ARC Build system tweak
PATCH 1/1 ARC Build system tweak
Hi Michal,
Here's a ARC build system quirk that we are trying to change. I would appreciate if you could take a glance and suggest if that is silly or better way. Would we be inducing more shell invocations now for build ? Also I could not find an existing construct in /scripts/Kbuild.include so opencoded the pre-processor check.
Thx,
-Vineet
Vineet Gupta (1):
ARC: build: Better way to detect ISA compatible toolchain
arch/arc/Makefile | 14 ++++++++++++++ arch/arc/include/asm/arcregs.h | 6 ------ 2 files changed, 14 insertions(+), 6 deletions(-)
Signature · 1 line
2.5.0
PATCH 1/1 ARC: build: Better way to detect ISA compatible toolchain
ARC architecture has 2 instruction sets: ARCompact/ARCv2. While same gcc supports compiling for either (using appropriate toggles), we can't use the same toolchain to build kernel because libgcc needs to be unique and the toolchian (uClibc based) is not multilibed.
uClibc toolchain is convenient since it allows all userspace and kernel to be built with a single install for an ISA.
This however means 2 gnu installs (with same triplet prefix) are needed for building for 2 ISA and need to be in PATH.
As developers we keep switching the builds, but would occassionally fail to update the PATH leading to usage of wrong tools. And this would only show up at the end of kernel build when linking incompatible libgcc.
So the initial solution was to have gcc define a special preprocessor macro DEFAULT_CPU_xxx which is unique for default toolchain configuration. Claudiu proposed using grep for an existing preprocessor macro which is again uniquely defined per ISA.
--- arch/arc/Makefile | 14 ++++++++++++++ arch/arc/include/asm/arcregs.h | 6 ------ 2 files changed, 14 insertions(+), 6 deletions(-)
arch/arc/Makefile +14 -0
@@ -18,6 +18,20 @@ cflags-y += -fno-common -pipe -fno-builtin -D__linux__ cflags-$(CONFIG_ISA_ARCOMPACT) += -mA7 cflags-$(CONFIG_ISA_ARCV2) += -mcpu=archs +is_700 = $(shell $(CC) -dM -E - < /dev/null | grep -q "ARC700" && echo 1 || echo 0) + +ifdef CONFIG_ISA_ARCOMPACT +ifeq ($(is_700), 0) + $(error Toolchain not configured for ARCompact builds) +endif +endif + +ifdef CONFIG_ISA_ARCV2 +ifeq ($(is_700), 1) + $(error Toolchain not configured for ARCv2 builds) +endif +endif + ifdef CONFIG_ARC_CURR_IN_REG # For a global register defintion, make sure it gets passed to every file # We had a customer reported bug where some code built in kernel was NOT using
arch/arc/include/asm/arcregs.h +0 -6
@@ -381,12 +381,6 @@ static inline int is_isa_arcompact(void)return IS_ENABLED (CONFIG_ISA_ARCOMPACT ); } -#if defined(CONFIG_ISA_ARCOMPACT ) && !defined(_CPU_DEFAULT_A7) -#error "Toolchain not configured for ARCompact builds" -#elif defined(CONFIG_ISA_ARCV2 ) && !defined(_CPU_DEFAULT_HS) -#error "Toolchain not configured for ARCv2 builds" -#endif -#endif /* __ASEMBLY__ */ #endif /* _ASM_ARC_ARCREGS_H */
Signature · 1 line
2.5.0
Re: [PATCH] ARC: build: Better way to detect ISA compatible toolchain
Hi Michal,
Can u please take a look at patch below !
Thx,
-Vineet
Quoted 70 lines · Vineet Gupta
ARC architecture has 2 instruction sets: ARCompact/ARCv2. While same gcc supports compiling for either (using appropriate toggles), we can't use the same toolchain to build kernel because libgcc needs to be unique and the toolchian (uClibc based) is not multilibed.
uClibc toolchain is convenient since it allows all userspace and kernel to be built with a single install for an ISA.
This however means 2 gnu installs (with same triplet prefix) are needed for building for 2 ISA and need to be in PATH.
As developers we keep switching the builds, but would occassionally fail to update the PATH leading to usage of wrong tools. And this would only show up at the end of kernel build when linking incompatible libgcc.So the initial solution was to have gcc define a special preprocessor macro
DEFAULT_CPU_xxxwhich is unique for default toolchain configuration. Claudiu proposed using grep for an existing preprocessor macro which is again uniquely defined per ISA.Cc Michal Marek <mmarek at suse.cz>Suggested-by Claudiu Zissulescu <claziss at synopsys.com>Signed-off-by Vineet Gupta <vgupta at synopsys.com>--- arch/arc/Makefile | 14 ++++++++++++++ arch/arc/include/asm/arcregs.h | 6 ------ 2 files changed, 14 insertions(+), 6 deletions(-)arch/arc/Makefile +14
-0@@ -18,6 +18,20 @@ cflags-y += -fno-common -pipe -fno-builtin -D__linux__ cflags-$(CONFIG_ISA_ARCOMPACT) += -mA7 cflags-$(CONFIG_ISA_ARCV2) += -mcpu=archs +is_700 = $(shell $(CC) -dM -E - < /dev/null | grep -q "ARC700" && echo 1 || echo 0) + +ifdef CONFIG_ISA_ARCOMPACT +ifeq ($(is_700), 0) + $(error Toolchain not configured for ARCompact builds) +endif +endif + +ifdef CONFIG_ISA_ARCV2 +ifeq ($(is_700), 1) + $(error Toolchain not configured for ARCv2 builds) +endif +endif + ifdef CONFIG_ARC_CURR_IN_REG # For a global register defintion, make sure it gets passed to every file # We had a customer reported bug where some code built in kernel was NOT usingarch/arc/include/asm/arcregs.h +0
-6@@ -381,12 +381,6 @@ static inline int is_isa_arcompact(void)return IS_ENABLED (CONFIG_ISA_ARCOMPACT ); } -#if defined(CONFIG_ISA_ARCOMPACT ) && !defined(_CPU_DEFAULT_A7) -#error "Toolchain not configured for ARCompact builds" -#elif defined(CONFIG_ISA_ARCV2 ) && !defined(_CPU_DEFAULT_HS) -#error "Toolchain not configured for ARCv2 builds" -#endif -#endif /* __ASEMBLY__ */ #endif /* _ASM_ARC_ARCREGS_H */