partition manager doesn't place the modem shared memory correctly, pm_static.yml required?

[Anthony Ambuehl]

I am currently trying to port an application derived from multiple samples to nrf9160dk_nrf9160_ns.  I'm running into an issue with the modem shlib:

error: static assertion failed: "The libmodem shmem configuration exceeds the range of memory readable by the Modem core"
81 | #define BUILD_ASSERT(EXPR, MSG...) _Static_assert(EXPR, "" MSG)

From another thread it appears this happens when the partition manager places the modem shared memory beyond the first 128-k of sram.

In my application, I am trying to delay switching to static partition management until the expected sizes of the tfm and application are better understood, since each time a region changes there tends to be multiple cascading changes in hardcoded addresses.

I have found that the partition manager places the shared modem region into non-secure sram region (sram_nonsecure) which is placed after the tfm_sram region which happens to be larger than 128k.  

If possible I would like to find a way to get the modem shared space placed in the first 128k WITHOUT locking the rest of the SRAM into rigid/fixed sizes and definitely without locking the flash partitioning. 

 Is there any way to tell partition manager the modem shared memory needs to be placed  in the first 128KB of SRAM?

I'm guessing that the minimal configuration for tfm reduces the  sram partition.  How can I determine the actual memory needed by my non-minimal TFM configuration.. perhaps TFM can get by with less than the 0x46000

[Håkon Alseth]

Hi,

 

Could you share your build-folder/partitions.yml file?

 

 Is there any way to tell partition manager the modem shared memory needs to be placed  in the first 128KB of SRAM?

Here's an example of "ninja partition_manager_report" from the stock "udp" sample:

  sram_primary (0x40000 - 256kB): 
+--------------------------------------------------+
+---0x20000000: sram_secure (0x8000 - 32kB)--------+
| 0x20000000: tfm_sram (0x8000 - 32kB)             |
+---0x20008000: sram_nonsecure (0x38000 - 224kB)---+
+---0x20008000: nrf_modem_lib_sram (0x4568 - 17kB)-+
| 0x20008000: nrf_modem_lib_ctrl (0x4e8 - 1kB)     |
| 0x200084e8: nrf_modem_lib_tx (0x2080 - 8kB)      |
| 0x2000a568: nrf_modem_lib_rx (0x2000 - 8kB)      |
+--------------------------------------------------+
| 0x2000c568: sram_primary (0x33a98 - 206kB)       |
+--------------------------------------------------+

I suspect there's another reason why the static assertion is being triggered here, probably related to one or more of the nrf_modem_lib* region sizes or the tfm_sram region.

 

Kind regards,

Håkon

[Anthony Ambuehl]

I believe the issue is that my TF-M is not using the minimal configuration since I want to add a custom service in a ARoT partition and also I am using ITS with encryption as well as PSA Crypto.

I suspect the minimal TF-M shrinks the sram and flash size. 

Where can I find the modifications for TF-M minimal mode?

I was able to workaround this issue after adding this config for nrf9160 builds:

#reduce TFM sram partition so the modem shared memory can be placed with the first 128-KB
CONFIG_PM_PARTITION_SIZE_TFM_SRAM=18000

However I'm still wondering..

What if I needed that more SRAM in TF-M?  Is it possible with the SPU to create the share modem shared memory as a separate region that comes before the secure sram?  Perhaps this would be an improvement opportunity..

Until then perhaps the default TF-M SRAM region for nrf9160 should be reduced for non-minimal TF-M.

Here is my partions.yml after modifying the TF-M SRAM,  I am still having problems with the overall project fitting into flash space.

Fullscreen partitions_yml.txt Download

EMPTY_0:
  address: 0x14200
  end_address: 0x18000
  placement:
    before:
    - s1_pad
  region: flash_primary
  size: 0x3e00
EMPTY_1:
  address: 0x24200
  end_address: 0x28000
  placement:
    before:
    - mcuboot_pad
  region: flash_primary
  size: 0x3e00
EMPTY_2:
  address: 0xfc000
  end_address: 0x100000
  placement:
    after:
    - tfm_ps
  region: flash_primary
  size: 0x4000
EMPTY_3:
  address: 0xf2000
  end_address: 0xf4000
  placement:
    after:
    - settings_storage
  region: flash_primary
  size: 0x2000
EMPTY_4:
  address: 0xee000
  end_address: 0xf0000
  placement:
    after:
    - littlefs_storage
  region: flash_primary
  size: 0x2000
app:
  address: 0x48000
  end_address: 0x88000
  region: flash_primary
  size: 0x40000
app_image:
  address: 0x28200
  end_address: 0x88000
  orig_span: &id001
  - tfm
  - app
  region: flash_primary
  size: 0x5fe00
  span: *id001
b0:
  address: 0x0
  end_address: 0x8000
  placement:
    after:
    - start
  region: flash_primary
  size: 0x8000
b0_container:
  address: 0x0
  end_address: 0x8000
  orig_span: &id002
  - b0
  region: flash_primary
  size: 0x8000
  span: *id002
littlefs_storage:
  address: 0xe8000
  end_address: 0xee000
  inside:
  - nonsecure_storage
  placement:
    align:
      start: 0x8000
    before:
    - settings_storage
  region: flash_primary
  size: 0x6000
mcuboot:
  address: 0x8200
  end_address: 0x14200
  placement:
    before:
    - mcuboot_primary
  region: flash_primary
  sharers: 0x1
  size: 0xc000
mcuboot_pad:
  address: 0x28000
  end_address: 0x28200
  placement:
    align:
      start: 0x8000
    before:
    - mcuboot_primary_app
  region: flash_primary
  sharers: 0x2
  size: 0x200
mcuboot_primary:
  address: 0x28000
  end_address: 0x88000
  orig_span: &id003
  - tfm
  - app
  - mcuboot_pad
  region: flash_primary
  sharers: 0x1
  size: 0x60000
  span: *id003
mcuboot_primary_app:
  address: 0x28200
  end_address: 0x88000
  orig_span: &id004
  - app
  - tfm
  region: flash_primary
  size: 0x5fe00
  span: *id004
mcuboot_secondary:
  address: 0x88000
  end_address: 0xe8000
  placement:
    after:
    - mcuboot_primary
    align:
      start: 0x8000
  region: flash_primary
  share_size:
  - mcuboot_primary
  size: 0x60000
mcuboot_sram:
  address: 0x20000000
  end_address: 0x20018000
  orig_span: &id005
  - tfm_sram
  region: sram_primary
  size: 0x18000
  span: *id005
nonsecure_storage:
  address: 0xe8000
  end_address: 0xf0000
  orig_span: &id006
  - settings_storage
  - littlefs_storage
  region: flash_primary
  size: 0x8000
  span: *id006
nrf_modem_lib_ctrl:
  address: 0x20018000
  end_address: 0x200184e8
  inside:
  - sram_nonsecure
  placement:
    after:
    - tfm_sram
    - start
  region: sram_primary
  size: 0x4e8
nrf_modem_lib_rx:
  address: 0x2001a568
  end_address: 0x2001c568
  inside:
  - sram_nonsecure
  placement:
    after:
    - nrf_modem_lib_tx
  region: sram_primary
  size: 0x2000
nrf_modem_lib_sram:
  address: 0x20018000
  end_address: 0x2001c568
  orig_span: &id007
  - nrf_modem_lib_ctrl
  - nrf_modem_lib_tx
  - nrf_modem_lib_rx
  region: sram_primary
  size: 0x4568
  span: *id007
nrf_modem_lib_tx:
  address: 0x200184e8
  end_address: 0x2001a568
  inside:
  - sram_nonsecure
  placement:
    after:
    - nrf_modem_lib_ctrl
  region: sram_primary
  size: 0x2080
otp:
  address: 0xff8388
  end_address: 0xff83fc
  region: otp
  size: 0x74
provision:
  address: 0xff8108
  end_address: 0xff8388
  region: otp
  size: 0x280
s0:
  address: 0x8000
  end_address: 0x14200
  orig_span: &id008
  - mcuboot
  - s0_pad
  region: flash_primary
  size: 0xc200
  span: *id008
s0_image:
  address: 0x8200
  end_address: 0x14200
  orig_span: &id009
  - mcuboot
  region: flash_primary
  size: 0xc000
  span: *id009
s0_pad:
  address: 0x8000
  end_address: 0x8200
  placement:
    after:
    - b0_container
    align:
      start: 0x8000
  region: flash_primary
  share_size:
  - mcuboot_pad
  size: 0x200
s1:
  address: 0x18000
  end_address: 0x24200
  orig_span: &id010
  - s1_pad
  - s1_image
  region: flash_primary
  size: 0xc200
  span: *id010
s1_image:
  address: 0x18200
  end_address: 0x24200
  placement:
    after:
    - s1_pad
    - s0
  region: flash_primary
  share_size:
  - mcuboot
  size: 0xc000
s1_pad:
  address: 0x18000
  end_address: 0x18200
  placement:
    after:
    - s0
    align:
      start: 0x8000
  region: flash_primary
  share_size:
  - mcuboot_pad
  size: 0x200
settings_storage:
  address: 0xf0000
  end_address: 0xf2000
  inside:
  - nonsecure_storage
  placement:
    align:
      start: 0x8000
    before:
    - tfm_storage
    - end
  region: flash_primary
  size: 0x2000
sram_nonsecure:
  address: 0x20018000
  end_address: 0x20040000
  orig_span: &id011
  - sram_primary
  - nrf_modem_lib_ctrl
  - nrf_modem_lib_tx
  - nrf_modem_lib_rx
  region: sram_primary
  size: 0x28000
  span: *id011
sram_primary:
  address: 0x2001c568
  end_address: 0x20040000
  region: sram_primary
  size: 0x23a98
sram_secure:
  address: 0x20000000
  end_address: 0x20018000
  orig_span: &id012
  - tfm_sram
  region: sram_primary
  size: 0x18000
  span: *id012
tfm:
  address: 0x28200
  end_address: 0x48000
  inside:
  - mcuboot_primary_app
  placement:
    before:
    - app
  region: flash_primary
  size: 0x1fe00
tfm_its:
  address: 0xf4000
  end_address: 0xf6000
  inside:
  - tfm_storage
  placement:
    before:
    - tfm_otp_nv_counters
  region: flash_primary
  size: 0x2000
tfm_nonsecure:
  address: 0x48000
  end_address: 0x88000
  orig_span: &id013
  - app
  region: flash_primary
  size: 0x40000
  span: *id013
tfm_otp_nv_counters:
  address: 0xf6000
  end_address: 0xf8000
  inside:
  - tfm_storage
  placement:
    before:
    - tfm_ps
  region: flash_primary
  size: 0x2000
tfm_ps:
  address: 0xf8000
  end_address: 0xfc000
  inside:
  - tfm_storage
  placement:
    align:
      start: 0x8000
    before:
    - end
  region: flash_primary
  size: 0x4000
tfm_secure:
  address: 0x28000
  end_address: 0x48000
  orig_span: &id014
  - mcuboot_pad
  - tfm
  region: flash_primary
  size: 0x20000
  span: *id014
tfm_sram:
  address: 0x20000000
  end_address: 0x20018000
  inside:
  - sram_secure
  placement:
    after:
    - start
  region: sram_primary
  size: 0x18000
tfm_storage:
  address: 0xf4000
  end_address: 0xfc000
  orig_span: &id015
  - tfm_ps
  - tfm_its
  - tfm_otp_nv_counters
  region: flash_primary
  size: 0x8000
  span: *id015

[Håkon Alseth]

Hi,

 

I am glad to hear that you solved the RAM issue.

Anthony Ambuehl said:

Where can I find the modifications for TF-M minimal mode?

I was able to workaround this issue after adding this config for nrf9160 builds:

#reduce TFM sram partition so the modem shared memory can be placed with the first 128-KB
CONFIG_PM_PARTITION_SIZE_TFM_SRAM=18000

However I'm still wondering..

You can see the ROM/RAM use of tfm by issuing tfm_rom_report / tfm_ram_report:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/services/tfm/build.html#footprint-and-memory-usage

For the RAM, this includes the static RAM (ie. BSS + DATA section)

To reduce the flash usage, you can select the TFM_PROFILE_TYPE_MEDIUM. I've recently posted a sample on this here: 

 How to reduce the code size of TF-M 

 

And if you do not want to use a pm_static.yml file at this point, reduce the flash usage by setting CONFIG_PM_PARTITION_SIZE_TFM=0x2FE00. Please let me know if you run into any issues, and be sure to share the relevant prj.conf settings and the generated build/partitions.yml file.

Anthony Ambuehl said:

What if I needed that more SRAM in TF-M?  Is it possible with the SPU to create the share modem shared memory as a separate region that comes before the secure sram? 

Technically, it does seem possible: https://infocenter.nordicsemi.com/topic/ps_nrf9160/spu.html?cp=2_0_0_5_14_2#ram_access_control

But, I believe it is easier to slim down the tfm image in your case. I am not sure how the build-system handles uneven distribution of S/NS regions.

 

Kind regards,

Håkon

[Anthony Ambuehl]

west built -t tfm_ram_report really helps here.

The modem share memory is ram and must be placed in the non-secure region therefore adjusting CONFIG_PM_PARTITION_SIZE_TFM_SRAM or creating a static partition config are necessary to fix the share memory issue.