[0/2] allow control DTB to double as "FIT image"

[Simon Glass]

Hi Rasmus,

On 2026-05-12T16:16:29, Rasmus Villemoes <ravi at prevas.dk> wrote:

> RFC: allow the control DTB to act as a FIT image

Thanks for the write-up. Makes sense to me.

A couple of series-level concerns beyond the per-patch comments.

First, this needs documentation. The control DTB doubling as a FIT
image, and 'source ${fdtcontroladdr}:foo' becoming a supported idiom,
deserves a short page under doc/usage/ covering how to set up
CONFIG_DEVICE_TREE_INCLUDES with an 'images' node, the constraints
(script type, compression none, etc.) and the security argument from
the cover letter.

> I am of course happy to put this exemption for gd->fdt_blob under a
> CONFIG_ knob if that is deemed necessary.

Please decide this now rather than leaving it open. My preference is a
Kconfig option (default n) so boards keep the strict
fit_check_format() behaviour unless they opt in. That also gives a
natural home for the doc/usage/ page and makes it discoverable via
menuconfig. What do you think?

Regards,
Simon