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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 00/12] xen/arm: Add support to build with clang
On 18/04/2019 10:15, Artem Mygaiev wrote: Hello Julien, Stefano Hi Artem, On Wed, 2019-04-17 at 10:42 +0100, Julien Grall wrote:Hi, On 16/04/2019 23:43, Stefano Stabellini wrote:On Fri, 29 Mar 2019, Julien Grall wrote:On 28/03/2019 11:27, Artem Mygaiev wrote:Hi Julien,Hi Artem,On Wed, 2019-03-27 at 18:45 +0000, Julien Grall wrote:Hi all, This series adds support to build Xen Arm with clang. This series was tested with clang 8.0. Note that I only did build for arm64. I still need to look at the arm32 build.I wonder if you have time to try the series with Arm Compiler 6? I am asking because AFAIK it is based on clang/llvm [1] and there's a safety-compliant version of it certified by TUV [2]. I don't have a license yet so cannot try it myself but maybe you have access.I gave a quick try to the Arm Compiler. I had to hack a bit config/StdGNU.mk to pass armclang and the appropriate target option. I also had a linking issue at the end where __2snprintf was not found. It seems the compiler replace snprintf with __2snprintf, I haven't figured out why yet.But after these changes, does it work?I haven't tried to fix the linking issues. I only gave a quick try because Artem asked. I have no plan at the moment to go further than that for now. Patches are welcomed to add support for armclang.I have implemented a bunch of HACKs [1] so can build Xen master with armclang 6.12. Not even "smoke"-tested, just trying to identify missing parameters and proper linker configuration. Thank you for looking at it. Some comments below. Not yet fixed section placement, lots of warnings from linker like: Warning: L6170W: Mapping symbol #40 '$x.20' in .altinstr_replacement(ns16550.o:42) identifies code, but is in a section not marked as executable. Instruction in the sections .altinstr_replacement are never meant to be executed.I guess this is coming from armlink? Any particular reason to use armlink and not ld as we do on clang? Also armlink sometimes fails with Internal fault: [0xe81a5a:6120001] Do you have more output? [1] Diff below just for reference with xen master + Julien's clang patch series applied --- diff --git a/Config.mk b/Config.mk index 417039d7f6..0fc84293f9 100644 --- a/Config.mk +++ b/Config.mk @@ -221,7 +221,9 @@ CFLAGS += -Wall -Wstrict-prototypes$(call cc-option-add,HOSTCFLAGS,HOSTCC,-Wdeclaration-after-statement)$(call cc-option-add,CFLAGS,CC,-Wdeclaration-after-statement) +ifneq ($(armds),y) $(call cc-option-add,CFLAGS,CC,-Wno-unused-but-set-variable) I didn't need this on Arm Compiler 6.11. Can you provide the list of error you get here? +endif $(call cc-option-add,CFLAGS,CC,-Wno-unused-local-typedefs)LDFLAGS += $(foreach i, $(EXTRA_LIB), -L$(i))@@ -234,9 +236,15 @@ endif APPEND_LDFLAGS += $(foreach i, $(APPEND_LIB), -L$(i)) APPEND_CFLAGS += $(foreach i, $(APPEND_INCLUDES), -I$(i))-EMBEDDED_EXTRA_CFLAGS := -nopie -fno-stack-protector -fno-stack-protector-all +EMBEDDED_EXTRA_CFLAGS := -fno-stack-protector -fno-stack-protector-all EMBEDDED_EXTRA_CFLAGS += -fno-exceptions+ifeq ($(armds),y)+EMBEDDED_EXTRA_CFLAGS += -fno-ropi -fno-rwpi Why do you need this? Is it because armlink does not support -nopie? +else +EMBEDDED_EXTRA_CFLAGS += -nopie +endif + XEN_EXTFILES_URL ?= http://xenbits.xen.org/xen-extfiles # All the files at that location were downloaded from elsewhere on # the internet. The original download URL is preserved as a comment diff --git a/config/StdGNU.mk b/config/StdGNU.mk index 48c50b5ad7..585d076d4f 100644 --- a/config/StdGNU.mk +++ b/config/StdGNU.mk @@ -1,6 +1,15 @@ AS = $(CROSS_COMPILE)as +AR = $(CROSS_COMPILE)ar LD = $(CROSS_COMPILE)ld ifeq ($(clang),y) +ifeq ($(armds),y) +CC = armclang +CXX = armclang +LD_LTO = armlink +LD = armlink -v +AS = armasm +AR = armar +else ifneq ($(CROSS_COMPILE),) CC = clang -target $(CROSS_COMPILE:-=) CXX = clang++ -target $(CROSS_COMPILE:-=) @@ -9,13 +18,13 @@ CC = clang CXX = clang++ endif LD_LTO = $(CROSS_COMPILE)llvm-ld +endif else CC = $(CROSS_COMPILE)gcc CXX = $(CROSS_COMPILE)g++ LD_LTO = $(CROSS_COMPILE)ld endif CPP = $(CC) -E -AR = $(CROSS_COMPILE)ar RANLIB = $(CROSS_COMPILE)ranlib NM = $(CROSS_COMPILE)nm STRIP = $(CROSS_COMPILE)strip diff --git a/config/arm32.mk b/config/arm32.mk index f95228e3c0..5afed07357 100644 --- a/config/arm32.mk +++ b/config/arm32.mk @@ -4,12 +4,14 @@ CONFIG_ARM_$(XEN_OS) := yCONFIG_XEN_INSTALL_SUFFIX := -# -march= -mcpu=- # Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb: -CFLAGS += -marm - +ifeq ($(armds),y) +# VE needed +CFLAGS += --target=arm-arm-none-eabi -march=armv7-a -marm should do the right thing even on armclang.You would still need --target=.... but that's should depend on $CROSS_COMPILE (or any other name we decide). +else +CFLAGS += -marm # -march= -mcpu= # Use only if calling $(LD) directly. LDFLAGS_DIRECT += -EL +endifIOEMU_CPU_ARCH ?= armdiff --git a/config/arm64.mk b/config/arm64.mk index aa45772b61..46b203d384 100644 --- a/config/arm64.mk +++ b/config/arm64.mk @@ -4,10 +4,14 @@ CONFIG_ARM_$(XEN_OS) := yCONFIG_XEN_INSTALL_SUFFIX := +ifeq ($(armds),y)+# VE needed +CFLAGS += --target=aarch64-arm-none-eabi -march=armv8.1-a+nofp+nosimd Same remark for --target.Also, -march=armv8.1 looks wrong to me because this may generate code that will not work on armv8.0 platform. +else CFLAGS += #-marm -march= -mcpu= etc - # Use only if calling $(LD) directly. LDFLAGS_DIRECT += -EL +endifIOEMU_CPU_ARCH ?= aarch64 diff --git a/xen/Rules.mk b/xen/Rules.mkindex a151b3f625..72b34451d2 100644 --- a/xen/Rules.mk +++ b/xen/Rules.mk @@ -76,9 +76,11 @@ AFLAGS-y += -D__ASSEMBLY__ # Older clang's built-in assembler doesn't understand .skip with labels: # https://bugs.llvm.org/show_bug.cgi?id=27369 ifeq ($(clang),y) +ifneq ($(armds),y) $(call as-option-add,CFLAGS,CC,".L0:\n.L1:\n.skip (.L1 - .L0)",,\ -no-integrated-as) endif +endifALL_OBJS := $(ALL_OBJS-y) Cheers, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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