Flash Address change issue in nRF connect SDK

[Sunil vignesh]

Hi,

I need to store the 1kB of data in the flash storage and it need to be read anytime and change the data anywhere.

I am using nrf52840 DK and also nrf5340 DK to perform these Flash storage

I found the example code in this link

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/reference/storage/nvs/nvs.html?highlight=flash%20storage

and i have tested the code.

I have difficulty to change the data storage address. where we need to change the starting address. size of flash storage. If i use DFU how to assign the flash storage

I have checked this and print the info value

but I tried to change the value but it not write the given address

Did i need to change any thing ?

[Håkon Alseth]

Hi,

 

The storage partition is statically defined by the device tree, here's an example for the nRF52840:

https://github.com/nrfconnect/sdk-zephyr/blob/master/boards/arm/nrf52840dk_nrf52840/nrf52840dk_nrf52840.dts#L275-L278

 

You'll find similar definitions for other devices, like the nrf52832:

https://github.com/nrfconnect/sdk-zephyr/blob/master/boards/arm/nrf52dk_nrf52832/nrf52dk_nrf52832.dts#L220-L222

 

When doing a DFU, you need to ensure that the storage_partition does not change between the original image and the dfu image.

 

Kind regards,

Håkon

[Sunil vignesh]

Hi Håkon,

from nRF52840

reg = <0x000f8000 0x00008000>;

f8000 - flash start address

8000 - flash storage size

isn't it ?

and during addition of DFU Bootloader how do i measure and change the flash address

[Håkon Alseth]

Hi,

 

Sunil vignesh said:

isn't it ?

Yes, that is true. 

 

Sunil vignesh said:

and during addition of DFU Bootloader how do i measure and change the flash address

Do you really want to change the address of the storage_partition? This will make the layout of the images differ, which is normally not a wanted scenario.

Kind regards,

Håkon 

[Sunil vignesh]

Hi ,

I found this lines in nrf52dk_nrf52832.dts

boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x00000000 0xc000>;
		};
		slot0_partition: partition@c000 {
			label = "image-0";
			reg = <0x0000C000 0x32000>;
		};
		slot1_partition: partition@3e000 {
			label = "image-1";
			reg = <0x0003E000 0x32000>;
		};
		scratch_partition: partition@70000 {
			label = "image-scratch";
			reg = <0x00070000 0xa000>;
		};
		storage_partition: partition@7a000 {
			label = "storage";
			reg = <0x0007a000 0x00006000>;
		};

there it show the

storage_partition: partition@7a000 {
            label = "storage";
            reg = <0x0007a000 0x00006000>;
        };

if 0x7a000 then what is 0x00006000  (storage size?) how it calculate in kB.

and if i change the start address from 0x7a000 to 0x7000 then what will be the storage size .

My case i need to store the

1. Bond state PM address

2. 1 KB (Kilo Byte) sensor data

3. 2 KB second sensor data

[Håkon Alseth]

Hi,

 

Sunil vignesh said:

if 0x7a000 then what is 0x00006000  (storage size?) how it calculate in kB.

0x7a000 is the start address, and 0x6000 is the size (1 page = 4k (0x1000), thus 6 flash pages). 

Convert to decimal, and you will get the amount of bytes available in the given partition.

 

Sunil vignesh said:

and if i change the start address from 0x7a000 to 0x7000 then what will be the storage size .

 It will be out-of-bounds. you will go outside of the total flash area of the nRF52832.

 

Kind regards,

Håkon

[Sunil vignesh]

Hi Håkon,

Thanks for the fast response.

I have one last question

I worked in nRF5 SDK flash_fstorage

int8_t mas[12];
      for (int i = 0; i<12; i++)
      {
          mas[i] = i+1;
      }
      /* Let's write to flash. */
      NRF_LOG_INFO("Writing \"%x\" to flash.", mas);
      rc = nrf_fstorage_write(&fstorage, 0x3f500, &mas, sizeof(mas), NULL);
      APP_ERROR_CHECK(rc);

      wait_for_flash_ready(&fstorage);
      NRF_LOG_INFO("Done.");
    
    NRF_LOG_INFO("Writing \"%s\" to flash.", m_hello_world);
    rc = nrf_fstorage_write(&fstorage, 0x3f000, m_hello_world, sizeof(m_hello_world), NULL);
    APP_ERROR_CHECK(rc);

Like this

How can I write the array of data in the particular address

example

Storage partition
Flash start : 0x7a000

Flash size : 0x0006000


i want to write the int8_t arr[1000]; to the particular 0x7b000

How can i assign 0x7b000 to write the array data

In nrf connect sdk

#define ADDRESS_ID 1
#define KEY_ID 2
#define RBT_CNT_ID 3
#define STRING_ID 4
#define LONG_ID 5



	/* ADDRESS_ID is used to store an address, lets see if we can
	 * read it from flash, since we don't know the size read the
	 * maximum possible
	 */
	rc = nvs_read(&fs, ADDRESS_ID, &buf, sizeof(buf));
	if (rc > 0) { /* item was found, show it */
		printk("Id: %d, Address: %s\n", ADDRESS_ID, buf);
	} else   {/* item was not found, add it */
		strcpy(buf, "192.168.1.1");
		printk("No address found, adding %s at id %d\n", buf,
		       ADDRESS_ID);
		(void)nvs_write(&fs, ADDRESS_ID, &buf, strlen(buf)+1);
	}

How the Address_ID 1 

this 1 2 3 4 5  are noting Pages or any other how the address is assigned

[Håkon Alseth]

Hi,

 

For how NVS works, please see the zephyr documentation:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/reference/storage/nvs/nvs.html

 

It is more complex than writing to a specific address and reading that back. there is a specific protocol and behavior that is running behind the scenes here.

If you want to write directly to the flash, you can look at the zephyr/samples/drivers/soc_flash_nrf/, although this does not integrate well into other applications that use flash storage modules (like storing bonds)

 

Kind regards,

Håkon