When building a firmware image, is there a way to apply `scripts/diffconfig.sh` to the kernel's `.config`?

[hnyman]

@jkool702

somewhere there has to be information about just the options you selected, right?

Sorry, but that information is not stored.
The .config is just a simple flat file about option selections, but there is no info about the reason why an option has been toggled.

@jkool702

I suppose I could save this full config, then rever to the original targets/<...>/config-6.1 file, regenerate the .config, diff them and add the differences to the targets/<...>/config-6.1 file. But It would be nice is there was a more straightforward solution here.

That is pretty much what the normal diffconfig does for the normal .config

Personally I keep a short .config recipe, originally pruned from diffconfig.
See

Programmatically (non-interactively) configure the OpenWrt build

The easiest thing is probably to manually craft a short .config recipe for each target, and then tailor it for each OpenWrt version. The .config recipe can easily be originally based on ./scripts/diffconfig.sh output I am building several community builds with that approach. (WNDR3700 with ar71xx and ath79 , R7800 ipq806x), and privately also WRT3200ACM mvebu, and I build master and 19.07 for all of them. Pretty easy, once you get the .config recipe for master. It usually needs only slight ch…

Regarding kernel config, you might look into my earlier suggestion about git diff, and using is output.