[Buildroot] How to rebuild following .config change?

Thomas Petazzoni thomas.petazzoni at free-electrons.com
Wed Jun 24 07:13:53 UTC 2009

Le Tue, 23 Jun 2009 20:05:06 +0000 (UTC),
Grant Edwards <grant.b.edwards at gmail.com> a écrit :

> You can do a "distclean", but then all the sources get
> re-downloaded and toolchains re-built -- which takes a _long_
> time.

It's true that Buildroot doesn't handle partial rebuilds very well.
This is something we should improve.

In the mean time, here is how I use Buildroot :

 * Set the BUILDROOT_DL_DIR environment variable, so that downloads are
   made to a completely separate directory from the Buildroot source
   and Buildroot build directories ;

 * Use an external toolchain (such as one generated by Crosstool-NG,
   for example). This way, the toolchain generation process is
   independent from Buildroot, and you don't need to re-generate the
   toolchain everytime you want to recompile the root filesystem from
   scratch ;

 * Use out-of-tree generation in Buildroot with "make
   O=/path/to/somewhere". This way, all generated files are in a
   separate directory, which makes it easy to clean everything.


Thomas Petazzoni, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.

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