[Buildroot] Forcing build of custom kernel headers

[Buildroot] Forcing build of custom kernel headers

[Christian Kellermann]

Hi List,

I have a rather peculiar system setup: A 64 bit PPC kernel running a 32
bit buildroot. ATM I solve this by using two default configs ? one for
the kernel and one for the rootfs. A simple shell script copies the
kernel artifacts back and forth so the kernel can be included in the
rootfs image.

The kernel in question is a custom kernel tree in a git repository.
Now some userland application needs kernel headers from that kernel. As
I understand buildroot would install the uapi-headers into staging/
automatically. But with my setup no kernel gets build for the 32bit
rootfs.

I have tried to set BR2_KERNEL_HEADERS_AS_KERNEL and the respective
CUSTOM kernel variables in my defconfig. However the build system will
always fall back to the BR2_DEFAULT_KERNEL_HEADERS version.

So tl;dr: I want to make the linux-headers package use my custom kernel
headers from a git repo but don?t know how to do this without building a
kernel.

Any thoughts?

Thanks,

Christian

[Buildroot] Forcing build of custom kernel headers

[Arnout Vandecappelle]

On 03-07-17 17:00, Christian Kellermann wrote:
> Hi List,
> 
> I have a rather peculiar system setup: A 64 bit PPC kernel running a 32
> bit buildroot. ATM I solve this by using two default configs ? one for
> the kernel and one for the rootfs. A simple shell script copies the
> kernel artifacts back and forth so the kernel can be included in the
> rootfs image.
> 
> The kernel in question is a custom kernel tree in a git repository.
> Now some userland application needs kernel headers from that kernel. As
> I understand buildroot would install the uapi-headers into staging/
> automatically. But with my setup no kernel gets build for the 32bit
> rootfs.
> 
> I have tried to set BR2_KERNEL_HEADERS_AS_KERNEL and the respective
> CUSTOM kernel variables in my defconfig. However the build system will
> always fall back to the BR2_DEFAULT_KERNEL_HEADERS version.
> 
> So tl;dr: I want to make the linux-headers package use my custom kernel
> headers from a git repo but don?t know how to do this without building a
> kernel.

 The easiest is to check out the linux tree separately and make
LINUX_HEADERS_OVERRIDE_SRCDIR point to it.

 Regards,
 Arnout

> 
> Any thoughts?
> 
> Thanks,
> 
> Christian
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> 

-- 
Arnout Vandecappelle                          arnout at mind be
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Essensium/Mind                                http://www.mind.be
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