Messages in this thread | | | From | Nick Desaulniers <> | Date | Tue, 19 May 2020 17:37:37 -0700 | Subject | Re: [PATCH] ARM: pass -msoft-float to gcc earlier |
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On Tue, May 19, 2020 at 3:09 PM Arnd Bergmann <arnd@arndb.de> wrote: > > Szabolcs Nagy ran into a kernel build failure with a custom gcc > toochain that sets -mfpu=auto -mfloat-abi=hard: > > /tmp/ccmNdcdf.s:1898: Error: selected processor does not support `cpsid i' in ARM mode > > The problem is that $(call cc-option, -march=armv7-a) fails before the > kernel overrides the gcc options to also pass -msoft-float.
The call to `$(call cc-option, -march=armv7-a)
> > Move the option to the beginning the Makefile, before we call
beginning of the
> cc-option for the first time. > > Reported-by: Szabolcs Nagy <szabolcs.nagy@arm.com> > Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87302 > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Moving this looks harmless enough, though it's not clear to me how the failure you're describing would occur. I don't see calls to as-instr in arch/arm/Makefile. Which object is being built before -msoft-float is being set?
> --- > arch/arm/Makefile | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/Makefile b/arch/arm/Makefile > index 7d5cd0f85461..e428ea6eb0fa 100644 > --- a/arch/arm/Makefile > +++ b/arch/arm/Makefile > @@ -16,6 +16,8 @@ LDFLAGS_vmlinux += --be8 > KBUILD_LDFLAGS_MODULE += --be8 > endif > > +KBUILD_CFLAGS += -msoft-float > + > ifeq ($(CONFIG_ARM_MODULE_PLTS),y) > KBUILD_LDS_MODULE += $(srctree)/arch/arm/kernel/module.lds > endif > @@ -135,7 +137,7 @@ AFLAGS_ISA :=$(CFLAGS_ISA) > endif > > # Need -Uarm for gcc < 3.x > -KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm > +KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -Uarm > KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float > > CHECKFLAGS += -D__arm__ > -- > 2.26.2 >
-- Thanks, ~Nick Desaulniers
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