[Buildroot] [PATCHv7 2/5] core: introduce the BR2_EXTERNAL variable

Samuel Martin s.martin49 at gmail.com
Thu Dec 5 19:42:54 UTC 2013


2013/12/5 Thomas Petazzoni <thomas.petazzoni at free-electrons.com>

> This commit introduces the BR2_EXTERNAL environment variable, which
> will allow to keep Buildroot customization (board-specific
> configuration files or root filesystem overlays, package Config.in and
> makefiles, as well as defconfigs) outside of the Buildroot tree.
>
> This commit only introduces the variable itself, and ensures that it
> is available within Config.in options. This allows us to use
> $BR2_EXTERNAL in a 'source' statement in Config.in.
>
> Following patches extend the usage of BR2_EXTERNAL to other areas
> (packages and defconfigs).
>
> In details, this commit:
>
>  * Introduces the BR2_EXTERNAL Kconfig option. This option has no
>    prompt, and is therefore not visible to the user and also not
>    stored in the .config file. It is automatically set to the value of
>    the BR2_EXTERNAL environment variable. The only purpose of this
>    BR2_EXTERNAL Kconfig option is to allow $BR2_EXTERNAL to be
>    properly expanded when used inside Kconfig source statements.
>
>  * Calculates the BR2_EXTERNAL value to use. If passed on the command
>    line, then this value is taken in priority, and saved to a
>    .br-external hidden file in the output directory. If not passed on
>    the command line, then we read the .br-external file from the
>    output directory. This allows the user to not pass the BR2_EXTERNAL
>    value at each make invocation. If no BR2_EXTERNAL value is passed,
>    we define it to support/dummy-external, so that the kconfig code
>    finds an existing $(BR2_EXTERNAL)/package/Config.in file to
>    include.
>
>  * Passes the BR2_EXTERNAL into the *config environment, so that its
>    value is found when parsing/evaluating Config.in files and .config
>    values.
>
> Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> Reviewed-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
> Tested-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
> Acked-by: Ryan Barnett <rjbarnet at rockwellcollins.com>
>
Tested-by: "Samuel Martin" <s.martin49 at gmail.com>
Acked-by: "Samuel Martin" <s.martin49 at gmail.com>


Regards,

-- 
Samuel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.busybox.net/pipermail/buildroot/attachments/20131205/15901f05/attachment-0002.html>


More information about the buildroot mailing list