Re: delete-node without label or address from overlay dts

[David Gibson <david@gibson.dropbear.id.au>]

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On Thu, Jan 15, 2026 at 12:00:13PM +0000, Phil Dawson wrote:
> Hi,
> 
> Apologies if this is covered in documentation that I've missed.
> Is there a way to use /delete-node/ to remove a node with no label or
> address from a plugin/overlay dts file?

No.  /delete-node/ has no representation within overlay files.  One of
several examples of how plugin/overlays are misleading in that they
sort of resemble dtc's older build-time overlays, but not really.

> I have a device tree overlay file pl.dtsi that is auto generated by
> vendor tools. Unfortunately many nodes in this file are generated
> wrong and the overlay fails to apply.
> I've been removing the broken nodes with /delete-node/ &label; syntax
> in a second dtsi file and then compiling the two together with a
> wrapper dts file and the commands:
> gcc -E -nostdinc -undef -D__DTS__ -x assembler-with-cpp -o pl.dts.pp
> <path redacted>/pl.dts
> dtc -R 8 -b 0 -p 0 -@ -H epapr -o pl.dtbo -I dts -O dtb pl.dts.pp
> (These are run as part of a larger yocto build so there may be some
> other work around this I'm missing!)
> 
> The auto generated pl.dtsi also has a few broken nodes without labels
> or addresses like this:
> 
> /dts-v1/;
> /plugin/;
> &amba {
>     vcap_hdmi_input_1_v_proc_ss_1 {
>     <contents removed for brevity>
>     };
> };
> 
> I am unable to figure out the syntax to remove these nodes with
> /delete-node/, should this be possible?
> 
> I've tried using the below syntax:
> &amba {
>     /delete-node/ vcap_hdmi_input_1_v_proc_ss_1;
> };
> 
> But while dtc doesn't complain, the nodes are not removed from the
> resulting dtbo.

Hm, we probably should make this generate an error.  I'm unlikely to
get to that any time soon, though.

> I also can't remove using the full path as there is no root node/full
> path in the generated dtsi file.
> 
> According to this discussion on an unrelated project
> (https://github.com/zephyrproject-rtos/zephyr/discussions/67228)
> trying to delete a node with a name and address without using the
> address won't work. But in my case the node has no address.
> 
> I can work around my issue by hacking the auto generated files (while
> I try to persuade the vendor to fix them!) to add a label for these
> nodes and then removing them using the label. But is there a correct
> way of doing this just using my separate dtsi file and dtc?
> 
> Best Regards,
> Phil Dawson
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

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