[PATCH 2/4] tools: mkeficapsule: remove device-tree related operation

Heinrich Schuchardt xypron.glpk at gmx.de
Wed May 12 12:01:32 CEST 2021

On 12.05.21 10:01, Ilias Apalodimas wrote:
> On Wed, May 12, 2021 at 04:49:02PM +0900, Masami Hiramatsu wrote:
>> Hi Ilias,
>> 2021年5月12日(水) 16:21 Ilias Apalodimas <ilias.apalodimas at linaro.org>:
>>> Akashi-san,
>>> On Wed, May 12, 2021 at 01:57:51PM +0900, AKASHI Takahiro wrote:
>>>> As we discussed, "-K" and "-D" options have nothing to do with
>>>> creating a capsule file. The same result can be obtained by
>>>> using standard commands like:
>>>>   === signature.dts ===
>>>>   /dts-v1/;
>>>>   /plugin/;
>>>>   &{/} {
>>>>         signature {
>>>>                 capsule-key = /incbin/("SIGNER.esl");
>>>>         };
>>>>   };
>>>>   ===
>>>>   $ dtc -@ -I dts -O dtb -o signature.dtbo signature.dts
>>>>   $ fdtoverlay -i test.dtb -o test_sig.dtb -v signature.dtbo
>>>> So just remove this feature.
>>>> (Effectively revert the commit 322c813f4bec ("mkeficapsule: Add support
>>>> for embedding public key in a dtb").)
>>>> The same feature is implemented by a shell script (tools/fdtsig.sh).
>>> The only reason I can see to keep this, is if mkeficapsule gets included
>>> intro distro packages in the future.  That would make end users life a bit
>>> easier, since they would need a single binary to create the whole
>>> CapsuleUpdate sequence.
>> Hmm, I think it is better to write a manpage of mkeficapsule which
>> also describes
>> how to embed the key into dtb as in the above example if it is so short.
>> Or, distros can package the above shell script with mkeficapsule.
>> Embedding a key and signing a capsule are different operations but
>> using the same tool may confuse users (at least me).
> Sure fair enough.  I am merely pointing out we need a way to explain all of
> those to users.

This is currently our only documentation:


For mkimage we have a man-page ./doc/mkimage.1 that is packaged with
Debians u-boot-tools package. Please, provide a similar man-page as

Best regards


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