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authorNicolas Pitre <nicolas.pitre@linaro.org>2017-11-29 07:52:52 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2017-12-17 22:14:21 +0000
commit75fea300d73ae5b18957949a53ec770daaeb6fc2 (patch)
tree9e07e50f5b8992512603774358e0979906237a59 /arch/arm/Makefile
parent55e7cff44c7c322310aded74ed92c54b22ccccd4 (diff)
downloadlinux-75fea300d73ae5b18957949a53ec770daaeb6fc2.tar.bz2
ARM: 8723/2: always assume the "unified" syntax for assembly code
The GNU assembler has implemented the "unified syntax" parsing since 2005. This "unified" syntax is required when the kernel is built in Thumb2 mode. However the "unified" syntax is a mixed bag of features, including not requiring a `#' prefix with immediate operands. This leads to situations where some code builds just fine in Thumb2 mode and fails to build in ARM mode if that prefix is missing. This behavior discrepancy makes build tests less valuable, forcing both ARM and Thumb2 builds for proper coverage. Let's "fix" this issue by always using the "unified" syntax for both ARM and Thumb2 mode. Given that the documented minimum binutils version that properly builds the kernel is version 2.20 released in 2010, we can assume that any toolchain capable of building the latest kernel is also "unified syntax" capable. Whith this, a bunch of macros used to mask some differences between both syntaxes can be removed, with the side effect of making LTO easier. Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/Makefile')
-rw-r--r--arch/arm/Makefile6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 80351e505fd5..e83f5161fdd8 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -115,9 +115,11 @@ ifeq ($(CONFIG_ARM_UNWIND),y)
CFLAGS_ABI +=-funwind-tables
endif
+# Accept old syntax despite ".syntax unified"
+AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
+
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_ISA :=-mthumb $(AFLAGS_AUTOIT) $(AFLAGS_NOWARN)
AFLAGS_ISA :=$(CFLAGS_ISA) -Wa$(comma)-mthumb
# Work around buggy relocation from gas if requested:
@@ -125,7 +127,7 @@ ifeq ($(CONFIG_THUMB2_AVOID_R_ARM_THM_JUMP11),y)
KBUILD_CFLAGS_MODULE +=-fno-optimize-sibling-calls
endif
else
-CFLAGS_ISA :=$(call cc-option,-marm,)
+CFLAGS_ISA :=$(call cc-option,-marm,) $(AFLAGS_NOWARN)
AFLAGS_ISA :=$(CFLAGS_ISA)
endif