NRF9160 Using customized flash partition

[Maaike]

Dear all,

For our project we want to store information on the device in an additional flash partition.
We have created a new flash partition, called factory_settings_partition, by defining it in our custom board files as follows:

&flash0 {
	/*
	 * For more information, see:
	 * https://docs.zephyrproject.org/latest/guides/dts/legacy-macros.html#legacy-flash-partitions
	 */
	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x00000000 0x10000>;
		};
		slot0_partition: partition@10000 {
			label = "image-0";
		};
		slot0_ns_partition: partition@50000 {
			label = "image-0-nonsecure";
		};
		slot1_partition: partition@80000 {
			label = "image-1";
		};
		slot1_ns_partition: partition@c0000 {
			label = "image-1-nonsecure";
		};
		scratch_partition: partition@f0000 {
			label = "image-scratch";
			reg = <0x000f0000 0xa000>;
		};
		storage_partition: partition@fa000 {
			label = "storage";
			reg = <0x000fa000 0x00006000>;
		};
		factory_settings_partition: partition@100000 {
			label = "factory_settings";
			reg = <0x00100000 0x000007d0>;
		};
	};
};

Now when trying to read and write to the flash we get an error from the FLASH_AREA_OFFSET(factory_settings):

 error: 'PM_PM_PM_factory_settings_ID_LABEL_ADDRESS' undeclared (first use in this function)
  UTIL_CAT(PM_, UTIL_CAT(UTIL_CAT(PM_, UTIL_CAT(PM_ID(label), _LABEL)), _ADDRESS))

I also tried getting my code to work with an already existing flash partition, namely storage_partition, and that worked fine, I got no errors.
My issue is the same as the issue in this post; for us the first solution offered is not an option and the second solution is a bit unclear to me.

Can you give me guidance to how I can implement and use my own flash partition?

Kind regards,
Maaike

[Carl Richard]

Hi, Maaike!

As Didrik mentioned in the thread you've linked to any device tree configuration of flash partitions are ignored by the Partition Manager script. This script is used by the build system to properly allocate space for multi-image builds, and is thus used for most nRF9160 applications.

I agree that his second option in general is more suitable. The partition manager documentation should cover how to configure your own static partitions and I suggest looking into that. For examples the asset_tracker example defines a static partition configuration for the Thingy:91.

Best regards,
Carl Richard

[Maaike]

Hi Carl,

Thank you for your reply.

I have added the partition the the pm_static.yml file and it seems that the flash configuration now works well, as I see the partition in the partitions.yml file in the build folder. 

However, I now get the following error

fs_nvs: Unable to get page info

It seems that the page of the offset does not exist.

This is my pm_static.yml file:

factory_settings_partition:
   address: 0x00100000
   size: 0x000007d0
   #span: [example]  # Only if this partition had the span property set originally.

And this is what I see in partitions.yml after building

app:
  address: 0xc000
  region: flash_primary
  size: 0xee000
bsdlib_sram:
  address: 0x20010000
  placement:
    after:
    - spm_sram
    - start
  region: sram_primary
  size: 0x10000
factory_settings_partition:
  address: 0x100000
  region: flash_primary
  size: 0x7d0
nvs_storage:
  address: 0xfa000
  placement:
    before:
    - end
  region: flash_primary
  size: 0x6000
otp:
  address: 0xff8108
  region: otp
  size: 0x2f4
spm:
  address: 0x0
  placement:
    before:
    - app
  region: flash_primary
  size: 0xc000
spm_sram:
  address: 0x20000000
  inside:
  - sram_secure
  placement:
    after:
    - start
  region: sram_primary
  size: 0x10000
sram_primary:
  address: 0x20020000
  region: sram_primary
  size: 0x20000
sram_secure:
  address: 0x20000000
  orig_span: &id001
  - spm_sram
  region: sram_primary
  size: 0x10000
  span: *id001

Here is how I initialize flash

static struct nvs_fs fs;
   
static bool set_config_hwver(const char* majorString, const char* minorString)
{   
   
    fs.offset = FLASH_AREA_OFFSET(factory_settings_partition);

    int rc = 0;
    char buf[32];
    
    struct flash_pages_info info;
    rc = flash_get_page_info_by_offs(
        device_get_binding(DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL), fs.offset, &info);
    if (rc) {
        printk("rc: %d\n", rc);
        LOG_DBG("Unable to get page info");
    }

    fs.sector_size = info.size;
    fs.sector_count = 3U;
    rc = nvs_init(&fs, DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL);
    if (rc) {
        LOG_DBG("Flash Init failed\n");
    }

I am not sure what I am missing, is the offset of my partition defined badly? 

Kind regards,
Maaike

[Carl Richard]

Hi again!

This is failing as the address 0x100000 is outside the flash_primary region. To stay within the region I suggest lowering the NVS partition size using CONFIG_PM_PARTITION_SIZE_NVS_STORAGE and then changing the start address and size of your static partition accordingly. 

For example by setting the NVS storage partition size to 0x0 the following pm_static.yml should work:

factory_settings_partition:
   address: 0x1f7d0
   size: 0xE0830
   #span: [example]  # Only if this partition had the span property set originally.

Best regards,
Carl Richard

[Maaike]

Hi Carl,

Many thanks, this solved the problem and using the partition works now.
I made the storage_partition smaller in our custom board files (as we still need to use it) and created space for our own custom partition.

Kind regards,
Maaike