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Date:   Sat, 29 Jul 2023 10:35:30 +0200
From:   Willy Tarreau <w@1wt.eu>
To:     Zhangjin Wu <falcon@tinylab.org>
Cc:     thomas@t-8ch.de, arnd@arndb.de, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v3 06/12] selftests/nolibc: customize CROSS_COMPILE for
 32/64-bit powerpc
Message-ID: <20230729083530.GN956@1wt.eu>
References: <cover.1690489039.git.falcon@tinylab.org>
 <41e2aa9e4299dd35cfeef9fecc2a6a02a7b49d90.1690489039.git.falcon@tinylab.org>
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On Fri, Jul 28, 2023 at 04:28:17AM +0800, Zhangjin Wu wrote:
> The little-endian powerpc64le compilers provided by Ubuntu and Fedora
> are able to compile big endian kernel and big endian nolibc-test [1].
> 
> These default CROSS_COMPILE settings allow to test target architectures
> with:
> 
>     $ cd /path/to/tools/testing/selftests/nolibc/
> 
>     $ for arch in ppc ppc64 ppc64le; do \
>         make run-user ARCH=$arch | grep "status: "; \
>       done
> 
> If want to use another cross compiler, please simply pass CROSS_COMPILE
> or CC as before.
> 
> For example, it is able to build 64-bit nolibc-test with the big endian
> powerpc64-linux-gcc crosstool from [2]:
> 
>     $ wget -c https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/13.1.0/x86_64-gcc-13.1.0-nolibc-powerpc64-linux.tar.xz
>     $ tar xvf x86_64-gcc-13.1.0-nolibc-powerpc64-linux.tar.xz
>     $ export PATH=$PWD/gcc-13.1.0-nolibc/powerpc64-linux/bin/:$PATH
> 
>     $ export CROSS_COMPILE_ppc64=powerpc64-linux-
>     $ export CROSS_COMPILE_ppc64le=powerpc64-linux-
>     $ for arch in ppc64 ppc64le; do \
>         make run-user ARCH=$arch | grep "status: "; \
>       done
> 
> Or specify CC directly with full path:
> 
>     $ export CC=$PWD/gcc-13.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc
>     $ for arch in ppc64 ppc64le; do \
>         make run-user ARCH=$arch | grep "status: "; \
>       done
> 
> [1]: https://github.com/open-power/skiboot
> [2]: https://mirrors.edge.kernel.org/pub/tools/crosstool/
> 
> Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
> ---
>  tools/testing/selftests/nolibc/Makefile | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
> index 3f15c7f7ef76..6385915d16c9 100644
> --- a/tools/testing/selftests/nolibc/Makefile
> +++ b/tools/testing/selftests/nolibc/Makefile
> @@ -46,6 +46,9 @@ IMAGE            = $(IMAGE_$(XARCH))
>  IMAGE_NAME       = $(notdir $(IMAGE))
>  
>  # CROSS_COMPILE: cross toolchain prefix by architecture
> +CROSS_COMPILE_ppc       ?= powerpc-linux-gnu-
> +CROSS_COMPILE_ppc64     ?= powerpc64le-linux-gnu-
> +CROSS_COMPILE_ppc64le   ?= powerpc64le-linux-gnu-
>  CROSS_COMPILE           ?= $(CROSS_COMPILE_$(XARCH))

It seems to me that this patch and the previous one were rather
for the PPC series as I'm not seeing the relation with the tiny
config here.

Willy