@@ -356,6 +356,7 @@ STRIP = $(CROSS_COMPILE)strip
OBJCOPY = $(CROSS_COMPILE)objcopy
OBJDUMP = $(CROSS_COMPILE)objdump
AWK = awk
+DTC = scripts/dtc/dtc
GENKSYMS = scripts/genksyms/genksyms
INSTALLKERNEL := installkernel
DEPMOD = /sbin/depmod
@@ -365,6 +366,7 @@ CHECK = sparse
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void $(CF)
+DTC_FLAGS :=
NOSTDINC_FLAGS =
CFLAGS_MODULE =
AFLAGS_MODULE =
@@ -419,7 +421,7 @@ export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
export CPP AR NM STRIP OBJCOPY OBJDUMP
export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
-export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
+export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS DTC DTC_FLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN
@@ -2,7 +2,7 @@
# Makefile for device trees
#
-DTC_FLAGS ?= -p 1024
+DTC_FLAGS += -p 1024
ifneq ($(DTB),)
obj-y += linked_dtb.o
@@ -15,4 +15,4 @@ quiet_cmd_cp = CP $< $@$2
cmd_cp = cat $< >$@$2 || (rm -f $@ && echo false)
# Rule to build device tree blobs
-DTC_FLAGS := -p 1024
+DTC_FLAGS += -p 1024
@@ -7,4 +7,4 @@ obj-y += $(BUILTIN_DTB)
clean-files := *.dtb.S
-#DTC_FLAGS ?= -p 1024
+#DTC_FLAGS += -p 1024
@@ -50,7 +50,7 @@ endif
BOOTCFLAGS += -I$(objtree)/$(obj) -I$(srctree)/$(obj)
-DTC_FLAGS ?= -p 1024
+DTC_FLAGS += -p 1024
$(obj)/4xx.o: BOOTCFLAGS += -mcpu=405
$(obj)/ebony.o: BOOTCFLAGS += -mcpu=405
@@ -171,6 +171,20 @@ ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
# Usage: $(call ld-ifversion, -ge, 22252, y)
ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4))
+# dtc-option
+# Usage: DTC_FLAGS += $(call dtc-option,-Wno-unit_address_vs_reg)
+#
+# When we use the external dtc, check if the desired options are supported.
+# When we use the kernel's copy (scripts/dtc/dtc), just use the fixed option.
+# Until Kbuild descends into the scripts/dtc/ directory, scripts/dtc/dtc may
+# not exist, i.e. $(call try-run,...) may not work.
+ifeq ("$(origin DTC)", "command line")
+dtc-option = $(call try-run,\
+ echo '/dts-v1/; / {};' | $(DTC) $(1),$(1),$(2))
+else
+dtc-option = $(1)
+endif
+
######
###
@@ -69,4 +69,8 @@ KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)
KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)
KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)
endif
+
+# Disable noisy checks by default
+DTC_FLAGS += $(call dtc-option,-Wno-unit_address_vs_reg)
+
endif
@@ -276,12 +276,6 @@ cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \
# DTC
# ---------------------------------------------------------------------------
-DTC ?= $(objtree)/scripts/dtc/dtc
-
-# Disable noisy checks by default
-ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
-DTC_FLAGS += -Wno-unit_address_vs_reg
-endif
# Generate an assembly file to wrap the output of the device tree compiler
quiet_cmd_dt_S_dtb= DTB $@
Since commit 6b22b3d1614a ("kbuild: Allow using host dtc instead of kernel's copy"), it is possible to use an external dtc. In this case, we do not know which options are supported on it. Commit bc553986a2f7 ("dtc: turn off dtc unit address warnings by default") gives -Wno-unit_address_vs_reg, but this options is only recognized by v1.4.2 or later. If an older version is specified, the build fails: $ dtc --version Version: DTC 1.4.0 $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- DTC=dtc dtbs [ snip ] DTC arch/arm64/boot/dts/al/alpine-v2-evp.dtb FATAL ERROR: Unrecognized check name "unit_address_vs_reg" make[2]: *** [arch/arm64/boot/dts/al/alpine-v2-evp.dtb] Error 1 make[1]: *** [arch/arm64/boot/dts/al] Error 2 make: *** [dtbs] Error 2 This commit adds a new helper dtc-option to check if the given option is supported, like cc-option, ld-option, etc. The check for the -Wno-unit_address_vs_reg has been moved from Makefile.lib to Makefile.extrawarn. Since Makefile.lib is included recursively, it is not efficient to evaluate the $(call dtc-option) at every descend. On the other hand, Makefile.extrawarn is included just once from the top Makefile. Besides, it seems more suitable to collect extra warning things into the Makefile.extrawarn. The variable, DTC, has also been moved to the top Makefile so that the Makefile.extrawarn can reference it. Here is one problem for the dtc-option helper; the kernel's copy (scripts/dtc/dtc) is not compiled until Kbuild descends into the scripts/dtc/ directory. This happens later after Makefile.extrawarn is evaluated. So, dtc-options should its job only when DTC is overridden from the command line (i.e. pre-built dtc is used). If the kernel's copy is used, dtc-option falls back to a fixed option because we know which options are supported on the internal one. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- Makefile | 4 +++- arch/c6x/boot/dts/Makefile | 2 +- arch/microblaze/boot/dts/Makefile | 2 +- arch/openrisc/boot/dts/Makefile | 2 +- arch/powerpc/boot/Makefile | 2 +- scripts/Kbuild.include | 14 ++++++++++++++ scripts/Makefile.extrawarn | 4 ++++ scripts/Makefile.lib | 6 ------ 8 files changed, 25 insertions(+), 11 deletions(-) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html