diff options
| author | Gang Yan <yangang@kylinos.cn> | 2025-10-17 10:12:09 +0800 |
|---|---|---|
| committer | Nicolas Schier <nsc@kernel.org> | 2025-11-08 12:17:58 +0100 |
| commit | bfb046f67ae1f20572d4dee73a173c6db706f5d4 (patch) | |
| tree | 6c46deb9f03935b5197ec5fbfe62c39ad4286d44 | |
| parent | af61da281f52aba0c5b090bafb3a31c5739850ff (diff) | |
kbuild: doc: improve KBUILD_BUILD_TIMESTAMP documentation
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>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251017021209.6586-1-gang.yan@linux.dev
Signed-off-by: Nicolas Schier <nsc@kernel.org>
| -rw-r--r-- | Documentation/kbuild/kbuild.rst | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst index 3388a10f2dcc..82826b0332df 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 + +The default value is the output of the date command at one point during +build. If provided, this timestamp will also be used for mtime fields +within any initramfs archive. Initramfs mtimes are 32-bit, so dates before +the 1970 Unix epoch, or after 2106-02-07 06:28:15 UTC will fail. KBUILD_BUILD_USER, KBUILD_BUILD_HOST ------------------------------------ |