External Memory on 9160dk

[Felipe Dantas]

Hi everyone,

  I working on a project for nrf9160 in 9160DK and i need to use the external flash memory onboard with nvs.h but i can't get it to work by anyway and a try to looking for an example or sample in Nordic site and forum but all topics that i founded are much old and don't compile (consider that i'm on ncs v2.6.1). Can someone provide me one example or sample for this? Thanks!

[Maria Gilje]

Hello,

Have you followed the guidelines for configuring external flash on nRF9160 DK here?

The Modem trace external flash backend sample configures and uses the external flash.

Best regards,

Maria

[Felipe Dantas]

Hello Maria,

I saw this sample now. Early i followed the guideline for external memory use, flashing the 52840 firmware corretly and creating the necessary overlay like as described. My problem (i guess) is for instanciate and use the memory in aplication. This sample (modem_trace_flash) also don't show how do that (I don't see nothing in main.c about memory usage). 

[Maria Gilje]

Hi Felipe,

Felipe Dantas said:

I saw this sample now. Early i followed the guideline for external memory use, flashing the 52840 firmware corretly and creating the necessary overlay like as described.

Great!

Felipe Dantas said:

My problem (i guess) is for instanciate and use the memory in aplication. This sample (modem_trace_flash) also don't show how do that (I don't see nothing in main.c about memory usage). 

You can refer to the NVS sample from Zephyr. When external flash is enabled, the NVS partition is automatically placed in external flash, and nvs_write() and nvs_read() can be used to write to/read from external flash.

Best regards,

Maria

[Felipe Dantas]

Ohh, interesting! 

I already used NVS to get start non volatile memory usage some time before, and, cause this, already familiarized with NVS sample. In my application, i use NVS with internal flash to store some user config variables like as server hostname, username, password... You say that NVS is automatically placed in external flash. By this way, i understood that isn't possible use internal and external flash with NVS at same time, is it?

I understand that the linkage between fisical memory sector and "code" occurs here( this is in NVS Sample):

#define NVS_PARTITION       storage_partition

#define NVS_PARTITION_DEVICE    FIXED_PARTITION_DEVICE(NVS_PARTITION)

#define NVS_PARTITION_OFFSET    FIXED_PARTITION_OFFSET(NVS_PARTITION)

static struct nvs_fs fs;

fs.flash_device = NVS_PARTITION_DEVICE;

I thinking in try something like this:

#define NVS_PARTITION       external_flash

But now, I don't know if is the correctly way. 

Can you understand my doubts at this point?

[Felipe Dantas]

So,

today i´ve made a lot of tests and get some conclusions:

Don´t seems to me that NVS partition are automatically placed on external flash if i only put the overlay and prj configs, cause i use nvs_calc_free_space() and this function always return 8176 bytes, with or without overlay and configs.

In other test, i try this on NVS sample:

#define NVS_PARTITION external_flash

and put overlay and configs, so i get the following out in console:

[00:00:00.377,410] <inf> spi_nor: mx25r6435f@1: 8 MiBy flash
*** Booting nRF Connect SDK 3758bcbfa5cd ***
[00:00:00.377,563] <err> fs_nvs: Invalid sector size
Flash Init failed

This is the entire code that i use:

Main:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ncs_version.h>
#include <zephyr/kernel.h>
#include <zephyr/devicetree.h>
#include <zephyr/logging/log.h>
#include <zephyr/drivers/uart.h>
#include <zephyr/sys/printk.h>
#include <zephyr/drivers/flash.h>
#include <zephyr/storage/flash_map.h>
#include <zephyr/fs/nvs.h>

static struct nvs_fs fs;

#define NVS_PARTITION external_flash
#define NVS_PARTITION_DEVICE FIXED_PARTITION_DEVICE(NVS_PARTITION)
#define NVS_PARTITION_OFFSET FIXED_PARTITION_OFFSET(NVS_PARTITION)

#define NVS_BOOT_COUNTER_ID 0

int init_counter = 0;

void main(void)
{
    int rc = 0;
    struct flash_pages_info info;
    
    fs.flash_device = NVS_PARTITION_DEVICE;
    if (!device_is_ready(fs.flash_device))
    {
        printk("Flash device %s is not ready\n", fs.flash_device->name);
        return 0;
    }
    fs.offset = NVS_PARTITION_OFFSET;
    rc = flash_get_page_info_by_offs(fs.flash_device, fs.offset, &info);
    if (rc)
    {
        printk("Unable to get page info\n");
        return 0;
    }
    fs.sector_size = info.size;
    fs.sector_count = 3U;

    rc = nvs_mount(&fs);
    if (rc)
    {
        printk("Flash Init failed\n");
        return 0;
    }

    ssize_t my_var = nvs_calc_free_space(&fs);
    printk("Value of my_var before operations: %zd\n", my_var);

    nvs_read(&fs, NVS_BOOT_COUNTER_ID, &init_counter, sizeof(init_counter));

    init_counter++;

    nvs_write(&fs, NVS_BOOT_COUNTER_ID, &init_counter, sizeof(init_counter));

    printk("Hello World! Initialization number: %d.\r\n", init_counter);

    my_var = nvs_calc_free_space(&fs);
    printk("Value of my_var after operations: %zd\n", my_var);
    /*
        while (1)
        {
        }
    */
}

nrf9160dk_nrf9160_ns.overlay:

/* Enable the external flash device (required) */
&mx25r64 {
    status = "okay";
};

/* Configure partition manager to use mx25r64 as the external flash device */
/ {
   chosen {
       nordic,pm-ext-flash = &mx25r64;
   };
};

/* Enable high performance mode to increase write/erase performance */
&mx25r64 {
   mxicy,mx25r-power-mode = "high-performance";
};  

prj.conf:

# Logging
CONFIG_LOG=y

# Memory
CONFIG_NVS=y
CONFIG_FLASH=y
CONFIG_FLASH_MAP=y

# Working:
CONFIG_SPI=y
CONFIG_SPI_NOR=y
CONFIG_SPI_NOR_SFDP_DEVICETREE=y
CONFIG_PM_OVERRIDE_EXTERNAL_DRIVER_CHECK=y