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authorArnd Bergmann <arnd@arndb.de>2012-08-10 11:12:20 +0000
committerArnd Bergmann <arnd@arndb.de>2012-10-09 20:29:05 +0200
commit91802a8ef410810db58907d2ea4c4adc00ef4688 (patch)
tree778be8d346a007457f430b113f10467e66591a64 /arch/arm/Makefile
parentf880b67dcbdedb49453f88d2ccb1a0937b046d82 (diff)
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ARM: pass -marm to gcc by default for both C and assembler
The Linaro cross toolchain and probably others nowadays default to building in THUMB2 mode. When building a kernel for a CPU that does not support THUMB2, the compiler complains about incorrect flags. We can work around this by setting -marm for all non-T2 builds. -marm was passed unconditionally for C files previously, but nothing was passed to the gcc frontend when processing .S files, resulting in a warning. The assembler never defaults to ARM unless -Wa,-mthumb is supplied explicitly, so the files were still assembled correctly. This patch makes sure that -marm is passed for .S files too, and also avoids the redundant gcc -marm -mthumb in Thumb kernels. Without this patch, building assabet_defconfig results in: usr/initramfs_data.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default] arch/arm/nwfpe/entry.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default] firmware/cis/PCMLM28.cis.gen.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default] (and many more) Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Dave Martin <dave.martin@linaro.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/Makefile')
-rw-r--r--arch/arm/Makefile13
1 files changed, 7 insertions, 6 deletions
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index f023e3a..5f914fc 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -21,8 +21,6 @@ endif
OBJCOPYFLAGS :=-O binary -R .comment -S
GZFLAGS :=-9
#KBUILD_CFLAGS +=-pipe
-# Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb:
-KBUILD_CFLAGS +=$(call cc-option,-marm,)
# Never generate .eh_frame
KBUILD_CFLAGS += $(call cc-option,-fno-dwarf2-cfi-asm)
@@ -105,17 +103,20 @@ endif
ifeq ($(CONFIG_THUMB2_KERNEL),y)
AFLAGS_AUTOIT :=$(call as-option,-Wa$(comma)-mimplicit-it=always,-Wa$(comma)-mauto-it)
AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
-CFLAGS_THUMB2 :=-mthumb $(AFLAGS_AUTOIT) $(AFLAGS_NOWARN)
-AFLAGS_THUMB2 :=$(CFLAGS_THUMB2) -Wa$(comma)-mthumb
+CFLAGS_ISA :=-mthumb $(AFLAGS_AUTOIT) $(AFLAGS_NOWARN)
+AFLAGS_ISA :=$(CFLAGS_ISA) -Wa$(comma)-mthumb
# Work around buggy relocation from gas if requested:
ifeq ($(CONFIG_THUMB2_AVOID_R_ARM_THM_JUMP11),y)
CFLAGS_MODULE +=-fno-optimize-sibling-calls
endif
+else
+CFLAGS_ISA :=$(call cc-option,-marm,)
+AFLAGS_ISA :=$(CFLAGS_ISA)
endif
# Need -Uarm for gcc < 3.x
-KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_THUMB2) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
-KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_THUMB2) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
+KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
+KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
CHECKFLAGS += -D__arm__
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