dts: re-write dts/Makefile more simply with Kbuild

Useful rules in scripts/Makefile.lib allows us to easily
generate a device tree blob and wrap it in assembly code.

We do not need to parse a linker script to get output format and arch.

This commit deletes ./u-boot.dtb since it is a copy of dts/dt.dtb.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

.gitignore

@@ -48,7 +48,6 @@
 /u-boot.lds
 /u-boot.ubl
 /u-boot.ais
-/u-boot.dtb
 /u-boot.sb
 
 #

Makefile

@@ -720,7 +720,7 @@ ALL-$(CONFIG_RAMBOOT_PBL) += u-boot.pbl
 ALL-$(CONFIG_SPL) += spl/u-boot-spl.bin
 ALL-$(CONFIG_SPL_FRAMEWORK) += u-boot.img
 ALL-$(CONFIG_TPL) += tpl/u-boot-tpl.bin
-ALL-$(CONFIG_OF_SEPARATE) += u-boot.dtb u-boot-dtb.bin
+ALL-$(CONFIG_OF_SEPARATE) += u-boot-dtb.bin
 ifneq ($(CONFIG_SPL_TARGET),)
 ALL-$(CONFIG_SPL) += $(CONFIG_SPL_TARGET:"%"=%)
 endif
@@ -744,11 +744,11 @@ endif
 
 all:		$(ALL-y)
 
-u-boot.dtb:	checkdtc u-boot
-		$(MAKE) $(build)=dts binary
-		mv dts/dt.dtb $@
+PHONY += dtbs
+dtbs dts/dt.dtb: checkdtc u-boot
+	$(Q)$(MAKE) $(build)=dts dtbs
 
-u-boot-dtb.bin:	u-boot.bin u-boot.dtb
+u-boot-dtb.bin: u-boot.bin dts/dt.dtb
 		cat $^ >$@
 
 u-boot.hex:	u-boot
@@ -875,8 +875,8 @@ u-boot-nodtb-tegra.bin: spl/u-boot-spl.bin u-boot.bin
 		rm spl/u-boot-spl-pad.bin
 
 ifeq ($(CONFIG_OF_SEPARATE),y)
-u-boot-dtb-tegra.bin: u-boot-nodtb-tegra.bin u-boot.dtb
-		cat u-boot-nodtb-tegra.bin u-boot.dtb > $@
+u-boot-dtb-tegra.bin: u-boot-nodtb-tegra.bin dts/dt.dtb
+		cat $^ > $@
 endif
 endif
 
@@ -1171,7 +1171,7 @@ include/license.h: tools/bin2header COPYING
 # Directories & files removed with 'make clean'
 CLEAN_DIRS  += $(MODVERDIR)
 CLEAN_FILES += u-boot.lds include/bmp_logo.h include/bmp_logo_data.h \
-	       board/*/config.tmp board/*/*/config.tmp dts/*.tmp \
+	       board/*/config.tmp board/*/*/config.tmp \
 	       include/autoconf.mk* include/spl-autoconf.mk \
 	       include/tpl-autoconf.mk
 

arch/arm/lib/board.c

@@ -280,7 +280,7 @@ void board_init_f(ulong bootflag)
 	gd->mon_len = _bss_end_ofs;
 #ifdef CONFIG_OF_EMBED
 	/* Get a pointer to the FDT */
-	gd->fdt_blob = _binary_dt_dtb_start;
+	gd->fdt_blob = __dtb_db_begin;
 #elif defined CONFIG_OF_SEPARATE
 	/* FDT is at end of image */
 	gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);

arch/microblaze/lib/board.c

@@ -87,7 +87,7 @@ void board_init_f(ulong not_used)
 
 #ifdef CONFIG_OF_EMBED
 	/* Get a pointer to the FDT */
-	gd->fdt_blob = _binary_dt_dtb_start;
+	gd->fdt_blob = __dtb_dt_begin;
 #elif defined CONFIG_OF_SEPARATE
 	/* FDT is at end of image */
 	gd->fdt_blob = (void *)__end;

arch/x86/lib/init_helpers.c

@@ -92,7 +92,7 @@ int find_fdt(void)
 {
 #ifdef CONFIG_OF_EMBED
 	/* Get a pointer to the FDT */
-	gd->fdt_blob = _binary_dt_dtb_start;
+	gd->fdt_blob = __dtb_dt_begin;
 #elif defined CONFIG_OF_SEPARATE
 	/* FDT is at end of image */
 	gd->fdt_blob = (ulong *)&_end;

common/board_f.c

@@ -360,7 +360,7 @@ static int setup_fdt(void)
 {
 #ifdef CONFIG_OF_EMBED
 	/* Get a pointer to the FDT */
-	gd->fdt_blob = _binary_dt_dtb_start;
+	gd->fdt_blob = __dtb_dt_begin;
 #elif defined CONFIG_OF_SEPARATE
 	/* FDT is at end of image */
 # ifdef CONFIG_SYS_SYM_OFFSETS

dts/.gitignore

@@ -0,0 +1,2 @@
+*.dtb
+*.dtb.S

dts/Makefile

@@ -7,64 +7,32 @@
 # This Makefile builds the internal U-Boot fdt if CONFIG_OF_CONTROL is
 # enabled. See doc/README.fdt-control for more details.
 
-DTS_INCDIRS =  $(SRCTREE)/board/$(VENDOR)/$(BOARD)/dts
-DTS_INCDIRS += $(SRCTREE)/board/$(VENDOR)/dts
-DTS_INCDIRS += $(SRCTREE)/arch/$(ARCH)/dts
-
-DTS_CPPFLAGS := -x assembler-with-cpp -undef -D__DTS__ \
-		-nostdinc $(addprefix -I,$(DTS_INCDIRS))
-
-DTC_FLAGS := -R 4 -p 0x1000 \
-	$(addprefix -i ,$(DTS_INCDIRS))
-
-# Use a constant name for this so we can access it from C code.
-# objcopy doesn't seem to allow us to set the symbol name independently of
-# the filename.
-DT_BIN	:= $(obj)/dt.dtb
-
 DEVICE_TREE ?= $(CONFIG_DEFAULT_DEVICE_TREE:"%"=%)
 ifeq ($(DEVICE_TREE),)
-$(DT_BIN): FORCE
-	echo >&2 "Please define CONFIG_DEFAULT_DEVICE_TREE in your board header file"
-else
-$(DT_BIN): $(TOPDIR)/board/$(VENDOR)/dts/$(DEVICE_TREE).dts
-	$(CPP) $(DTS_CPPFLAGS) $< -o $(DT_BIN).dts.tmp
-	$(DTC) $(DTC_FLAGS) -O dtb -o ${DT_BIN} $(DT_BIN).dts.tmp
+DEVICE_TREE := notfound
 endif
 
-process_lds = \
-	$(1) | sed -r -n 's/^OUTPUT_$(2)[ ("]*([^")]*).*/\1/p'
+DTS := $(srctree)/board/$(VENDOR)/dts/$(DEVICE_TREE).dts
 
-# Run the compiler and get the link script from the linker
-GET_LDS = $(CC) $(c_flags) $(ld_flags) -Wl,--verbose 2>&1
+DTC_FLAGS += -i $(srctree)/arch/$(ARCH)/dts -R 4 -p 0x1000
 
-$(obj)/dt.o: $(DT_BIN)
-	# We want the output format and arch.
-	# We also hope to win a prize for ugliest Makefile / shell interaction
-	# We look in the LDSCRIPT first.
-	# Then try the linker which should give us the answer.
-	# Then check it worked.
-	[ -n "$(LDSCRIPT)" ] && \
-		oformat=`$(call process_lds,cat $(LDSCRIPT),FORMAT)` && \
-		oarch=`$(call process_lds,cat $(LDSCRIPT),ARCH)` ;\
-	\
-	[ -z $${oformat} ] && \
-		oformat=`$(call process_lds,$(GET_LDS),FORMAT)` ;\
-	[ -z $${oarch} ] && \
-		oarch=`$(call process_lds,$(GET_LDS),ARCH)` ;\
-	\
-	[ -z $${oformat} ] && \
-		echo "Cannot read OUTPUT_FORMAT from lds file $(LDSCRIPT)" && \
-		exit 1 || true ;\
-	[ -z $${oarch} ] && \
-		echo "Cannot read OUTPUT_ARCH from lds file $(LDSCRIPT)" && \
-		exit 1 || true ;\
-	\
-	cd $(dir ${DT_BIN}) && \
-	$(OBJCOPY) -I binary -O $${oformat} -B $${oarch} \
-		$(notdir ${DT_BIN}) $(notdir $@)
-	rm $(DT_BIN)
+$(obj)/dt.dtb: $(DTS) FORCE
+	$(call if_changed_dep,dtc)
 
-obj-$(CONFIG_OF_EMBED)	:= dt.o
+targets += dt.dtb
 
-binary:	$(DT_BIN)
+$(DTS):
+	@echo >&2
+	@echo >&2 "Device Tree Source is not specified."
+	@echo >&2 "Please define 'CONFIG_DEFAULT_DEVICE_TREE'"
+	@echo >&2 "or build with 'DEVICE_TREE=<dts-file-name>' argument"
+	@/bin/false
+
+.SECONDARY: $(obj)/dt.dtb.S
+
+obj-$(CONFIG_OF_EMBED) := dt.dtb.o
+
+dtbs: $(obj)/dt.dtb
+	@:
+
+clean-files := dt.dtb.S

include/common.h

@@ -302,7 +302,7 @@ int	checkdram     (void);
 int	last_stage_init(void);
 extern ulong monitor_flash_len;
 int mac_read_from_eeprom(void);
-extern u8 _binary_dt_dtb_start[];	/* embedded device tree blob */
+extern u8 __dtb_dt_begin[];	/* embedded device tree blob */
 int set_cpu_clk_info(void);
 int print_cpuinfo(void);
 int update_flash_size(int flash_size);

scripts/Makefile.lib

@@ -151,9 +151,10 @@ cpp_flags      = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(UBOOTINCLUDE)     \
 
 ld_flags       = $(LDFLAGS) $(ldflags-y)
 
+# Modified for U-Boot
 dtc_cpp_flags  = -Wp,-MD,$(depfile).pre.tmp -nostdinc                    \
-		 -I$(srctree)/arch/$(SRCARCH)/boot/dts                   \
-		 -I$(srctree)/arch/$(SRCARCH)/boot/dts/include           \
+		 -I$(srctree)/board/$(VENDOR)/dts/                       \
+		 -I$(srctree)/arch/$(ARCH)/dts                           \
 		 -undef -D__DTS__
 
 # Finds the multi-part object the current object will be linked into
@@ -247,25 +248,24 @@ cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \
 
 # Generate an assembly file to wrap the output of the device tree compiler
 quiet_cmd_dt_S_dtb= DTB     $@
+# Modified for U-Boot
 cmd_dt_S_dtb=						\
 (							\
-	echo '\#include <asm-generic/vmlinux.lds.h>'; 	\
 	echo '.section .dtb.init.rodata,"a"';		\
-	echo '.balign STRUCT_ALIGNMENT';		\
 	echo '.global __dtb_$(*F)_begin';		\
 	echo '__dtb_$(*F)_begin:';			\
 	echo '.incbin "$<" ';				\
 	echo '__dtb_$(*F)_end:';			\
 	echo '.global __dtb_$(*F)_end';			\
-	echo '.balign STRUCT_ALIGNMENT'; 		\
 ) > $@
 
 $(obj)/%.dtb.S: $(obj)/%.dtb
 	$(call cmd,dt_S_dtb)
 
 quiet_cmd_dtc = DTC     $@
+# Modified for U-Boot
 cmd_dtc = $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
-	$(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 \
+	dtc -O dtb -o $@ -b 0 \
 		-i $(dir $<) $(DTC_FLAGS) \
 		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
 	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)