Re: [PATCH] kbuild: add documentation of KBUILD_BUILD_VERSION

Michal Marek
2015-04-11T19:54:17Z

Dne 11.4.2015 v 15:20 Nicholas Mc Guire napsal(a):
> On Sat, 11 Apr 2015, Jonathan Corbet wrote:
>
>> On Sun, 5 Apr 2015 08:44:28 +0200
>> Nicholas Mc Guire <hofrat@osadl.org> wrote:
>>
>>> KBUILD_BUILD_VERSION is currently not documented but it is
>>> needed when rebuilding a kernel that should result in the identical
>>> binary. This is a brief documentation of KBUILD_BUILD_VERSION.
>>
>> Can we add something like the above to the document itself so that
>> readers have an idea of why they might want to tweak this?
>>
>> Either way, I can take it in the docs tree if that's best..Michal?
>>
> I thought of that but it would be inconsistent as all other descriptions
> here are only the function not the use.

Most of the entries in this file predate efforts at deterministic
builds, so I'd prefer usefulness over consistency here :-).

> I did not find a file where
> the problem of identical rebuild would really fit.

... unless, of course, you want to start a new file covering this topic.
Because it's not just the few override variables, but also some options
have to be turned off (I remember CONFIG_GCOV_KERNEL) and the paths must
be the same, or relative paths must be used.

Michal