Generating binaries on vscode with prepended zeroed header to the image

[Ubaid_M]

Hello ,

I am using nrf Connect SDK v1.9.1 with nRF Connect extension for my application development.

With reference to the nordic documentation : https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/mcuboot/imgtool.html#incorporating-the-public-key-into-the-code:~:text=Zephyr%20build%20system%20will%20already%20prepended%20a%20zeroed%20header%20to%20the%20image

Please find as in below snap the binaries generated from vscode and nCS I am using, There is no padded zeroed header to my build binaries at 0x000000 (Right image below)

While the left image below is the binary i generated with just zephyr and no nCS. It clearly has zero padded header.

So my question is, How can I have zero padded header to binaries generated out of nCS..?
Can i use any config..?

Thanks,

Ubaid

[Sigurd Hellesvik]

Hi Ubaid,

I will look into this and return with more information tomorrow.

Regards,
Sigurd Hellesvik

[Ubaid_M]

Sigurd Hellesvik said:

I will look into this and return with more information tomorrow.

Yes please, 

Thanks

[Sigurd Hellesvik]

Hi,

I will assume the file you refer to is build/zephyr/app_update.bin.

Our build system automatically generates this file.
To see the command used to generate this file, you can build using CLI and add "-vvv" to the west command like this:

west -vvv build -p -b nrf52840dk_nrf52840

From my code, the generation looks like this:

[19/24] cd /home/bruk/git/samples_for_nrf_connect_sdk/bootloader_samples/smp/mcuboot_smp_uart/build/modules/mcuboot && /home/bruk/zephyr-sdk-0.15.1/arm-zephyr-eabi/bin/arm-zephyr-eabi-objcopy --input-target=ihex --output-target=binary --gap-fill=0xff /home/bruk/git/samples_for_nrf_connect_sdk/bootloader_samples/smp/mcuboot_smp_uart/build/zephyr/mcuboot_primary_app.hex /home/bruk/git/samples_for_nrf_connect_sdk/bootloader_samples/smp/mcuboot_smp_uart/build/zephyr/app_to_sign.bin && /usr/bin/python3.10 /home/bruk/nrf_connect_sdk/bootloader/mcuboot/scripts/imgtool.py sign --key /home/bruk/nrf_connect_sdk/bootloader/mcuboot/root-ec-p256.pem --header-size 0x200 --align 4 --version 0.0.0+0 --pad-header --slot-size 0x7a000 /home/bruk/git/samples_for_nrf_connect_sdk/bootloader_samples/smp/mcuboot_smp_uart/build/zephyr/app_to_sign.bin /home/bruk/git/samples_for_nrf_connect_sdk/bootloader_samples/smp/mcuboot_smp_uart/build/zephyr/app_update.bin

As you can see from this, imgtool generates the binary.

You can try to generate app_update.bin manually from this command and then change arguments to your liking.

Can you also send the contents of the partition_manager_report? Maybe the padding could be related to the partitions?

west build -t partition_manager_report

Regards,
Sigurd Hellesvik

[Ubaid_M]

Hello Sigurd Hellesvik,

Thanks for the info.

The snap of comparision I attached is of zephyr.bin, Sorry I forgot to mention.

Ubaid_M said:

While the left image below is the binary i generated with just zephyr and no nCS. It clearly has zero padded header.

Now If I build simple LED code, on zephyr RTOS+eclipse, I am getting zero prepended "zephyr.bin".
While for same code if I build on nRF Connect Extension on vscode, I am not getting zero prepended "zephyr.bin".

So, I need to be able to build zero prepended "zephyr.bin" from nRF Connect Extension on vscode.

I am attaching the partition file:

app:
  address: 0xf200
  end_address: 0x70000
  region: flash_primary
  size: 0x60e00
external_flash:
  address: 0x0
  end_address: 0x100000
  region: external_flash
  size: 0x100000
mcuboot:
  address: 0x0
  end_address: 0xf000
  placement:
    before:
    - mcuboot_primary
  region: flash_primary
  size: 0xf000
mcuboot_pad:
  address: 0xf000
  end_address: 0xf200
  placement:
    before:
    - mcuboot_primary_app
  region: flash_primary
  size: 0x200
mcuboot_primary:
  address: 0xf000
  end_address: 0x6f000
  orig_span: &id001
  - mcuboot_pad
  - app
  region: flash_primary
  size: 0x60000
  span: *id001
mcuboot_primary_app:
  address: 0xf200
  end_address: 0x6f000
  orig_span: &id002
  - app
  region: flash_primary
  size: 0x5fe00
  span: *id002
mcuboot_secondary:
  address: 0x0
  device: IS25
  end_address: 0x60000
  placement:
    align:
      start: 0x4
  region: external_flash
  share_size:
  - mcuboot_primary
  size: 0x60000
settings_storage:
  address: 0x70000
  end_address: 0x80000
  placement:
    before:
    - end
  region: flash_primary
  size: 0x10000
sram_primary:
  address: 0x20000000
  end_address: 0x20020000
  region: sram_primary
  size: 0x20000

Also, I have never used CLI build, please help me where I can fire the commands.

Thanks,

[Sigurd Hellesvik]

Ubaid_M said:

Also, I have never used CLI build, please help me where I can fire the commands.

For VS Code, press the arrow beside the "+" sign in the terminal view.
Then select "nRF Connect SDK". Now you should get a CLI below to type commands.

Ubaid_M said:

Now If I build simple LED code, on zephyr RTOS+eclipse, I am getting zero prepended "zephyr.bin".
While for same code if I build on nRF Connect Extension on vscode, I am not getting zero prepended "zephyr.bin".

Aha, so you want to get the Zero padding.

Do you build with MCUboot for both projects?
Do you see the same issue if you build without MCUboot for both projects?

Regards,
Sigurd Hellesvik

[Ubaid_M]

Hello Sigurd Hellesvik,

Sigurd Hellesvik said:

Aha, so you want to get the Zero padding.

Yes, This is what I need.

Sigurd Hellesvik said:

Do you build with MCUboot for both projects?
Do you see the same issue if you build without MCUboot for both projects?

Yes, I tried without mcuboot configured build and found that still generated binaries do not have zero prepended.

Thanks,

[Sigurd Hellesvik]

Hi,

I realize that you will need a bootloader if you offset the image in flash, as the chip will start at address 0x0000.

If you enable MCUboot in an nRF Connect SDK project, the address off zephyr.hex will be offset:

Here is a sample from zephyr.hex in the hello_world sample with CONFIG_BOOTLOADER_MCUBOOT=y:

Does this help?

Regards,
Sigurd Hellesvik

[Ubaid_M]

Hello Sigurd Hellesvik,

So now how will I achieve this on my bin files..?

Sigurd Hellesvik said:

Aha, so you want to get the Zero padding.

Thanks

[Sigurd Hellesvik]

From the same hello_world sample mentioned below, I take build/zephyr/zephyr.bin and convert it to hex using bin2hex.py.

bin2hex.py zephyr.bin converted_zephyr.hex

The resulting hex-file also has this padding:

converted_zephyr.hex

Regards,
Sigurd Hellesvik