kbuild: change out-of-tree build

This commit changes the working directory
where the build process occurs.

Before this commit, build process occurred under the source
tree for both in-tree and out-of-tree build.

That's why we needed to add $(obj) prefix to all generated
files in makefiles like follows:
  $(obj)u-boot.bin:  $(obj)u-boot

Here, $(obj) is empty for in-tree build, whereas it points
to the output directory for out-of-tree build.

And our old build system changes the current working directory
with "make -C <sub-dir>" syntax when descending into the
sub-directories.

On the other hand, Kbuild uses a different idea
to handle out-of-tree build and directory descending.

The build process of Kbuild always occurs under the output tree.
When "O=dir/to/store/output/files" is given, the build system
changes the current working directory to that directory and
restarts the make.

Kbuild uses "make -f $(srctree)/scripts/Makefile.build obj=<sub-dir>"
syntax for descending into sub-directories.
(We can write it like "make $(obj)=<sub-dir>" with a shorthand.)
This means the current working directory is always the top
of the output directory.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
diff --git a/Makefile b/Makefile
index b24b425..1409c8b 100644
--- a/Makefile
+++ b/Makefile
@@ -14,8 +14,8 @@
 else
 U_BOOT_VERSION = $(VERSION).$(PATCHLEVEL)$(EXTRAVERSION)
 endif
-TIMESTAMP_FILE = $(obj)include/generated/timestamp_autogenerated.h
-VERSION_FILE = $(obj)include/generated/version_autogenerated.h
+TIMESTAMP_FILE = include/generated/timestamp_autogenerated.h
+VERSION_FILE = include/generated/version_autogenerated.h
 
 HOSTARCH := $(shell uname -m | \
 	sed -e s/i.86/x86/ \
@@ -43,32 +43,82 @@
 XECHO = :
 endif
 
-#########################################################################
-#
-# U-boot build supports generating object files in a separate external
-# directory. Two use cases are supported:
-#
-# 1) Add O= to the make command line
-# 'make O=/tmp/build all'
-#
-# 2) Set environment variable BUILD_DIR to point to the desired location
-# 'export BUILD_DIR=/tmp/build'
-# 'make'
-#
-# The second approach can also be used with a MAKEALL script
-# 'export BUILD_DIR=/tmp/build'
-# './MAKEALL'
+# kbuild supports saving output files in a separate directory.
+# To locate output files in a separate directory two syntaxes are supported.
+# In both cases the working directory must be the root of the kernel src.
+# 1) O=
+# Use "make O=dir/to/store/output/files/"
 #
-# Command line 'O=' setting overrides BUILD_DIR environment variable.
+# 2) Set KBUILD_OUTPUT
+# Set the environment variable KBUILD_OUTPUT to point to the directory
+# where the output files shall be placed.
+# export KBUILD_OUTPUT=dir/to/store/output/files/
+# make
 #
-# When none of the above methods is used the local build is performed and
-# the object files are placed in the source directory.
-#
+# The O= assignment takes precedence over the KBUILD_OUTPUT environment
+# variable.
+
 
+# KBUILD_SRC is set on invocation of make in OBJ directory
+# KBUILD_SRC is not intended to be used by the regular user (for now)
+ifeq ($(KBUILD_SRC),)
+
+# OK, Make called in directory where kernel src resides
+# Do we want to locate output files in a separate directory?
 ifeq ("$(origin O)", "command line")
-BUILD_DIR := $(O)
+  KBUILD_OUTPUT := $(O)
+endif
+
+ifeq ("$(origin W)", "command line")
+  export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)
 endif
 
+# That's our default target when none is given on the command line
+PHONY := _all
+_all:
+
+# Cancel implicit rules on top Makefile
+$(CURDIR)/Makefile Makefile: ;
+
+ifneq ($(KBUILD_OUTPUT),)
+# Invoke a second make in the output directory, passing relevant variables
+# check that the output directory actually exists
+saved-output := $(KBUILD_OUTPUT)
+KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)
+$(if $(KBUILD_OUTPUT),, \
+     $(error output directory "$(saved-output)" does not exist))
+
+PHONY += $(MAKECMDGOALS) sub-make
+
+$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
+	@:
+
+sub-make: FORCE
+	$(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT) \
+	KBUILD_SRC=$(CURDIR) \
+	KBUILD_EXTMOD="$(KBUILD_EXTMOD)" -f $(CURDIR)/Makefile \
+	$(filter-out _all sub-make,$(MAKECMDGOALS))
+
+# Leave processing to above invocation of make
+skip-makefile := 1
+endif # ifneq ($(KBUILD_OUTPUT),)
+endif # ifeq ($(KBUILD_SRC),)
+
+# We process the rest of the Makefile if this is the final invocation of make
+ifeq ($(skip-makefile),)
+
+PHONY += all
+_all: all
+
+srctree		:= $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR))
+objtree		:= $(CURDIR)
+src		:= $(srctree)
+obj		:= $(objtree)
+
+VPATH		:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
+
+export srctree objtree VPATH
+
 # Call a source code checker (by default, "sparse") as part of the
 # C compilation.
 #
@@ -87,41 +137,16 @@
 endif
 export CHECKSRC
 
-ifneq ($(BUILD_DIR),)
-saved-output := $(BUILD_DIR)
-
-# Attempt to create a output directory.
-$(shell [ -d ${BUILD_DIR} ] || mkdir -p ${BUILD_DIR})
-
-# Verify if it was successful.
-BUILD_DIR := $(shell cd $(BUILD_DIR) && /bin/pwd)
-$(if $(BUILD_DIR),,$(error output directory "$(saved-output)" does not exist))
-endif # ifneq ($(BUILD_DIR),)
-
-OBJTREE		:= $(if $(BUILD_DIR),$(BUILD_DIR),$(CURDIR))
+OBJTREE		:= $(objtree)
 SPLTREE		:= $(OBJTREE)/spl
 TPLTREE		:= $(OBJTREE)/tpl
-SRCTREE		:= $(CURDIR)
-srctree		:= $(SRCTREE)
+SRCTREE		:= $(srctree)
 TOPDIR		:= $(SRCTREE)
-LNDIR		:= $(OBJTREE)
-export	TOPDIR SRCTREE srctree OBJTREE SPLTREE TPLTREE
+export	TOPDIR SRCTREE OBJTREE SPLTREE TPLTREE
 
 MKCONFIG	:= $(SRCTREE)/mkconfig
 export MKCONFIG
 
-# $(obj) and (src) are defined in config.mk but here in main Makefile
-# we also need them before config.mk is included which is the case for
-# some targets like unconfig, clean, clobber, distclean, etc.
-ifneq ($(OBJTREE),$(SRCTREE))
-obj := $(OBJTREE)/
-src := $(SRCTREE)/
-else
-obj :=
-src :=
-endif
-export obj src
-
 # Make sure CDPATH settings don't interfere
 unexport CDPATH
 
@@ -136,14 +161,14 @@
 
 .PHONY : $(SUBDIRS) $(VERSION_FILE) $(TIMESTAMP_FILE)
 
-ifeq ($(obj)include/config.mk,$(wildcard $(obj)include/config.mk))
+ifeq (include/config.mk,$(wildcard include/config.mk))
 
 # Include autoconf.mk before config.mk so that the config options are available
 # to all top level build files.  We need the dummy all: target to prevent the
 # dependency target in autoconf.mk.dep from being the default.
 all:
-sinclude $(obj)include/autoconf.mk.dep
-sinclude $(obj)include/autoconf.mk
+sinclude include/autoconf.mk.dep
+sinclude include/autoconf.mk
 
 SUBDIR_EXAMPLES-y := examples/standalone
 SUBDIR_EXAMPLES-$(CONFIG_API) += examples/api
@@ -152,7 +177,7 @@
 endif
 
 # load ARCH, BOARD, and CPU configuration
-include $(obj)include/config.mk
+include include/config.mk
 export	ARCH CPU BOARD VENDOR SOC
 
 # set default to nothing for native builds
@@ -197,6 +222,9 @@
 HOSTLDFLAGS += $(call os_x_before, 10, 5, "-multiply_defined suppress")
 endif
 
+# Look for make include files relative to root of kernel src
+MAKEFLAGS += --include-dir=$(srctree)
+
 # We need some generic definitions (do not try to remake the file).
 $(srctree)/scripts/Kbuild.include: ;
 include $(srctree)/scripts/Kbuild.include
@@ -287,7 +315,7 @@
 
 export CONFIG_SYS_TEXT_BASE
 
-LDFLAGS_u-boot += -T $(obj)u-boot.lds $(LDFLAGS_FINAL)
+LDFLAGS_u-boot += -T u-boot.lds $(LDFLAGS_FINAL)
 ifneq ($(CONFIG_SYS_TEXT_BASE),)
 LDFLAGS_u-boot += -Ttext $(CONFIG_SYS_TEXT_BASE)
 endif
@@ -350,9 +378,9 @@
 head-$(CONFIG_4xx) += arch/powerpc/cpu/ppc4xx/resetvec.o
 head-$(CONFIG_MPC85xx) += arch/powerpc/cpu/mpc85xx/resetvec.o
 
-OBJS := $(addprefix $(obj),$(head-y))
+OBJS := $(head-y)
 
-HAVE_VENDOR_COMMON_LIB = $(if $(wildcard board/$(VENDOR)/common/Makefile),y,n)
+HAVE_VENDOR_COMMON_LIB = $(if $(wildcard $(srctree)/board/$(VENDOR)/common/Makefile),y,n)
 
 LIBS-y += lib/
 LIBS-$(HAVE_VENDOR_COMMON_LIB) += board/$(VENDOR)/common/
@@ -412,7 +440,7 @@
 LIBS-y += board/$(BOARDDIR)/
 
 LIBS-y := $(patsubst %/, %/built-in.o, $(LIBS-y))
-LIBS := $(addprefix $(obj),$(sort $(LIBS-y)))
+LIBS := $(sort $(LIBS-y))
 .PHONY : $(LIBS)
 
 # Add GCC lib
@@ -437,9 +465,6 @@
 	$(shell $(LD) --version | \
 	  sed -ne 's/GNU ld version \([0-9][0-9]*\)\.\([0-9][0-9]*\).*/-DLD_MAJOR=\1 -DLD_MINOR=\2/p')
 
-__OBJS := $(subst $(obj),,$(OBJS))
-__LIBS := $(subst $(obj),,$(LIBS))
-
 #########################################################################
 #########################################################################
 
@@ -464,66 +489,66 @@
 DO_STATIC_RELA = \
 	start=$$($(NM) $(1) | grep __rel_dyn_start | cut -f 1 -d ' '); \
 	end=$$($(NM) $(1) | grep __rel_dyn_end | cut -f 1 -d ' '); \
-	$(obj)tools/relocate-rela $(2) $(3) $$start $$end
+	tools/relocate-rela $(2) $(3) $$start $$end
 else
 DO_STATIC_RELA =
 endif
 
 # Always append ALL so that arch config.mk's can add custom ones
-ALL-y += $(obj)u-boot.srec $(obj)u-boot.bin $(obj)System.map
+ALL-y += u-boot.srec u-boot.bin System.map
 
-ALL-$(CONFIG_NAND_U_BOOT) += $(obj)u-boot-nand.bin
-ALL-$(CONFIG_ONENAND_U_BOOT) += $(obj)u-boot-onenand.bin
-ALL-$(CONFIG_RAMBOOT_PBL) += $(obj)u-boot.pbl
-ALL-$(CONFIG_SPL) += $(obj)spl/u-boot-spl.bin
-ALL-$(CONFIG_SPL_FRAMEWORK) += $(obj)u-boot.img
-ALL-$(CONFIG_TPL) += $(obj)tpl/u-boot-tpl.bin
-ALL-$(CONFIG_OF_SEPARATE) += $(obj)u-boot.dtb $(obj)u-boot-dtb.bin
+ALL-$(CONFIG_NAND_U_BOOT) += u-boot-nand.bin
+ALL-$(CONFIG_ONENAND_U_BOOT) += u-boot-onenand.bin
+ALL-$(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
 ifneq ($(CONFIG_SPL_TARGET),)
-ALL-$(CONFIG_SPL) += $(obj)$(CONFIG_SPL_TARGET:"%"=%)
+ALL-$(CONFIG_SPL) += $(CONFIG_SPL_TARGET:"%"=%)
 endif
-ALL-$(CONFIG_REMAKE_ELF) += $(obj)u-boot.elf
+ALL-$(CONFIG_REMAKE_ELF) += u-boot.elf
 
 # enable combined SPL/u-boot/dtb rules for tegra
 ifneq ($(CONFIG_TEGRA),)
 ifeq ($(CONFIG_SPL),y)
 ifeq ($(CONFIG_OF_SEPARATE),y)
-ALL-y += $(obj)u-boot-dtb-tegra.bin
+ALL-y += u-boot-dtb-tegra.bin
 else
-ALL-y += $(obj)u-boot-nodtb-tegra.bin
+ALL-y += u-boot-nodtb-tegra.bin
 endif
 endif
 endif
 
 all:		$(ALL-y) $(SUBDIR_EXAMPLES-y)
 
-$(obj)u-boot.dtb:	checkdtc $(obj)u-boot
-		$(MAKE) $(build) dts binary
-		mv $(obj)dts/dt.dtb $@
+u-boot.dtb:	checkdtc u-boot
+		$(MAKE) $(build)=dts binary
+		mv dts/dt.dtb $@
 
-$(obj)u-boot-dtb.bin:	$(obj)u-boot.bin $(obj)u-boot.dtb
+u-boot-dtb.bin:	u-boot.bin u-boot.dtb
 		cat $^ >$@
 
-$(obj)u-boot.hex:	$(obj)u-boot
+u-boot.hex:	u-boot
 		$(OBJCOPY) ${OBJCFLAGS} -O ihex $< $@
 
-$(obj)u-boot.srec:	$(obj)u-boot
+u-boot.srec:	u-boot
 		$(OBJCOPY) ${OBJCFLAGS} -O srec $< $@
 
-$(obj)u-boot.bin:	$(obj)u-boot
+u-boot.bin:	u-boot
 		$(OBJCOPY) ${OBJCFLAGS} -O binary $< $@
 		$(call DO_STATIC_RELA,$<,$@,$(CONFIG_SYS_TEXT_BASE))
 		$(BOARD_SIZE_CHECK)
 
-$(obj)u-boot.ldr:	$(obj)u-boot
+u-boot.ldr:	u-boot
 		$(CREATE_LDR_ENV)
 		$(LDR) -T $(CONFIG_BFIN_CPU) -c $@ $< $(LDR_FLAGS)
 		$(BOARD_SIZE_CHECK)
 
-$(obj)u-boot.ldr.hex:	$(obj)u-boot.ldr
+u-boot.ldr.hex:	u-boot.ldr
 		$(OBJCOPY) ${OBJCFLAGS} -O ihex $< $@ -I binary
 
-$(obj)u-boot.ldr.srec:	$(obj)u-boot.ldr
+u-boot.ldr.srec:	u-boot.ldr
 		$(OBJCOPY) ${OBJCFLAGS} -O srec $< $@ -I binary
 
 #
@@ -534,79 +559,78 @@
 CONFIG_SYS_UBOOT_START := 0
 endif
 
-$(obj)u-boot.img:	$(obj)u-boot.bin
-		$(obj)tools/mkimage -A $(ARCH) -T firmware -C none \
+u-boot.img:	u-boot.bin
+		tools/mkimage -A $(ARCH) -T firmware -C none \
 		-O u-boot -a $(CONFIG_SYS_TEXT_BASE) \
 		-e $(CONFIG_SYS_UBOOT_START) \
 		-n $(shell sed -n -e 's/.*U_BOOT_VERSION//p' $(VERSION_FILE) | \
 			sed -e 's/"[	 ]*$$/ for $(BOARD) board"/') \
 		-d $< $@
 
-$(obj)u-boot.imx: $(obj)u-boot.bin depend
-		$(MAKE) $(build) $(SRCTREE)/arch/arm/imx-common $(OBJTREE)/u-boot.imx
+u-boot.imx: u-boot.bin depend
+		$(MAKE) $(build)=arch/arm/imx-common $(objtree)/u-boot.imx
 
-$(obj)u-boot.kwb:       $(obj)u-boot.bin
-		$(obj)tools/mkimage -n $(CONFIG_SYS_KWD_CONFIG) -T kwbimage \
+u-boot.kwb:       u-boot.bin
+		tools/mkimage -n $(CONFIG_SYS_KWD_CONFIG) -T kwbimage \
 		-a $(CONFIG_SYS_TEXT_BASE) -e $(CONFIG_SYS_TEXT_BASE) -d $< $@
 
-$(obj)u-boot.pbl:	$(obj)u-boot.bin
-		$(obj)tools/mkimage -n $(CONFIG_SYS_FSL_PBL_RCW) \
+u-boot.pbl:	u-boot.bin
+		tools/mkimage -n $(CONFIG_SYS_FSL_PBL_RCW) \
 		-R $(CONFIG_SYS_FSL_PBL_PBI) -T pblimage \
 		-d $< $@
 
-$(obj)u-boot.sha1:	$(obj)u-boot.bin
-		$(obj)tools/ubsha1 $(obj)u-boot.bin
+u-boot.sha1:	u-boot.bin
+		tools/ubsha1 u-boot.bin
 
-$(obj)u-boot.dis:	$(obj)u-boot
+u-boot.dis:	u-boot
 		$(OBJDUMP) -d $< > $@
 
 # $@ is output, $(1) and $(2) are inputs, $(3) is padded intermediate,
 # $(4) is pad-to
 SPL_PAD_APPEND = \
 		$(OBJCOPY) ${OBJCFLAGS} --pad-to=$(4) -I binary -O binary \
-		$(1) $(obj)$(3); \
-		cat $(obj)$(3) $(2) > $@; \
-		rm $(obj)$(3)
+		$(1) $(3); \
+		cat $(3) $(2) > $@; \
+		rm $(3)
 
 ifdef CONFIG_TPL
-SPL_PAYLOAD := $(obj)tpl/u-boot-with-tpl.bin
+SPL_PAYLOAD := tpl/u-boot-with-tpl.bin
 else
-SPL_PAYLOAD := $(obj)u-boot.bin
+SPL_PAYLOAD := u-boot.bin
 endif
 
-$(obj)u-boot-with-spl.bin: $(obj)spl/u-boot-spl.bin $(SPL_PAYLOAD)
+u-boot-with-spl.bin: spl/u-boot-spl.bin $(SPL_PAYLOAD)
 		$(call SPL_PAD_APPEND,$<,$(SPL_PAYLOAD),spl/u-boot-spl-pad.bin,$(CONFIG_SPL_PAD_TO))
 
-$(obj)tpl/u-boot-with-tpl.bin: $(obj)tpl/u-boot-tpl.bin $(obj)u-boot.bin
-		$(call SPL_PAD_APPEND,$<,$(obj)u-boot.bin,tpl/u-boot-tpl-pad.bin,$(CONFIG_TPL_PAD_TO))
+tpl/u-boot-with-tpl.bin: tpl/u-boot-tpl.bin u-boot.bin
+		$(call SPL_PAD_APPEND,$<,u-boot.bin,tpl/u-boot-tpl-pad.bin,$(CONFIG_TPL_PAD_TO))
 
-$(obj)u-boot-with-spl.imx: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin
-		$(MAKE) $(build) $(SRCTREE)/arch/arm/imx-common \
+u-boot-with-spl.imx: spl/u-boot-spl.bin u-boot.bin
+		$(MAKE) $(build)=arch/arm/imx-common \
 			$(OBJTREE)/u-boot-with-spl.imx
 
-$(obj)u-boot-with-nand-spl.imx: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin
-		$(MAKE) $(build) $(SRCTREE)/arch/arm/imx-common \
+u-boot-with-nand-spl.imx: spl/u-boot-spl.bin u-boot.bin
+		$(MAKE) $(build)=arch/arm/imx-common \
 			$(OBJTREE)/u-boot-with-nand-spl.imx
 
-$(obj)u-boot.ubl:       $(obj)u-boot-with-spl.bin
-		$(obj)tools/mkimage -n $(UBL_CONFIG) -T ublimage \
-		-e $(CONFIG_SYS_TEXT_BASE) -d $< $(obj)u-boot.ubl
+u-boot.ubl:       u-boot-with-spl.bin
+		tools/mkimage -n $(UBL_CONFIG) -T ublimage \
+		-e $(CONFIG_SYS_TEXT_BASE) -d $< u-boot.ubl
 
-$(obj)u-boot.ais:       $(obj)spl/u-boot-spl.bin $(obj)u-boot.img
-		$(obj)tools/mkimage -s -n $(if $(CONFIG_AIS_CONFIG_FILE),$(CONFIG_AIS_CONFIG_FILE),"/dev/null") \
+u-boot.ais:       spl/u-boot-spl.bin u-boot.img
+		tools/mkimage -s -n $(if $(CONFIG_AIS_CONFIG_FILE),$(srctree)/$(CONFIG_AIS_CONFIG_FILE:"%"=%),"/dev/null") \
 			-T aisimage \
 			-e $(CONFIG_SPL_TEXT_BASE) \
-			-d $(obj)spl/u-boot-spl.bin \
-			$(obj)spl/u-boot-spl.ais
+			-d spl/u-boot-spl.bin \
+			spl/u-boot-spl.ais
 		$(OBJCOPY) ${OBJCFLAGS} -I binary \
 			--pad-to=$(CONFIG_SPL_MAX_SIZE) -O binary \
-			$(obj)spl/u-boot-spl.ais $(obj)spl/u-boot-spl-pad.ais
-		cat $(obj)spl/u-boot-spl-pad.ais $(obj)u-boot.img > \
-			$(obj)u-boot.ais
+			spl/u-boot-spl.ais spl/u-boot-spl-pad.ais
+		cat spl/u-boot-spl-pad.ais u-boot.img > u-boot.ais
 
 
-$(obj)u-boot.sb:       $(obj)u-boot.bin $(obj)spl/u-boot-spl.bin
-		$(MAKE) $(build) $(SRCTREE)/$(CPUDIR)/$(SOC)/ $(OBJTREE)/u-boot.sb
+u-boot.sb:       u-boot.bin spl/u-boot-spl.bin
+		$(MAKE) $(build)=$(CPUDIR)/$(SOC)/ $(OBJTREE)/u-boot.sb
 
 # On x600 (SPEAr600) U-Boot is appended to U-Boot SPL.
 # Both images are created using mkimage (crc etc), so that the ROM
@@ -614,124 +638,123 @@
 # SPL image (with mkimage header) and not the binary. Otherwise the resulting image
 # which is loaded/copied by the ROM bootloader to SRAM doesn't fit.
 # The resulting image containing both U-Boot images is called u-boot.spr
-$(obj)u-boot.spr:	$(obj)u-boot.img $(obj)spl/u-boot-spl.bin
-		$(obj)tools/mkimage -A $(ARCH) -T firmware -C none \
+u-boot.spr:	u-boot.img spl/u-boot-spl.bin
+		tools/mkimage -A $(ARCH) -T firmware -C none \
 		-a $(CONFIG_SPL_TEXT_BASE) -e $(CONFIG_SPL_TEXT_BASE) -n XLOADER \
-		-d $(obj)spl/u-boot-spl.bin $@
+		-d spl/u-boot-spl.bin $@
 		$(OBJCOPY) -I binary -O binary \
 			--pad-to=$(CONFIG_SPL_PAD_TO) --gap-fill=0xff $@
-		cat $(obj)u-boot.img >> $@
+		cat u-boot.img >> $@
 
 ifneq ($(CONFIG_TEGRA),)
-$(obj)u-boot-nodtb-tegra.bin: $(obj)spl/u-boot-spl.bin $(obj)u-boot.bin
-		$(OBJCOPY) ${OBJCFLAGS} --pad-to=$(CONFIG_SYS_TEXT_BASE) -O binary $(obj)spl/u-boot-spl $(obj)spl/u-boot-spl-pad.bin
-		cat $(obj)spl/u-boot-spl-pad.bin $(obj)u-boot.bin > $@
-		rm $(obj)spl/u-boot-spl-pad.bin
+u-boot-nodtb-tegra.bin: spl/u-boot-spl.bin u-boot.bin
+		$(OBJCOPY) ${OBJCFLAGS} --pad-to=$(CONFIG_SYS_TEXT_BASE) -O binary spl/u-boot-spl spl/u-boot-spl-pad.bin
+		cat spl/u-boot-spl-pad.bin u-boot.bin > $@
+		rm spl/u-boot-spl-pad.bin
 
 ifeq ($(CONFIG_OF_SEPARATE),y)
-$(obj)u-boot-dtb-tegra.bin: $(obj)u-boot-nodtb-tegra.bin $(obj)u-boot.dtb
-		cat $(obj)u-boot-nodtb-tegra.bin $(obj)u-boot.dtb > $@
+u-boot-dtb-tegra.bin: u-boot-nodtb-tegra.bin u-boot.dtb
+		cat u-boot-nodtb-tegra.bin u-boot.dtb > $@
 endif
 endif
 
-$(obj)u-boot-img.bin: $(obj)spl/u-boot-spl.bin $(obj)u-boot.img
-		cat $(obj)spl/u-boot-spl.bin $(obj)u-boot.img > $@
+u-boot-img.bin: spl/u-boot-spl.bin u-boot.img
+		cat spl/u-boot-spl.bin u-boot.img > $@
 
 # PPC4xx needs the SPL at the end of the image, since the reset vector
 # is located at 0xfffffffc. So we can't use the "u-boot-img.bin" target
 # and need to introduce a new build target with the full blown U-Boot
 # at the start padded up to the start of the SPL image. And then concat
 # the SPL image to the end.
-$(obj)u-boot-img-spl-at-end.bin: $(obj)spl/u-boot-spl.bin $(obj)u-boot.img
+u-boot-img-spl-at-end.bin: spl/u-boot-spl.bin u-boot.img
 		$(OBJCOPY) -I binary -O binary --pad-to=$(CONFIG_UBOOT_PAD_TO) \
-			 --gap-fill=0xff $(obj)u-boot.img $@
-		cat $(obj)spl/u-boot-spl.bin >> $@
+			 --gap-fill=0xff u-boot.img $@
+		cat spl/u-boot-spl.bin >> $@
 
 # Create a new ELF from a raw binary file.  This is useful for arm64
 # where static relocation needs to be performed on the raw binary,
 # but certain simulators only accept an ELF file (but don't do the
 # relocation).
 # FIXME refactor dts/Makefile to share target/arch detection
-$(obj)u-boot.elf: $(obj)u-boot.bin
+u-boot.elf: u-boot.bin
 	@$(OBJCOPY)  -B aarch64 -I binary -O elf64-littleaarch64 \
-		$< $(obj)u-boot-elf.o
-	@$(LD) $(obj)u-boot-elf.o -o $@ \
+		$< u-boot-elf.o
+	@$(LD) u-boot-elf.o -o $@ \
 		--defsym=_start=$(CONFIG_SYS_TEXT_BASE) \
 		-Ttext=$(CONFIG_SYS_TEXT_BASE)
 
 ifeq ($(CONFIG_SANDBOX),y)
 GEN_UBOOT = \
-		cd $(LNDIR) && $(CC) $(SYMS) -T $(obj)u-boot.lds \
-			-Wl,--start-group $(__LIBS) -Wl,--end-group \
+		$(CC) $(SYMS) -T u-boot.lds \
+			-Wl,--start-group $(LIBS) -Wl,--end-group \
 			$(PLATFORM_LIBS) -Wl,-Map -Wl,u-boot.map -o u-boot
 else
 GEN_UBOOT = \
-		cd $(LNDIR) && $(LD) $(LDFLAGS) $(LDFLAGS_$(@F)) \
-			$(__OBJS) \
-			--start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \
+		$(LD) $(LDFLAGS) $(LDFLAGS_$(@F)) \
+			$(OBJS) \
+			--start-group $(LIBS) --end-group $(PLATFORM_LIBS) \
 			-Map u-boot.map -o u-boot
 endif
 
-$(obj)u-boot:	depend \
-		$(SUBDIR_TOOLS) $(OBJS) $(LIBS) $(obj)u-boot.lds
+u-boot:	depend $(SUBDIR_TOOLS) $(OBJS) $(LIBS) u-boot.lds
 		$(GEN_UBOOT)
 ifeq ($(CONFIG_KALLSYMS),y)
-		smap=`$(call SYSTEM_MAP,$(obj)u-boot) | \
+		smap=`$(call SYSTEM_MAP,u-boot) | \
 			awk '$$2 ~ /[tTwW]/ {printf $$1 $$3 "\\\\000"}'` ; \
 		$(CC) $(CFLAGS) -DSYSTEM_MAP="\"$${smap}\"" \
-			-c common/system_map.c -o $(obj)common/system_map.o
-		$(GEN_UBOOT) $(obj)common/system_map.o
+			-c $(srctree)/common/system_map.c -o common/system_map.o
+		$(GEN_UBOOT) common/system_map.o
 endif
 
 $(OBJS):
 	@:
 
 $(LIBS):	depend $(SUBDIR_TOOLS)
-		$(MAKE) $(build) $(dir $(subst $(obj),,$@))
+		$(MAKE) $(build)=$(patsubst %/,%,$(dir $@))
 
 $(SUBDIRS):	depend
-		$(MAKE) $(build) $@ all
+		$(MAKE) $(build)=$@ all
 
-$(SUBDIR_EXAMPLES-y): $(obj)u-boot
+$(SUBDIR_EXAMPLES-y): u-boot
 
-$(obj)u-boot.lds: $(LDSCRIPT) depend
+u-boot.lds: $(LDSCRIPT) depend
 		$(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - <$< >$@
 
 nand_spl:	$(TIMESTAMP_FILE) $(VERSION_FILE) depend
-		$(MAKE) $(build) nand_spl/board/$(BOARDDIR) all
+		$(MAKE) $(build)=nand_spl/board/$(BOARDDIR) all
 
-$(obj)u-boot-nand.bin:	nand_spl $(obj)u-boot.bin
-		cat $(obj)nand_spl/u-boot-spl-16k.bin $(obj)u-boot.bin > $(obj)u-boot-nand.bin
+u-boot-nand.bin:	nand_spl u-boot.bin
+		cat nand_spl/u-boot-spl-16k.bin u-boot.bin > u-boot-nand.bin
 
-$(obj)spl/u-boot-spl.bin:	$(SUBDIR_TOOLS) depend
-		$(MAKE) -C spl all
+spl/u-boot-spl.bin:	$(SUBDIR_TOOLS) depend
+		$(MAKE) obj=spl -f $(srctree)/spl/Makefile all
 
-$(obj)tpl/u-boot-tpl.bin:	$(SUBDIR_TOOLS) depend
-		$(MAKE) -C spl all CONFIG_TPL_BUILD=y
+tpl/u-boot-tpl.bin:	$(SUBDIR_TOOLS) depend
+		$(MAKE) obj=tpl -f $(srctree)/spl/Makefile all CONFIG_TPL_BUILD=y
 
 # Explicitly make _depend in subdirs containing multiple targets to prevent
 # parallel sub-makes creating .depend files simultaneously.
 depend dep:	$(TIMESTAMP_FILE) $(VERSION_FILE) \
-		$(obj)include/spl-autoconf.mk \
-		$(obj)include/tpl-autoconf.mk \
-		$(obj)include/autoconf.mk \
-		$(obj)include/generated/generic-asm-offsets.h \
-		$(obj)include/generated/asm-offsets.h
+		include/spl-autoconf.mk \
+		include/tpl-autoconf.mk \
+		include/autoconf.mk \
+		include/generated/generic-asm-offsets.h \
+		include/generated/asm-offsets.h
 
 TAG_SUBDIRS = $(SUBDIRS)
-TAG_SUBDIRS += $(dir $(__LIBS))
+TAG_SUBDIRS += $(dir $(LIBS))
 TAG_SUBDIRS += include
 
 FIND := find
 FINDFLAGS := -L
 
 checkstack:
-		$(CROSS_COMPILE)objdump -d $(obj)u-boot \
-			`$(FIND) $(obj) -name u-boot-spl -print` | \
-			perl $(src)scripts/checkstack.pl $(ARCH)
+		$(CROSS_COMPILE)objdump -d u-boot \
+			`$(FIND) . -name u-boot-spl -print` | \
+			perl $(src)/scripts/checkstack.pl $(ARCH)
 
 tags ctags:
-		ctags -w -o $(obj)ctags `$(FIND) $(FINDFLAGS) $(TAG_SUBDIRS) \
+		ctags -w -o ctags `$(FIND) $(FINDFLAGS) $(TAG_SUBDIRS) \
 						-name '*.[chS]' -print`
 
 etags:
@@ -746,7 +769,7 @@
 		$(NM) $1 | \
 		grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] \)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' | \
 		LC_ALL=C sort
-$(obj)System.map:	$(obj)u-boot
+System.map:	u-boot
 		@$(call SYSTEM_MAP,$<) > $@
 
 checkthumb:
@@ -778,76 +801,76 @@
 # This target actually generates 2 files; autoconf.mk and autoconf.mk.dep.
 # the dep file is only include in this top level makefile to determine when
 # to regenerate the autoconf.mk file.
-$(obj)include/autoconf.mk.dep: $(obj)include/config.h include/common.h
+include/autoconf.mk.dep: include/config.h include/common.h
 	@$(XECHO) Generating $@ ; \
 	: Generate the dependancies ; \
 	$(CC) -x c -DDO_DEPS_ONLY -M $(CFLAGS) $(CPPFLAGS) \
-		-MQ $(obj)include/autoconf.mk include/common.h > $@ || \
+		-MQ include/autoconf.mk $(srctree)/include/common.h > $@ || \
 		rm $@
 
-$(obj)include/autoconf.mk: $(obj)include/config.h
+include/autoconf.mk: include/config.h
 	@$(XECHO) Generating $@ ; \
 	: Extract the config macros ; \
-	$(CPP) $(CFLAGS) -DDO_DEPS_ONLY -dM include/common.h > $@.tmp && \
-		sed -n -f tools/scripts/define2mk.sed $@.tmp > $@; \
+	$(CPP) $(CFLAGS) -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
+		sed -n -f $(srctree)/tools/scripts/define2mk.sed $@.tmp > $@; \
 	rm $@.tmp
 
 # Auto-generate the spl-autoconf.mk file (which is included by all makefiles for SPL)
-$(obj)include/tpl-autoconf.mk: $(obj)include/config.h
+include/tpl-autoconf.mk: include/config.h
 	@$(XECHO) Generating $@ ; \
 	: Extract the config macros ; \
 	$(CPP) $(CFLAGS) -DCONFIG_TPL_BUILD  -DCONFIG_SPL_BUILD\
-			-DDO_DEPS_ONLY -dM include/common.h > $@.tmp && \
-		sed -n -f tools/scripts/define2mk.sed $@.tmp > $@; \
+			-DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
+		sed -n -f $(srctree)/tools/scripts/define2mk.sed $@.tmp > $@; \
 	rm $@.tmp
 
-$(obj)include/spl-autoconf.mk: $(obj)include/config.h
+include/spl-autoconf.mk: include/config.h
 	@$(XECHO) Generating $@ ; \
 	: Extract the config macros ; \
-	$(CPP) $(CFLAGS) -DCONFIG_SPL_BUILD -DDO_DEPS_ONLY -dM include/common.h > $@.tmp && \
-		sed -n -f tools/scripts/define2mk.sed $@.tmp > $@; \
+	$(CPP) $(CFLAGS) -DCONFIG_SPL_BUILD -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
+		sed -n -f $(srctree)/tools/scripts/define2mk.sed $@.tmp > $@; \
 	rm $@.tmp
 
-$(obj)include/generated/generic-asm-offsets.h: $(obj)lib/asm-offsets.s
+include/generated/generic-asm-offsets.h: lib/asm-offsets.s
 	@$(XECHO) Generating $@
-	tools/scripts/make-asm-offsets $(obj)lib/asm-offsets.s $@
+	$(srctree)/tools/scripts/make-asm-offsets lib/asm-offsets.s $@
 
-$(obj)lib/asm-offsets.s: $(obj)include/config.h $(src)lib/asm-offsets.c
-	@mkdir -p $(obj)lib
+lib/asm-offsets.s: include/config.h $(srctree)/lib/asm-offsets.c
+	@mkdir -p lib
 	$(CC) -DDO_DEPS_ONLY \
 		$(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
-		-o $@ $(src)lib/asm-offsets.c -c -S
+		-o $@ $(srctree)/lib/asm-offsets.c -c -S
 
-$(obj)include/generated/asm-offsets.h: $(obj)$(CPUDIR)/$(SOC)/asm-offsets.s
+include/generated/asm-offsets.h: $(CPUDIR)/$(SOC)/asm-offsets.s
 	@$(XECHO) Generating $@
-	tools/scripts/make-asm-offsets $(obj)$(CPUDIR)/$(SOC)/asm-offsets.s $@
+	$(srctree)/tools/scripts/make-asm-offsets $(CPUDIR)/$(SOC)/asm-offsets.s $@
 
-$(obj)$(CPUDIR)/$(SOC)/asm-offsets.s: $(obj)include/config.h
-	@mkdir -p $(obj)$(CPUDIR)/$(SOC)
-	if [ -f $(src)$(CPUDIR)/$(SOC)/asm-offsets.c ];then \
+$(CPUDIR)/$(SOC)/asm-offsets.s:	include/config.h
+	@mkdir -p $(CPUDIR)/$(SOC)
+	if [ -f $(srctree)/$(CPUDIR)/$(SOC)/asm-offsets.c ];then \
 		$(CC) -DDO_DEPS_ONLY \
 		$(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
-			-o $@ $(src)$(CPUDIR)/$(SOC)/asm-offsets.c -c -S; \
+			-o $@ $(srctree)/$(CPUDIR)/$(SOC)/asm-offsets.c -c -S; \
 	else \
 		touch $@; \
 	fi
 
 #########################################################################
 else	# !config.mk
-all $(obj)u-boot.hex $(obj)u-boot.srec $(obj)u-boot.bin \
-$(obj)u-boot.img $(obj)u-boot.dis $(obj)u-boot \
+all u-boot.hex u-boot.srec u-boot.bin \
+u-boot.img u-boot.dis u-boot \
 $(filter-out tools,$(SUBDIRS)) \
-depend dep tags ctags etags cscope $(obj)System.map:
+depend dep tags ctags etags cscope System.map:
 	@echo "System not configured - see README" >&2
 	@ exit 1
 
 tools: $(VERSION_FILE) $(TIMESTAMP_FILE)
-	$(MAKE) $(build) $@ all
+	$(MAKE) $(build)=$@ all
 endif	# config.mk
 
 # ARM relocations should all be R_ARM_RELATIVE (32-bit) or
 # R_AARCH64_RELATIVE (64-bit).
-checkarmreloc: $(obj)u-boot
+checkarmreloc: u-boot
 	@RELOC="`$(CROSS_COMPILE)readelf -r -W $< | cut -d ' ' -f 4 | \
 		grep R_A | sort -u`"; \
 	if test "$$RELOC" != "R_ARM_RELATIVE" -a \
@@ -877,15 +900,15 @@
 		@cmp -s $@ $@.tmp && rm -f $@.tmp || mv -f $@.tmp $@
 
 easylogo env gdb:
-	$(MAKE) $(build) tools/$@ MTD_VERSION=${MTD_VERSION}
+	$(MAKE) $(build)=tools/$@ MTD_VERSION=${MTD_VERSION}
 
 gdbtools: gdb
 
 xmldocs pdfdocs psdocs htmldocs mandocs: tools/kernel-doc/docproc
-	$(MAKE) U_BOOT_VERSION=$(U_BOOT_VERSION) -C doc/DocBook/ $@
+	$(MAKE) U_BOOT_VERSION=$(U_BOOT_VERSION) $(build)=doc/DocBook $@
 
 tools-all: easylogo env gdb $(VERSION_FILE) $(TIMESTAMP_FILE)
-	$(MAKE) $(build) tools HOST_TOOLS_ALL=y
+	$(MAKE) $(build)=tools HOST_TOOLS_ALL=y
 
 .PHONY : CHANGELOG
 CHANGELOG:
@@ -897,57 +920,52 @@
 #########################################################################
 
 unconfig:
-	@rm -f $(obj)include/config.h $(obj)include/config.mk \
-		$(obj)board/*/config.tmp $(obj)board/*/*/config.tmp \
-		$(obj)include/autoconf.mk $(obj)include/autoconf.mk.dep \
-		$(obj)include/spl-autoconf.mk \
-		$(obj)include/tpl-autoconf.mk
+	@rm -f include/config.h include/config.mk \
+		board/*/config.tmp board/*/*/config.tmp \
+		include/autoconf.mk include/autoconf.mk.dep \
+		include/spl-autoconf.mk \
+		include/tpl-autoconf.mk
 
 %_config::	unconfig
 	@$(MKCONFIG) -A $(@:_config=)
 
-sinclude $(obj).boards.depend
-$(obj).boards.depend:	boards.cfg
-	@awk '(NF && $$1 !~ /^#/) { print $$7 ": " $$7 "_config; $$(MAKE)" }' $< > $@
-
-#########################################################################
 #########################################################################
 
 clean:
-	@rm -f $(obj)examples/standalone/atmel_df_pow2			  \
-	       $(obj)examples/standalone/hello_world			  \
-	       $(obj)examples/standalone/interrupt			  \
-	       $(obj)examples/standalone/mem_to_mem_idma2intr		  \
-	       $(obj)examples/standalone/sched				  \
-	       $(addprefix $(obj)examples/standalone/, smc91111_eeprom smc911x_eeprom) \
-	       $(obj)examples/standalone/test_burst			  \
-	       $(obj)examples/standalone/timer
-	@rm -f $(addprefix $(obj)examples/api/, demo demo.bin)
-	@rm -f $(obj)tools/bmp_logo	   $(obj)tools/easylogo/easylogo  \
-	       $(obj)tools/env/fw_printenv				  \
-	       $(obj)tools/envcrc					  \
-	       $(addprefix $(obj)tools/gdb/, gdbcont gdbsend)		  \
-	       $(obj)tools/gen_eth_addr    $(obj)tools/img2srec		  \
-	       $(obj)tools/dumpimage					  \
-	       $(addprefix $(obj)tools/, mkenvimage mkimage)		  \
-	       $(obj)tools/mpc86x_clk					  \
-	       $(addprefix $(obj)tools/, mk$(BOARD)spl mkexynosspl)	  \
-	       $(obj)tools/mxsboot					  \
-	       $(obj)tools/ncb		   $(obj)tools/ubsha1		  \
-	       $(obj)tools/kernel-doc/docproc				  \
-	       $(obj)tools/proftool
-	@rm -f $(addprefix $(obj)board/cray/L1/, bootscript.c bootscript.image) \
-	       $(obj)board/matrix_vision/*/bootscript.img		  \
-	       $(obj)spl/board/samsung/$(BOARD)/tools/mk$(BOARD)spl	  \
-	       $(obj)u-boot.lds						  \
-	       $(addprefix $(obj)arch/blackfin/cpu/, init.lds init.elf)
-	@rm -f $(obj)include/bmp_logo.h
-	@rm -f $(obj)include/bmp_logo_data.h
-	@rm -f $(obj)lib/asm-offsets.s
-	@rm -f $(obj)include/generated/asm-offsets.h
-	@rm -f $(obj)$(CPUDIR)/$(SOC)/asm-offsets.s
+	@rm -f examples/standalone/atmel_df_pow2			  \
+	       examples/standalone/hello_world				  \
+	       examples/standalone/interrupt				  \
+	       examples/standalone/mem_to_mem_idma2intr			  \
+	       examples/standalone/sched				  \
+	       $(addprefix examples/standalone/, smc91111_eeprom smc911x_eeprom) \
+	       examples/standalone/test_burst				  \
+	       examples/standalone/timer
+	@rm -f $(addprefix examples/api/, demo demo.bin)
+	@rm -f tools/bmp_logo	   tools/easylogo/easylogo		  \
+	       tools/env/fw_printenv					  \
+	       tools/envcrc						  \
+	       $(addprefix tools/gdb/, gdbcont gdbsend)			  \
+	       tools/gen_eth_addr    tools/img2srec			  \
+	       tools/dumpimage						  \
+	       $(addprefix tools/, mkenvimage mkimage)			  \
+	       tools/mpc86x_clk						  \
+	       $(addprefix tools/, mk$(BOARD)spl mkexynosspl)		  \
+	       tools/mxsboot						  \
+	       tools/ncb		   tools/ubsha1			  \
+	       tools/kernel-doc/docproc					  \
+	       tools/proftool
+	@rm -f $(addprefix board/cray/L1/, bootscript.c bootscript.image) \
+	       board/matrix_vision/*/bootscript.img			  \
+	       spl/board/samsung/$(BOARD)/tools/mk$(BOARD)spl		  \
+	       u-boot.lds						  \
+	       $(addprefix arch/blackfin/cpu/, init.lds init.elf)
+	@rm -f include/bmp_logo.h
+	@rm -f include/bmp_logo_data.h
+	@rm -f lib/asm-offsets.s
+	@rm -f include/generated/asm-offsets.h
+	@rm -f $(CPUDIR)/$(SOC)/asm-offsets.s
 	@rm -f $(TIMESTAMP_FILE) $(VERSION_FILE)
-	@$(MAKE) -s -C doc/DocBook/ cleandocs
+	@$(MAKE) -f $(srctree)/doc/DocBook/Makefile cleandocs
 	@find $(OBJTREE) -type f \
 		\( -name 'core' -o -name '*.bak' -o -name '*~' -o -name '*.su' \
 		-o -name '*.o'	-o -name '*.a' -o -name '*.exe' \
@@ -962,38 +980,38 @@
 	@find $(OBJTREE) -type f \( -name '*.srec' \
 		-o -name '*.bin' -o -name u-boot.img \) \
 		-print0 | xargs -0 rm -f
-	@rm -f $(OBJS) $(obj)*.bak $(obj)ctags $(obj)etags $(obj)TAGS \
-		$(obj)cscope.* $(obj)*.*~
-	@rm -f $(obj)u-boot $(obj)u-boot.map $(obj)u-boot.hex $(ALL-y)
-	@rm -f $(obj)u-boot.kwb
-	@rm -f $(obj)u-boot.pbl
-	@rm -f $(obj)u-boot.imx
-	@rm -f $(obj)u-boot-with-spl.imx
-	@rm -f $(obj)u-boot-with-nand-spl.imx
-	@rm -f $(obj)u-boot.ubl
-	@rm -f $(obj)u-boot.ais
-	@rm -f $(obj)u-boot.dtb
-	@rm -f $(obj)u-boot.sb
-	@rm -f $(obj)u-boot.spr
-	@rm -f $(addprefix $(obj)nand_spl/, u-boot.lds u-boot.lst System.map)
-	@rm -f $(addprefix $(obj)nand_spl/, u-boot-nand_spl.lds u-boot-spl u-boot-spl.map)
-	@rm -f $(addprefix $(obj)spl/, u-boot-spl u-boot-spl.bin u-boot-spl.map)
-	@rm -f $(obj)spl/u-boot-spl.lds
-	@rm -f $(addprefix $(obj)tpl/, u-boot-tpl u-boot-tpl.bin u-boot-tpl.map)
-	@rm -f $(obj)tpl/u-boot-spl.lds
-	@rm -f $(obj)MLO MLO.byteswap
-	@rm -f $(obj)SPL
-	@rm -f $(obj)tools/xway-swap-bytes
-	@rm -fr $(obj)include/asm/proc $(obj)include/asm/arch $(obj)include/asm
-	@rm -fr $(obj)include/generated
-	@[ ! -d $(obj)nand_spl ] || find $(obj)nand_spl -name "*" -type l -print | xargs rm -f
-	@rm -f $(obj)dts/*.tmp
-	@rm -f $(addprefix $(obj)spl/, u-boot-spl.ais, u-boot-spl-pad.ais)
+	@rm -f $(OBJS) *.bak ctags etags TAGS \
+		cscope.* *.*~
+	@rm -f u-boot u-boot.map u-boot.hex $(ALL-y)
+	@rm -f u-boot.kwb
+	@rm -f u-boot.pbl
+	@rm -f u-boot.imx
+	@rm -f u-boot-with-spl.imx
+	@rm -f u-boot-with-nand-spl.imx
+	@rm -f u-boot.ubl
+	@rm -f u-boot.ais
+	@rm -f u-boot.dtb
+	@rm -f u-boot.sb
+	@rm -f u-boot.spr
+	@rm -f $(addprefix nand_spl/, u-boot.lds u-boot.lst System.map)
+	@rm -f $(addprefix nand_spl/, u-boot-nand_spl.lds u-boot-spl u-boot-spl.map)
+	@rm -f $(addprefix spl/, u-boot-spl u-boot-spl.bin u-boot-spl.map)
+	@rm -f spl/u-boot-spl.lds
+	@rm -f $(addprefix tpl/, u-boot-tpl u-boot-tpl.bin u-boot-tpl.map)
+	@rm -f tpl/u-boot-spl.lds
+	@rm -f MLO MLO.byteswap
+	@rm -f SPL
+	@rm -f tools/xway-swap-bytes
+	@rm -fr include/asm/proc include/asm/arch include/asm
+	@rm -fr include/generated
+	@[ ! -d nand_spl ] || find nand_spl -name "*" -type l -print | xargs rm -f
+	@rm -f dts/*.tmp
+	@rm -f $(addprefix spl/, u-boot-spl.ais, u-boot-spl-pad.ais)
 
 mrproper \
 distclean:	clobber unconfig
 ifneq ($(OBJTREE),$(SRCTREE))
-	rm -rf $(obj)*
+	rm -rf *
 endif
 
 backup:
@@ -1001,3 +1019,12 @@
 	gtar --force-local -zcvf `LC_ALL=C date "+$$F-%Y-%m-%d-%T.tar.gz"` $$F
 
 #########################################################################
+
+endif	# skip-makefile
+
+PHONY += FORCE
+FORCE:
+
+# Declare the contents of the .PHONY variable as phony.  We keep that
+# information in a variable so we can use it in if_changed and friends.
+.PHONY: $(PHONY)