Serial recovery mynewt bootloader

[Spi]

Lesson 8 of "nRF Connect SDK Intermediate" DevAcademy course deals with Bootloaders.  I've successfully done the exercise of updating firmware using the off-the-shelf mcuboot bootloader. Unfortunately our actual product does not include a button so we can't enter bootload mode using that mechanism.  The 'mynewt' bootloader appears to support both a timeout and a special UART string that allow a device to enter bootload mode without a GPIO-based button. I'd like to learn how to use mynewt bootloader instead of mcuboot.

From what I gather, the bootloader is somehow specified by west.yml, perhaps these lines:

    - name: mcuboot
      repo-path: sdk-mcuboot
      revision: v2.0.99-ncs1
      path: bootloader/mcuboot

1) How would I change west.yml to select the 'mynewt' bootloader logic instead of the 'zephyr' bootloader?  If I make a project-specific version of west.yml, where would I place it in my folder structure so that nRF Connect SDK running under VSCode uses it instead of the standard west.yml in the ncs installation?

2) What else would I need to do?

Thank you.

[Vidar Berg]

Hello,

Yes, you can create your own west manifest (see T2: Star topology, application is the manifest repository) and specify additional dependencies, such as another fork of the bootloader. But MCUBoot already supports other methods for buttonless entry into serial recovery: https://github.com/nrfconnect/sdk-mcuboot/blob/b82206c15fff357c151c24bf97c99c4348d14a46/boot/zephyr/Kconfig.serial_recovery#L139.

Best regards,

Vidar 

[Spi]

Hello Vidar. Thanks for your response.  Using the off-the-shelf mcuboot and off-the-shelf west.yml would be ideal (and I think BOOT_SERIAL_BOOT_MODE could be what we need).  If that fails I might come back with follow-up questions as to the specifics of "forking" the bootloader plus getting a modified west.yml to point to that fork.