diff --git a/xen/Makefile b/xen/Makefile
index 80679b4a6b17..22ca963994c8 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -113,6 +113,76 @@ $(KCONFIG_CONFIG):
 %/auto.conf %/auto.conf.cmd: $(KCONFIG_CONFIG)
 	$(MAKE) -f $(BASEDIR)/tools/kconfig/Makefile.kconfig ARCH=$(ARCH) SRCARCH=$(SRCARCH) HOSTCC="$(HOSTCC)" HOSTCXX="$(HOSTCXX)" syncconfig
 
+ifeq ($(CONFIG_DEBUG),y)
+CFLAGS += -O1
+else
+CFLAGS += -O2
+endif
+
+ifeq ($(CONFIG_FRAME_POINTER),y)
+CFLAGS += -fno-omit-frame-pointer
+else
+CFLAGS += -fomit-frame-pointer
+endif
+
+CFLAGS += -nostdinc -fno-builtin -fno-common
+CFLAGS += -Werror -Wredundant-decls -Wno-pointer-arith
+$(call cc-option-add,CFLAGS,CC,-Wvla)
+CFLAGS += -pipe -D__XEN__ -include $(BASEDIR)/include/xen/config.h
+CFLAGS-$(CONFIG_DEBUG_INFO) += -g
+
+ifneq ($(CONFIG_CC_IS_CLANG),y)
+# Clang doesn't understand this command line argument, and doesn't appear to
+# have an suitable alternative.  The resulting compiled binary does function,
+# but has an excessively large symbol table.
+CFLAGS += -Wa,--strip-local-absolute
+endif
+
+AFLAGS-y                += -D__ASSEMBLY__
+
+CFLAGS += $(CFLAGS-y)
+# allow extra CFLAGS externally via EXTRA_CFLAGS_XEN_CORE
+CFLAGS += $(EXTRA_CFLAGS_XEN_CORE)
+
+# Most CFLAGS are safe for assembly files:
+#  -std=gnu{89,99} gets confused by #-prefixed end-of-line comments
+#  -flto makes no sense and annoys clang
+AFLAGS += $(AFLAGS-y) $(filter-out -std=gnu% -flto,$(CFLAGS))
+
+# LDFLAGS are only passed directly to $(LD)
+LDFLAGS += $(LDFLAGS_DIRECT)
+
+LDFLAGS += $(LDFLAGS-y)
+
+ifeq ($(CONFIG_COVERAGE),y)
+ifeq ($(CONFIG_CC_IS_CLANG),y)
+    COV_FLAGS := -fprofile-instr-generate -fcoverage-mapping
+else
+    COV_FLAGS := -fprofile-arcs -ftest-coverage
+endif
+else
+COV_FLAGS :=
+endif
+
+ifeq ($(CONFIG_UBSAN),y)
+CFLAGS_UBSAN := -fsanitize=undefined
+else
+CFLAGS_UBSAN :=
+endif
+
+ifeq ($(CONFIG_LTO),y)
+CFLAGS += -flto
+LDFLAGS-$(CONFIG_CC_IS_CLANG) += -plugin LLVMgold.so
+endif
+
+include $(BASEDIR)/arch/$(TARGET_ARCH)/arch.mk
+
+# define new variables to avoid the ones defines in Config.mk
+export XEN_CFLAGS := $(CFLAGS)
+export XEN_AFLAGS := $(AFLAGS)
+export XEN_LDFLAGS := $(LDFLAGS)
+export COV_FLAGS CFLAGS_UBSAN
+
 endif # need-config
 
 .PHONY: build install uninstall clean distclean MAP
diff --git a/xen/Rules.mk b/xen/Rules.mk
index f0111f2bc1b4..faf462a0178a 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -38,52 +38,12 @@ ALL_OBJS-y               += $(BASEDIR)/arch/$(TARGET_ARCH)/built_in.o
 ALL_OBJS-$(CONFIG_CRYPTO)   += $(BASEDIR)/crypto/built_in.o
 
 # Initialise some variables
-CFLAGS_UBSAN :=
 ccflags-y :=
-
-ifeq ($(CONFIG_DEBUG),y)
-CFLAGS += -O1
-else
-CFLAGS += -O2
-endif
-
-ifeq ($(CONFIG_FRAME_POINTER),y)
-CFLAGS += -fno-omit-frame-pointer
-else
-CFLAGS += -fomit-frame-pointer
-endif
-
-CFLAGS += -nostdinc -fno-builtin -fno-common
-CFLAGS += -Werror -Wredundant-decls -Wno-pointer-arith
-$(call cc-option-add,CFLAGS,CC,-Wvla)
-CFLAGS += -pipe -D__XEN__ -include $(BASEDIR)/include/xen/config.h
-CFLAGS-$(CONFIG_DEBUG_INFO) += -g
-
-ifneq ($(CONFIG_CC_IS_CLANG),y)
-# Clang doesn't understand this command line argument, and doesn't appear to
-# have an suitable alternative.  The resulting compiled binary does function,
-# but has an excessively large symbol table.
-CFLAGS += -Wa,--strip-local-absolute
-endif
-
-AFLAGS-y                += -D__ASSEMBLY__
+# Allow arch specific cflags, to be calculated for each objects.
+arch_ccflags =
 
 ALL_OBJS := $(ALL_OBJS-y)
 
-CFLAGS += $(CFLAGS-y)
-# allow extra CFLAGS externally via EXTRA_CFLAGS_XEN_CORE
-CFLAGS += $(EXTRA_CFLAGS_XEN_CORE)
-
-# Most CFLAGS are safe for assembly files:
-#  -std=gnu{89,99} gets confused by #-prefixed end-of-line comments
-#  -flto makes no sense and annoys clang
-AFLAGS += $(AFLAGS-y) $(filter-out -std=gnu% -flto,$(CFLAGS))
-
-# LDFLAGS are only passed directly to $(LD)
-LDFLAGS += $(LDFLAGS_DIRECT)
-
-LDFLAGS += $(LDFLAGS-y)
-
 include $(BASEDIR)/arch/$(TARGET_ARCH)/Rules.mk
 
 include Makefile
@@ -103,27 +63,19 @@ __subdir-y	:= $(filter %/, $(obj-y))
 subdir-y	+= $(__subdir-y)
 obj-y		:= $(patsubst %/, %/built_in.o, $(obj-y))
 
-$(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): CFLAGS += -DINIT_SECTIONS_ONLY
+$(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): ccflags-y += -DINIT_SECTIONS_ONLY
 
 ifeq ($(CONFIG_COVERAGE),y)
-ifeq ($(CONFIG_CC_IS_CLANG),y)
-    COV_FLAGS := -fprofile-instr-generate -fcoverage-mapping
-else
-    COV_FLAGS := -fprofile-arcs -ftest-coverage
-endif
-$(filter-out %.init.o $(nocov-y),$(obj-y) $(obj-bin-y) $(extra-y)): CFLAGS += $(COV_FLAGS)
+$(filter-out %.init.o $(nocov-y),$(obj-y) $(obj-bin-y) $(extra-y)): ccflags-y += $(COV_FLAGS)
 endif
 
 ifeq ($(CONFIG_UBSAN),y)
-CFLAGS_UBSAN += -fsanitize=undefined
 # Any -fno-sanitize= options need to come after any -fsanitize= options
 $(filter-out %.init.o $(noubsan-y),$(obj-y) $(obj-bin-y) $(extra-y)): \
-CFLAGS += $(filter-out -fno-%,$(CFLAGS_UBSAN)) $(filter -fno-%,$(CFLAGS_UBSAN))
+ccflags-y += $(filter-out -fno-%,$(CFLAGS_UBSAN)) $(filter -fno-%,$(CFLAGS_UBSAN))
 endif
 
 ifeq ($(CONFIG_LTO),y)
-CFLAGS += -flto
-LDFLAGS-$(CONFIG_CC_IS_CLANG) += -plugin LLVMgold.so
 # Would like to handle all object files as bitcode, but objects made from
 # pure asm are in a different format and have to be collected separately.
 # Mirror the directory tree, collecting them as built_in_bin.o.
@@ -136,18 +88,20 @@ obj-bin-y :=
 endif
 
 # Always build obj-bin files as binary even if they come from C source. 
-$(obj-bin-y): CFLAGS := $(filter-out -flto,$(CFLAGS))
+# FIXME LTO broken, but we would need a different way to filter -flto out
+# $(obj-bin-y): CFLAGS := $(filter-out -flto,$(CFLAGS))
 
 # target with its suffix stripped
 target-stem = $(basename $@)
 
 c_flags = -MMD -MF $(@D)/.$(@F).d \
-          $(CFLAGS) \
+          $(XEN_CFLAGS) \
+          $(arch_ccflags) \
           '-D__OBJECT_FILE__="$@"' \
           $(ccflags-y) $(CFLAGS_$(target-stem).o)
 
 a_flags = -MMD -MF $(@D)/.$(@F).d \
-          $(AFLAGS)
+          $(XEN_AFLAGS)
 
 built_in.o: $(obj-y) $(extra-y)
 ifeq ($(obj-y),)
@@ -156,7 +110,7 @@ else
 ifeq ($(CONFIG_LTO),y)
 	$(LD_LTO) -r -o $@ $(filter-out $(extra-y),$^)
 else
-	$(LD) $(LDFLAGS) -r -o $@ $(filter-out $(extra-y),$^)
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $(filter-out $(extra-y),$^)
 endif
 endif
 
@@ -164,7 +118,7 @@ built_in_bin.o: $(obj-bin-y) $(extra-y)
 ifeq ($(obj-bin-y),)
 	$(CC) $(a_flags) -c -x assembler /dev/null -o $@
 else
-	$(LD) $(LDFLAGS) -r -o $@ $(filter-out $(extra-y),$^)
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $(filter-out $(extra-y),$^)
 endif
 
 # Force execution of pattern rules (for which PHONY cannot be directly used).
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 7f1427630b96..1599e2ba4058 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -96,24 +96,24 @@ prelink_lto.o: $(ALL_OBJS)
 
 # Link it with all the binary objects
 prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o
-	$(LD) $(LDFLAGS) -r -o $@ $^
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $^
 else
 prelink.o: $(ALL_OBJS)
-	$(LD) $(LDFLAGS) -r -o $@ $^
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $^
 endif
 
 $(TARGET)-syms: prelink.o xen.lds
-	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o \
+	$(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o \
 	    $(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0
 	$(NM) -pa --format=sysv $(@D)/.$(@F).0 \
 		| $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).0.S
 	$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).0.o
-	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o \
+	$(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o \
 	    $(@D)/.$(@F).0.o -o $(@D)/.$(@F).1
 	$(NM) -pa --format=sysv $(@D)/.$(@F).1 \
 		| $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).1.S
 	$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1.o
-	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
+	$(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
 	    $(@D)/.$(@F).1.o -o $@
 	$(NM) -pa --format=sysv $(@D)/$(@F) \
 		| $(BASEDIR)/tools/symbols --xensyms --sysv --sort \
diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
index 022a3a6f82ba..e69de29bb2d1 100644
--- a/xen/arch/arm/Rules.mk
+++ b/xen/arch/arm/Rules.mk
@@ -1,93 +0,0 @@
-########################################
-# arm-specific definitions
-
-#
-# If you change any of these configuration options then you must
-# 'make clean' before rebuilding.
-#
-
-CFLAGS += -I$(BASEDIR)/include
-
-$(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
-$(call cc-option-add,CFLAGS,CC,-Wnested-externs)
-
-# Prevent floating-point variables from creeping into Xen.
-CFLAGS-$(CONFIG_ARM_32) += -msoft-float
-CFLAGS-$(CONFIG_ARM_32) += -mcpu=cortex-a15
-
-CFLAGS-$(CONFIG_ARM_64) += -mcpu=generic
-CFLAGS-$(CONFIG_ARM_64) += -mgeneral-regs-only # No fp registers etc
-
-EARLY_PRINTK := n
-
-ifeq ($(CONFIG_DEBUG),y)
-
-# See docs/misc/arm/early-printk.txt for syntax
-
-EARLY_PRINTK_brcm           := 8250,0xF040AB00,2
-EARLY_PRINTK_dra7           := 8250,0x4806A000,2
-EARLY_PRINTK_fastmodel      := pl011,0x1c090000,115200
-EARLY_PRINTK_exynos5250     := exynos4210,0x12c20000
-EARLY_PRINTK_hikey960       := pl011,0xfff32000
-EARLY_PRINTK_juno           := pl011,0x7ff80000
-EARLY_PRINTK_lager          := scif,0xe6e60000
-EARLY_PRINTK_midway         := pl011,0xfff36000
-EARLY_PRINTK_mvebu          := mvebu,0xd0012000
-EARLY_PRINTK_omap5432       := 8250,0x48020000,2
-EARLY_PRINTK_rcar3          := scif,0xe6e88000
-EARLY_PRINTK_seattle        := pl011,0xe1010000
-EARLY_PRINTK_sun6i          := 8250,0x01c28000,2
-EARLY_PRINTK_sun7i          := 8250,0x01c28000,2
-EARLY_PRINTK_thunderx       := pl011,0x87e024000000
-EARLY_PRINTK_vexpress       := pl011,0x1c090000
-EARLY_PRINTK_xgene-mcdivitt := 8250,0x1c021000,2
-EARLY_PRINTK_xgene-storm    := 8250,0x1c020000,2
-EARLY_PRINTK_zynqmp         := cadence,0xff000000
-
-ifneq ($(EARLY_PRINTK_$(CONFIG_EARLY_PRINTK)),)
-EARLY_PRINTK_CFG := $(subst $(comma), ,$(EARLY_PRINTK_$(CONFIG_EARLY_PRINTK)))
-else
-EARLY_PRINTK_CFG := $(subst $(comma), ,$(CONFIG_EARLY_PRINTK))
-endif
-
-# Extract configuration from string
-EARLY_PRINTK_INC := $(word 1,$(EARLY_PRINTK_CFG))
-EARLY_UART_BASE_ADDRESS := $(word 2,$(EARLY_PRINTK_CFG))
-
-# UART specific options
-ifeq ($(EARLY_PRINTK_INC),8250)
-EARLY_UART_REG_SHIFT := $(word 3,$(EARLY_PRINTK_CFG))
-endif
-ifeq ($(EARLY_PRINTK_INC),pl011)
-ifneq ($(word 3,$(EARLY_PRINTK_CFG)),)
-EARLY_PRINTK_INIT_UART := y
-EARLY_PRINTK_BAUD := $(word 3,$(EARLY_PRINTK_CFG))
-endif
-endif
-ifeq ($(EARLY_PRINTK_INC),scif)
-ifneq ($(word 3,$(EARLY_PRINTK_CFG)),)
-CFLAGS-y += -DEARLY_PRINTK_VERSION_$(word 3,$(EARLY_PRINTK_CFG))
-else
-CFLAGS-y += -DEARLY_PRINTK_VERSION_NONE
-endif
-endif
-
-ifneq ($(EARLY_PRINTK_INC),)
-EARLY_PRINTK := y
-endif
-
-CFLAGS-$(EARLY_PRINTK) += -DCONFIG_EARLY_PRINTK
-CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART
-CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
-CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
-CFLAGS-$(EARLY_PRINTK) += -DEARLY_UART_BASE_ADDRESS=$(EARLY_UART_BASE_ADDRESS)
-CFLAGS-$(EARLY_PRINTK) += -DEARLY_UART_REG_SHIFT=$(EARLY_UART_REG_SHIFT)
-
-else # !CONFIG_DEBUG
-
-ifneq ($(CONFIG_EARLY_PRINTK),)
-# Early printk is dependant on a debug build.
-$(error CONFIG_EARLY_PRINTK enabled for non-debug build)
-endif
-
-endif
diff --git a/xen/arch/arm/arch.mk b/xen/arch/arm/arch.mk
new file mode 100644
index 000000000000..296d6c6cf526
--- /dev/null
+++ b/xen/arch/arm/arch.mk
@@ -0,0 +1,88 @@
+########################################
+# arm-specific definitions
+
+CFLAGS += -I$(BASEDIR)/include
+
+$(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
+$(call cc-option-add,CFLAGS,CC,-Wnested-externs)
+
+# Prevent floating-point variables from creeping into Xen.
+CFLAGS-$(CONFIG_ARM_32) += -msoft-float
+CFLAGS-$(CONFIG_ARM_32) += -mcpu=cortex-a15
+
+CFLAGS-$(CONFIG_ARM_64) += -mcpu=generic
+CFLAGS-$(CONFIG_ARM_64) += -mgeneral-regs-only # No fp registers etc
+
+EARLY_PRINTK := n
+
+ifeq ($(CONFIG_DEBUG),y)
+
+# See docs/misc/arm/early-printk.txt for syntax
+
+EARLY_PRINTK_brcm           := 8250,0xF040AB00,2
+EARLY_PRINTK_dra7           := 8250,0x4806A000,2
+EARLY_PRINTK_fastmodel      := pl011,0x1c090000,115200
+EARLY_PRINTK_exynos5250     := exynos4210,0x12c20000
+EARLY_PRINTK_hikey960       := pl011,0xfff32000
+EARLY_PRINTK_juno           := pl011,0x7ff80000
+EARLY_PRINTK_lager          := scif,0xe6e60000
+EARLY_PRINTK_midway         := pl011,0xfff36000
+EARLY_PRINTK_mvebu          := mvebu,0xd0012000
+EARLY_PRINTK_omap5432       := 8250,0x48020000,2
+EARLY_PRINTK_rcar3          := scif,0xe6e88000
+EARLY_PRINTK_seattle        := pl011,0xe1010000
+EARLY_PRINTK_sun6i          := 8250,0x01c28000,2
+EARLY_PRINTK_sun7i          := 8250,0x01c28000,2
+EARLY_PRINTK_thunderx       := pl011,0x87e024000000
+EARLY_PRINTK_vexpress       := pl011,0x1c090000
+EARLY_PRINTK_xgene-mcdivitt := 8250,0x1c021000,2
+EARLY_PRINTK_xgene-storm    := 8250,0x1c020000,2
+EARLY_PRINTK_zynqmp         := cadence,0xff000000
+
+ifneq ($(EARLY_PRINTK_$(CONFIG_EARLY_PRINTK)),)
+EARLY_PRINTK_CFG := $(subst $(comma), ,$(EARLY_PRINTK_$(CONFIG_EARLY_PRINTK)))
+else
+EARLY_PRINTK_CFG := $(subst $(comma), ,$(CONFIG_EARLY_PRINTK))
+endif
+
+# Extract configuration from string
+EARLY_PRINTK_INC := $(word 1,$(EARLY_PRINTK_CFG))
+EARLY_UART_BASE_ADDRESS := $(word 2,$(EARLY_PRINTK_CFG))
+
+# UART specific options
+ifeq ($(EARLY_PRINTK_INC),8250)
+EARLY_UART_REG_SHIFT := $(word 3,$(EARLY_PRINTK_CFG))
+endif
+ifeq ($(EARLY_PRINTK_INC),pl011)
+ifneq ($(word 3,$(EARLY_PRINTK_CFG)),)
+EARLY_PRINTK_INIT_UART := y
+EARLY_PRINTK_BAUD := $(word 3,$(EARLY_PRINTK_CFG))
+endif
+endif
+ifeq ($(EARLY_PRINTK_INC),scif)
+ifneq ($(word 3,$(EARLY_PRINTK_CFG)),)
+CFLAGS-y += -DEARLY_PRINTK_VERSION_$(word 3,$(EARLY_PRINTK_CFG))
+else
+CFLAGS-y += -DEARLY_PRINTK_VERSION_NONE
+endif
+endif
+
+ifneq ($(EARLY_PRINTK_INC),)
+EARLY_PRINTK := y
+endif
+
+CFLAGS-$(EARLY_PRINTK) += -DCONFIG_EARLY_PRINTK
+CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART
+CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
+CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
+CFLAGS-$(EARLY_PRINTK) += -DEARLY_UART_BASE_ADDRESS=$(EARLY_UART_BASE_ADDRESS)
+CFLAGS-$(EARLY_PRINTK) += -DEARLY_UART_REG_SHIFT=$(EARLY_UART_REG_SHIFT)
+
+else # !CONFIG_DEBUG
+
+ifneq ($(CONFIG_EARLY_PRINTK),)
+# Early printk is dependant on a debug build.
+$(error CONFIG_EARLY_PRINTK enabled for non-debug build)
+endif
+
+endif
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index acf4c145c896..6724572eb84b 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -124,32 +124,32 @@ prelink-efi_lto.o: $(ALL_OBJS) efi/runtime.o efi/compat.o
 
 # Link it with all the binary objects
 prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o
-	$(LD) $(LDFLAGS) -r -o $@ $^
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $^
 
 prelink-efi.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink-efi_lto.o efi/boot.init.o
-	$(LD) $(LDFLAGS) -r -o $@ $^
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $^
 else
 prelink.o: $(ALL_OBJS)
-	$(LD) $(LDFLAGS) -r -o $@ $^
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $^
 
 prelink-efi.o: $(ALL_OBJS) efi/boot.init.o efi/runtime.o efi/compat.o
-	$(LD) $(LDFLAGS) -r -o $@ $(filter-out %/efi/built_in.o,$^)
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $(filter-out %/efi/built_in.o,$^)
 endif
 
 $(TARGET)-syms: prelink.o xen.lds
-	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
+	$(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
 	    $(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0
 	$(NM) -pa --format=sysv $(@D)/.$(@F).0 \
 		| $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort \
 		>$(@D)/.$(@F).0.S
 	$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).0.o
-	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
+	$(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
 	    $(@D)/.$(@F).0.o -o $(@D)/.$(@F).1
 	$(NM) -pa --format=sysv $(@D)/.$(@F).1 \
 		| $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort $(syms-warn-dup-y) \
 		>$(@D)/.$(@F).1.S
 	$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1.o
-	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
+	$(LD) $(XEN_LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
 	    $(@D)/.$(@F).1.o -o $@
 	$(NM) -pa --format=sysv $(@D)/$(@F) \
 		| $(BASEDIR)/tools/symbols --xensyms --sysv --sort \
@@ -162,7 +162,7 @@ note.o: $(TARGET)-syms
 		--rename-section=.data=.note.gnu.build-id -S $@.bin $@
 	rm -f $@.bin
 
-EFI_LDFLAGS = $(patsubst -m%,-mi386pep,$(LDFLAGS)) --subsystem=10
+EFI_LDFLAGS = $(patsubst -m%,-mi386pep,$(XEN_LDFLAGS)) --subsystem=10
 EFI_LDFLAGS += --image-base=$(1) --stack=0,0 --heap=0,0 --strip-debug
 EFI_LDFLAGS += --section-alignment=0x200000 --file-alignment=0x20
 EFI_LDFLAGS += --major-image-version=$(XEN_VERSION)
diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk
index e69b8e697cc0..7867f9ccef83 100644
--- a/xen/arch/x86/Rules.mk
+++ b/xen/arch/x86/Rules.mk
@@ -1,89 +1,10 @@
 ########################################
 # x86-specific definitions
 
-XEN_IMG_OFFSET := 0x200000
-
-CFLAGS += -I$(BASEDIR)/include
-CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-generic
-CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-default
-CFLAGS += -DXEN_IMG_OFFSET=$(XEN_IMG_OFFSET)
-CFLAGS += '-D__OBJECT_LABEL__=$(subst /,$$,$(subst -,_,$(subst $(BASEDIR)/,,$(CURDIR))/$@))'
-
-# Prevent floating-point variables from creeping into Xen.
-CFLAGS += -msoft-float
-
-ifeq ($(CONFIG_CC_IS_CLANG),y)
-# Note: Any test which adds -no-integrated-as will cause subsequent tests to
-# succeed, and not trigger further additions.
-#
-# The tests to select whether the integrated assembler is usable need to happen
-# before testing any assembler features, or else the result of the tests would
-# be stale if the integrated assembler is not used.
-
-# Older clang's built-in assembler doesn't understand .skip with labels:
-# https://bugs.llvm.org/show_bug.cgi?id=27369
-$(call as-option-add,CFLAGS,CC,".L0: .L1: .skip (.L1 - .L0)",,\
-                     -no-integrated-as)
-
-# Check whether clang asm()-s support .include.
-$(call as-option-add,CFLAGS,CC,".include \"asm/indirect_thunk_asm.h\"",,\
-                     -no-integrated-as)
-
-# Check whether clang keeps .macro-s between asm()-s:
-# https://bugs.llvm.org/show_bug.cgi?id=36110
-$(call as-option-add,CFLAGS,CC,\
-                     ".macro FOO;.endm"$$(close); asm volatile $$(open)".macro FOO;.endm",\
-                     -no-integrated-as)
-endif
-
-$(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
-$(call cc-option-add,CFLAGS,CC,-Wnested-externs)
-$(call as-option-add,CFLAGS,CC,"vmcall",-DHAVE_AS_VMX)
-$(call as-option-add,CFLAGS,CC,"crc32 %eax$$(comma)%eax",-DHAVE_AS_SSE4_2)
-$(call as-option-add,CFLAGS,CC,"invept (%rax)$$(comma)%rax",-DHAVE_AS_EPT)
-$(call as-option-add,CFLAGS,CC,"rdrand %eax",-DHAVE_AS_RDRAND)
-$(call as-option-add,CFLAGS,CC,"rdfsbase %rax",-DHAVE_AS_FSGSBASE)
-$(call as-option-add,CFLAGS,CC,"xsaveopt (%rax)",-DHAVE_AS_XSAVEOPT)
-$(call as-option-add,CFLAGS,CC,"rdseed %eax",-DHAVE_AS_RDSEED)
-$(call as-option-add,CFLAGS,CC,"clwb (%rax)",-DHAVE_AS_CLWB)
-$(call as-option-add,CFLAGS,CC,".equ \"x\"$$(comma)1", \
-                     -U__OBJECT_LABEL__ -DHAVE_AS_QUOTED_SYM \
-                     '-D__OBJECT_LABEL__=$(subst $(BASEDIR)/,,$(CURDIR))/$$@')
-$(call as-option-add,CFLAGS,CC,"invpcid (%rax)$$(comma)%rax",-DHAVE_AS_INVPCID)
-
-# GAS's idea of true is -1.  Clang's idea is 1
-$(call as-option-add,CFLAGS,CC,\
-    ".if ((1 > 0) < 0); .error \"\";.endif",,-DHAVE_AS_NEGATIVE_TRUE)
-
-# Check to see whether the assmbler supports the .nop directive.
-$(call as-option-add,CFLAGS,CC,\
-    ".L1: .L2: .nops (.L2 - .L1)$$(comma)9",-DHAVE_AS_NOPS_DIRECTIVE)
-
-CFLAGS += -mno-red-zone -fpic -fno-asynchronous-unwind-tables
-
-# Xen doesn't use SSE interally.  If the compiler supports it, also skip the
-# SSE setup for variadic function calls.
-CFLAGS += -mno-sse $(call cc-option,$(CC),-mskip-rax-setup)
-
-# Compile with thunk-extern, indirect-branch-register if avaiable.
-ifeq ($(CONFIG_INDIRECT_THUNK),y)
-CFLAGS += -mindirect-branch=thunk-extern -mindirect-branch-register
-CFLAGS += -fno-jump-tables
+ifdef HAVE_AS_QUOTED_SYM
+arch_ccflags += -DHAVE_AS_QUOTED_SYM \
+		'-D__OBJECT_LABEL__=$(subst $(BASEDIR)/,,$(CURDIR))/$@'
+else
+arch_ccflags += '-D__OBJECT_LABEL__=$(subst /,$$,$(subst -,_,$(subst $(BASEDIR)/,,$(CURDIR))/$@))'
 endif
-
-# If supported by the compiler, reduce stack alignment to 8 bytes. But allow
-# this to be overridden elsewhere.
-$(call cc-option-add,CFLAGS-stack-boundary,CC,-mpreferred-stack-boundary=3)
-CFLAGS += $(CFLAGS-stack-boundary)
-
-ifeq ($(CONFIG_UBSAN),y)
-# Don't enable alignment sanitisation.  x86 has efficient unaligned accesses,
-# and various things (ACPI tables, hypercall pages, stubs, etc) are wont-fix.
-# It also causes an as-yet-unidentified crash on native boot before the
-# console starts.
-$(call cc-option-add,CFLAGS_UBSAN,CC,-fno-sanitize=alignment)
-endif
-
-# Set up the assembler include path properly for older toolchains.
-CFLAGS += -Wa,-I$(BASEDIR)/include
-
+arch_ccflags += $(CFLAGS-stack-boundary)
diff --git a/xen/arch/x86/arch.mk b/xen/arch/x86/arch.mk
new file mode 100644
index 000000000000..1073f6cc99e9
--- /dev/null
+++ b/xen/arch/x86/arch.mk
@@ -0,0 +1,87 @@
+########################################
+# x86-specific definitions
+
+export XEN_IMG_OFFSET := 0x200000
+
+CFLAGS += -I$(BASEDIR)/include
+CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-generic
+CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-default
+CFLAGS += -DXEN_IMG_OFFSET=$(XEN_IMG_OFFSET)
+
+# Prevent floating-point variables from creeping into Xen.
+CFLAGS += -msoft-float
+
+ifeq ($(CONFIG_CC_IS_CLANG),y)
+# Note: Any test which adds -no-integrated-as will cause subsequent tests to
+# succeed, and not trigger further additions.
+#
+# The tests to select whether the integrated assembler is usable need to happen
+# before testing any assembler features, or else the result of the tests would
+# be stale if the integrated assembler is not used.
+
+# Older clang's built-in assembler doesn't understand .skip with labels:
+# https://bugs.llvm.org/show_bug.cgi?id=27369
+$(call as-option-add,CFLAGS,CC,".L0: .L1: .skip (.L1 - .L0)",,\
+                     -no-integrated-as)
+
+# Check whether clang asm()-s support .include.
+$(call as-option-add,CFLAGS,CC,".include \"asm/indirect_thunk_asm.h\"",,\
+                     -no-integrated-as)
+
+# Check whether clang keeps .macro-s between asm()-s:
+# https://bugs.llvm.org/show_bug.cgi?id=36110
+$(call as-option-add,CFLAGS,CC,\
+                     ".macro FOO;.endm"$$(close); asm volatile $$(open)".macro FOO;.endm",\
+                     -no-integrated-as)
+endif
+
+$(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
+$(call cc-option-add,CFLAGS,CC,-Wnested-externs)
+$(call as-option-add,CFLAGS,CC,"vmcall",-DHAVE_AS_VMX)
+$(call as-option-add,CFLAGS,CC,"crc32 %eax$$(comma)%eax",-DHAVE_AS_SSE4_2)
+$(call as-option-add,CFLAGS,CC,"invept (%rax)$$(comma)%rax",-DHAVE_AS_EPT)
+$(call as-option-add,CFLAGS,CC,"rdrand %eax",-DHAVE_AS_RDRAND)
+$(call as-option-add,CFLAGS,CC,"rdfsbase %rax",-DHAVE_AS_FSGSBASE)
+$(call as-option-add,CFLAGS,CC,"xsaveopt (%rax)",-DHAVE_AS_XSAVEOPT)
+$(call as-option-add,CFLAGS,CC,"rdseed %eax",-DHAVE_AS_RDSEED)
+$(call as-option-add,CFLAGS,CC,"clwb (%rax)",-DHAVE_AS_CLWB)
+ifeq ($(call as-insn,$(CC) $(CFLAGS),".equ \"x\"$(comma)1",y),y)
+  export HAVE_AS_QUOTED_SYM := y
+endif
+$(call as-option-add,CFLAGS,CC,"invpcid (%rax)$$(comma)%rax",-DHAVE_AS_INVPCID)
+
+# GAS's idea of true is -1.  Clang's idea is 1
+$(call as-option-add,CFLAGS,CC,\
+    ".if ((1 > 0) < 0); .error \"\";.endif",,-DHAVE_AS_NEGATIVE_TRUE)
+
+# Check to see whether the assmbler supports the .nop directive.
+$(call as-option-add,CFLAGS,CC,\
+    ".L1: .L2: .nops (.L2 - .L1)$$(comma)9",-DHAVE_AS_NOPS_DIRECTIVE)
+
+CFLAGS += -mno-red-zone -fpic -fno-asynchronous-unwind-tables
+
+# Xen doesn't use SSE interally.  If the compiler supports it, also skip the
+# SSE setup for variadic function calls.
+CFLAGS += -mno-sse $(call cc-option,$(CC),-mskip-rax-setup)
+
+# Compile with thunk-extern, indirect-branch-register if avaiable.
+ifeq ($(CONFIG_INDIRECT_THUNK),y)
+CFLAGS += -mindirect-branch=thunk-extern -mindirect-branch-register
+CFLAGS += -fno-jump-tables
+endif
+
+# If supported by the compiler, reduce stack alignment to 8 bytes. But allow
+# this to be overridden elsewhere.
+$(call cc-option-add,CFLAGS-stack-boundary,CC,-mpreferred-stack-boundary=3)
+export CFLAGS-stack-boundary
+
+ifeq ($(CONFIG_UBSAN),y)
+# Don't enable alignment sanitisation.  x86 has efficient unaligned accesses,
+# and various things (ACPI tables, hypercall pages, stubs, etc) are wont-fix.
+# It also causes an as-yet-unidentified crash on native boot before the
+# console starts.
+$(call cc-option-add,CFLAGS_UBSAN,CC,-fno-sanitize=alignment)
+endif
+
+# Set up the assembler include path properly for older toolchains.
+CFLAGS += -Wa,-I$(BASEDIR)/include
diff --git a/xen/common/libelf/Makefile b/xen/common/libelf/Makefile
index 9a433f01fbd4..8f8508dd842e 100644
--- a/xen/common/libelf/Makefile
+++ b/xen/common/libelf/Makefile
@@ -9,4 +9,4 @@ libelf.o: libelf-temp.o Makefile
 	$(OBJCOPY) $(foreach s,$(SECTIONS),--rename-section .$(s)=.init.$(s)) $< $@
 
 libelf-temp.o: libelf-tools.o libelf-loader.o libelf-dominfo.o #libelf-relocate.o
-	$(LD) $(LDFLAGS) -r -o $@ $^
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $^
diff --git a/xen/common/libfdt/Makefile b/xen/common/libfdt/Makefile
index 9ea5c696d52a..42986e118ebf 100644
--- a/xen/common/libfdt/Makefile
+++ b/xen/common/libfdt/Makefile
@@ -11,4 +11,4 @@ libfdt.o: libfdt-temp.o Makefile
 	$(OBJCOPY) $(foreach s,$(SECTIONS),--rename-section .$(s)=.init.$(s)) $< $@
 
 libfdt-temp.o: $(LIBFDT_OBJS)
-	$(LD) $(LDFLAGS) -r -o $@ $^
+	$(LD) $(XEN_LDFLAGS) -r -o $@ $^
