kconfig: switch to single .config configuration

When Kconfig for U-boot was examined, one of the biggest issues was
how to support multiple images (Normal, SPL, TPL).  There were
actually two options, "single .config" and "multiple .config".
After some discussions and thought experiments, I chose the latter,
i.e. to create ".config", "spl/.config", "tpl/.config" for Normal,
SPL, TPL, respectively.

It is true that the "multiple .config" strategy provided us the
maximum flexibility and helped to avoid duplicating CONFIGs among
Normal, SPL, TPL, but I have noticed some fatal problems:

[1] It is impossible to share CONFIG options across the images.
  If you change the configuration of Main image, you often have to
  adjust some SPL configurations correspondingly.  Currently, we
  cannot handle the dependencies between them.  It means one of the
  biggest advantages of Kconfig is lost.

[2] It is too painful to change both ".config" and "spl/.config".
  Sunxi guys started to work around this problem by creating a new
  configuration target.  Commit cbdd9a9737cc (sunxi: kconfig: Add
  %_felconfig rule to enable FEL build of sunxi platforms.) added
  "make *_felconfig" to enable CONFIG_SPL_FEL on both images.
  Changing the configuration of multiple images in one command is a
  generic demand.  The current implementation cannot propose any
  good solution about this.

[3] Kconfig files are getting ugly and difficult to understand.
  Commit b724bd7d6349 (dm: Kconfig: Move CONFIG_SYS_MALLOC_F_LEN to
  Kconfig) has sprinkled "if !SPL_BUILD" over the Kconfig files.

[4] The build system got more complicated than it should be.
  To adjust Linux-originated Kconfig to U-Boot, the helper script
  "scripts/multiconfig.sh" was introduced.  Writing a complicated
  text processor is a shell script sometimes caused problems.

Now I believe the "single .config" will serve us better.  With it,
all the problems above would go away.  Instead, we will have to add
some CONFIG_SPL_* (and CONFIG_TPL_*) options such as CONFIG_SPL_DM,
but we will not have much.  Anyway, this is what we do now in
scripts/Makefile.spl.

I admit my mistake with my apology and this commit switches to the
single .config configuration.

It is not so difficult to do that:

 - Remove unnecessary processings from scripts/multiconfig.sh
  This file will remain for a while to support the current defconfig
  format.  It will be removed after more cleanups are done.

 - Adjust some makefiles and Kconfigs

 - Add some entries to include/config_uncmd_spl.h and the new file
   scripts/Makefile.uncmd_spl.  Some CONFIG options that are not
   supported on SPL must be disabled because one .config is shared
   between SPL and U-Boot proper going forward.  I know this is not
   a beautiful solution and I think we can do better, but let's see
   how much we will have to describe them.

 - update doc/README.kconfig

More cleaning up patches will follow this.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

5 files changed, 57 insertions, 269 deletions

diff --git a/scripts/Makefile.autoconf b/scripts/Makefile.autoconf
index 58e1642fb9..f054081c98 100644
--- a/scripts/Makefile.autoconf
+++ b/scripts/Makefile.autoconf
@@ -7,9 +7,17 @@
 # (= When we move all CONFIGs from header files to Kconfig)
 # this makefile can be deleted.
 
-# obj is "include" or "spl/include" or "tpl/include"
-# for non-SPL, SPL, TPL, respectively
-include $(obj)/config/auto.conf
+__all: include/autoconf.mk include/autoconf.mk.dep
+
+ifeq ($(shell grep -q '^CONFIG_SPL=y' include/config/auto.conf 2>/dev/null && echo y),y)
+__all: spl/include/autoconf.mk
+endif
+
+ifeq ($(shell grep -q '^CONFIG_TPL=y' include/config/auto.conf 2>/dev/null && echo y),y)
+__all: tpl/include/autoconf.mk
+endif
+
+include include/config/auto.conf
 
 include scripts/Kbuild.include
 
@@ -22,7 +30,6 @@ CPP		= $(CC) -E
 include config.mk
 
 UBOOTINCLUDE    := \
-		-I$(obj) \
 		-Iinclude \
 		$(if $(KBUILD_SRC), -I$(srctree)/include) \
 		-I$(srctree)/arch/$(ARCH)/include \
@@ -48,10 +55,10 @@ include/autoconf.mk.dep: FORCE
 # same CONFIG macros
 quiet_cmd_autoconf = GEN     $@
       cmd_autoconf = \
-	$(CPP) $(c_flags) -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && {	\
+	$(CPP) $(c_flags) $2 -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && { \
 		sed -n -f $(srctree)/tools/scripts/define2mk.sed $@.tmp |		\
 		while read line; do							\
-			if ! grep -q "$${line%=*}=" $(obj)/config/auto.conf; then	\
+			if ! grep -q "$${line%=*}=" include/config/auto.conf; then	\
 				echo "$$line";						\
 			fi								\
 		done > $@;								\
@@ -60,10 +67,19 @@ quiet_cmd_autoconf = GEN     $@
 		rm $@.tmp; false;							\
 	}
 
-$(obj)/autoconf.mk: FORCE
+include/autoconf.mk: FORCE
 	$(call cmd,autoconf)
 
-include/autoconf.mk include/autoconf.mk.dep: include/config.h
+spl/include/autoconf.mk: FORCE
+	$(Q)mkdir -p $(dir $@)
+	$(call cmd,autoconf,-DCONFIG_SPL_BUILD)
+
+tpl/include/autoconf.mk: FORCE
+	$(Q)mkdir -p $(dir $@)
+	$(call cmd,autoconf,-DCONFIG_SPL_BUILD -DCONFIG_TPL_BUILD)
+
+include/autoconf.mk include/autoconf.mk.dep \
+	spl/include/autoconf.mk tpl/include/autoconf.mk: include/config.h
 
 # include/config.h
 # Prior to Kconfig, it was generated by mkconfig. Now it is created here.
@@ -75,10 +91,10 @@ define filechk_config_h
 	done;								\
 	echo \#define CONFIG_BOARDDIR board/$(if $(VENDOR),$(VENDOR)/)$(BOARD);\
 	echo \#include \<config_defaults.h\>;				\
+	echo \#include \<config_uncmd_spl.h\>;				\
 	echo \#include \<configs/$(CONFIG_SYS_CONFIG_NAME).h\>;		\
 	echo \#include \<asm/config.h\>;				\
-	echo \#include \<config_fallbacks.h\>;				\
-	echo \#include \<config_uncmd_spl.h\>; )
+	echo \#include \<config_fallbacks.h\>;)
 endef
 
 include/config.h: scripts/Makefile.autoconf create_symlink FORCE
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 14cf0925d2..ac0554eeae 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -41,8 +41,9 @@ subdir-ccflags-y :=
 
 # Read auto.conf if it exists, otherwise ignore
 # Modified for U-Boot
--include $(prefix)/include/config/auto.conf
+-include include/config/auto.conf
 -include $(prefix)/include/autoconf.mk
+include scripts/Makefile.uncmd_spl
 
 include scripts/Kbuild.include
 
diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl
index cc189adc0c..fcacb7fcb4 100644
--- a/scripts/Makefile.spl
+++ b/scripts/Makefile.spl
@@ -21,13 +21,15 @@ _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
 
 include $(srctree)/scripts/Kbuild.include
 
-UBOOTINCLUDE := -I$(obj)/include $(UBOOTINCLUDE)
-
--include $(obj)/include/config/auto.conf
+-include include/config/auto.conf
 -include $(obj)/include/autoconf.mk
 
+KBUILD_CPPFLAGS += -DCONFIG_SPL_BUILD
+ifeq ($(CONFIG_TPL_BUILD),y)
+KBUILD_CPPFLAGS += -DCONFIG_TPL_BUILD
+endif
+
 ifeq ($(CONFIG_TPL_BUILD),y)
-export CONFIG_TPL_BUILD
 SPL_BIN := u-boot-tpl
 else
 SPL_BIN := u-boot-spl
diff --git a/scripts/Makefile.uncmd_spl b/scripts/Makefile.uncmd_spl
new file mode 100644
index 0000000000..86c938e1f9
--- /dev/null
+++ b/scripts/Makefile.uncmd_spl
@@ -0,0 +1,16 @@
+# Makefile version of include/config_uncmd_spl.h
+#
+# TODO: Invent a better way
+
+ifdef CONFIG_SPL_BUILD
+CONFIG_OF_CONTROL=
+
+ifndef CONFIG_SPL_DM
+CONFIG_DM_SERIAL=
+CONFIG_DM_GPIO=
+CONIFG_DM_I2C=
+CONFIG_DM_SPI=
+CONFIG_DM_SPI_FLASH=
+endif
+
+endif
diff --git a/scripts/multiconfig.sh b/scripts/multiconfig.sh
index 366e8faaa6..cc8a787f88 100755
--- a/scripts/multiconfig.sh
+++ b/scripts/multiconfig.sh
@@ -2,11 +2,7 @@
 #
 # A wrapper script to adjust Kconfig for U-Boot
 #
-# Instead of touching various parts under the scripts/kconfig/ directory,
-# pushing necessary adjustments into this single script would be better
-# for code maintainance.  All the make targets related to the configuration
-# (make %config) should be invoked via this script.
-# See doc/README.kconfig for further information of Kconfig.
+# This file will be removed after cleaning up defconfig files
 #
 # Copyright (C) 2014, Masahiro Yamada <yamada.m@jp.panasonic.com>
 #
@@ -15,77 +11,23 @@
 
 set -e
 
-# Set "DEBUG" enavironment variable to show debug messages
-debug () {
-	if [ $DEBUG ]; then
-		echo "$@"
-	fi
-}
-
-# Useful shorthands
-build () {
-	debug $progname: $MAKE -f $srctree/scripts/Makefile.build obj="$@"
-	$MAKE -f $srctree/scripts/Makefile.build obj="$@"
-}
-
-autoconf () {
-	debug $progname: $MAKE -f $srctree/scripts/Makefile.autoconf obj="$@"
-	$MAKE -f $srctree/scripts/Makefile.autoconf obj="$@"
-}
-
 # Make a configuration target
 # Usage:
 #   run_make_config <target> <objdir>
 # <target>: Make target such as "config", "menuconfig", "defconfig", etc.
-# <objdir>: Target directory where the make command is run.
-#           Typically "", "spl", "tpl" for Normal, SPL, TPL, respectively.
 run_make_config () {
-	target=$1
-	objdir=$2
-
 	# Linux expects defconfig files in arch/$(SRCARCH)/configs/ directory,
 	# but U-Boot has them in configs/ directory.
 	# Give SRCARCH=.. to fake scripts/kconfig/Makefile.
-	options="SRCARCH=.. KCONFIG_OBJDIR=$objdir"
-	if [ "$objdir" ]; then
-		options="$options KCONFIG_CONFIG=$objdir/$KCONFIG_CONFIG"
-		mkdir -p $objdir
-	fi
-
-	build scripts/kconfig $options $target
-}
-
-# Parse .config file to detect if CONFIG_SPL, CONFIG_TPL is enabled
-# and returns:
-#   ""        if neither CONFIG_SPL nor CONFIG_TPL is defined
-#   "spl"     if CONFIG_SPL is defined but CONFIG_TPL is not
-#   "spl tpl" if both CONFIG_SPL and CONFIG_TPL are defined
-get_enabled_subimages() {
-	if [ ! -r "$KCONFIG_CONFIG" ]; then
-		# This should never happen
-		echo "$progname: $KCONFIG_CONFIG not found" >&2
-		exit 1
-	fi
-
-	# CONFIG_SPL=y -> spl
-	# CONFIG_TPL=y -> tpl
-	sed -n -e 's/^CONFIG_SPL=y$/spl/p' -e 's/^CONFIG_TPL=y$/tpl/p' \
-							 $KCONFIG_CONFIG
+	$MAKE -f $srctree/scripts/Makefile.build obj=scripts/kconfig SRCARCH=.. $1
 }
 
 do_silentoldconfig () {
 	run_make_config silentoldconfig
-	subimages=$(get_enabled_subimages)
-
-	for obj in $subimages
-	do
-		mkdir -p $obj/include/config $obj/include/generated
-		run_make_config silentoldconfig $obj
-	done
 
 	# If the following part fails, include/config/auto.conf should be
 	# deleted so "make silentoldconfig" will be re-run on the next build.
-	autoconf include include/autoconf.mk include/autoconf.mk.dep || {
+	$MAKE -f $srctree/scripts/Makefile.autoconf || {
 		rm -f include/config/auto.conf
 		exit 1
 	}
@@ -95,14 +37,6 @@ do_silentoldconfig () {
 	# than include/config.h.
 	# Otherwise, 'make silentoldconfig' would be invoked twice.
 	touch include/config/auto.conf
-
-	for obj in $subimages
-	do
-		autoconf $obj/include $obj/include/autoconf.mk || {
-			rm -f include/config/auto.conf
-			exit 1
-		}
-	done
 }
 
 cleanup_after_defconfig () {
@@ -116,7 +50,6 @@ cleanup_after_defconfig () {
 #  do_board_defconfig <board>_defconfig
 do_board_defconfig () {
 	defconfig_path=$srctree/configs/$1
-	tmp_defconfig_path=configs/.tmp_defconfig
 
 	if [ ! -r $defconfig_path ]; then
 		echo >&2 "***"
@@ -126,42 +59,17 @@ do_board_defconfig () {
 	fi
 
 	mkdir -p arch configs
-	# defconfig for Normal:
-	#  pick lines without prefixes and lines starting '+' prefix
-	#  and rip the prefixes off.
-	sed -n -e '/^[+A-Z]*:/!p' -e 's/^+[A-Z]*://p' $defconfig_path \
-						> configs/.tmp_defconfig
+	# prefix "*:" is deprecated.  Drop it simply.
+	sed -e 's/^[+A-Z]*://' $defconfig_path > configs/.tmp_defconfig
 
 	run_make_config .tmp_defconfig || {
 		cleanup_after_defconfig
 		exit 1
 	}
 
-	for img in $(get_enabled_subimages)
-	do
-		symbol=$(echo $img | cut -c 1 | tr '[a-z]' '[A-Z]')
-		# defconfig for SPL, TPL:
-		#   pick lines with 'S', 'T' prefix and rip the prefixes off
-		sed -n -e 's/^[+A-Z]*'$symbol'[A-Z]*://p' $defconfig_path \
-						> configs/.tmp_defconfig
-		run_make_config .tmp_defconfig $img || {
-			cleanup_after_defconfig
-			exit 1
-		}
-	done
-
 	cleanup_after_defconfig
 }
 
-do_defconfig () {
-	if [ "$KBUILD_DEFCONFIG" ]; then
-		do_board_defconfig $KBUILD_DEFCONFIG
-		echo "*** Default configuration is based on '$KBUILD_DEFCONFIG'"
-	else
-		run_make_config defconfig
-	fi
-}
-
 do_board_felconfig () {
     do_board_defconfig ${1%%_felconfig}_defconfig
     if ! grep -q CONFIG_ARCH_SUNXI=y .config || ! grep -q CONFIG_SPL=y .config ; then
@@ -169,162 +77,11 @@ do_board_felconfig () {
 	exit 1
     fi
     sed -i -e 's/\# CONFIG_SPL_FEL is not set/CONFIG_SPL_FEL=y\nCONFIG_UART0_PORT_F=n/g' \
-	.config spl/.config
+	.config
 }
 
-do_savedefconfig () {
-	if [ -r "$KCONFIG_CONFIG" ]; then
-		subimages=$(get_enabled_subimages)
-	else
-		subimages=
-	fi
-
-	run_make_config savedefconfig
-
-	output_lines=
-
-	# -r option is necessay because some string-type configs may include
-	# backslashes as an escape character
-	while read -r line
-	do
-		output_lines="$output_lines%$line"
-	done < defconfig
-
-	for img in $subimages
-	do
-		run_make_config savedefconfig $img
-
-		symbol=$(echo $img | cut -c 1 | tr '[a-z]' '[A-Z]')
-		unmatched=
-
-		while read -r line
-		do
-			tmp=
-			match=
-
-			# "# CONFIG_FOO is not set" should not be divided.
-			# Use "%" as a separator, instead of a whitespace.
-			# "%" is unlikely to appear in defconfig context.
-			save_IFS=$IFS
-			IFS=%
-			# coalesce common lines together
-			for i in $output_lines
-			do
-				case "$i" in
-				[+A-Z]*:$line)
-					tmp="$tmp%$unmatched"
-					i=$(echo "$i" | \
-					    sed -e "s/^\([^:]*\)/\1$symbol/")
-					tmp="$tmp%$i"
-					match=1
-					;;
-				$line)
-					tmp="$tmp%$unmatched"
-					tmp="$tmp%+$symbol:$i"
-					match=1
-					;;
-				*)
-					tmp="$tmp%$i"
-					;;
-				esac
-			done
-
-			# Restore the default separator for the outer for loop.
-			IFS=$save_IFS
-
-			if [ "$match" ]; then
-				output_lines="$tmp"
-				unmatched=
-			else
-				unmatched="$unmatched%$symbol:$line"
-			fi
-		done < defconfig
-
-		output_lines="$output_lines%$unmatched"
-	done
-
-	rm -f defconfig
-	touch defconfig
-
-	save_IFS=$IFS
-	IFS=%
-
-	for line in $output_lines
-	do
-		case "$line" in
-		"")
-			# do not output blank lines
-			;;
-		*)
-			echo $line >> defconfig
-			;;
-		esac
-	done
-
-	IFS=$save_IFS
-}
-
-# Some sanity checks before running "make <objdir>/<target>",
-# where <objdir> should be either "spl" or "tpl".
-# Doing "make spl/menuconfig" etc. on a non-SPL board makes no sense.
-# It should be allowed only when ".config" exists and "CONFIG_SPL" is enabled.
-#
-# Usage:
-#   check_enabled_sumbimage <objdir>/<target> <objdir>
-check_enabled_subimage () {
-
-	case $2 in
-	spl|tpl) ;;
-	*)
-		echo >&2 "***"
-		echo >&2 "*** \"make $1\" is not supported."
-		echo >&2 "***"
-		exit 1
-		;;
-	esac
-	test -r "$KCONFIG_CONFIG" && get_enabled_subimages | grep -q $2 || {
-		config=CONFIG_$(echo $2 | tr '[a-z]' '[A-Z]')
-
-		echo >&2 "***"
-		echo >&2 "*** Create \"$KCONFIG_CONFIG\" with \"$config\" enabled"
-		echo >&2 "*** before \"make $1\"."
-		echo >&2 "***"
-		exit 1
-	}
-}
-
-# Usage:
-#   do_others <objdir>/<target>
-# The field "<objdir>/" is typically empy, "spl/", "tpl/" for Normal, SPL, TPL,
-# respectively.
-# The field "<target>" is a configuration target such as "config",
-# "menuconfig", etc.
 do_others () {
-	target=${1##*/}
-
-	if [ "$target" = "$1" ]; then
-		objdir=
-	else
-		objdir=${1%/*}
-		check_enabled_subimage $1 $objdir
-
-		if [ -f "$objdir/$KCONFIG_CONFIG" ]; then
-			timestamp_before=$(stat --printf="%Y" \
-						$objdir/$KCONFIG_CONFIG)
-		fi
-	fi
-
-	run_make_config $target $objdir
-
-	if [ "$timestamp_before" -a -f "$objdir/$KCONFIG_CONFIG" ]; then
-		timestamp_after=$(stat --printf="%Y" $objdir/$KCONFIG_CONFIG)
-
-		if [ "$timestamp_after" -gt "$timestamp_before" ]; then
-			# $objdir/.config has been updated.
-			# touch .config to invoke "make silentoldconfig"
-			touch $KCONFIG_CONFIG
-		fi
-	fi
+	run_make_config $1
 }
 
 progname=$(basename $0)
@@ -340,10 +97,6 @@ case $target in
 	do_board_defconfig ${target%_config}_defconfig;;
 silentoldconfig)
 	do_silentoldconfig;;
-defconfig)
-	do_defconfig;;
-savedefconfig)
-	do_savedefconfig;;
 *)
 	do_others $target;;
 esac