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>

Make sunxi's FEL code fit with the normal U-Boot boot sequence instead of
creating its own. There are some #ifdefs required in start.S. Future work
will hopefully remove these.

This series is available at u-boot-dm, branch sunxi-working.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Luka Perkov <luka.perkov@sartura.hr>

Introduce a Makefile under arch/$ARCH/ and include it in the
top Makefile (similar to Linux kernel). This allows further
refactoringi like moving architecture-specific code out of global
makefiles, deprecating config variables (CPU, CPUDIR, SOC) or
deprecating arch/$ARCH/config.mk.

In contrary to Linux kernel, U-Boot defines the ARCH variable by
Kconfig, thus the arch Makefile can only included conditionally
after the top config.mk.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Acked-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

Conflicts:
	drivers/serial/serial-uclass.c

Signed-off-by: Tom Rini <trini@ti.com>

SPL should not reference CONFIG_CMD_NAND to decide whether or not
it should build drivers/mtd/nand.  CONFIG_CMD_NAND should be only
used to select the NAND utility command on the command parser.

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

Some CPUs of some architectures have SOC directories.
At present, the build system directly descends into SOC directories
from the top Makefile, but it should generally descend into each
directory from its parent directory.

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

When enabled, set up driver model for SPL. This allows SPL to use the same
drivers as the main U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Tom Rini <trini@ti.com>

generate the boot.bin file for all atmel SoC (arm920, arm926, armv7)

Signed-off-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Andreas Bießmann <andreas.devel@googlemail.com>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
[fix subject]
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>

cmd_u-boot-spl includes $(PLATFORM_LIBS) which changes
when CONFIG_USE_PRIVATE_GCC is updated.  The u-boot-spl image
should be re-linked if any prerequisite is newer than it
or the command line has changed.
$(call, if_changed,...) should be used instead of $(call cmd,...).

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