I can't use mcuboot to boot a firmware on my external flash

[d.ovetrigo]

Hi,

I am trying to use mcuboot to load a version that is stored in my external flash, and I cannot get it to boot. My project is being built using sysbuild and my target is an nrf9161 with an external flash connected through SPI. Tests have been made where the flash could be read from the main application, so physical connections between the memory and the processor should not be an issue for this problem. The SDK version I am using is still the 2.9.1.

The process I am following is that I am building a version which I code using the VERSION file with a version higher than the program I plan to run on the processor. I generate the zephyr.signed.bin file like that and I write it on the flash.

Then, I build another version with a lower version number coded in the VERSION file, and I flash the merged.hex on the processor.

Each version has a print at the beginning where I check if the version that is running is the flashed one or the one that I wrote on the flash, and all the time I am seeing the one that I actively flash on the processor directly. The external flash does have the version because I could read the flash with my J-Link and I could confirm that the version was stored.

I have used the following configuration out of the devacademy examples.

sysbuild.conf:

# Activate the MCUBOOT bootloader for sysbuild

SB_CONFIG_BOOTLOADER_MCUBOOT=y

# STEP 3.1 - MCUboot should use external flash

SB_CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY=y

# STEP 3.1 - For SPI, we need to set this

SB_CONFIG_PM_OVERRIDE_EXTERNAL_DRIVER_CHECK=y

SB_CONFIG_BOOT_SIGNATURE_TYPE_RSA=y

SB_CONFIG_MCUBOOT_MODE_OVERWRITE_ONLY=y

SB_CONFIG_PARTITION_MANAGER=y

SB_CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY=y

sysbuild/mcuboot/prj.conf:

CONFIG_PM=n

CONFIG_MAIN_STACK_SIZE=10240

CONFIG_MBEDTLS_CFG_FILE="mcuboot-mbedtls-cfg.h"

CONFIG_BOOT_SWAP_SAVE_ENCTLV=n

CONFIG_BOOT_ENCRYPT_IMAGE=n

CONFIG_BOOT_UPGRADE_ONLY=n

CONFIG_BOOT_BOOTSTRAP=n

# Configurations added for mcuboot

CONFIG_BOOT_UPGRADE_ONLY=n

CONFIG_MCUBOOT_DOWNGRADE_PREVENTION=n

CONFIG_BOOT_BOOTSTRAP=n

CONFIG_PM_EXTERNAL_FLASH_BASE=0x0

CONFIG_PM_EXTERNAL_FLASH_MCUBOOT_SECONDARY=y

CONFIG_GPIO=y

CONFIG_FLASH=y

CONFIG_SPI=y

CONFIG_SPI_NOR=y

CONFIG_SPI_NOR_SFDP_DEVICETREE=y

CONFIG_NORDIC_QSPI_NOR=n

# required by SPI driver

CONFIG_MULTITHREADING=y

CONFIG_FPROTECT=y

# This must be increased to accommodate the bigger images.

CONFIG_BOOT_MAX_IMG_SECTORS=256

CONFIG_LOG=y

CONFIG_MCUBOOT_UTIL_LOG_LEVEL_DBG=y

### Decrease footprint by ~4 KB in comparison to CBPRINTF_COMPLETE=y

CONFIG_CBPRINTF_NANO=y

CONFIG_NRF_RTC_TIMER_USER_CHAN_COUNT=0

### Use the minimal C library to reduce flash usage

CONFIG_MINIMAL_LIBC=y

# Increase the monotonic firmware version before building a firmware update

CONFIG_FW_INFO=y

CONFIG_FW_INFO_FIRMWARE_VERSION=1

I also added to the sysbuild/mcuboot/app.overlay the external flash:

// The external flash must be added to the mcuboot overlay

&spi_main {

    ext_flash: w25q16@1 {

        compatible = "jedec,spi-nor";

        status = "okay";

        reg = <1>;

        spi-max-frequency = <800000>;

        size = <16777216>;

        has-dpd;

        t-enter-dpd = <10000>;

        t-exit-dpd = <35000>;

    };

};

/ {

    chosen {

        zephyr,code-partition = &boot_partition;

        nordic,pm-ext-flash = &ext_flash;

    };

};

I also tried to use it without the &spi_main definition here and just adding the flash to the chosen and the behavior was the same.

When I generate both the merged.hex as the zephyr.signed.bin I also use this config in the main application to sign the firmwares:

CONFIG_MCUBOOT_SIGNATURE_KEY_FILE="bootloader/mcuboot/root-rsa-2048.pem"

I am also trying to make debug prints on the mcuboot files to try to find out if there is any problem while trying to authenticate, but I have not been able to make any newer logging prints on my console.

There is probably something on the overall configuration that I am missing or any step that I unconsciously missed, so any advice can be useful.

Thank you very much,

Daniel

[Vidar Berg]

Hi Daniel,

I don't see any issues with the configurations you've posted. Are you testing with a nRF9161 DK? In that case, you should have debug logging over UART enabled by default in mcuboot.

If you are loading the firmware image (zephyr.signed.bin) directly to external flash via your debugger, you must also include the MCUboot image trailer to signal the bootloader that it should swap the image. (The trailer is usually created by the application after it has received the image). To make the zephyr.signed.bin file from the build output include the trailer, you can add either CONFIG_MCUBOOT_EXTRA_IMGTOOL_ARGS="--pad" or CONFIG_MCUBOOT_EXTRA_IMGTOOL_ARGS="--confirm" to your prj.conf file.

Note: to check the content of your signed binary, you can run "imgtool  dumpinfo zephyr.signed.bin" from your terminal.

Best regards,

Vidar

[d.ovetrigo]

Hi Vidar,

Thank you for your quick response. I am testing with a custom board which has an NRF9161 connected through SPI to a flash memory.

I just applied your suggestion with CONFIG_MCUBOOT_EXTRA_IMGTOOL_ARGS="--confirm" to the prj.conf file of my application (not to the mcuboot/prj.conf), but it still has not worked yet.

The output I get when I program the nrf9161 is as follows:

*** Booting nRF Connect SDK v2.9.1-60d0d6c8d42d ***
*** Using Zephyr OS v3.7.99-ca954a6216c9 ***
Attempting to boot slot 0.
Attempting to boot from address 0x8200.
I: Trying to get Firmware version
I: Verifying signature against key 0.
I: Hash: 0x7c...a0
I: Firmware signature verified.
Firmware version 1
I: Setting monotonic counter (version: 1, slot: 0)
I: w25q16@1: SFDP v 1.6 AP ff with 2 PH
I: PH0: ff00 rev 1.6: 16 DW @ 80
I: w25q16@1: 2 MiBy flash
I: PH1: ff84 rev 1.0: 2 DW @ d0
*** Booting My Application v2.1.0-dev-12e5ee106034 ***
*** Using nRF Connect SDK v2.9.1-60d0d6c8d42d ***
*** Using Zephyr OS v3.7.99-ca954a6216c9 ***
I: Starting bootloader
I: Image index: 0, Swap type: none
I: Bootloader chainload address offset: 0x38000
All pins have been configured as non-secure
Booting TF-M v2.1.0
[Sec Thread] Secure image initializing!
TF-M Float ABI: Hard
Lazy stacking enabled

It looks like it knows that there is something to check on the external flash, since I get some messages from it, but it does not use it to boot.

I get the following information when I apply the imgtool dumpinfo zephyr.signed.bin command:

#### Image header (offset: 0x0) ############################
magic:              0x96f3b83d
load_addr:          0x0
hdr_size:           0x200
protected_tlv_size: 0x0
img_size:           0x5cc64
flags:              0x0
version:            4.1.2+0

.......

#### Image trailer (offset: unknown) #######################
(Note: some fields may not be used, depending on the update
strategy)

swap status: (len: unknown)
enc. keys:   Image not encrypted
swap size:   unknown
swap_info:   INVALID (0xff)
copy_done:   INVALID (0xff)
image_ok:    SET (0x1)

After this there was a boot magic field but I thought that it is not necessary to share in this message.

Is there anything here that does not seem correct?

Thank you very much,

Daniel

EDIT: I am also showing what I have set as a pm_static.yaml:

mcuboot_secondary:

  region: external_flash

  address: 0x00000

  size: 0xe0000

[Vidar Berg]

Hi Daniel,

Thanks for the additional info. It looks like the check here: https://github.com/nrfconnect/sdk-mcuboot/blob/9d9d524407df6da0815c79c5b9cf645f1ce25592/boot/bootutil/src/bootutil_public.c#L456  is failing in the bootloader, but it is not clear why from the configuration you posted. Can you please post the generated partitions.yml file from your build folder as well? 

Best regards,

Vidar

[d.ovetrigo]

Hi Vidar,

That could be an issue, I will debug that further.

As for my generated partitions yml file, it is as follows:

EMPTY_0:

  address: 0x1c000

  end_address: 0x20000

  placement:

    before:

    - s1_pad

  region: flash_primary

  size: 0x4000

EMPTY_1:

  address: 0x34000

  end_address: 0x38000

  placement:

    before:

    - mcuboot_pad

  region: flash_primary

  size: 0x4000

EMPTY_2:

  address: 0xfa000

  end_address: 0x100000

  placement:

    after:

    - settings_storage

  region: flash_primary

  size: 0x6000

app:

  address: 0x40000

  end_address: 0xf8000

  region: flash_primary

  size: 0xb8000

app_image:

  address: 0x38200

  end_address: 0xf8000

  orig_span: &id001

  - tfm

  - app

  region: flash_primary

  size: 0xbfe00

  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

external_flash:

  address: 0xe0000

  end_address: 0x200000

  region: external_flash

  size: 0x120000

mcuboot:

  address: 0x8200

  end_address: 0x1c000

  placement:

    align:

      end: 0x1000

    before:

    - mcuboot_primary

  region: flash_primary

  sharers: 0x1

  size: 0x13e00

mcuboot_pad:

  address: 0x38000

  end_address: 0x38200

  placement:

    align:

      start: 0x8000

    before:

    - mcuboot_primary_app

  region: flash_primary

  sharers: 0x2

  size: 0x200

mcuboot_primary:

  address: 0x38000

  end_address: 0xf8000

  orig_span: &id003

  - app

  - mcuboot_pad

  - tfm

  region: flash_primary

  size: 0xc0000

  span: *id003

mcuboot_primary_app:

  address: 0x38200

  end_address: 0xf8000

  orig_span: &id004

  - app

  - tfm

  region: flash_primary

  size: 0xbfe00

  span: *id004

mcuboot_secondary:

  address: 0x0

  end_address: 0xe0000

  region: external_flash

  size: 0xe0000

mcuboot_sram:

  address: 0x20000000

  end_address: 0x20008000

  orig_span: &id005

  - tfm_sram

  region: sram_primary

  size: 0x8000

  span: *id005

nonsecure_storage:

  address: 0xf8000

  end_address: 0xfa000

  orig_span: &id006

  - settings_storage

  region: flash_primary

  size: 0x2000

  span: *id006

nrf_modem_lib_ctrl:

  address: 0x20008000

  end_address: 0x200084e8

  inside:

  - sram_nonsecure

  placement:

    after:

    - tfm_sram

    - start

  region: sram_primary

  size: 0x4e8

nrf_modem_lib_rx:

  address: 0x2000a568

  end_address: 0x2000c568

  inside:

  - sram_nonsecure

  placement:

    after:

    - nrf_modem_lib_tx

  region: sram_primary

  size: 0x2000

nrf_modem_lib_sram:

  address: 0x20008000

  end_address: 0x2000c568

  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: 0x200084e8

  end_address: 0x2000a568

  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: 0x1c000

  orig_span: &id008

  - s0_pad

  - mcuboot

  region: flash_primary

  size: 0x14000

  span: *id008

s0_image:

  address: 0x8200

  end_address: 0x1c000

  orig_span: &id009

  - mcuboot

  region: flash_primary

  size: 0x13e00

  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: 0x20000

  end_address: 0x34000

  orig_span: &id010

  - s1_pad

  - s1_image

  region: flash_primary

  size: 0x14000

  span: *id010

s1_image:

  address: 0x20200

  end_address: 0x34000

  placement:

    after:

    - s1_pad

    - s0

  region: flash_primary

  share_size:

  - mcuboot

  size: 0x13e00

s1_pad:

  address: 0x20000

  end_address: 0x20200

  placement:

    after:

    - s0

    align:

      start: 0x8000

  region: flash_primary

  share_size:

  - mcuboot_pad

  size: 0x200

settings_storage:

  address: 0xf8000

  end_address: 0xfa000

  inside:

  - nonsecure_storage

  placement:

    align:

      start: 0x8000

    before:

    - end

  region: flash_primary

  size: 0x2000

sram_nonsecure:

  address: 0x20008000

  end_address: 0x20040000

  orig_span: &id011

  - sram_primary

  - nrf_modem_lib_ctrl

  - nrf_modem_lib_tx

  - nrf_modem_lib_rx

  region: sram_primary

  size: 0x38000

  span: *id011

sram_primary:

  address: 0x2000c568

  end_address: 0x20040000

  region: sram_primary

  size: 0x33a98

sram_secure:

  address: 0x20000000

  end_address: 0x20008000

  orig_span: &id012

  - tfm_sram

  region: sram_primary

  size: 0x8000

  span: *id012

tfm:

  address: 0x38200

  end_address: 0x40000

  inside:

  - mcuboot_primary_app

  placement:

    before:

    - app

  region: flash_primary

  size: 0x7e00

tfm_nonsecure:

  address: 0x40000

  end_address: 0xf8000

  orig_span: &id013

  - app

  region: flash_primary

  size: 0xb8000

  span: *id013

tfm_secure:

  address: 0x38000

  end_address: 0x40000

  orig_span: &id014

  - mcuboot_pad

  - tfm

  region: flash_primary

  size: 0x8000

  span: *id014

tfm_sram:

  address: 0x20000000

  end_address: 0x20008000

  inside:

  - sram_secure

  placement:

    after:

    - start

  region: sram_primary

  size: 0x8000

[Vidar Berg]

The Secondary slot is set larger than the primary slot, and they are meant to have the same size. This could explain why the slots are not read. Though I would have expected a warning about this in the debug log. Maybe you need to increase the log level.

d.ovetrigo said:

EDIT: I am also showing what I have set as a pm_static.yaml:

If you remove this and do a pristine build to allow the partition manager to size the partition, then try again, does it work?