RE: Little FS mount issues

AHaug — Mon, 13 Nov 2023 14:16:45 GMT

Hi Kaushalya

I've had a very quick look at the code and I can't see any issues with it. However I recommend that you run tests and set up some routine to catch edge cases so you can verify in your own environment that the code works as you've designed it to do

We also have the settings sample that you can base your application on and have a look at: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/samples/subsys/settings/README.html

Kind regards,
Andreas

RE: Little FS mount issues

kaushalyasat — Sun, 12 Nov 2023 09:28:42 GMT

Hi,

I think I managed to fix it by dropping the liitleFS mount and just using settings subsystem.

My current prj.conf is as follows. (just the part relevant for Settings subsystem)

CONFIG_NVS=y
CONFIG_SETTINGS_NVS=y
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y

CONFIG_SETTINGS=y
CONFIG_SETTINGS_RUNTIME=y

# CONFIG_FLASH=y
# CONFIG_FLASH_PAGE_LAYOUT=y
# CONFIG_FLASH_MAP=y
# CONFIG_FILE_SYSTEM=y
# CONFIG_FILE_SYSTEM_LITTLEFS=y
# CONFIG_SETTINGS_FS=y
# CONFIG_SETTINGS_FS_FILE="/lfs/settings"

Then I added the following code for direct access (without a handler as I am not 100% clear about it)

struct direct_immediate_value {
	size_t len;
	void *dest;
	uint8_t fetched;
};

static int direct_loader_immediate_value(const char *name, size_t len, settings_read_cb read_cb, void *cb_arg, void *param) {
	const char *next;
	size_t name_len;
	int rc;
	struct direct_immediate_value *one_value = (struct direct_immediate_value *)param;

	name_len = settings_name_next(name, &next);

	if (name_len == 0) {
		if (len == one_value->len) {
			rc = read_cb(cb_arg, one_value->dest, len);
			if (rc >= 0) {
				one_value->fetched = 1;
				return 0;
			}

			LOG_ERR("load fail %d", rc);
			return rc;
		}
		return -EINVAL;
	}

	/* other keys aren't served by the callback
	 * Return success in order to skip them
	 * and keep storage processing.
	 */
	return 0;
}

int load_immediate_value(const char *name, void *dest, size_t len)
{
	int rc;
	struct direct_immediate_value dov;

	dov.fetched = 0;
	dov.len = len;
	dov.dest = dest;

	rc = settings_load_subtree_direct(name, direct_loader_immediate_value, (void *)&dov);
	if (rc == 0) {
		if (!dov.fetched) {
			rc = -ENOENT;
		}
	}

	return rc;
}

void settings_initiallization (void) {
	int rc;

#if IS_ENABLED(CONFIG_FILE_SYSTEM_LITTLEFS)
	FS_LITTLEFS_DECLARE_DEFAULT_CONFIG(storage);

	/* mounting info */
	static struct fs_mount_t littlefs_mnt = {
		.type = FS_LITTLEFS,
		.fs_data = &storage,
		.storage_dev = (void *)FLASH_AREA_ID (storage),
		.mnt_point = "/lfs"
	};

	rc = fs_mount(&littlefs_mnt);

	if (rc != 0) {
		LOG_ERR ("mounting littlefs error: [%d]\n", rc);
	} else {

		rc = fs_unlink(CONFIG_SETTINGS_FS_FILE);

		if ((rc != 0) && (rc != -ENOENT)) {
			LOG_ERR ("can't delete config file%d", rc);
		} else {
			LOG_INF ("FS initialized: OK");
		}
	}
#endif

	rc = settings_subsys_init();
	if (rc) {
		LOG_ERR ("settings subsys initialization: fail (err %d)", rc);
		return;
	}

	LOG_INF ("settings subsys initialization: OK");
}

Then the read / write code is as follows.

int eraseIPV6inFlash () {
	int rc;
	uint32_t flag = 0x00000000;
	uint32_t hostIP = 0x00000000;
	uint16_t hostFWver = 0x0000;

	rc = settings_save_one ("flag", (const void *)&flag, sizeof(flag));	// erase flag
	if (rc != 0) {
		LOG_ERR ("unexpected error eraseing flag", rc);
	}
	rc = settings_save_one ("hostIP", (const void *)&hostIP, sizeof(hostIP));	// erase host IP
	if (rc != 0) {
		LOG_ERR ("unexpected error erasing host IP", rc);
	}
	rc = settings_save_one ("hostFWver", (const void *)&hostFWver, sizeof(hostFWver));	// erase host fw ver
	if (rc != 0) {
		LOG_ERR ("unexpected error host FW ver", rc);
	}
	
	return rc;
}

void restoreIPV6fromFlash (uint32_t *myExtAddr) {
	int rc;
	uint32_t hostIP[4];

	rc = load_immediate_value("hostIP", &hostIP, sizeof(hostIP));
	if (rc == -ENOENT) {
		LOG_ERR ("host IP value not found!!");
	} 
	else if (rc == 0) {		// valid host IP value read
		LOG_INF ("Restore host IP %x", *myExtAddr);

	} else 
		LOG_ERR ("unexpected error %d", rc);

	*myExtAddr = hostIP [0];
	*(myExtAddr+1) = hostIP [1];
	*(myExtAddr+2) = hostIP [2];
	*(myExtAddr+3) = hostIP [3];
}

Please let me know what I have done is correct.

Cheers,

Kaushalya