Commit graph

540 commits

Author SHA1 Message Date
Daniel Schwierzeck
92bca3981d get_maintainer.pl: import script from linux 3.15
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
2014-08-09 11:17:05 -04:00
Masahiro Yamada
51148790f2 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>
2014-07-30 08:48:03 -04:00
Masahiro Yamada
0a9064fb47 kconfig: import Kconfig files from Linux 3.16-rc7
Import
  - scripts/kconfig/*
  - include/linux/kconfig.h
from Linux 3.16-rc7.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2014-07-30 08:47:46 -04:00
Masahiro Yamada
b68a406263 scripts: add scripts/show-gnu-make to get GNU Make command name
U-Boot is expected to be built on various platforms.

We should keep in mind that the command 'make' is not always GNU Make,
while all the makefiles are written for GNU Make.

For example, on Linux, people generally do:

  make <board>_config; make

But FreeBSD folks do

  gmake <board>_config; gmake

(The command 'make' on FreeBSD is BSD Make, not GNU Make)

It is not a good idea to hard-code the command name 'make'
in MAKEALL or buildman.

They should call this helper script and get the command name
for GNU Make.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-07-29 11:48:36 -04:00
Masahiro Yamada
45765eeda2 scripts: add mailmapper, a tool to create/update mailmap file
This tool helps to create/update the mailmap file.

It runs 'git shortlog' internally and searches differently spelled author
names which share the same email address. The author name with the most
commits is asuumed to be a canonical real name. If the number of commits
from the cananonical name is equal to or greater than 'MIN_COMMITS' (=50),
the entry for the cananical name will be output. ('MIN_COMMITS' is used
here because we do not want to create a fat mailmap by adding every author
with only a few commits.)

If there exists a mailmap file specified by the mailmap.file configuration
options or '.mailmap' at the toplevel of the repository, it is used as
a base file.

The base file and the newly added entries are merged together and sorted
alphabetically (but the comment block is kept untouched), and then printed
to standard output.

 Usage
 -----

  scripts/mailmapper

prints the mailmapping to standard output.

  scripts/mailmapper > tmp; mv tmp .mailmap

will be useful for updating '.mailmap' file.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-07-22 07:44:27 -04:00
Tom Rini
39b6d07fd7 Merge branch 'master' of git://git.denx.de/u-boot-dm 2014-06-20 20:03:51 -04:00
Simon Glass
5957ac2a9f Makefile: Support include files for .dts files
Linux supports this, and if we are to have compatible device tree files,
U-Boot should also.

Avoid giving the device tree files access to U-Boot's include/ directory.
Only include/dt-bindings is accessible.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-06-20 11:55:03 -06:00
Masahiro Yamada
45f0ad9545 cosmetic: kbuild: clean-up coding style (sync with Linux 3.16-rc1)
Import the following trivial commits from Linux v3.16-rc1:

 bb66fc6 kbuild: trivial - use tabs for code indent where possible
 7eb6e34 kbuild: trivial - remove trailing empty lines
 3fbb43d kbuild: trivial - fix comment block indent
 38385f8 kbuild: trivial - remove trailing spaces

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-06-20 11:56:26 -04:00
Masahiro Yamada
c71630838d kbuild: move spl/Makefile to scripts/Makefile.spl
All files under spl/ and tpl/ are generated during the build process
except spl/Makefile.

We can simplify clean-rule and git-ignore by moving spl/Makefile
to somewhere else.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-06-11 16:27:05 -04:00
Masahiro Yamada
ba8dd7755e kbuild: move cmd_mkimage to scripts/Makefile.lib
Because cmd_mkimage is used in various subdirectories,
it seems reasonable to define it in scripts/Makefile.lib.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-06-05 17:01:58 -04:00
Masahiro Yamada
598e2d3388 kbuild: sync with Linux Kernel v3.15-rc1
This commit imports Kbuild-related updates
from v3.14 to v3.15-rc1.

 - commit 3d3d6b8474204b6819688c9800774d52d370a538
    kbuild: LLVMLinux: Adapt warnings for compilation with clang
 - commit 61163efae02040f66a95c8ed17f4407951ba58fa
    kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
 - commit 79192ca8ebd9a25c583aa46024a250fef1e7766f
    scripts: objdiff: detect object code changes between two commits
 - commit 1c9e70a55b088d97a59241744fe459409d0c3582
    kbuild: create a build directory automatically for out-of-tree build
 - commit a03fcb50e816a69acffb13b5e56db75063aeba8a
    kbuild: remove redundant '.*.cmd' pattern from make distclean
 - commit 13338935f1574a2dcd1c891461b0dcc42f8cff42
    kbuild: move "quote" to Kbuild.include to be consistent
 - commit bfdfaeae500a3b194b73b01e92a8034791a58b7f
    kbuild: specify build_docproc as a phony target
 - commit f4d4ffc03efc864645b990e1d579bbe1b8e358a4
    kbuild: dtbs_install: new make target
 - commit 1e64ff42ea3d8d2fc8aa71f9717b3c1cb6c2f893
    Kbuild, lto: Disable LTO for asm-offsets.c
 - commit ccbef1674a1579842c7dbdf554efca85d2cd245a
    Kbuild, lto: add ld-version and ld-ifversion macros
 - commit ae63b2d7bdd9bd66b88843be0daf8e37d8f0b574
    scripts/tags.sh: Ignore *.mod.c
 - commit e36aaea28972c57a32a3ba5365e61633739719b9
    kbuild: Fix silent builds with make-4

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-04-18 11:43:36 -04:00
Masahiro Yamada
6bd04bb487 kbuild: fix bugs in cleaning targets
"make clean", "make clobber", "make mrproper" and "make distclean"
missed to clean-up some files when they were run with
O=<some_dir> option.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reported-by: Wolfgang Denk <wd@denx.de>
2014-03-28 15:06:32 -04:00
Masahiro Yamada
026f9cf24f kbuild: improve Kbuild speed
Kbuild brought about many advantages for us but a significant
performance regression was reported by Simon Glass.

After some discussions and analysis, it turned out
its main cause is in $(call cc-option,...).

Historically, U-Boot parses all config.mk
(arch/*/config.mk and board/*/config.mk)
every time descending into subdirectories.
That means cc-options are evaluated over and over again.

$(call cc-option,...) is useful but costly.
So we want to evaluate them only in ./Makefile
and spl/Makefile and export compiler flags.

This commit changes the build system as follows:

  - Modify scripts/Makefile.build to not include config.mk
    Instead, add $(PLATFORM_CPPFLAGS) to asflags-y, ccflags-y,
    cppflags-y.

  - Export many variables
    Going forward, Kbuild will not parse config.mk files
    when it descends into subdirectories.
    If we want to set variables in config.mk and use them
    in subdirectories, they must be exported.

    This is the list of variables to get exported:
      PLATFORM_CPPFLAGS
      CPUDIR
      BOARDDIR
      OBJCOPYFLAGS
      LDFLAGS
      LDFLAGS_FINAL
        (used in nand_spl/board/*/*/Makefile)
      CONFIG_STANDALONE_LOAD_ADDR
        (used in examples/standalone/Makefile)
      SYM_PREFIX
        (used in examples/standalone/Makefile)
      RELFLAGS
        (used in examples/standalone/Makefile)

  - Delete CPPFLAGS
    This variable has been replaced with PLATFORM_CPPFLAGS

  - Copy gcclibdir from example/standalone/Makefile
    to arch/sparc/config.mk
    The reference in CONFIG_STANDALONE_LOAD_ADDR must be
    resolved before it is exported.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reported-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org> [on Sandbox]
Tested-by: Stephen Warren <swarren@nvidia.com> [on Tegra]
2014-03-07 10:59:06 -05:00
Tom Rini
6b9709d914 scripts: update checkpatch.pl to latest upstream version
Update to v3.14-rc4's version of checkpatch.pl.  In doing so we drop the
changes to top_of_kernel_tree() as we pass in --no-tree and drop our
changes about MAINTAINERS as that's for reporting checkpatch.pl problems
itself (and upstream has said they'll reword this section to be
clearer).

Signed-off-by: Tom Rini <trini@ti.com>
2014-03-04 12:15:30 -05:00
Tom Rini
eeb72e6761 Merge branch 'master' of git://git.denx.de/u-boot-arm
Conflicts:
	arch/arm/cpu/armv7/config.mk
	board/ti/am43xx/mux.c
	include/configs/am43xx_evm.h

Signed-off-by: Tom Rini <trini@ti.com>
2014-02-26 16:49:58 -05:00
Tom Rini
f503cc49a5 checkpatch.pl: Add warning for new __packed additions
While there are valid reasons to use __packed, often the answer is that
you should be doing something else here instead.

Signed-off-by: Tom Rini <trini@ti.com>
2014-02-26 21:19:29 +01:00
Masahiro Yamada
7424145f30 kbuild: consolidate version and timestamp headers generation
- Generate include/generated/{timestamp.h, version.h}
   more simply by using filechk rule.

 - Add $(UBOOTRELEASE) variable and re-write u-boot.imx rule
   more simply.

 - Rename U_BOOT_VERSION in Makefile to UBOOTVERSION

   Before this commit, the same variable name, "U_BOOT_VERSION"
   was used for two different strings.

   One of them was defined in Makefile.
   It takes the form like "2014.01-rc1" and used in
   makefiles and script files.

   The other is defined in include/generated/version.h
   It takes the form like "U-Boot 2014.01-rc1-00010-gbe6d426-dirty"
   and used in C and Aseembler.

   It is confusing when grepping the source tree. So, this commit
   renames the former to UBOOTVERSION.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-25 11:01:28 -05:00
Masahiro Yamada
5b1f1f4aff Makefile: add a new script to check -fstack-usage support
If -fstack-usage option is given to crosstools
that do not support it, gcc displays a warning message
but still exits with status 0.

This means we can not rely on $(call cc-option,...)
to detect if -fstack-usage option is supported or not.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-25 07:51:08 -05:00
Masahiro Yamada
5ab502cb89 dts: move device tree sources to arch/$(ARCH)/dts/
Unlike Linux Kernel, U-Boot historically had *.dts files under
board/$(VENDOR)/dts/ and *.dtsi files under arch/$(ARCH)/dts/.

I think arch/$(ARCH)/dts dicretory is a better location
to store both *.dts and *.dtsi files.

For example, before this commit, board/xilinx/dts directory
had both Microblaze dts (microblaze-generic.dts) and
ARM dts (zynq-*.dts), which are totally unrelated.

This commit moves *.dts to arch/$(ARCH)/dts/ directories,
allowing us to describe nicely mutiple DTBs generation in the next commit.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:10:05 -05:00
Masahiro Yamada
6ab6b2afa0 dts: re-write dts/Makefile more simply with Kbuild
Useful rules in scripts/Makefile.lib allows us to easily
generate a device tree blob and wrap it in assembly code.

We do not need to parse a linker script to get output format and arch.

This commit deletes ./u-boot.dtb since it is a copy of dts/dt.dtb.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:10:05 -05:00
Masahiro Yamada
ced032989a kernel-doc: update kernel-doc related files to Linux v3.13
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
2014-02-19 11:10:04 -05:00
Masahiro Yamada
8fac9c7b7d kernel-doc: move kernel-doc tools to scripts/
tools/kernel-doc/docproc.c and tools/kernel-doc/kernel-doc are
files imported from Linux Kernel.

They originally resided under scripts/ directory in Linux Kernel.

This commit moves them to the original location.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
2014-02-19 11:10:04 -05:00
Masahiro Yamada
9a368d0f58 kbuild: Do not generate .*.su files at the top directory
Without this workaround, you will see a lot of ".*.su" files
at the top directory after building with a compiler
which supports "-fstack-usage" option.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:10:04 -05:00
Masahiro Yamada
efcf861931 kbuild: use scripts/Makefile.clean
This commit refactors cleaning targets such as
clean, clobber, mrpropper, distclean
with scripts/Makefile.clean.

By using scripts/Makefile.clean, we can recursively descend
into subdirectories and delete generated files there.

We do not need add a big list of generated files
to the "clean" target.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:10:04 -05:00
Masahiro Yamada
01072b44db kbuild: move include directives of board configuration files
This commit changes the location of include directives
of board configuration files.

The purpose of this change is:
 - Slim down $(TOPDIR)/config.mk
 - Prevent $(TOPDIR)/Makefile from including the same
    configuration file twice
 - Do not include include/config.mk multiple times
    because ARCH, CPU, BOARD, VENDOR, SOC are exported

Before this commit:

 - include/autoconf.mk was included from $(TOPDIR)/Makefile
   and $(TOPDIR)/config.mk
   (This means $(TOPDIR)/Makefile included include/autoconf.mk twice)

 - include/{spl,tpl}-autoconf.mk was included from $(TOPDIR)/config.mk

 - include/config.mk was included from $(TOPDIR)/Makefile
   and $(TOPDIR)/config.mk
   (This means $(TOPDIR)/Makefile included include/config.mk twice)

After this commit:

 - include/autoconf.mk is included from $(TOPDIR)/Makefile
   and $(TOPDIR)/scripts/Makefile.build

 - include/{spl,tpl}-autoconf.mk is included from $(TOPDIR)/spl/Makefile
   and $(TOPDIR)/scripts/Makefile.build

 - include/config.mk is included from $(TOPDIR)/config.mk and
   $(TOPDIR)/spl/Makefile

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:51 -05:00
Masahiro Yamada
f2d293d0f8 kbuild: delete temporary build scripts
We had switched to Kbuild.
We do not need old build scripts any more.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
6825a95b0b kbuild: use Linux Kernel build scripts
Now we are ready to switch over to real Kbuild.

This commit disables temporary scripts:
  scripts/{Makefile.build.tmp, Makefile.host.tmp}
and enables real Kbuild scripts:
  scripts/{Makefile.build,Makefile.host,Makefile.lib}.

This switch is triggered by the line in scripts/Kbuild.include
  -build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build.tmp obj
  +build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj

We need to adjust some build scripts for U-Boot.
But smaller amount of modification is preferable.

Additionally, we need to fix compiler flags which are
locally added or removed.

In Kbuild, it is not allowed to change CFLAGS locally.
Instead, ccflags-y, asflags-y, cppflags-y,
CFLAGS_$(basetarget).o, CFLAGS_REMOVE_$(basetarget).o
are prepared for that purpose.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
22433fc54b kbuild: import more build scripts from Linux v3.13 tag
This commit imports build scripts from Linux Kernel v3.13
as they are.

I know they include some trailing spaces
but I am intentionally keeping them untouched.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
ec626f1139 Makefile: rename scripts/Makefile.build to scripts/Makefile.build.tmp
Some build scripts including scripts/Makefile.build
will be imported from Linux Kernel in the next commit.
We need to adjust them for U-Boot in the following commits.

To make it easier for reviewers to track the modification,
this commit renames scripts/Makefile.build to
scripts/Makefile.build.tmp beforehand.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
9e4140329e 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>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
bf4b3de101 kbuild: Use Kbuild.include
This commit adjusts some files to use Kbuild.include.

 - Use cc-option defined in Kbuild.include
    (Delete cc-option in config.mk)
 - Use cc-version defined in
    (Delete cc-version in config.mk)
 - Move binutils-version and dtc-version to Kbuild.include
     by analogy to cc-version

This commit also adds srctree (same as SRCTREE)
to use Kbuild scripts.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
ceec4c8746 kbuild: import Kbuild.include from linux v3.13 tag
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
5651ccffa4 Makfile: move suffix rules to Makefile.build
This commit moves suffix rules from config.mk
to scripts/Makefile.build, which will allow us
to switch smoothly to real Kbuild.

Note1:
post/lib_powerpc/fpu/Makefile has
its own rule to compile C sources.
We need to tweak it to keep the same behavior.

Note2:
There are two file2 with the same name:
arch/arm/lib/crt0.S and eamples/api/crt0.S.
To keep the same build behavior,
examples/api/Makefile also has to be treaked.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:50 -05:00
Masahiro Yamada
4a20df395d examples: Use scripts/Makefile.build
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:07:49 -05:00
Masahiro Yamada
ad71fa9971 Makefile.host.tmp: add a new script to refactor tools
This commit adds scripts/Makefile.host.tmp which will
be used in the next commit to convert makefiles
under tools/ directory to Kbuild style.

Notice this script, scripts/Makefile.host.tmp
is temporary.

When switching over to real Kbuild,
it will be replaced with scripts/Makefile.host of Linux Kernel.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-02-19 11:05:13 -05:00
Masahiro Yamada
dd88ab325c Makefile: Move some scripts imported from Linux
We have some scripts imported from Linux Kernel:
setlocalversion, checkstack.pl, checkpatch.pl, cleanpatch

They are located under tools/ directory in U-Boot now.
But they were originally located under scripts/ directory
in Linux Kernel.

This commit moves them to the original location.

It is true that binutils-version.sh and dtc-version.sh
do not originate in Linux Kernel, but they should
be moved by analogy to gcc-version.sh.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2013-12-13 09:18:45 -05:00
Masahiro Yamada
e5c5301f14 Makefile: make directories by Makefile.build
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2013-11-17 14:11:31 -05:00
Masahiro Yamada
3fdf5c8e94 Makefile: abolish COBJS, SOBJS, etc.
The support for COBJS, COBJS-y, SOBJS, SOBJS-y, GLCOBJS, GLSOBJS
from scripts/Makefile.build.
Going forward we need to use Kbuild style consistently.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2013-11-17 14:11:30 -05:00
Masahiro Yamada
ac7e735322 Makefile: support descending down to subdirectories
This patch tweaks scripts/Makefile.build to allow
the build system to descend into subdirectories like Kbuild.

To use this feature, use "obj-y += foo/" syntax.

Example:
    obj-$(CONFIG_FOO) += foo/

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
2013-10-31 13:26:44 -04:00
Masahiro Yamada
ce28d7ac6d Makefile: prepare for using Kbuild-style Makefile
Every makefile in sub directories has common lines
at the top and the bottom.
This commit pushes the common parts into script/Makefile.build.

Going forward sub-makefiles only need to describe this part:

    COBJS := ...
    COBJS += ...
    SOBJS := ...

But using obj-y is preferable to prepare for switching to Kbuild.

The conventional (non-Kbuild) Makefile style is still supported.
This is achieved by greping the Makefile before entering into it.
U-Boot conventional sub makefiles always include some other makefiles.
So the build system searches a line beginning with "include" keyword
in the makefile in order to distinguish which style it is.
If the Makefile include a "include" line, we assume it is a conventional
U-Boot style. Otherwise, it is treated as a Kbuild-style makefile.

With this tweak, we can switch sub-makefiles
from U-Boot style to Kbuild style little by little.

obj-y := foo/
syntax (descending into the sub directory) is not supportd yet.
It will be implemented in the upcomming commit.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@ti.com>
2013-10-31 12:53:39 -04:00