Move dtc and libfdt sources from arch/powerpc/boot to scripts/dtc

The powerpc kernel always requires an Open Firmware like device tree
to supply device information. On systems without OF, this comes from
a flattened device tree blob. This blob is usually generated by dtc,
a tool which compiles a text description of the device tree into the
flattened format used by the kernel. Sometimes, the bootwrapper makes
small changes to the pre-compiled device tree blob (e.g. filling in
the size of RAM). To do this it uses the libfdt library.

Because these are only used on powerpc, the code for both these tools
is included under arch/powerpc/boot (these were imported and are
periodically updated from the upstream dtc tree).

However, the microblaze architecture, currently being prepared for
merging to mainline also uses dtc to produce device tree blobs. A few
other archs have also mentioned some interest in using dtc.
Therefore, this patch moves dtc and libfdt from arch/powerpc into
scripts, where it can be used by any architecture.

The vast bulk of this patch is a literal move, the rest is adjusting
the various Makefiles to use dtc and libfdt correctly from their new
locations.

Signed-off-by: David Gibson <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/powerpc/Kconfig

···
 	default y if PMAC_APM_EMU
 	bool
 
+config DTC
+       bool
+       default y
+
 config DEFAULT_UIMAGE
 	bool
 	help

arch/powerpc/boot/Makefile

···
 BOOTCFLAGS	+= -fno-stack-protector
 endif
 
-BOOTCFLAGS	+= -I$(obj) -I$(srctree)/$(obj) -I$(srctree)/$(src)/libfdt
+BOOTCFLAGS	+= -I$(obj) -I$(srctree)/$(obj)
 
 DTS_FLAGS	?= -p 1024
 
···
 $(addprefix $(obj)/,$(zlib) cuboot-c2k.o gunzip_util.o main.o prpmc2800.o): \
 	$(addprefix $(obj)/,$(zliblinuxheader)) $(addprefix $(obj)/,$(zlibheader))
 
-src-libfdt := fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_rw.c fdt_strerror.c
+libfdt       := fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_rw.c fdt_strerror.c
+libfdtheader := fdt.h libfdt.h libfdt_internal.h
+
+$(addprefix $(obj)/,$(libfdt) libfdt-wrapper.o simpleboot.o): \
+	$(addprefix $(obj)/,$(libfdtheader))
+
 src-wlib := string.S crt0.S crtsavres.S stdio.c main.c \
-		$(addprefix libfdt/,$(src-libfdt)) libfdt-wrapper.c \
+		$(libfdt) libfdt-wrapper.c \
 		ns16550.c serial.c simple_alloc.c div64.S util.S \
 		gunzip_util.c elf_util.c $(zlib) devtree.c oflib.c ofconsole.c \
 		4xx.c ebony.c mv64x60.c mpsc.c mv64x60_i2c.c cuboot.c bamboo.c \
···
 $(addprefix $(obj)/,$(zliblinuxheader)): $(obj)/%: $(srctree)/include/linux/%
 	$(call cmd,copy_zliblinuxheader)
 
+quiet_cmd_copy_libfdt = COPY    $@
+      cmd_copy_libfdt = cp $< $@
+
+$(addprefix $(obj)/,$(libfdt) $(libfdtheader)): $(obj)/%: $(srctree)/scripts/dtc/libfdt/%
+	$(call cmd,copy_libfdt)
+
 $(obj)/empty.c:
 	@touch $@
 
···
 	@cp $< $@
 
 clean-files := $(zlib) $(zlibheader) $(zliblinuxheader) \
+		$(libfdt) $(libfdtheader) \
 		empty.c zImage.coff.lds zImage.ps3.lds zImage.lds
 
 quiet_cmd_bootcc = BOOTCC  $@
···
 quiet_cmd_bootar = BOOTAR  $@
       cmd_bootar = $(CROSS32AR) -cr $@.$$$$ $(filter-out FORCE,$^); mv $@.$$$$ $@
 
+$(obj-libfdt): $(obj)/%.o: $(srctree)/scripts/dtc/libfdt/%.c FORCE
+	$(call if_changed_dep,bootcc)
 $(patsubst %.c,%.o, $(filter %.c, $(src-boot))): %.o: %.c FORCE
 	$(Q)mkdir -p $(dir $@)
 	$(call if_changed_dep,bootcc)
···
 $(obj)/wrapper.a: $(obj-wlib) FORCE
 	$(call if_changed,bootar)
 
-hostprogs-y	:= addnote addRamDisk hack-coff mktree dtc
+hostprogs-y	:= addnote addRamDisk hack-coff mktree
 
 targets		+= $(patsubst $(obj)/%,%,$(obj-boot) wrapper.a)
 extra-y		:= $(obj)/wrapper.a $(obj-plat) $(obj)/empty.o \
···
 dtstree		:= $(srctree)/$(src)/dts
 
 wrapper		:=$(srctree)/$(src)/wrapper
-wrapperbits	:= $(extra-y) $(addprefix $(obj)/,addnote hack-coff mktree dtc) \
+wrapperbits	:= $(extra-y) $(addprefix $(obj)/,addnote hack-coff mktree) \
 			$(wrapper) FORCE
-
-#############
-# Bits for building dtc
-# DTC_GENPARSER      := 1    # Uncomment to rebuild flex/bison output
-
-dtc-objs := dtc.o flattree.o fstree.o data.o livetree.o treesource.o srcpos.o checks.o
-dtc-objs += dtc-lexer.lex.o dtc-parser.tab.o
-dtc-objs := $(addprefix dtc-src/, $(dtc-objs))
-
-# prerequisites on generated files needs to be explicit
-$(obj)/dtc-src/dtc-parser.tab.o: $(obj)/dtc-src/dtc-parser.tab.c $(obj)/dtc-src/dtc-parser.tab.h
-$(obj)/dtc-src/dtc-lexer.lex.o:  $(obj)/dtc-src/dtc-lexer.lex.c $(obj)/dtc-src/dtc-parser.tab.h
-
-HOSTCFLAGS += -I$(src)/dtc-src/ -I$(src)/libfdt/
-
-targets += dtc-src/dtc-parser.tab.c
-targets += dtc-src/dtc-lexer.lex.c
-
-clean-files += dtc-src/dtc-parser.tab.h
-
-ifdef DTC_GENPARSER
-BISON = bison
-FLEX = flex
-
-quiet_cmd_bison = BISON   $@
-      cmd_bison = $(BISON) -o$@ -d $<; cp $@ $@_shipped
-quiet_cmd_flex = FLEX    $@
-      cmd_flex = $(FLEX) -o$@ $<; cp $@ $@_shipped
-
-$(obj)/dtc-src/dtc-parser.tab.c: $(src)/dtc-src/dtc-parser.y FORCE
-	$(call if_changed,bison)
-
-$(obj)/dtc-src/dtc-parser.tab.h: $(obj)/dtc-src/dtc-parser.tab.c
-
-$(obj)/dtc-src/dtc-lexer.lex.c: $(src)/dtc-src/dtc-lexer.l FORCE
-	$(call if_changed,flex)
-endif
 
 #############
 # Bits for building various flavours of zImage
···
 	$(call if_changed,wrap,treeboot-$*,,$(obj)/$*.dtb)
 
 # Rule to build device tree blobs
-$(obj)/%.dtb: $(dtstree)/%.dts $(obj)/dtc
-	$(obj)/dtc -O dtb -o $(obj)/$*.dtb -b 0 $(DTS_FLAGS) $(dtstree)/$*.dts
+DTC = $(objtree)/scripts/dtc/dtc
+
+$(obj)/%.dtb: $(dtstree)/%.dts
+	$(DTC) -O dtb -o $(obj)/$*.dtb -b 0 $(DTS_FLAGS) $(dtstree)/$*.dts
 
 # If there isn't a platform selected then just strip the vmlinux.
 ifeq (,$(image-y))

arch/powerpc/boot/simpleboot.c

···
 #include "types.h"
 #include "io.h"
 #include "stdio.h"
-#include "libfdt/libfdt.h"
+#include <libfdt.h>
 
 BSS_STACK(4*1024);
 

scripts/Makefile

···
 subdir-$(CONFIG_MODVERSIONS) += genksyms
 subdir-y                     += mod
 subdir-$(CONFIG_SECURITY_SELINUX) += selinux
+subdir-$(CONFIG_DTC)         += dtc
 
 # Let clean descend into subdirs
 subdir-	+= basic kconfig package selinux

scripts/dtc/Makefile

···
+# scripts/dtc makefile
+
+hostprogs-y	:= dtc
+always		:= $(hostprogs-y)
+
+dtc-objs	:= dtc.o flattree.o fstree.o data.o livetree.o treesource.o \
+		   srcpos.o checks.o
+dtc-objs	+= dtc-lexer.lex.o dtc-parser.tab.o
+
+# Source files need to get at the userspace version of libfdt_env.h to compile
+
+HOSTCFLAGS_DTC := -I$(src) -I$(src)/libfdt
+
+HOSTCFLAGS_checks.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_data.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_dtc.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_flattree.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_fstree.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_livetree.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_srcpos.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_treesource.o := $(HOSTCFLAGS_DTC)
+
+HOSTCFLAGS_dtc-lexer.lex.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_dtc-parser.tab.o := $(HOSTCFLAGS_DTC)
+
+# dependencies on generated files need to be listed explicitly
+$(obj)/dtc-parser.tab.o: $(obj)/dtc-parser.tab.c $(obj)/dtc-parser.tab.h
+$(obj)/dtc-lexer.lex.o:  $(obj)/dtc-lexer.lex.c $(obj)/dtc-parser.tab.h
+
+targets += dtc-parser.tab.c dtc-lexer.lex.c
+
+clean-files += dtc-parser.tab.h
+
+# GENERATE_PARSER := 1		# Uncomment to rebuild flex/bison output
+
+ifdef GENERATE_PARSER
+
+BISON = bison
+FLEX = flex
+
+quiet_cmd_bison = BISON   $@
+      cmd_bison = $(BISON) -o$@ -d $<; cp $@ $@_shipped
+quiet_cmd_flex = FLEX    $@
+      cmd_flex = $(FLEX) -o$@ $<; cp $@ $@_shipped
+
+$(obj)/dtc-parser.tab.c: $(src)/dtc-parser.y FORCE
+        $(call if_changed,bison)
+
+$(obj)/dtc-parser.tab.h: $(obj)/dtc-parser.tab.c
+
+$(obj)/dtc-lexer.lex.c: $(src)/dtc-lexer.l FORCE
+        $(call if_changed,flex)
+
+endif