[RFD] How to support KBUILD_OUTPUT for kselftest?

[RFD] How to support KBUILD_OUTPUT for kselftest?

[Bamvor Jian Zhang]

Hi,

I am trying to improve cross compiling support for kselftest recently. Right
now I am stuck when I want to enable KBUILD_OUTPUT(O=xxx). It exist in wiki of
kselftest[1]. Hope it is not a duplicated work.

It seems that only perf tools(tools/perf) support it. And I could know that the
following Makefile are called when building perf:
tools/Makefile
tools/perf/Makefile
tools/perf/Makefile.perf
tools/build/Makefile.build

But I could not get the idea that how to do it for kselftest. Is there any
existed infrastructure I could use?

I am appreciated if there is any suggestions or ideas. Thanks in advance.

Regards

Bamvor

[1] https://kselftest.wiki.kernel.org/support_cross-compilation

Re: [RFD] How to support KBUILD_OUTPUT for kselftest?

[Kevin Hilman]

Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> writes:

> I am trying to improve cross compiling support for kselftest recently. Right
> now I am stuck when I want to enable KBUILD_OUTPUT(O=xxx). It exist in wiki of
> kselftest[1]. Hope it is not a duplicated work.

Just want to echo the need for this feature because trying to build
kselftests for a kernel built with KBUILD_OUTPUT is broken due to
hard-coded assumptions about paths to headers, etc.

I haven't dug any deeper into how to fix it though...

Kevin