RE: NVS not compatible with MCUBOOT

anisaw — Mon, 07 Nov 2022 01:43:59 GMT

Great thanks! This did the trick.

RE: NVS not compatible with MCUBOOT

Vidar Berg — Mon, 31 Oct 2022 14:37:30 GMT

Hello Andrew,

In general, we recommend using the CUSTOMER registers in UICR for keeping permanent values such serial numbers, Bluetooth addresses, etc, as it is easier (does not require FLASH area to be allocated by the linker). It's better to use a filesystem in FLASH when you have data that needs to get updated at some point (Note: the ERASEUICR operation is blocked when APPROTECT is enabled - Access port protection behavior).

Example of how you can write to a UICR.CUSTOMER[] register with nrfjprog:

$ nrfjprog --memwr 0x10001080 --val 0x12345678 // Write 0x12345678 to UICR.CUSTOMER[0].

But if you prefer to use NVS, please have a look at the example I made below. It's based on the peripheral_lbs sample from SDK 2.1.1 and the code snippets you posted. But instead of making a separate storage partition for the user data I opted to share the storage partition between the NVS instance used by BT settings and the one used by the app.

devzone.nordicsemi.com/.../2260.peripheral_5F00_lbs_5F00_w_5F00_nvs.zip

Note: NVS requires a minimum of 2 sectors ( 2x 4096 bytes) for each instance, but there are not checks in my implementation to ensure this requirement is met.

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/services/storage/nvs/nvs.html#nvs-api

Changes:

--- /home/vidarbe/ncs/v2.1.1/nrf/samples/bluetooth/peripheral_lbs/prj.conf	2022-10-24 09:14:32.019870394 +0200
+++ prj.conf	2022-10-31 14:36:06.904168035 +0100
@@ -15,3 +15,13 @@
 CONFIG_DK_LIBRARY=y
 
 CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048
+
+CONFIG_BOOTLOADER_MCUBOOT=y
+
+CONFIG_NVS=y
+CONFIG_NVS_LOG_LEVEL_DBG=y
+# Double the size of the settings storage partition,
+# and allocate the first half of it to BT_SETTINGS.
+CONFIG_PM_PARTITION_SIZE_SETTINGS_STORAGE=0x4000
+CONFIG_SETTINGS_NVS_SECTOR_COUNT=2
+
--- /home/vidarbe/ncs/v2.1.1/nrf/samples/bluetooth/peripheral_lbs/src/main.c	2022-10-24 09:14:32.019870394 +0200
+++ src/main.c	2022-10-31 15:12:25.290963916 +0100
@@ -26,6 +26,13 @@
 
 #include <dk_buttons_and_leds.h>
 
+#include <zephyr/drivers/flash.h>
+#include <zephyr/storage/flash_map.h>
+#include <zephyr/fs/nvs.h>
+
+#define STORAGE_NODE_LABEL 		storage
+#define RBT_CNT_ID 				3
+
 #define DEVICE_NAME             CONFIG_BT_DEVICE_NAME
 #define DEVICE_NAME_LEN         (sizeof(DEVICE_NAME) - 1)
 
@@ -38,6 +45,8 @@
 
 #define USER_BUTTON             DK_BTN1_MSK
 
+static struct nvs_fs fs;
+
 static bool app_button_state;
 
 static const struct bt_data ad[] = {
@@ -181,6 +190,67 @@
 	return err;
 }
 
+static void nvs_test(void)
+{
+	int rc = 0;
+	struct flash_pages_info info;
+	uint32_t reboot_counter = 0U;
+	/* define the nvs file system by settings with:
+	 *	sector_size equal to the pagesize,
+	 *	starting at FLASH_AREA_OFFSET(STORAGE_NODE_LABEL)
+	 */
+	fs.flash_device = FLASH_AREA_DEVICE(STORAGE_NODE_LABEL);
+	if (!device_is_ready(fs.flash_device)) {
+		printk("Flash device %s is not ready\n", fs.flash_device->name);
+		return;
+	}
+
+	fs.offset = FLASH_AREA_OFFSET(STORAGE_NODE_LABEL);
+	printk("Storage partition start address 0x%x\n", fs.offset);
+
+	rc = flash_get_page_info_by_offs(fs.flash_device, fs.offset, &info);
+	if (rc) {
+		printk("Unable to get page info\n");
+		return;
+	}
+
+	fs.offset += (info.size * CONFIG_SETTINGS_NVS_SECTOR_COUNT);
+    printk("Offset user data 0x%x\n", fs.offset);
+
+	fs.sector_size = info.size;
+	printk("Sector size 0x%x\n", fs.sector_size);
+	fs.sector_count = (CONFIG_PM_PARTITION_SIZE_SETTINGS_STORAGE / info.size) -
+					CONFIG_SETTINGS_NVS_SECTOR_COUNT;
+	printk("Sector count 0x%x\n", fs.sector_count);
+
+	rc = nvs_mount(&fs);
+	if (rc) {
+		printk("Flash Init failed\n");
+		return;
+	}
+
+	/* RBT_CNT_ID is used to store the reboot counter, lets see
+	 * if we can read it from flash
+	 */
+	rc = nvs_read(&fs, RBT_CNT_ID, &reboot_counter, sizeof(reboot_counter));
+	if (rc > 0) { /* item was found, show it */
+		printk("Id: %d, Reboot_counter: %d\n",
+			RBT_CNT_ID, reboot_counter);
+	} else   {/* item was not found, add it */
+		printk("No Reboot counter found, adding it at id %d\n",
+		       RBT_CNT_ID);
+		(void)nvs_write(&fs, RBT_CNT_ID, &reboot_counter,
+			  sizeof(reboot_counter));
+	}
+
+	reboot_counter++;
+	(void)nvs_write(
+		&fs, RBT_CNT_ID, &reboot_counter,
+		sizeof(reboot_counter));
+
+
+}
+
 void main(void)
 {
 	int blink_status = 0;
@@ -241,6 +311,8 @@
 
 	printk("Advertising successfully started\n");
 
+	nvs_test();
+
 	for (;;) {
 		dk_set_led(RUN_STATUS_LED, (++blink_status) % 2);
 		k_sleep(K_MSEC(RUN_LED_BLINK_INTERVAL));

Best regards,

Vidar