret = fwu_sync_mdata(mdata, BOTH_PARTS);
 	if (ret) {
 		log_debug("Failed to update FWU metadata partitions\n");
 		ret = -EIO;
 	}

 	return ret;
 }

 /**
  * fwu_clrset_image_accept() - Set or Clear the Acceptance bit for the image
  * @img_type_id: GUID of the image type for which the accepted bit is to be
  *               set or cleared
  * @bank: Bank of which the image's Accept bit is to be set or cleared
  * @action: Action which specifies whether image's Accept bit is to be set or
  *          cleared
  *
  * Set/Clear the accepted bit for the image specified by the img_guid parameter.
  * This indicates acceptance or rejection of image for subsequent boots by some
  * governing component like OS(or firmware).
  *
  * Return: 0 if OK, -ve on error
  *
  */
 static int fwu_clrset_image_accept(efi_guid_t *img_type_id, u32 bank, u8 action)
 {
 	int ret, i;
 	struct fwu_mdata *mdata = &g_mdata;
 	struct fwu_image_entry *img_entry;
 	struct fwu_image_bank_info *img_bank_info;

 	img_entry = &mdata->img_entry[0];
 	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
 		if (!guidcmp(&img_entry[i].image_type_uuid, img_type_id)) {
 			img_bank_info = &img_entry[i].img_bank_info[bank];
 			if (action == IMAGE_ACCEPT_SET)
 				img_bank_info->accepted |= FWU_IMAGE_ACCEPTED;
 			else
 				img_bank_info->accepted = 0;

 			ret = fwu_sync_mdata(mdata, BOTH_PARTS);
 			goto out;
 		}
 	}

 	/* Image not found */
 	ret = -ENOENT;

 out:
 	return ret;
 }

 /**
  * fwu_accept_image() - Set the Acceptance bit for the image
  * @img_type_id: GUID of the image type for which the accepted bit is to be
  *               cleared
  * @bank: Bank of which the image's Accept bit is to be set
  *
  * Set the accepted bit for the image specified by the img_guid parameter. This
  * indicates acceptance of image for subsequent boots by some governing component
  * like OS(or firmware).
  *
  * Return: 0 if OK, -ve on error
  *
  */
 int fwu_accept_image(efi_guid_t *img_type_id, u32 bank)
 {
 	return fwu_clrset_image_accept(img_type_id, bank,
 				       IMAGE_ACCEPT_SET);
 }

 /**
  * fwu_clear_accept_image() - Clear the Acceptance bit for the image
  * @img_type_id: GUID of the image type for which the accepted bit is to be
  *               cleared
  * @bank: Bank of which the image's Accept bit is to be cleared
  *
  * Clear the accepted bit for the image type specified by the img_type_id parameter.
  * This function is called after the image has been updated. The accepted bit is
  * cleared to be set subsequently after passing the image acceptance criteria, by
  * either the OS(or firmware)
  *
  * Return: 0 if OK, -ve on error
  *
  */
 int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank)
 {
 	return fwu_clrset_image_accept(img_type_id, bank,
 				       IMAGE_ACCEPT_CLEAR);
 }

 /**
  * fwu_plat_get_update_index() - Get the value of the update bank
  * @update_idx: Bank number to which images are to be updated
  *
  * Get the value of the bank(partition) to which the update needs to be
  * made.
  *
  * Note: This is a weak function and platforms can override this with
  * their own implementation for selection of the update bank.
  *
  * Return: 0 if OK, -ve on error
  *
  */
 __weak int fwu_plat_get_update_index(uint *update_idx)
 {
 	int ret;
 	u32 active_idx;

 	ret = fwu_get_active_index(&active_idx);
 	if (ret < 0)
 		return -1;

 	*update_idx = (active_idx + 1) % CONFIG_FWU_NUM_BANKS;

 	return ret;
 }

 /**
  * fwu_plat_get_bootidx() - Get the value of the boot index
  * @boot_idx: Boot index value
  *
  * Get the value of the bank(partition) from which the platform
  * has booted. This value is passed to U-Boot from the earlier
  * stage bootloader which loads and boots all the relevant
  * firmware images
  */
 __weak void fwu_plat_get_bootidx(uint *boot_idx)
 {
 	int ret;

 	ret = fwu_get_active_index(boot_idx);
 	if (ret < 0)
 		*boot_idx = 0; /* Dummy value */
 }

 /**
  * fwu_update_checks_pass() - Check if FWU update can be done
  *
  * Check if the FWU update can be executed. The updates are
  * allowed only when the platform is not in Trial State and
  * the boot time checks have passed
  *
  * Return: 1 if OK, 0 if checks do not pass
  *
  */
 u8 fwu_update_checks_pass(void)
 {
 	return !in_trial && boottime_check;
 }

 /**
  * fwu_empty_capsule_checks_pass() - Check if empty capsule can be processed
  *
  * Check if the empty capsule can be processed to either accept or revert
  * an earlier executed update. The empty capsules need to be processed
  * only when the platform is in Trial State and the boot time checks have
  * passed
  *
  * Return: 1 if OK, 0 if not to be allowed
  *
  */
 u8 fwu_empty_capsule_checks_pass(void)
 {
 	return in_trial && boottime_check;
 }

 /**
  * fwu_trial_state_ctr_start() - Start the Trial State counter
  *
  * Start the counter to identify the platform booting in the
  * Trial State. The counter is implemented as an EFI variable.
  *
  * Return: 0 if OK, -ve on error
  *
  */
 int fwu_trial_state_ctr_start(void)
 {
 	int ret;
 	u16 trial_state_ctr;

 	trial_state_ctr = 0;
 	ret = trial_counter_update(&trial_state_ctr);
 	if (ret)
 		log_err("Unable to initialise TrialStateCtr\n");

 	return ret;
 }

 static int fwu_boottime_checks(void *ctx, struct event *event)
 {
 	int ret;
 	u32 boot_idx, active_idx;

 	/* Don't have boot time checks on sandbox */
 	if (IS_ENABLED(CONFIG_SANDBOX)) {
 		boottime_check = 1;
 		return 0;
 	}

 	ret = uclass_first_device_err(UCLASS_FWU_MDATA, &g_dev);
 	if (ret) {
 		log_debug("Cannot find fwu device\n");
 		return ret;
 	}

 	ret = fwu_get_mdata(NULL);
 	if (ret) {
 		log_debug("Unable to read meta-data\n");
 		return ret;
 	}

 	/*
 	 * Get the Boot Index, i.e. the bank from
 	 * which the platform has booted. This value
 	 * gets passed from the ealier stage bootloader
 	 * which booted u-boot, e.g. tf-a. If the
 	 * boot index is not the same as the
 	 * active_index read from the FWU metadata,
 	 * update the active_index.
 	 */
 	fwu_plat_get_bootidx(&boot_idx);
 	if (boot_idx >= CONFIG_FWU_NUM_BANKS) {
 		log_err("Received incorrect value of boot_index\n");
 		return 0;
 	}

 	ret = fwu_get_active_index(&active_idx);
 	if (ret) {
 		log_err("Unable to read active_index\n");
 		return 0;
 	}

 	if (boot_idx != active_idx) {
 		log_info("Boot idx %u is not matching active idx %u, changing active_idx\n",
 			 boot_idx, active_idx);
 		ret = fwu_set_active_index(boot_idx);
 		if (!ret)
 			boottime_check = 1;
 	}

 	if (efi_init_obj_list() != EFI_SUCCESS)
 		return 0;

 	in_trial = in_trial_state(&g_mdata);
 	if (!in_trial || (ret = fwu_trial_count_update()) > 0)
 		ret = trial_counter_update(NULL);

 	if (!ret)
 		boottime_check = 1;

 	return 0;
 }
 EVENT_SPY(EVT_MAIN_LOOP, fwu_boottime_checks);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (c) 2022, Linaro Limited
	*/

	#include <dm.h>
	#include <efi.h>
	#include <efi_loader.h>
	#include <efi_variable.h>
	#include <event.h>
	#include <fwu.h>
	#include <fwu_mdata.h>
	#include <malloc.h>

	#include <linux/errno.h>
	#include <linux/types.h>

	#include <u-boot/crc.h>

	static struct fwu_mdata g_mdata; /* = {0} makes uninit crc32 always invalid */
	static struct udevice *g_dev;
	static u8 in_trial;
	static u8 boottime_check;

	enum {
	IMAGE_ACCEPT_SET = 1,
	IMAGE_ACCEPT_CLEAR,
	};

	enum {
	PRIMARY_PART = 1,
	SECONDARY_PART,
	BOTH_PARTS,
	};

	static int trial_counter_update(u16 *trial_state_ctr)
	{
	bool delete;
	u32 var_attr;
	efi_status_t status;
	efi_uintn_t var_size;

	delete = !trial_state_ctr ? true : false;
	var_size = !trial_state_ctr ? 0 : (efi_uintn_t)sizeof(*trial_state_ctr);
	var_attr = !trial_state_ctr ? 0 : EFI_VARIABLE_NON_VOLATILE \|
	EFI_VARIABLE_BOOTSERVICE_ACCESS;
	status = efi_set_variable_int(u"TrialStateCtr",
	&efi_global_variable_guid,
	var_attr,
	var_size, trial_state_ctr, false);

	if ((delete && (status != EFI_NOT_FOUND &&
	status != EFI_SUCCESS)) \|\|
	(!delete && status != EFI_SUCCESS))
	return -1;

	return 0;
	}

	static int trial_counter_read(u16 *trial_state_ctr)
	{
	efi_status_t status;
	efi_uintn_t var_size;

	var_size = (efi_uintn_t)sizeof(trial_state_ctr);
	status = efi_get_variable_int(u"TrialStateCtr",
	&efi_global_variable_guid,
	NULL,
	&var_size, trial_state_ctr,
	NULL);
	if (status != EFI_SUCCESS) {
	log_err("Unable to read TrialStateCtr variable\n");
	return -1;
	}

	return 0;
	}

	static int fwu_trial_count_update(void)
	{
	int ret;
	u16 trial_state_ctr;

	ret = trial_counter_read(&trial_state_ctr);
	if (ret) {
	log_debug("Unable to read trial_state_ctr\n");
	goto out;
	}

	++trial_state_ctr;
	if (trial_state_ctr > CONFIG_FWU_TRIAL_STATE_CNT) {
	log_info("Trial State count exceeded. Revert back to previous_active_index\n");
	ret = fwu_revert_boot_index();
	if (ret)
	log_err("Unable to revert active_index\n");
	ret = 1;
	} else {
	log_info("Trial State count: attempt %d out of %d\n",
	trial_state_ctr, CONFIG_FWU_TRIAL_STATE_CNT);
	ret = trial_counter_update(&trial_state_ctr);
	if (ret)
	log_err("Unable to increment TrialStateCtr variable\n");
	}

	out:
	return ret;
	}

	static int in_trial_state(struct fwu_mdata *mdata)
	{
	u32 i, active_bank;
	struct fwu_image_entry *img_entry;
	struct fwu_image_bank_info *img_bank_info;

	active_bank = mdata->active_index;
	img_entry = &mdata->img_entry[0];
	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
	img_bank_info = &img_entry[i].img_bank_info[active_bank];
	if (!img_bank_info->accepted) {
	log_info("System booting in Trial State\n");
	return 1;
	}
	}

	return 0;
	}

	static int fwu_get_image_type_id(u8 image_index, efi_guid_t image_type_id)
	{
	u8 index;
	int i;
	struct efi_fw_image *image;

	index = *image_index;
	image = update_info.images;
	for (i = 0; i < update_info.num_images; i++) {
	if (index == image[i].image_index) {
	guidcpy(image_type_id, &image[i].image_type_id);
	return 0;
	}
	}

	return -ENOENT;
	}

	/**
	* fwu_sync_mdata() - Update given meta-data partition(s) with the copy provided
	* @mdata: FWU metadata structure
	* @part: Bitmask of FWU metadata partitions to be written to
	*
	* Return: 0 if OK, -ve on error
	*/
	static int fwu_sync_mdata(struct fwu_mdata *mdata, int part)
	{
	void *buf = &mdata->version;
	int err;

	if (part == BOTH_PARTS) {
	err = fwu_sync_mdata(mdata, SECONDARY_PART);
	if (err)
	return err;
	part = PRIMARY_PART;
	}

	/*
	* Calculate the crc32 for the updated FWU metadata
	* and put the updated value in the FWU metadata crc32
	* field
	*/
	mdata->crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));

	err = fwu_write_mdata(g_dev, mdata, part == PRIMARY_PART);
	if (err) {
	log_err("Unable to write %s mdata\n",
	part == PRIMARY_PART ? "primary" : "secondary");
	return err;
	}

	/* update the cached copy of meta-data */
	memcpy(&g_mdata, mdata, sizeof(struct fwu_mdata));

	return 0;
	}

	static inline int mdata_crc_check(struct fwu_mdata *mdata)
	{
	void *buf = &mdata->version;
	u32 calc_crc32 = crc32(0, buf, sizeof(*mdata) - sizeof(u32));

	return calc_crc32 == mdata->crc32 ? 0 : -EINVAL;
	}

	/**
	* fwu_get_mdata() - Read, verify and return the FWU metadata
	* @mdata: Output FWU metadata read or NULL
	*
	* Read both the metadata copies from the storage media, verify their checksum,
	* and ascertain that both copies match. If one of the copies has gone bad,
	* restore it from the good copy.
	*
	* Return: 0 if OK, -ve on error
	*/
	int fwu_get_mdata(struct fwu_mdata *mdata)
	{
	int err;
	bool parts_ok[2] = { false };
	struct fwu_mdata s, *parts_mdata[2];

	parts_mdata[0] = &g_mdata;
	parts_mdata[1] = &s;

	/* if mdata already read and ready */
	err = mdata_crc_check(parts_mdata[0]);
	if (!err)
	goto ret_mdata;
	/* else read, verify and, if needed, fix mdata */

	for (int i = 0; i < 2; i++) {
	parts_ok[i] = false;
	err = fwu_read_mdata(g_dev, parts_mdata[i], !i);
	if (!err) {
	err = mdata_crc_check(parts_mdata[i]);
	if (!err)
	parts_ok[i] = true;
	else
	log_debug("mdata : %s crc32 failed\n", i ? "secondary" : "primary");
	}
	}

	if (parts_ok[0] && parts_ok[1]) {
	/*
	* Before returning, check that both the
	* FWU metadata copies are the same.
	*/
	err = memcmp(parts_mdata[0], parts_mdata[1], sizeof(struct fwu_mdata));
	if (!err)
	goto ret_mdata;

	/*
	* If not, populate the secondary partition from the
	* primary partition copy.
	*/
	log_info("Both FWU metadata copies are valid but do not match.");
	log_info(" Restoring the secondary partition from the primary\n");
	parts_ok[1] = false;
	}

	for (int i = 0; i < 2; i++) {
	if (parts_ok[i])
	continue;

	memcpy(parts_mdata[i], parts_mdata[1 - i], sizeof(struct fwu_mdata));
	err = fwu_sync_mdata(parts_mdata[i], i ? SECONDARY_PART : PRIMARY_PART);
	if (err) {
	log_debug("mdata : %s write failed\n", i ? "secondary" : "primary");
	return err;
	}
	}

	ret_mdata:
	if (!err && mdata)
	memcpy(mdata, parts_mdata[0], sizeof(struct fwu_mdata));

	return err;
	}

	/**
	* fwu_get_active_index() - Get active_index from the FWU metadata
	* @active_idx: active_index value to be read
	*
	* Read the active_index field from the FWU metadata and place it in
	* the variable pointed to be the function argument.
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	int fwu_get_active_index(uint *active_idx)
	{
	int ret = 0;
	struct fwu_mdata *mdata = &g_mdata;

	/*
	* Found the FWU metadata partition, now read the active_index
	* value
	*/
	*active_idx = mdata->active_index;
	if (*active_idx >= CONFIG_FWU_NUM_BANKS) {
	log_debug("Active index value read is incorrect\n");
	ret = -EINVAL;
	}

	return ret;
	}

	/**
	* fwu_set_active_index() - Set active_index in the FWU metadata
	* @active_idx: active_index value to be set
	*
	* Update the active_index field in the FWU metadata
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	int fwu_set_active_index(uint active_idx)
	{
	int ret;
	struct fwu_mdata *mdata = &g_mdata;

	if (active_idx >= CONFIG_FWU_NUM_BANKS) {
	log_debug("Invalid active index value\n");
	return -EINVAL;
	}

	/*
	* Update the active index and previous_active_index fields
	* in the FWU metadata
	*/
	mdata->previous_active_index = mdata->active_index;
	mdata->active_index = active_idx;

	/*
	* Now write this updated FWU metadata to both the
	* FWU metadata partitions
	*/
	ret = fwu_sync_mdata(mdata, BOTH_PARTS);
	if (ret) {
	log_debug("Failed to update FWU metadata partitions\n");
	ret = -EIO;
	}

	return ret;
	}

	/**
	* fwu_get_image_index() - Get the Image Index to be used for capsule update
	* @image_index: The Image Index for the image
	*
	* The FWU multi bank update feature computes the value of image_index at
	* runtime, based on the bank to which the image needs to be written to.
	* Derive the image_index value for the image.
	*
	* Currently, the capsule update driver uses the DFU framework for
	* the updates. This function gets the DFU alt number which is to
	* be used as the Image Index
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	int fwu_get_image_index(u8 *image_index)
	{
	int ret, i;
	u8 alt_num;
	uint update_bank;
	efi_guid_t *image_guid, image_type_id;
	struct fwu_mdata *mdata = &g_mdata;
	struct fwu_image_entry *img_entry;
	struct fwu_image_bank_info *img_bank_info;

	ret = fwu_plat_get_update_index(&update_bank);
	if (ret) {
	log_debug("Failed to get the FWU update bank\n");
	goto out;
	}

	ret = fwu_get_image_type_id(image_index, &image_type_id);
	if (ret) {
	log_debug("Unable to get image_type_id for image_index %u\n",
	*image_index);
	goto out;
	}

	ret = -EINVAL;
	/*
	* The FWU metadata has been read. Now get the image_uuid for the
	* image with the update_bank.
	*/
	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
	if (!guidcmp(&image_type_id,
	&mdata->img_entry[i].image_type_uuid)) {
	img_entry = &mdata->img_entry[i];
	img_bank_info = &img_entry->img_bank_info[update_bank];
	image_guid = &img_bank_info->image_uuid;
	ret = fwu_plat_get_alt_num(g_dev, image_guid, &alt_num);
	if (ret) {
	log_debug("alt_num not found for partition with GUID %pUs\n",
	image_guid);
	} else {
	log_debug("alt_num %d for partition %pUs\n",
	alt_num, image_guid);
	*image_index = alt_num + 1;
	}

	goto out;
	}
	}

	log_err("Partition with the image type %pUs not found\n",
	&image_type_id);

	out:
	return ret;
	}

	/**
	* fwu_revert_boot_index() - Revert the active index in the FWU metadata
	*
	* Revert the active_index value in the FWU metadata, by swapping the values
	* of active_index and previous_active_index in both copies of the
	* FWU metadata.
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	int fwu_revert_boot_index(void)
	{
	int ret;
	u32 cur_active_index;
	struct fwu_mdata *mdata = &g_mdata;

	/*
	* Swap the active index and previous_active_index fields
	* in the FWU metadata
	*/
	cur_active_index = mdata->active_index;
	mdata->active_index = mdata->previous_active_index;
	mdata->previous_active_index = cur_active_index;

	/*
	* Now write this updated FWU metadata to both the
	* FWU metadata partitions
	*/
	ret = fwu_sync_mdata(mdata, BOTH_PARTS);
	if (ret) {
	log_debug("Failed to update FWU metadata partitions\n");
	ret = -EIO;
	}

	return ret;
	}

	/**
	* fwu_clrset_image_accept() - Set or Clear the Acceptance bit for the image
	* @img_type_id: GUID of the image type for which the accepted bit is to be
	* set or cleared
	* @bank: Bank of which the image's Accept bit is to be set or cleared
	* @action: Action which specifies whether image's Accept bit is to be set or
	* cleared
	*
	* Set/Clear the accepted bit for the image specified by the img_guid parameter.
	* This indicates acceptance or rejection of image for subsequent boots by some
	* governing component like OS(or firmware).
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	static int fwu_clrset_image_accept(efi_guid_t *img_type_id, u32 bank, u8 action)
	{
	int ret, i;
	struct fwu_mdata *mdata = &g_mdata;
	struct fwu_image_entry *img_entry;
	struct fwu_image_bank_info *img_bank_info;

	img_entry = &mdata->img_entry[0];
	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
	if (!guidcmp(&img_entry[i].image_type_uuid, img_type_id)) {
	img_bank_info = &img_entry[i].img_bank_info[bank];
	if (action == IMAGE_ACCEPT_SET)
	img_bank_info->accepted \|= FWU_IMAGE_ACCEPTED;
	else
	img_bank_info->accepted = 0;

	ret = fwu_sync_mdata(mdata, BOTH_PARTS);
	goto out;
	}
	}

	/* Image not found */
	ret = -ENOENT;

	out:
	return ret;
	}

	/**
	* fwu_accept_image() - Set the Acceptance bit for the image
	* @img_type_id: GUID of the image type for which the accepted bit is to be
	* cleared
	* @bank: Bank of which the image's Accept bit is to be set
	*
	* Set the accepted bit for the image specified by the img_guid parameter. This
	* indicates acceptance of image for subsequent boots by some governing component
	* like OS(or firmware).
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	int fwu_accept_image(efi_guid_t *img_type_id, u32 bank)
	{
	return fwu_clrset_image_accept(img_type_id, bank,
	IMAGE_ACCEPT_SET);
	}

	/**
	* fwu_clear_accept_image() - Clear the Acceptance bit for the image
	* @img_type_id: GUID of the image type for which the accepted bit is to be
	* cleared
	* @bank: Bank of which the image's Accept bit is to be cleared
	*
	* Clear the accepted bit for the image type specified by the img_type_id parameter.
	* This function is called after the image has been updated. The accepted bit is
	* cleared to be set subsequently after passing the image acceptance criteria, by
	* either the OS(or firmware)
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	int fwu_clear_accept_image(efi_guid_t *img_type_id, u32 bank)
	{
	return fwu_clrset_image_accept(img_type_id, bank,
	IMAGE_ACCEPT_CLEAR);
	}

	/**
	* fwu_plat_get_update_index() - Get the value of the update bank
	* @update_idx: Bank number to which images are to be updated
	*
	* Get the value of the bank(partition) to which the update needs to be
	* made.
	*
	* Note: This is a weak function and platforms can override this with
	* their own implementation for selection of the update bank.
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	__weak int fwu_plat_get_update_index(uint *update_idx)
	{
	int ret;
	u32 active_idx;

	ret = fwu_get_active_index(&active_idx);
	if (ret < 0)
	return -1;

	*update_idx = (active_idx + 1) % CONFIG_FWU_NUM_BANKS;

	return ret;
	}

	/**
	* fwu_plat_get_bootidx() - Get the value of the boot index
	* @boot_idx: Boot index value
	*
	* Get the value of the bank(partition) from which the platform
	* has booted. This value is passed to U-Boot from the earlier
	* stage bootloader which loads and boots all the relevant
	* firmware images
	*/
	__weak void fwu_plat_get_bootidx(uint *boot_idx)
	{
	int ret;

	ret = fwu_get_active_index(boot_idx);
	if (ret < 0)
	boot_idx = 0; / Dummy value */
	}

	/**
	* fwu_update_checks_pass() - Check if FWU update can be done
	*
	* Check if the FWU update can be executed. The updates are
	* allowed only when the platform is not in Trial State and
	* the boot time checks have passed
	*
	* Return: 1 if OK, 0 if checks do not pass
	*
	*/
	u8 fwu_update_checks_pass(void)
	{
	return !in_trial && boottime_check;
	}

	/**
	* fwu_empty_capsule_checks_pass() - Check if empty capsule can be processed
	*
	* Check if the empty capsule can be processed to either accept or revert
	* an earlier executed update. The empty capsules need to be processed
	* only when the platform is in Trial State and the boot time checks have
	* passed
	*
	* Return: 1 if OK, 0 if not to be allowed
	*
	*/
	u8 fwu_empty_capsule_checks_pass(void)
	{
	return in_trial && boottime_check;
	}

	/**
	* fwu_trial_state_ctr_start() - Start the Trial State counter
	*
	* Start the counter to identify the platform booting in the
	* Trial State. The counter is implemented as an EFI variable.
	*
	* Return: 0 if OK, -ve on error
	*
	*/
	int fwu_trial_state_ctr_start(void)
	{
	int ret;
	u16 trial_state_ctr;

	trial_state_ctr = 0;
	ret = trial_counter_update(&trial_state_ctr);
	if (ret)
	log_err("Unable to initialise TrialStateCtr\n");

	return ret;
	}

	static int fwu_boottime_checks(void ctx, struct event event)
	{
	int ret;
	u32 boot_idx, active_idx;

	/* Don't have boot time checks on sandbox */
	if (IS_ENABLED(CONFIG_SANDBOX)) {
	boottime_check = 1;
	return 0;
	}

	ret = uclass_first_device_err(UCLASS_FWU_MDATA, &g_dev);
	if (ret) {
	log_debug("Cannot find fwu device\n");
	return ret;
	}

	ret = fwu_get_mdata(NULL);
	if (ret) {
	log_debug("Unable to read meta-data\n");
	return ret;
	}

	/*
	* Get the Boot Index, i.e. the bank from
	* which the platform has booted. This value
	* gets passed from the ealier stage bootloader
	* which booted u-boot, e.g. tf-a. If the
	* boot index is not the same as the
	* active_index read from the FWU metadata,
	* update the active_index.
	*/
	fwu_plat_get_bootidx(&boot_idx);
	if (boot_idx >= CONFIG_FWU_NUM_BANKS) {
	log_err("Received incorrect value of boot_index\n");
	return 0;
	}

	ret = fwu_get_active_index(&active_idx);
	if (ret) {
	log_err("Unable to read active_index\n");
	return 0;
	}

	if (boot_idx != active_idx) {
	log_info("Boot idx %u is not matching active idx %u, changing active_idx\n",
	boot_idx, active_idx);
	ret = fwu_set_active_index(boot_idx);
	if (!ret)
	boottime_check = 1;
	}

	if (efi_init_obj_list() != EFI_SUCCESS)
	return 0;

	in_trial = in_trial_state(&g_mdata);
	if (!in_trial \|\| (ret = fwu_trial_count_update()) > 0)
	ret = trial_counter_update(NULL);

	if (!ret)
	boottime_check = 1;

	return 0;
	}
	EVENT_SPY(EVT_MAIN_LOOP, fwu_boottime_checks);