How to flash application to specific address.

[Theja]

Hi,

On the nRF54L15DK board, I flashed an application and then performed a full erase. However, after erasing, I noticed that approximately 2000 bytes of memory were still occupied when reading back the flash. Could you please clarify why this portion of memory remains in use even after recovering the device?

Additionally, on the nRF52833DK using nRF Connect SDK v2.5.0, I was able to flash my application to a specific address using the CONFIG_FLASH_LOAD_OFFSET configuration. However, on the nRF54L15DK with nRF Connect SDK v3.2.0, this configuration no longer works and appears to be deprecated. Could you please advise on the correct method to flash the application to a specific address as per our requirements in the newer SDK version?

Thank you for your guidance.

Best regards,
Theja.

[Vidar Berg]

Hi,

On the nRF54L15DK board, I flashed an application and then performed a full erase. However, after erasing, I noticed that approximately 2000 bytes of memory were still occupied when reading back the flash. Could you please clarify why this portion of memory remains in use even after recovering the device?

The recover operation includes flashing a FW after the ERASEALL operation in order to keep the APPROTECT mechanism disabled across resets.  

Additionally, on the nRF52833DK using nRF Connect SDK v2.5.0, I was able to flash my application to a specific address using the CONFIG_FLASH_LOAD_OFFSET configuration. However, on the nRF54L15DK with nRF Connect SDK v3.2.0, this configuration no longer works and appears to be deprecated. Could you please advise on the correct method to flash the application to a specific address as per our requirements in the newer SDK version?

If you want your app to start at an offset you need to specify a placeholder partition by creating a file named "pm_static.yml" with the following content:

bootloader:
address: 0x0
end_address: <specify offset in bytes>
placement:
after:
- start
region: flash_primary
size: <specify offset in bytes> e.g 0x10000

The partitition is named "bootloader" but can be named anything.

Best regards,

Vidar

[Theja]

Hi Vidar,

As per your suggestion, I added the pm_static.yml file to the src folder. However, even though the slot0_partition address is defined as 0x10000, I observed that the application is actually located at a different address when checked using the programmer.

I have attached the partition details and the memory read image from the programmer for your reference.
Your insights on this issue would be greatly appreciated.

boot_partition:
  address: 0x00000000
  size: 0x00010000
  region: flash_primary

slot0_partition:
  address: 0x00010000
  size: 0x00051000
  region: flash_primary

slot0_ns_partition:
  address: 0x00061000
  size: 0x00051000
  region: flash_primary
 
slot1_partition:
  address: 0x000B2000
  size: 0x00051000
  region: flash_primary

slot1_ns_partition:
  address: 0x00103000
  size: 0x00051000
  region: flash_primary

storage_partition:
  address: 0x0015C000
  size: 0x00009000
  region: flash_primary

      

 

Regards,

Theja

[Vidar Berg]

Hi Theja,

Sorry, I'm not sure what you're trying to achieve now. I thought the only goal was to have the application start at an offset, but here you've redefined the partitions from the device tree and included MCUboot slots. Are you planning to use MCUboot in your project? In that case, I would recommend removing the pm_static file for now and read through this https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-9-bootloaders-and-dfu-fota/ to find out how to configure the bootloader for your application.

Best regards,

Vidar

[Theja]

Hi Vidar,

Sorry for the misunderstanding. Here’s the requirement I wanted to clarify: we are implementing a custom bootloader that resides at the start address, along with two application slots and two custom storage partitions, as shown below. These will occupy the entire flash memory.

bootloader:
  address: 0x00000000
  size: 0x00020000
 
slot0_partiton:
  address: 0x00020000
  size: 0x00060000
  region: flash_primary
 
slot0_partiton:
  address: 0x00080000
  size: 0x00060000
  region: flash_primary
 
storage:
  address: 0x000E0000
  size: 0x00009000
  region: flash_primary
 
custom_data:
  address: 0x000E9000
  size: 0x0007C000
  region: flash_primary

I would like to know how to ensure that my application is placed in either slot 1 or slot 2. How can I achieve this?

[Theja]

Hi,

corrected flash partition name:

bootloader:
address: 0x00000000
size: 0x00020000

slot0_partiton:
address: 0x00020000
size: 0x00060000
region: flash_primary

slot1_partiton:
address: 0x00080000
size: 0x00060000
region: flash_primary

storage:
address: 0x000E0000
size: 0x00009000
region: flash_primary

custom_data:
address: 0x000E9000
size: 0x0007C000
region: flash_primary

[Vidar Berg]

Try to include the following in your pm_static.yml file: 

bootloader:
  address: 0x0
  end_address: 0x20000
  region: flash_primary
  size: 0x20000
app:
  address: 0x20000
  end_address: 0x80000
  region: flash_primary
  size: 0x60000
slot0_partiton:
  address: 0x20000
  end_address: 0x80000
  orig_span: &id001
  - app
  region: flash_primary
  sharers: 0x1
  size: 0x60000
  span: *id001
slot1_partiton:
  address: 0x80000
  end_address: 0xe0000
  region: flash_primary
  size: 0x60000
storage:
  address: 0xe0000
  end_address: 0xe9000
  region: flash_primary
  size: 0x9000
custom_data:
  address: 0xe9000
  end_address: 0x165000
  region: flash_primary
  size: 0x7c000

Here the app is placed in slot0. You can run the "memory report" action in VS code to confirm the placement.