Re: [PATCH, v2] kbuild: doc: improve KBUILD_BUILD_TIMESTAMP documentation

[Nicolas Schier <nsc@kernel.org>]

On Fri, Oct 17, 2025 at 10:12:09AM +0800, Gang Yan wrote:
> From: Gang Yan <yangang@kylinos.cn>
> 
> This patch adds an example of how to set KBUILD_BUILD_TIMESTAMP to a
> specific date. Also, note that the provided timestamp is used for
> initramfs mtime fields, which are 32-bit and thus limited to dates
> between the Unix epoch and 2106-02-07 06:28:15 UTC. Dates outside this
> range will cause errors.
> 
> Suggested-by: David Disseldorp <ddiss@suse.de>
> Signed-off-by: Gang Yan <yangang@kylinos.cn>
> Reviewed-by: David Disseldorp <ddiss@suse.de>
> ---
> Changelog:
>  v2:
>   - Replace the invalid example with a valid one.
>   - Apply David's suggestions.
> ---
>  Documentation/kbuild/kbuild.rst | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 

Thanks to both of you!

I have only found a tiny nit-pick, see below.

Reviewed-by: Nicolas Schier <nsc@kernel.org>

> diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> index 3388a10f2dcc..881189ecd0ca 100644
> --- a/Documentation/kbuild/kbuild.rst
> +++ b/Documentation/kbuild/kbuild.rst
> @@ -328,8 +328,14 @@ KBUILD_BUILD_TIMESTAMP
>  ----------------------
>  Setting this to a date string overrides the timestamp used in the
>  UTS_VERSION definition (uname -v in the running kernel). The value has to
> -be a string that can be passed to date -d. The default value
> -is the output of the date command at one point during build.
> +be a string that can be passed to date -d. E.g.::
> +
> +$ KBUILD_BUILD_TIMESTAMP="Mon Oct 13 00:00:00 UTC 2025" make

Other code blocks in kbuild.rst are indented by four spaces (and
accidentally five in one line).

I can add these when applying the patch for kbuild-next, if that is ok
for you.

Kind regards
Nicolas