[Buildroot] [PATCH 2/3] Add support for BR2_EXTERNAL

[Thomas Petazzoni]

Dear Arnout Vandecappelle,

On Fri, 13 Sep 2013 22:56:59 +0200, Arnout Vandecappelle wrote:

> > O= is stored in the generated makefile (as you know). However, it gets very
> > annoying to type BR2_EXTERNAL=/path/to/external and I don't always want to
> > export it as shell environment variable. Thus, adding that line to
> > mkmakefile is handy since usually when you specify O= you are doing a
> > specific build which BR2_EXTERNAL would definitely be a part of.
> 
>   My point is: it should (and can) be made part of the .config. It really 
> has to be part of the .config, because some options in the .config will 
> refer to the packages that are defined in the external directory.

I believe it cannot be part of the .config, because there is a
chicken-and-egg problem due to the fact that running 'make menuconfig'
requires to already know the BR2_EXTERNAL value.

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com