How to use nvs_read and nvs_write in aws_fota app?

[Yusuke]

I would like to use nvs_read and nvs_write in aws_fota app to store a mode value inside, but it doesn't work. Any help?

I added the following lines to aws_fota prj.conf

<prj.conf>

CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_MPU_ALLOW_FLASH_WRITE=y

I added the following code to aws_fota maiin.c

#include <drivers/flash.h>
#include <storage/flash_map.h>
#include <fs/nvs.h>
#define NVS_ID_MODE 1

int8_t init_nvs_sys()
{
    u8_t rc;
    struct flash_pages_info info;

	/* define the nvs file system by settings with:
	 *	sector_size equal to the pagesize,
	 *	3 sectors
	 *	starting at FLASH_AREA_OFFSET(storage)
	 */
	nvs_fs.offset = FLASH_AREA_OFFSET(storage);
	rc = flash_get_page_info_by_offs(
		device_get_binding(DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL),
		nvs_fs.offset, &info);
	if (rc) {
		printk("Unable to get page info");
        return -1;
	}
	nvs_fs.sector_size = info.size;
	nvs_fs.sector_count = 3U;

	rc = nvs_init(&nvs_fs, DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL);
	if (rc) {
		printk("Flash Init failed\n");
        return -1;
	}
}

void main(void)
{
	int err;

    /***************/
	/* Write and read params */
    int ret;
    u8_t mode;
	ret = init_nvs_sys();
	if (ret < 0) {
        printk("Error: init_nvs_sys\n");
	}
    // Write mode
	mode = 0;
	if(nvs_write(&nvs_fs, NVS_ID_MODE, &mode, 1) < 0){ // This causes Error -22
        printk("Error: nvs_write NVS_ID_MODE\n");
    }
    mode = 2;

    // Read mode
	ret = nvs_read(&nvs_fs, NVS_ID_MODE, &mode, 1);
	printk( "nvs_read ret = %d, id = %d, mode = %u\n", ret, NVS_ID_MODE, mode);
	if (ret < 0) {
		printk("Error: nvs_read NVS_ID_MODE\n");
	}

    .
    .
    .
        

	

I have inspected a while and it seems that this line in prj.conf causes the issue.

CONFIG_SETTING=y

Can you tell me how to solve this issue?

[Simonr]

Hi Yusuke

The settings loader module is enabled for every nRF Desktop device with Zephyr's :ref:`zephyr:settings_api` enabled. The :ref:`zephyr:settings_api` subsystem is enabled with the :option:`CONFIG_SETTINGS` Kconfig option. Zephyr's Bluetooth stack does not load the zephyr:settings_api data on its own, as Zephyr assumes that the application will call :cpp:func:`settings_load` after completing all necessary initialization. This function is called on the settings loader module initialization.

Please also make sure that you write CONFIG_SETTINGS=y, not SETTING. 

Best regards,

Simon

[Yusuke]

Hi,

Thank you for the detail and I'm reading this page

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/nrf_desktop/doc/settings_loader.html

but I'm not really understanding the settings loader module.. The settings loader module seems to be similar to nvs library.

https://docs.zephyrproject.org/latest/reference/storage/nvs/nvs.html 

>Please also make sure that you write CONFIG_SETTINGS=y, not SETTING. 

oh, sorry it's typo. Yes, it's CONFIG_SETTINGS=y.

I tried aws_fota app commenting out these two lines and it apparently works out.

<prj.conf>

# CONFIG_SETTINGS=y
# CONFIG_SETTINGS_NVS=y

Do you think it is ok to remove these lines. If so, we can use nvs in aws_fota app.

[Yusuke]

u8_t mode = 2;
ret = nvs_write(&nvs_fs, NVS_ID_MODE, &mode, 1);
if (ret < 0) {
	return;
}

I get -22 errno in nvs_write when I add it to aws_fota.

This comes from line 179 in ncs\v1.3.0\zephyr\drivers\flash\soc_flash_nrf.c

is_regular_addr_valid(addr, len) apparently fails. 

static int flash_nrf_read(struct device *dev, off_t addr,
			    void *data, size_t len)
{
	if (is_regular_addr_valid(addr, len)) { /* This fails */
		addr += DT_REG_ADDR(SOC_NV_FLASH_NODE);
	} else if (!is_uicr_addr_valid(addr, len)) {
		return -EINVAL; /* HERE */
	}

	if (!len) {
		return 0;
	}

#if CONFIG_ARM_NONSECURE_FIRMWARE && CONFIG_SPM && USE_PARTITION_MANAGER
	if (addr < PM_APP_ADDRESS) {
		return spm_request_read(data, addr, len);
	}
#endif

	memcpy(data, (void *)addr, len);

	return 0;
}

In addition, I printed out parameters.

static inline bool is_regular_addr_valid(off_t addr, size_t len)
{
	size_t flash_size = nrfx_nvmc_flash_size_get();

        printk("flash_size = %u\n", flash_size); /* ADD HERE */
        printk("addr = %ld\n", addr); /* ADD HERE */
        printk("len = %u\n", len); /* ADD HERE */

	if (addr >= flash_size ||
	    addr < 0 ||
	    len > flash_size ||
	    (addr) + len > flash_size) {
		return false;
	}

	return true;
}

* without CONFIG_SETTINGS = y

flash_size = 1048576
addr = 1028040
len = 8
flash_size = 1048576
addr = 1028048
len = 8
flash_size = 1048576
addr = 1028056
len = 8
flash_size = 1048576
addr = 1028064
len = 8
flash_size = 1048576
addr = 1028072
len = 8
flash_size = 1048576
addr = 1024004
len = 1

* with CONFIG_SETTINGS = y

flash_size = 1048576
addr = 1044464
len = 8
flash_size = 1048576
addr = 1052664
len = 8

=> errno -22 occurs

The following formula fails with CONFIG_SETTINGS = y.

(addr) + len > flash_size

Any advice to solve this issue?

[Simon]

I am sorry for the late reply. Currently, a huge portion of the support team is on summer vacation (including many of the nRF9160 experts), so you may experience delayed answers. I will look into your issue in the upcoming days.

Best regards,

Simon

[Simon]

Have you made any progress on this lately?

[Yusuke]

not really. Just remove the two lines and working out so far. I'm not sure this is fine or not

[Simon]

It seems like the settings driver is used in ncs\v1.3.0\nrf\subsys\dfu\src\dfu_target_mcuboot.c, and only if CONFIG_DFU_TARGET_MCUBOOT_SAVE_PROGRESS=y. I suggest you to read about the config here, and if that is something you want. If you set it to n, I don't think you'll get any conflicts.

Best regards,

Simon