Configuring MCU boot from Zephyr application

[dwalks]

Under bootloader/mcuboot/boot/zephyr there is a prj.conf and prj_miminal.conf. By default mcuboot uses the prj.conf. I'd like to know if:

1. it is possible to configure mcuboot from an application build to use minimal or other config 
2. what strategies exist for customizing the mcuboot build

Currently, in order to change the mcu configuration, I am modifying the prj.conf directly, which seems wrong. Ideally I would not have to modify the bootloader/mcuboot repository at all.

Thank you 

[rajeev]

I would suggest to go over the nRf Connect Intermediate course, specifically Lesson 8 to familiarize yourself how overall MCU boot works
https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-8-bootloaders-and-dfu-fota/

In this lesson you will see how to set mcuboot and related parameters without modifying the bootloader/mcuboot repository. hope that helps.

[dwalks]

Thank you for this. I was able to resolve my issue using the "child_image" approach. 

[rajeev]

Perfect, that's what that lesson actually focused on. I am glad you got that sorted out.

Using "child_image" approach is very helpful especially for out of tree build devices.

We use similar approach here: 

github.com/.../led_blink

[dwalks]

For anyone reading this, I have problems getting my project to build correctly with the child image. However, setting the mcuboot conf via cmake flags worked as expected. 

[Amanda Hsieh]

Hi,

dwalks said:

I have problems getting my project to build correctly with the child image.

Could you elaborate on the problems and provide logs?

Are you using child_imag/mcuboot.conf? If so, could you provide child_imag/mcuboot.conf?

Regards,
Amanda H.