NCS recommended MCUboot enabled apps build and flash methods

[n.sakamoto]

I am testing smp_srv (bluetooth) with NCS 1.3.2.
I don't know how to build and flash related apps for MCU boot in NCS.
MCUboot is unable to boot smp_srv even after running as documented.
All sample code related to MCUboot will fail to start the application.

1. Is this smp_srv build correct in NCS? Or what is the recommended build method?
2. How do you do the flash method related to MCU boot recommended by NCS?
I don't use west sign -t imgtool because it doesn't seem to be recommended by NCS.
I'm flashing merged.hex with west flash.

[challenged command]
cd ~/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr
west build -b nrf52dk_nrf52832 -d build_nrf52dk_nrf52832 . -- -DOVERLAY_CONFIG=overlay-bt.conf
west flash -d build_nrf52dk_nrf52832

nRF Connect SDK 1.3.2
Ubuntu 20.04.1 LTS

SEGGER J-Link V6.86e - Real time terminal output
J-Link OB-SAM3U128-V2-NordicSemi compiled Mar 17 2020 14:43:00 V1.0, SN=682102400
Process: JLinkExe
[00:00:00.003,753] <inf> mcuboot: Starting bootloader
[00:00:00.010,467] <inf> mcuboot: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
[00:00:00.021,667] <inf> mcuboot: Boot source: none
[00:00:00.027,770] <inf> mcuboot: Swap type: none
[00:00:00.244,415] <err> mcuboot: Image in the primary slot is not valid!
[00:00:00.252,838] <err> mcuboot: Unable to find bootable image

[Simon]

I'm sorry for the delay on this. I'll try to provide you with an answer within the next upcoming working days.

Best regards,

Simon

[n.sakamoto]

Reverting CONFIG_BOOT_SIGNATURE_KEY_FILE in prj.conf of MCUboot to the original file name and executing "imgtool.py getpub" to rebuild it solved the problem.
1.edit mcuboot prj.conf
[bootloader/mcuboot/boot/zephyr/prj.conf]
#CONFIG_BOOT_SIGNATURE_KEY_FILE="root-rsa-2048-new.pem" <-comment
CONFIG_BOOT_SIGNATURE_KEY_FILE="root-rsa-2048.pem" <-Revert to old code
2.
./scripts/imgtool.py getpub -k root-rsa-2048.pem

When I built mcuboot when bootloader / mcuboot / root-rsa-2048.pem did not exist, the build failed.
An error will occur if root-rsa-2048.pem'is missing.
Could not build with the newly generated root-rsa-2048-new.pem.
Is the method of specifying the key pair wrong?

error:
FileNotFoundError: [Errno 2] No such file or directory: '/home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/root-rsa-2048.pem'

1.edit mcuboot prj.conf
[bootloader/mcuboot/boot/zephyr/prj.conf]
CONFIG_BOOT_SIGNATURE_KEY_FILE="root-rsa-2048-new.pem" <-set new file
#CONFIG_BOOT_SIGNATURE_KEY_FILE="root-rsa-2048.pem" <-comment
2.
./scripts/imgtool.py getpub -k root-rsa-2048-new.pem

[smp_srv build log]

ncs@ubuntu:~/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr$ west build -b nrf52dk_nrf52832  -d build_nrf52dk_nrf52832 . -- -DOVERLAY=overlay-bt.conf
-- west build: generating a build system
Including boilerplate (Zephyr base): /home/ncs/ncs/v1.3.2/zephyr/cmake/app/boilerplate.cmake
-- Application: /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr
-- Zephyr version: 2.3.0-rc1 (/home/ncs/ncs/v1.3.2/zephyr)
-- Found Python3: /usr/bin/python3.8 (found suitable exact version "3.8.5") found components: Interpreter 
-- Board: nrf52dk_nrf52832
-- Found west: /home/ncs/.local/bin/west (found suitable version "0.7.2", minimum required is "0.7.1")

-- Found dtc: /usr/bin/dtc (found suitable version "1.5.0", minimum required is "1.4.6")
-- Found toolchain: gnuarmemb (/home/ncs/gnuarmemb)
-- Found BOARD.dts: /home/ncs/ncs/v1.3.2/zephyr/boards/arm/nrf52dk_nrf52832/nrf52dk_nrf52832.dts
-- Generated zephyr.dts: /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/zephyr.dts
-- Generated devicetree_unfixed.h: /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/include/generated/devicetree_unfixed.h
Parsing /home/ncs/ncs/v1.3.2/zephyr/Kconfig
Loaded configuration '/home/ncs/ncs/v1.3.2/zephyr/boards/arm/nrf52dk_nrf52832/nrf52dk_nrf52832_defconfig'
Merged configuration '/home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/prj.conf'
Merged configuration '/home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/boards/nrf52dk_nrf52832.conf'
Configuration saved to '/home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/.config'
Kconfig header saved to '/home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/include/generated/autoconf.h'
-- The C compiler identification is GNU 9.3.1
-- The CXX compiler identification is GNU 9.3.1
-- The ASM compiler identification is GNU
-- Found assembler: /home/ncs/gnuarmemb/bin/arm-none-eabi-gcc
-- Cache files will be written to: /home/ncs/.cache/zephyr

=== child image mcuboot - nrf52dk_nrf52832 begin ===
Including boilerplate (Zephyr base): /home/ncs/ncs/v1.3.2/zephyr/cmake/app/boilerplate.cmake
-- Application: /home/ncs/ncs/v1.3.2/bootloader/mcuboot/boot/zephyr
-- Zephyr version: 2.3.0-rc1 (/home/ncs/ncs/v1.3.2/zephyr)
-- Found Python3: /usr/bin/python3.8 (found suitable exact version "3.8.5") found components: Interpreter 
-- Board: nrf52dk_nrf52832
-- Found west: /home/ncs/.local/bin/west (found suitable version "0.7.2", minimum required is "0.7.1")
-- Found dtc: /usr/bin/dtc (found suitable version "1.5.0", minimum required is "1.4.6")
-- Found toolchain: gnuarmemb (/home/ncs/gnuarmemb)
-- Found BOARD.dts: /home/ncs/ncs/v1.3.2/zephyr/boards/arm/nrf52dk_nrf52832/nrf52dk_nrf52832.dts
-- Found devicetree overlay: /home/ncs/ncs/v1.3.2/bootloader/mcuboot/boot/zephyr/dts.overlay
-- Generated zephyr.dts: /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/mcuboot/zephyr/zephyr.dts
-- Generated devicetree_unfixed.h: /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/mcuboot/zephyr/include/generated/devicetree_unfixed.h
Parsing /home/ncs/ncs/v1.3.2/bootloader/mcuboot/boot/zephyr/Kconfig
Loaded configuration '/home/ncs/ncs/v1.3.2/zephyr/boards/arm/nrf52dk_nrf52832/nrf52dk_nrf52832_defconfig'
Merged configuration '/home/ncs/ncs/v1.3.2/bootloader/mcuboot/boot/zephyr/prj.conf'
Configuration saved to '/home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/mcuboot/zephyr/.config'
Kconfig header saved to '/home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/mcuboot/zephyr/include/generated/autoconf.h'
-- The C compiler identification is GNU 9.3.1
-- The CXX compiler identification is GNU 9.3.1
-- The ASM compiler identification is GNU
-- Found assembler: /home/ncs/gnuarmemb/bin/arm-none-eabi-gcc
-- Cache files will be written to: /home/ncs/.cache/zephyr
-- Configuring done
-- Generating done
-- Build files have been written to: /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/mcuboot
=== child image mcuboot - nrf52dk_nrf52832 end ===

-- Configuring done
-- Generating done
CMake Warning:
  Manually-specified variables were not used by the project:

    OVERLAY


-- Build files have been written to: /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832
-- west build: building application
[1/266] Preparing syscall dependency handling

[9/266] Performing build step for 'mcuboot_subimage'
[1/239] Preparing syscall dependency handling

[234/239] Linking C executable zephyr/zephyr_prebuilt.elf
Memory region         Used Size  Region Size  %age Used
           FLASH:       36060 B        48 KB     73.36%
            SRAM:       23608 B        64 KB     36.02%
        IDT_LIST:          72 B         2 KB      3.52%
[239/239] Linking C executable zephyr/zephyr.elf
[255/266] Linking C executable zephyr/zephyr_prebuilt.elf
Memory region         Used Size  Region Size  %age Used
           FLASH:      177420 B     224768 B     78.93%
            SRAM:       32280 B        64 KB     49.26%
        IDT_LIST:         136 B         2 KB      6.64%
[263/266] Generating ../../zephyr/app_...../../zephyr/app_moved_test_update.hex
FAILED: zephyr/app_update.bin zephyr/app_signed.hex zephyr/app_test_update.hex zephyr/app_moved_test_update.hex 
cd /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/modules/mcuboot && /usr/bin/python3.8 /home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/scripts/imgtool.py sign --key /home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/root-rsa-2048.pem --header-size 0x200 --align 4 --version 0.0.0+0 --slot-size 0x37000 --pad-header /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/mcuboot_primary_app.hex /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/app_signed.hex && /home/ncs/gnuarmemb/bin/arm-none-eabi-objcopy --input-target=ihex --output-target=binary /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/mcuboot_primary_app.hex /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/app_to_sign.bin && /usr/bin/python3.8 /home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/scripts/imgtool.py sign --key /home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/root-rsa-2048.pem --header-size 0x200 --align 4 --version 0.0.0+0 --slot-size 0x37000 --pad-header /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/app_to_sign.bin /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/app_update.bin && /usr/bin/python3.8 /home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/scripts/imgtool.py sign --key /home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/root-rsa-2048.pem --header-size 0x200 --align 4 --version 0.0.0+0 --slot-size 0x37000 --pad-header --pad /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/mcuboot_primary_app.hex /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/app_test_update.hex && /home/ncs/gnuarmemb/bin/arm-none-eabi-objcopy --input-target=ihex --output-target=ihex --change-address 0x37000 /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/app_test_update.hex /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832/zephyr/app_moved_test_update.hex
Traceback (most recent call last):
  File "/home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/scripts/imgtool.py", line 20, in <module>
    main.imgtool()
  File "/home/ncs/.local/lib/python3.8/site-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/home/ncs/.local/lib/python3.8/site-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/home/ncs/.local/lib/python3.8/site-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/ncs/.local/lib/python3.8/site-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/ncs/.local/lib/python3.8/site-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/home/ncs/ncs/v1.3.2/bootloader/mcuboot/scripts/imgtool/main.py", line 294, in sign
    key = load_key(key) if key else None
  File "/home/ncs/ncs/v1.3.2/bootloader/mcuboot/scripts/imgtool/main.py", line 72, in load_key
    key = keys.load(keyfile)
  File "/home/ncs/ncs/v1.3.2/bootloader/mcuboot/scripts/imgtool/keys/__init__.py", line 44, in load
    with open(path, 'rb') as f:
FileNotFoundError: [Errno 2] No such file or directory: '/home/ncs/ncs/v1.3.2/zephyr/../bootloader/mcuboot/root-rsa-2048.pem'
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: /usr/bin/cmake --build /home/ncs/ncs/v1.3.2/zephyr/samples/subsys/mgmt/mcumgr/smp_svr/build_nrf52dk_nrf52832

[n.sakamoto]

I found the following post about an issue where MCUboot's CONFIG_BOOT_SIGNATURE_KEY_FILE is not recognized.

[CONFIG_BOOT_SIGNATURE_KEY_FILE doesn't correctly get propagated to MCUBoot build]
devzone.nordicsemi.com/.../267627

[n.sakamoto]

I decided to avoid the problem by using the generated private key without changing the original file name, hoping that the problem that CONFIG_BOOT_SIGNATURE_KEY_FILE is not reflected in MCU boot will be solved by version upgrade.

[Simon]

I'm sorry for the delay on this. I have not looked into this topic (singing, keys, etc..)  very much and I put off some time yesterday and today to get an overview of how all this works. I'm gradually getting a better understanding of this and will try to provide you with an answer soon.

Best regards,

Simon