GCC 11 on ARM now complains like the following when trying to determine if
an arch is supported. Presumably because it enforces the default option
'--with-float=hard' which GCC 10 didn't do?
$ arm-linux-gnueabihf-gcc-11 -march=armv7-a -c -x c /dev/null
cc1: error: ‘-mfloat-abi=hard’: selected architecture lacks an FPU
Due to that, the kernel build system selects the wrong compiler options
which throws errros like this during the build:
/tmp/ccrHfZPj.s: Assembler messages:
/tmp/ccrHfZPj.s:116: Error: selected processor does not support `dmb ish' in ARM mode
/tmp/ccrHfZPj.s:150: Error: selected processor does not support `isb ' in ARM mode
/tmp/ccrHfZPj.s:160: Error: selected processor does not support `mrrc p15,1,r4,r5,c14' in ARM mode
/tmp/ccrHfZPj.s:245: Error: selected processor does not support `dmb ish' in ARM mode
/tmp/ccrHfZPj.s:503: Error: selected processor does not support `dmb ish' in ARM mode
/tmp/ccrHfZPj.s:527: Error: selected processor does not support `dmb ish' in ARM mode
/tmp/ccrHfZPj.s:698: Error: selected processor does not support `dmb ish' in ARM mode
/tmp/ccrHfZPj.s:731: Error: selected processor does not support `isb ' in ARM mode
Fix that by adding '-msoft-float' to KBUILD_CFLAGS before the definition of
the 'arch-$(CONFIG_CPU_<foo>)' instruction selection macros.
Signed-off-by: Juerg Haefliger <[email protected]>
---
arch/arm/Makefile | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 173da685a52e..d21198833997 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -56,6 +56,9 @@ endif
#
KBUILD_CFLAGS += $(call cc-option,-fno-ipa-sra)
+# Need -msoft-float for gcc 11 for the below instruction set selection
+KBUILD_CFLAGS += -msoft-float
+
# This selects which instruction set is used.
# Note that GCC does not numerically define an architecture version
# macro, but instead defines a whole series of macros which makes
@@ -125,7 +128,7 @@ AFLAGS_ISA :=$(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__
--
2.30.2