kconfig: switch to Kconfig

This commit enables Kconfig.
Going forward, we use Kconfig for the board configuration.
mkconfig will never be used. Nor will include/config.mk be generated.

Kconfig must be adjusted for U-Boot because our situation is
a little more complicated than Linux Kernel.
We have to generate multiple boot images (Normal, SPL, TPL)
from one source tree.
Each image needs its own configuration input.

Usage:

Run "make <board>_defconfig" to do the board configuration.

It will create the .config file and additionally spl/.config, tpl/.config
if SPL, TPL is enabled, respectively.

You can use "make config", "make menuconfig" etc. to create
a new .config or modify the existing one.

Use "make spl/config", "make spl/menuconfig" etc. for spl/.config
and do likewise for tpl/.config file.

The generic syntax of configuration targets for SPL, TPL is:

  <target_image>/<config_command>

Here, <target_image> is either 'spl' or 'tpl'
      <config_command> is 'config', 'menuconfig', 'xconfig', etc.

When the configuration is done, run "make".
(Or "make <board>_defconfig all" will do the configuration and build
in one time.)

For futher information of how Kconfig works in U-Boot,
please read the comment block of scripts/multiconfig.py.

By the way, there is another item worth remarking here:
coexistence of Kconfig and board herder files.

Prior to Kconfig, we used C headers to define a set of configs.

We expect a very long term to migrate from C headers to Kconfig.
Two different infractructure must coexist in the interim.

In our former configuration scheme, include/autoconf.mk was generated
for use in makefiles.
It is still generated under include/, spl/include/, tpl/include/ directory
for the Normal, SPL, TPL image, respectively.

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

1 files changed, 100 insertions, 0 deletions

diff --git a/scripts/Makefile.autoconf b/scripts/Makefile.autoconf
new file mode 100644
index 00000000000..44c39970f30
--- /dev/null
+++ b/scripts/Makefile.autoconf
@@ -0,0 +1,100 @@
+# This helper makefile is used for creating
+#  - symbolic links (arch/$ARCH/include/asm/arch
+#  - include/autoconf.mk, {spl,tpl}/include/autoconf.mk
+#  - include/config.h
+#
+# When our migration to Kconfig is done
+# (= 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 $(obj)/config/auto.conf
+
+include scripts/Kbuild.include
+
+# Need to define CC and CPP again here in case the top Makefile did not
+# include config.mk.  Some architectures expect CROSS_COMPILE to be defined
+# in arch/$(ARCH)/config.mk
+CC		= $(CROSS_COMPILE)gcc
+CPP		= $(CC) -E
+
+include config.mk
+
+UBOOTINCLUDE    := \
+		-I$(obj) \
+		-Iinclude \
+		$(if $(KBUILD_SRC), -I$(srctree)/include) \
+		-I$(srctree)/arch/$(ARCH)/include \
+		-include $(srctree)/include/linux/kconfig.h
+
+c_flags := $(KBUILD_CFLAGS) $(KBUILD_CPPFLAGS) $(PLATFORM_CPPFLAGS) \
+					$(UBOOTINCLUDE) $(NOSTDINC_FLAGS)
+
+quiet_cmd_autoconf_dep = GEN     $@
+      cmd_autoconf_dep = $(CC) -x c -DDO_DEPS_ONLY -M -MP $(c_flags) \
+	-MQ include/config/auto.conf $(srctree)/include/common.h > $@ || {	\
+		rm $@; false;							\
+	}
+include/autoconf.mk.dep: FORCE
+	$(call cmd,autoconf_dep)
+
+# We are migrating from board headers to Kconfig little by little.
+# In the interim, we use both of
+#  - include/config/auto.conf (generated by Kconfig)
+#  - include/autoconf.mk      (used in the U-Boot conventional configuration)
+# The following rule creates autoconf.mk
+# include/config/auto.conf is grepped in order to avoid duplication of the
+# same CONFIG macros
+quiet_cmd_autoconf = GEN     $@
+      cmd_autoconf = \
+	$(CPP) $(c_flags) -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 "$${line%=*}=" $(obj)/config/auto.conf; then	\
+				echo "$$line";						\
+			fi								\
+		done > $@;								\
+		rm $@.tmp;								\
+	} || {										\
+		rm $@.tmp; false;							\
+	}
+
+$(obj)/autoconf.mk: FORCE
+	$(call cmd,autoconf)
+
+include/autoconf.mk include/autoconf.mk.dep: include/config.h
+
+# include/config.h
+# Prior to Kconfig, it was generated by mkconfig. Now it is created here.
+define filechk_config_h
+	(echo "/* Automatically generated - do not edit */";		\
+	for i in $$(echo $(CONFIG_SYS_EXTRA_OPTIONS) | sed 's/,/ /g'); do \
+		echo \#define CONFIG_$$i				\
+		| sed '/=/ {s/=/	/;q; } ; { s/$$/	1/; }'; \
+	done;								\
+	echo \#define CONFIG_BOARDDIR board/$(if $(VENDOR),$(VENDOR)/)$(BOARD);\
+	echo \#include \<config_cmd_defaults.h\>;			\
+	echo \#include \<config_defaults.h\>;				\
+	echo \#include \<configs/$(CONFIG_SYS_CONFIG_NAME).h\>;		\
+	echo \#include \<asm/config.h\>;				\
+	echo \#include \<config_fallbacks.h\>;				\
+	echo \#include \<config_uncmd_spl.h\>; )
+endef
+
+include/config.h: scripts/Makefile.autoconf create_symlink FORCE
+	$(call filechk,config_h)
+
+# symbolic links
+PHONY += create_symlink
+create_symlink:
+ifneq ($(KBUILD_SRC),)
+	$(Q)mkdir -p include/asm
+endif
+	$(Q)ln -fsn $(srctree)/arch/$(ARCH)/include/asm/arch-$(if $(SOC),$(SOC),$(CPU)) \
+		$(if $(KBUILD_SRC),,arch/$(ARCH)/)include/asm/arch
+
+PHONY += FORCE
+FORCE:
+
+.PHONY: $(PHONY)