Configure devicetree overlay for mcuboot

[davidvanrijn]

Hi,

I am using the actinius icarus board, and i want to use external flash for bootloading. It all works fine, except i have to add this segment in the actinius dtsi file :

	chosen {
		nordic,pm-ext-flash = &w25q64;
	};

Which is unpractical, because we don't really want to use a custom zephyr repo. I have also tried to put it in my shield overlay, but this also didn't work.

So my questions are:

 - Can I specify a dts overlay to mcuboot via cmake?

- Does it make sense to make a merge request this code-snippet i added, or would this break stuff for other people?

Thanks,

[Achim Kraus]

At least when you use the current NCS (2.5.2), McuBoot is a "child image". The build of such child images are defined in the project's "child_image" folder (you may need to create one). For McuBoot this is "child_image/mcuboot.conf" and the overlays are in "child_image/mcuboot/boards".

[davidvanrijn]

Thank Achim,

This worked perfectly. I no have this tree structure in my project:

child_image
└── mcuboot
    ├── boards
    │   └── actinius_icarus.overlay
    └── prj.conf

It is worth noting that ncs changes my board from `actinius_icarus_ns` to `actinius_icarus`.

[Achim Kraus]

davidvanrijn said:

It is worth noting that ncs changes my board from `actinius_icarus_ns` to `actinius_icarus`.

Yes, I forgot that. McuBoot is part of the "secure build", while the application is part of the "none secure build".