From mboxrd@z Thu Jan 1 00:00:00 1970 From: raj.khem@gmail.com (Khem Raj) Date: Tue, 04 Oct 2011 19:04:09 -0700 Subject: [PATCH 05/11] ARM: vfp: use -mfloat-abi=soft to build vfp In-Reply-To: <20111003140411.GB2117@arm.com> References: <1317496920-7764-1-git-send-email-arnd@arndb.de> <1317496920-7764-6-git-send-email-arnd@arndb.de> <20111003140411.GB2117@arm.com> Message-ID: <4E8BBB19.8080303@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/3/2011 7:04 AM, Dave Martin wrote: > On Sat, Oct 01, 2011 at 09:21:54PM +0200, Arnd Bergmann wrote: >> Distros are starting to ship with toolchains defaulting to >> hardfloat. Using such a compiler to build the kernel fails >> in the VFP directory with >> >> arch/arm/vfp/entry.S:1:0: sorry, unimplemented: -mfloat-abi=hard and VFP >> >> Adding -mfloat-abi=soft to the gcc command line fixes this. >> >> Signed-off-by: Arnd Bergmann >> --- >> arch/arm/vfp/Makefile | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/arch/arm/vfp/Makefile b/arch/arm/vfp/Makefile >> index 6de73aa..a81404c 100644 >> --- a/arch/arm/vfp/Makefile >> +++ b/arch/arm/vfp/Makefile >> @@ -7,7 +7,7 @@ >> # ccflags-y := -DDEBUG >> # asflags-y := -DDEBUG >> >> -KBUILD_AFLAGS :=$(KBUILD_AFLAGS:-msoft-float=-Wa,-mfpu=softvfp+vfp) >> +KBUILD_AFLAGS :=$(KBUILD_AFLAGS:-msoft-float=-Wa,-mfpu=softvfp+vfp -mfloat-abi=soft) > > Although -mfpu=softvfp+vfp and -mfloat-abi=soft look mutually > contradictory, this seems to have the correct effect, i.e. the > assembler allows floating-point instructions but marks the resulting > object as using the soft-float calling conventions. I was wondering if this could also be achieved with -mfloat-abi=softfp this will also add Tag_FP_arch: VFPv2 into .attributes section and -Wa,-mfpu=softvfp+vfp may not be needed. > > The binutils documentation also seems to confirm that that's what > should happen. > > I don't see another combination of options for getting this effect. > > > So, if you like: > > Reviewed-by: Dave Martin > > Cheers > ---Dave > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel