From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from conssluserg-05.nifty.com ([210.131.2.90]:58897 "EHLO conssluserg-05.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933548AbeE2Nkw (ORCPT ); Tue, 29 May 2018 09:40:52 -0400 Received: from mail-vk0-f42.google.com (mail-vk0-f42.google.com [209.85.213.42]) (authenticated) by conssluserg-05.nifty.com with ESMTP id w4TDeTM2030708 for ; Tue, 29 May 2018 22:40:30 +0900 Received: by mail-vk0-f42.google.com with SMTP id 200-v6so6803911vkc.0 for ; Tue, 29 May 2018 06:40:30 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20180516141458.18996-2-npiggin@gmail.com> References: <20180516141458.18996-1-npiggin@gmail.com> <20180516141458.18996-2-npiggin@gmail.com> From: Masahiro Yamada Date: Tue, 29 May 2018 22:39:48 +0900 Message-ID: Subject: Re: [PATCH v4 1/4] powerpc/kbuild: set default generic machine type for 32-bit compile Content-Type: text/plain; charset="UTF-8" Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Nicholas Piggin Cc: Linux Kbuild mailing list , linuxppc-dev , Segher Boessenkool 2018-05-16 23:14 GMT+09:00 Nicholas Piggin : > Some 64-bit toolchains uses the wrong ISA variant for compiling 32-bit > kernels, even with -m32. Debian's powerpc64le is one such case, and > that is because it is built with --with-cpu=power8. > > So when cross compiling a 32-bit kernel with a 64-bit toolchain, set > -mcpu=powerpc initially, which is the generic 32-bit powerpc machine > type and scheduling model. CPU and platform code can override this > with subsequent -mcpu flags if necessary. > > This is not done for 32-bit toolchains otherwise it would override > their defaults, which are presumably set appropriately for the > environment (moreso than a 64-bit cross compiler). > > This fixes a lot of build failures due to incompatible assembly when > compiling 32-bit kernel with th Debian powerpc64le 64-bit toolchain. > > Cc: Segher Boessenkool > Signed-off-by: Nicholas Piggin > --- Can you please remove the noise changes? 1/4 adds some blank lines, then 2/4 removes them. > arch/powerpc/Makefile | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile > index 95813df90801..15ca4bafad82 100644 > --- a/arch/powerpc/Makefile > +++ b/arch/powerpc/Makefile > @@ -24,9 +24,20 @@ ifeq ($(HAS_BIARCH),y) > ifeq ($(CROSS32_COMPILE),) > CROSS32CC := $(CC) -m32 > KBUILD_ARFLAGS += --target=elf32-powerpc > + This blank line will be removed by the next patch. > +ifdef CONFIG_PPC32 > +# These options will be overridden by any -mcpu option that the CPU > +# or platform code sets later on the command line, but they are needed > +# to set a sane 32-bit cpu target for the 64-bit cross compiler which > +# may default to the wrong ISA. > +KBUILD_CFLAGS += -mcpu=powerpc > +KBUILD_AFLAGS += -mcpu=powerpc > +endif > + This blank line will be removed by the next patch. > endif > endif > > + This blank line will be removed by the next patch. > export CROSS32CC CROSS32AR > > ifeq ($(CROSS_COMPILE),) > -- > 2.17.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Best Regards Masahiro Yamada