On Thursday 18 August 2022 19:46:34 Pali Rohár wrote:
> On Monday 11 July 2022 16:19:30 Christophe Leroy wrote:
> > Since commit 4bf4f42a2feb ("powerpc/kbuild: Set default generic
> > machine type for 32-bit compile"), when building a 32 bits kernel
> > with a bi-arch version of GCC, or when building a book3s/32 kernel,
> > the option -mcpu=powerpc is passed to GCC at all time, relying on it
> > being eventually overriden by a subsequent -mcpu=xxxx.
> >
> > But when building the same kernel with a 32 bits only version of GCC,
> > that is not done, relying on gcc being built with the expected default
> > CPU.
> >
> > This logic has two problems. First, it is a bit fragile to rely on
> > whether the GCC version is bi-arch or not, because today we can have
> > bi-arch versions of GCC configured with a 32 bits default. Second,
> > there are some versions of GCC which don't support -mcpu=powerpc,
> > for instance for e500 SPE-only versions.
> >
> > So, stop relying on this approximative logic and allow the user to
> > decide whether he/she wants to use the toolchain's default CPU or if
> > he/she wants to set one, and allow only possible CPUs based on the
> > selected target.
>
> Hello! Exactly same issue is still in file arch/powerpc/boot/Makefile:
>
> ifdef CONFIG_PPC64_BOOT_WRAPPER
> ifdef CONFIG_CPU_LITTLE_ENDIAN
> BOOTCFLAGS += -m64 -mcpu=powerpc64le
> else
> BOOTCFLAGS += -m64 -mcpu=powerpc64
> endif
> else
> BOOTCFLAGS += -m32 -mcpu=powerpc
> endif
>
> It cause compile error:
>
> make ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnuspe- mpc85xx_smp_defconfig
> uImage
> ...
> BOOTAS arch/powerpc/boot/crt0.o
> powerpc-linux-gnuspe-gcc: error: unrecognized argument in option
> ‘-mcpu=powerpc’
> powerpc-linux-gnuspe-gcc: note: valid arguments to ‘-mcpu=’ are: 8540 8548
> native
> make[1]: *** [arch/powerpc/boot/Makefile:231: arch/powerpc/boot/crt0.o]
> Error 1
Now I have sent patch for this issue:
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20220820105200.30425-1-p...@kernel.org/
> > Reported-by: Pali Rohár <p...@kernel.org>
> > Tested-by: Pali Rohár <p...@kernel.org>
> > Reviewed-by: Arnd Bergmann <a...@arndb.de>
> > Cc: Segher Boessenkool <seg...@kernel.crashing.org>
> > Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
> > ---
> > arch/powerpc/Makefile | 26 +-------------------------
> > arch/powerpc/platforms/Kconfig.cputype | 21 ++++++++++++++++++---
> > 2 files changed, 19 insertions(+), 28 deletions(-)
