[PATCH v5 8/8] selftests/nolibc: customize CROSS_COMPILE for 32/64-bit powerpc

From: Zhangjin Wu
Date: Thu Aug 03 2023 - 07:52:19 EST


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 XARCH=$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_ppc=powerpc64-linux-
$ export CROSS_COMPILE_ppc64=powerpc64-linux-
$ export CROSS_COMPILE_ppc64le=powerpc64-linux-
$ for arch in ppc ppc64 ppc64le; do \
make run-user XARCH=$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 ppc ppc64 ppc64le; do \
make run-user XARCH=$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@xxxxxxxxxxx>
---
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 6e34d364a177..16cc33db54e3 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -56,6 +56,9 @@ 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))

# make sure CC is prefixed with CROSS_COMPILE
--
2.25.1