OTP allocation for NSIB

[Amira R.]

In the documentation for the secure bootloader, it's mentioned that the provisioning data gets stored in OTP memory for some chips (e.g. nRF5340). Is there a way to know what portion or address space of the OTP will be used by the bootloader?

The current project I'm working on, using the nRF5340, requires roughly 40-48B of OTP for manufacturer-specific data. Is there a way to ensure that these datasets will not overlap and corrupt one another? 

Thank you!

[AHaug]

Amira R. said:

I'm not using TF-M for this project, does the SPU alignment rule still apply? All my other static partitions are aligned by page size.

Yes, the page granularity is still something you need to consider for the devices

Amira R. said:

Also "provision" and "factory_data_otp" are not the only defined static partitions, but they're the only partitions in the "otp" region. Would partitions in other regions affect these partitions? 

Any region that may have addresses overlapping could affect any other region

Kind regards,
Andreas

[Amira R.]

Hi Andreas,

Thank you for getting back to me.

Since TF-M is not being used, I'll assume that partitions only need to be aligned by erase page size (0x1000), which is the case at the container level.

I'm attaching my partition file here if you don't mind checking for errors - I don't think partitions are overlapping, but perhaps I'm missing something.

Fullscreen pm_static_device_nrf5340_cpuapp.txt Download

b0:
  address: 0x0
  end_address: 0x8000
  placement:
    after: start
  region: flash_primary
  size: 0x8000
  
b0_container:
  address: 0x0
  span: [ b0 ]
  size: 0x8000

# B0 Provision Data stored in OTP for nRF5340
provision:
  address: 0xff8180
  end_address: 0xff8400
  region: otp
  size: 0x280

s0_pad:
  address: 0x8000
  end_address: 0x8200
  placement:
    after: b0_container
    align: { start: 0x1000 }
  region: flash_primary
  size: 0x200
  share_size: 
  - mcuboot_pad
s0_image:
  address: 0x8200
  span: [ mcuboot ]
  size: 0x4e00

mcuboot:
  address: 0x8200
  end_address: 0xd000
  inside: [ s0_image ]
  placement:
    after: s0_pad
  region: flash_primary
  size: 0x4e00

s0:
  address: 0x8000
  span: [ s0_pad, s0_image ]
  size: 0x5000

s1_pad:
  address: 0xd000
  end_address: 0xd200
  placement:
    after: s0
    align: { start: 0x1000 }
  region: flash_primary
  share_size:
  - mcuboot_pad
  size: 0x200
s1_image:
  address: 0xd200
  end_address: 0x12000
  placement:
    after: s1_pad
  region: flash_primary
  share_size:
  - mcuboot
  size: 0x4e00

s1:
  address: 0xd000
  span: [ s1_pad, s1_image ]
  size: 0x5000

mcuboot_pad:
  address: 0x12000
  end_address: 0x12200
  placement:
    after: s1
    align: { start: 0x1000 }
  region: flash_primary
  size: 0x200
mcuboot_primary_app:
  address: 0x12200
  span: [ app ]
  size: 0xeae00

app:
  address: 0x12200
  placement: 
    after: 
  inside: [ mcuboot_primary_app ]
  region: flash_primary
  size: 0xeae00

mcuboot_primary:
  address: 0x12000
  span: [ mcuboot_pad, app ]
  size: 0xeb000

# Device settings (app NVS)
project_settings:
  address: 0xfd000
  end_address: 0xfe000
  placement:
    after: mcuboot_primary_app
  region: flash_primary
  size: 0x1000
settings_storage:
  address: 0xfe000
  end_address: 0x100000
  placement:
    after: project_settings
  region: flash_primary
  size: 0x2000
factory_data_otp:
  address: 0xff8100
  end_address: 0xff8180
  placement:
    before: provision
  region: otp
  size: 0x80

# Shared RAM for network core
pcd_sram:
  address: 0x20000000
  region: sram_primary
  size: 0x2000
mcuboot_primary_1:
  address: 0x0
  device: flash_ctrl
  region: ram_flash
  size: 0x40000

# External Flash
mcuboot_secondary:
  address: 0x0
  device: HUB_EXTERNAL_FLASH_A
  region: external_flash
  size: 0xeb000
mcuboot_secondary_1:
  address: 0xeb000
  device: HUB_EXTERNAL_FLASH_A
  region: external_flash
  size: 0x40000
data_partition:
  address: 0x12b000
  device: HUB_EXTERNAL_FLASH_A
  region: external_flash
  size: 0x1ff000
sub_image_1:
  address: 0x32a000
  device: HUB_EXTERNAL_FLASH_A
  region: external_flash
  size: 0x8000
sub_image_2:
  address: 0x332000
  device: HUB_EXTERNAL_FLASH_A
  region: external_flash
  size: 0x65000
sub_image_3:
  address: 0x397000
  device: HUB_EXTERNAL_FLASH_A
  region: external_flash
  size: 0x7000
external_flash:
  address: 0x39e000
  device: HUB_EXTERNAL_FLASH_A
  region: external_flash
  size: 0x462000
  

Thank you!

[AHaug]

Amira R. said:

0x1000)

0x1000 = 4k, so this looks good for the nRF5340

Amira R. said:

I'm attaching my partition file here if you don't mind checking for errors

I can't see anything very obvious, so the best here would be to try it and see if it results in either negative spaces or you not being able to write to the uicr/otp partitions you're attempting to set up

Kind regards,
Andreas