[Buildroot] Kernel headers from an externally built kernel

Thomas Petazzoni thomas.petazzoni at free-electrons.com
Thu May 6 17:08:21 UTC 2010

On Thu, 6 May 2010 12:52:13 -0400
"Wagner, Scott" <swagner at vanteon.com> wrote:

> I would like to use buildroot to create a root file system only - I have
> an external toolchain and an external cross-built kernel made with that
> toolchain.
> How do I configure buildroot to reference the external kernel's headers?
> In poking through the makefiles, it looks like this is possible, but I
> have not yet found a way to specify it through menuconfig or by feeding
> environment variables to make.  I'm currently building with
> BR2_KERNEL_none=y.
> I think that as a result buildroot is trying to use the host platform's
> kernel headers, because the busybox build fails looking for an mtd
> header file, which is not present in the host's kernel headers - but
> this is just a guess.

In external toolchain mode, Buildroot simply uses the kernel headers as
available in the external toolchain. There is no option to use other
kernel headers, as it wouldn't make sense: kernel headers *are* part of
the external toolchain.

Concerning the MTD build problem, you may want to apply the patch


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

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