u-boot.git/scripts/Makefile.build, branch v2020.01-rc2

kbuild: add .SECONDARY special target to scripts/Kbuild.include

2019-01-15T20:28:53+00:00

Based on the following Linux commits:

 - 54a702f70589 ("kbuild: mark $(targets) as .SECONDARY and remove
   .PRECIOUS markers")

 - 8e9b61b293d9 ("kbuild: move .SECONDARY special target to
   Kbuild.include")

GNU Make automatically deletes intermediate files that are updated
in a chain of pattern rules.

Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
Example 2) %.o <- %.c <- %.c_shipped

A couple of makefiles mark such targets as .PRECIOUS to prevent Make
from deleting them, but the correct way is to use .SECONDARY.

  .SECONDARY
    Prerequisites of this special target are treated as intermediate
    files but are never automatically deleted.

  .PRECIOUS
    When make is interrupted during execution, it may delete the target
    file it is updating if the file was modified since make started.
    If you mark the file as precious, make will never delete the file
    if interrupted.

Both can avoid deletion of intermediate files, but the difference is
the behavior when Make is interrupted; .SECONDARY deletes the target,
but .PRECIOUS does not.

The use of .PRECIOUS is relatively rare since we do not want to keep
partially constructed (possibly corrupted) targets.

.SECONDARY with no prerequisites causes all targets to be treated as
secondary. This agrees the policy of Kbuild.

scripts/Kbuild.include seems a suitable place to add it because it is
included from almost all sub-makes.

Signed-off-by: Masahiro Yamada

kconfig: re-sync with Linux 4.17-rc4

2018-05-31T12:53:11+00:00

Align Kconfig to Linux 4.17-rc4 with minimal impact on non-kconfig files.

Previous Kconfig sync was done by commit bf7ab1e70fd762 ("kconfig:
re-sync with Linux 4.10") and it achieved almost perfect alignment with
a few (intended) exceptions, caused by below U-boot commits:

[A] v2015.04 5f9eb2207500 ("kbuild: remove scripts/multiconfig.sh")
[B] v2015.07 20c20826efab ("Kconfig: Enable usage of escape char '\' in string values")
[C] v2016.01 da58dec86616 ("Various Makefiles: Add SPDX-License-Identifier tags")
[D] v2016.03 5b8031ccb4ed ("Add more SPDX-License-Identifier tags")
[E] v2016.03 192bc6948b02 ("Fix GCC format-security errors and convert sprintfs.")

Here is the list of Kconfig commits which followed the v4.10 alignment:

[F] v2018.01 0931ed3c0d0f ("kconfig/symbol.c: use correct pointer type argument for sizeof")
[G] v2018.03 1414e09b4f25 ("kconfig: revert change that was not needed for -Wformat-security")
[H] v2018.05 83d290c56fab ("SPDX: Convert all of our single license tags to Linux Kernel style")

Commit [F] was subsequently applied to Linux kernel as commit [I]
with the same patch id, so it won't contribute to further misalignment.

[I] v4.15-rc1 88127dae6ed9 ("kconfig/symbol.c: use correct pointer type argument for sizeof")

Commit [G] is a Kconfig-specific revert of commit [E].
Commit [H] relocated and reformatted the license doing no functional change.

In summary, the only functional change that makes U-boot Kconfig
diverge from Linux Kconfig is commit [B]. After a brief analysis,
the purpose of [B] seems to be placing "\n" literals in string symbols
like CONFIG_AUTOBOOT_PROMPT="autoboot in %d seconds\n" in order to pass
them directly to printf and expect correct output at runtime. Currently,
Linux doesn't seem to have this requirement, so for the moment [B] looks
like a U-boot specific feature/fix. From point of view of further Kconfig
alignment and backporting efforts, it is highly desired that commits
like [B] are propagated to Linux and any Kconfig fixes/features are
contributed to Linux kernel first. This specific Kconfig re-sync just
keeps [B] in place.

Contrary to 4.10 Kconfig re-sync (which achieves zero non-kconfig
changes), 4.17-rc4 re-sync does some amount of updates in Kbuild
(striving to keep them at minimum), due to a number of reasons:
* Kbuild is affected by the removal of Kconfig "*shipped" files and now
  requires flex and bison pre-installed on the host.
* PYTHON{2,3} variables are defined in top-level Makefile as
  prerequisite for running the newly developed Kconfig unit tests.
* silentoldconfig becomes an "internal implementation detail" deprecated
  for external use, being renamed to syncconfig.

The exact non-kconfig files touched by this commit are:

$ git show --format="" --stat -- ':!scripts/kconfig'
 .gitignore             |  2 ++
 Makefile               |  9 +++++++--
 scripts/Makefile.build | 11 +++++++++++
 scripts/Makefile.lib   | 41 ++++++++++++-----------------------------

The imported Linux commits touching the above files are:

c054be10ffdbd5   ("remove gperf left-overs from build system")
73a4f6dbe70a1b   ("kbuild: add LEX and YACC variables")
033dba2ec06c47   ("kbuild: prepare to remove C files pre-generated by flex and bison")
eea199b445f64c   ("kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX")
e71de5ee08dcb0   ("kbuild: remove remaining use of undefined YACC_PREFIX")
d59fbbd09d5d6b   ("kbuild: replace hardcoded bison in cmd_bison_h with $(YACC)")
911a91c39cabcb H ("kconfig: rename silentoldconfig to syncconfig")
59889300274569   (".gitignore: move *.lex.c *.tab.[ch] patterns to the top-level .gitignore")
9a8dfb394c0467   ("kbuild: clean up *.lex.c and *.tab.[ch] patterns from top-level Makefile")
833e622459432e H ("genksyms: generate lexer and parser during build instead of shipping")
b23d1a241f4eb4 H ("kbuild: add %.lex.c and %.tab.[ch] to 'targets' automatically")
e9781b52d4e0e3 H ("kbuild: add PYTHON2 and PYTHON3 variables")

The commits marked with 'H' are assessed as "hard" (build will fail)
prerequisites and the rest of them are assessed as "soft" prerequisites
for the re-sync. In spite of relatively high number of non-H commits,
they belong to this Kconfig update topic-wise and decrease the number of
cherry pick conflicts for many commits in this series. Additional effort
can be put in eliminating the soft prerequisites, if really needed.

The commits which contributed to this Kconfig re-sync are listed below.
Whenever a conflict resolution has been performed (mostly by hand, but
sometimes automatically by git), it is revealed by the '!' sign in the
second column, which means a patch id mismatch between Linux and U-boot
commits:

9be3213b14d44f   ("gconfig: remove misleading parentheses around a condition")
ff85a1a80e0034   ("kconfig: Check for libncurses before menuconfig")
ad8181060788c8   ("kconfig: fix sparse warnings in nconfig")
cb77f0d623ff33 ! ("scripts: Switch to more portable Perl shebang")
bb3290d91695bb ! ("Remove gperf usage from toolchain")
c054be10ffdbd5   ("remove gperf left-overs from build system")
b24413180f5600 ! ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license")
9059a3493efea6 ! ("kconfig: fix relational operators for bool and tristate symbols")
2c37e08464a850   ("kconfig: Warn if choice default is not in choice")
33ca1a24866373   ("kconfig: Document the 'menu' struct")
52aede4ba5efd1   ("kconfig: Document the 'symbol' struct")
c873443430ebd1   ("kconfig: Sync zconf.y with zconf.tab.c_shipped")
9a826842ff2fbd   ("kconfig: Rename menu_check_dep() to rewrite_m()")
fa8cedaef814ce   ("kconfig: Clarify expression rewriting")
f77850d3fe0c96   ("kconfig: Clean up modules handling and fix crash")
e3b03bf29d6b99   ("kconfig: display recursive dependency resolution hint just once")
73a4f6dbe70a1b ! ("kbuild: add LEX and YACC variables")
033dba2ec06c47 ! ("kbuild: prepare to remove C files pre-generated by flex and bison")
29c833061c1d8c   ("kconfig: generate lexer and parser during build instead of shipping")
26e47a3c11a25c   ("kconfig: Don't leak symbol names during parsing")
24161a6711c945   ("kconfig: Don't leak 'source' filenames during parsing")
bc28fe1d5ede88   ("kconfig: Don't leak 'option' arguments during parsing")
0724a7c32a54e3   ("kconfig: Don't leak main menus during parsing")
ae7440ef0c8013   ("kconfig: Fix automatic menu creation mem leak")
5b1374b3b3c2fc   ("kconfig: Fix expr_free() E_NOT leak")
7cf33f88e29410   ("kconfig: Fix choice symbol expression leak")
05cccce580456d   ("kconfig: Document automatic submenu creation code")
0735f7e5def2ab   ("kconfig: Document important expression functions")
df60f4b92d3d0b   ("kconfig: Remove menu_end_entry()")
b92d804a51796b   ("kconfig: drop 'boolean' keyword")
6479f327dea60d   ("kconfig: Warn if there is more than one help text")
52e58a3caeba5d   ("kconfig: make input_mode static")
5a3dc717b3c785   ("kconfig: make xfgets() really static")
84dd95d4f87a0d   ("kconfig: make conf_unsaved a local variable of conf_read()")
765f4cdef6f80d   ("kconfig: use default 'yy' prefix for lexer and parser")
eea199b445f64c   ("kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX")
e71de5ee08dcb0   ("kbuild: remove remaining use of undefined YACC_PREFIX")
d59fbbd09d5d6b ! ("kbuild: replace hardcoded bison in cmd_bison_h with $(YACC)")
3e41ba05b6d60c   ("kconfig: Document SYMBOL_OPTIONAL logic")
d3465af60f4471   ("kconfig: Clarify choice dependency propagation")
9d1a9e8bc18bea   ("kconfig: Document 'if' flattening logic")
b53688014e3325   ("kconfig: Clarify menu and 'if' dependency propagation")
d0fd0428ecf04b   ("kconfig: fix make xconfig when gettext is missing")
312ee68752faaa   ("kconfig: announce removal of oldnoconfig if used")
1ccb27143360bd   ("kconfig: make "Selected by:" and "Implied by:" readable")
cedd55d49dee94 ! ("kconfig: Remove silentoldconfig from help and docs; fix kconfig/conf's help")
1b9eda2e4892cb   ("kconfig: Warn if help text is blank")
cb67ab2cd2b8ab   ("kconfig: do not write choice values when their dependency becomes n")
4f208f392103e8   ("kconfig: show '?' prompt even if no help text is available")
cd58a91def2acc   ("kconfig: remove 'config*' pattern from .gitignnore")
d2a04648a5dbc3   ("kconfig: remove check_stdin()")
f3ff6fb5db68bc   ("kconfig: echo stdin to stdout if either is redirected")
9e3e10c725360b   ("kconfig: send error messages to stderr")
d717f24d8c6808   ("kconfig: add xrealloc() helper")
523ca58b7db2e3   ("kconfig: remove const qualifier from sym_expand_string_value()")
cd81fc82b93fa4   ("kconfig: add xstrdup() helper")
f4bc1eefc1608e   ("kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list")
bf0bbdcf100322   ("kconfig: Don't leak choice names during parsing")
1a90ce36c6eff6   ("kconfig: Update ncurses package names for menuconfig")
5ae6fcc4bb82bd   ("kconfig: fix line number in recursive inclusion error message")
07a422bb213adb ! ("kbuild: restore autoksyms.h touch to the top Makefile")
9a47ceec543bfb   ("kconfig: clean-up reverse dependency help implementation")
d9119b5925a03b   ("kconfig: Print reverse dependencies in groups")
f467c5640c29ad   ("kconfig: only write '# CONFIG_FOO is not set' for visible symbols")
59a80b5e892dde   ("kconfig: do not call check_conf() for olddefconfig")
4bb3a5b085cd6f   ("kconfig: remove unneeded input_mode test in conf()")
99f0b6578bab44   ("kconfig: remove redundant input_mode test for check_conf() loop")
2aad9b89621386   ("kconfig: hide irrelevant sub-menus for oldconfig")
81d2bc2273052e   ("kconfig: invoke oldconfig instead of silentoldconfig from local*config")
911a91c39cabcb ! ("kconfig: rename silentoldconfig to syncconfig")
2a61625835c7c8 ! ("kconfig: remove redundant streamline_config.pl prerequisite")
022a4bf6b59dfd   ("kconfig: tests: add framework for Kconfig unit testing")
1903c511905984   ("kconfig: tests: add basic choice tests")
49ac3c0c3aa3b7   ("kconfig: tests: test automatic submenu creation")
b76960c0f6b25d   ("kconfig: tests: test if new symbols in choice are asked")
930c429a656fdb   ("kconfig: tests: check unneeded "is not set" with unmet dependency")
ee236610653ede   ("kconfig: tests: check visibility of tristate choice values in y choice")
beaaddb625400e   ("kconfig: tests: test defconfig when two choices interact")
3e4888c2e3d77d   ("kconfig: tests: test randconfig for choice in choice")
29c434f367ea7b   ("kconfig: tests: test if recursive dependencies are detected")
e2c75e7667c737   ("kconfig: tests: test if recursive inclusion is detected")
f622f827958162   ("kconfig: warn unmet direct dependency of tristate symbols selected by y")
f8f69dc0b4e070   ("kconfig: make unmet dependency warnings readable")
26561514cc9def   ("kconfig: do not include both curses.h and ncurses.h for nconfig")
32a94b8b0c3e5a   ("kconfig: remove duplicated file name and lineno of recursive inclusion")
379a8eb8eb1a55   ("kconfig: detect recursive inclusion earlier")
18492685e479fd   ("kconfig: use yylineno option instead of manual lineno increments")
59889300274569 ! (".gitignore: move *.lex.c *.tab.[ch] patterns to the top-level .gitignore")
9a8dfb394c0467 ! ("kbuild: clean up *.lex.c and *.tab.[ch] patterns from top-level Makefile")
833e622459432e ! ("genksyms: generate lexer and parser during build instead of shipping")
b23d1a241f4eb4 ! ("kbuild: add %.lex.c and %.tab.[ch] to 'targets' automatically")
17baab68d337a0   ("kconfig: extend output of 'listnewconfig'")
e9781b52d4e0e3 ! ("kbuild: add PYTHON2 and PYTHON3 variables")

The current Kconfig update generates below build-time warnings:
  YACC    scripts/dtc/dtc-parser.tab.h
scripts/dtc/dtc-parser.y: warning: 3 shift/reduce conflicts [-Wconflicts-sr]
  YACC    scripts/dtc/dtc-parser.tab.c
scripts/dtc/dtc-parser.y: warning: 3 shift/reduce conflicts [-Wconflicts-sr]

This seems to happen because the Kbuild updates apparently didn't make
room for both "*shipped"-based builds and flex/bison-based builds. A
similar problem has been reported for genksyms parser in v4.17-rc1
commit 833e622459432e ("genksyms: generate lexer and parser during build
instead of shipping"). I have figured out empirically that the warnings
are healed after updating the in-tree U-boot DTC to upstream v1.4.6-9,
same as done by Linux v4.17-rc1 commit 9130ba88464032 ("scripts/dtc:
Update to upstream version v1.4.6-9-gaadd0b65c987"). Whether fixing the
DTC-related yacc warnings should be done together with the Kconfig
re-sync, I would like to hear from community.

My testing was limited to:
- make defconfig all
- make ARCH=arm CROSS_COMPILE=aarch64-linux-gnu- r8a7795_ulcb_defconfig all
- comparing .config before and after the re-sync
- running the newly imported Kconfig unit tests as seen below:

$ make testconfig
Tested-by: Petr Vorel 

============================= test session starts =============================
scripts/kconfig/tests/auto_submenu/__init__.py::test PASSED             [  7%]
scripts/kconfig/tests/choice/__init__.py::test_oldask0 PASSED           [ 14%]
scripts/kconfig/tests/choice/__init__.py::test_oldask1 PASSED           [ 21%]
scripts/kconfig/tests/choice/__init__.py::test_allyes PASSED            [ 28%]
scripts/kconfig/tests/choice/__init__.py::test_allmod PASSED            [ 35%]
scripts/kconfig/tests/choice/__init__.py::test_allno PASSED             [ 42%]
scripts/kconfig/tests/choice/__init__.py::test_alldef PASSED            [ 50%]
scripts/kconfig/tests/choice_value_with_m_dep/__init__.py::test PASSED  [ 57%]
scripts/kconfig/tests/err_recursive_inc/__init__.py::test PASSED        [ 64%]
scripts/kconfig/tests/inter_choice/__init__.py::test PASSED             [ 71%]
scripts/kconfig/tests/new_choice_with_dep/__init__.py::test PASSED      [ 78%]
scripts/kconfig/tests/no_write_if_dep_unmet/__init__.py::test PASSED    [ 85%]
scripts/kconfig/tests/rand_nested_choice/__init__.py::test PASSED       [ 92%]
scripts/kconfig/tests/warn_recursive_dep/__init__.py::test PASSED       [100%]
========================== 14 passed in 0.34 seconds ==========================

Signed-off-by: Eugeniu Rosca 
Reviewed-by: Masahiro Yamada 
Tested-by: Petr Vorel

SPDX: Convert all of our single license tags to Linux Kernel style

2018-05-07T13:34:12+00:00

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini

scripts/Makefile* Add SPDX-License-Identifier tag

2016-01-19T13:31:17+00:00

A general best practice for SPDX is that Makefiles should have an
identifier, add these as everything else is currently covered.

Signed-off-by: Tom Rini

kbuild: sync with Linux 4.1

2015-07-27T19:01:54+00:00

Update some build scripts to match Linux 4.1.  Commit-based syncing
was done so as not to break U-Boot specific changes.
The previous big sync was from Linux 3.18-rc1 by commit 176d09827725
(kbuild: sync misc scripts with Linux 3.18-rc1).

The commits imported from Linux (some with adjustments) are:

[1] commit 9fb5e5372208973984a23ee6f5f025c05d364633
    Author: Robert Richter 
    dts, kbuild: Factor out dtbs install rules to Makefile.dtbinst

[2] commit 371fdc77af44f4cb32475fd499e1d912ccc30890
    Author: Masahiro Yamada 
    kbuild: collect shorthands into scripts/Kbuild.include

[3] commit a29b82326ed4eb5567b03c85b52c6891578d5a03
    Author: Michal Marek 
    kbuild: Remove duplicate $(cmd) definition in Makefile.clean

[4] commit 1846dfbde3e8a53f3673dcb1c1b79fd9b3f8d40d
    Author: Masahiro Yamada 
    kbuild: remove redundant -rR flag of hdr-inst

[5] commit 34948e0bbf98640fc1821751b01d2f0cd17d84d5
    Author: Michal Marek 
    kbuild: Drop support for clean-rule

[6] commit a16c5f99a28c9945165c46da27fff8e6f26f8736
    Author: Michal Marek 
    kbuild: Fix removal of the debian/ directory

[7] commit d0d38cd9e853db11e0242b3df4c9c3c4a663fbb4
    Author: Masahiro Yamada 
    kbuild: use mixed-targets when two or more config targets are given

[8] commit dd33c03b18b3f2db791eb6a17c37d2de66e4de18
    Author: Masahiro Yamada 
    kbuild: fix cc-ifversion macro

[9] commit 665d92e38f65d70796aad2b8e49e42e80815d4a4
    Author: Masahiro Yamada 
    kbuild: do not add $(call ...) to invoke cc-version or cc-fullversion

[10] commit 6dcb4e5edf39e3b65a75ca76f087b2fdbee8a808
    Author: Masahiro Yamada 
    kbuild: allow cc-ifversion to have the argument for false condition

[11] commit c0a80c0c27e5e65b180a25e6c4c2f7ef9e386cd3
    Author: Heiko Carstens 
    ftrace: allow architectures to specify ftrace compile options

[12] commit 0b24becc810dc3be6e3f94103a866f214c282394
    Author: Andrey Ryabinin 
    kasan: add kernel address sanitizer infrastructure

[13] commit 4218affdf57f938c04e3a916a9685ee27079f377
    Author: Masahiro Yamada 
    kbuild: remove warning about "make depend"

[14] commit 77479b38e2f58890eb221a0418357502a5b41cd6
    Author: Nathan Rossi 
    kbuild: Create directory for target DTB

Signed-off-by: Masahiro Yamada 
Signed-off-by: Robert Richter 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Andrey Ryabinin 
Signed-off-by: Nathan Rossi 
Signed-off-by: Michal Simek 
Signed-off-by: Olof Johansson 
Signed-off-by: Michal Marek 
Signed-off-by: Masahiro Yamada

kconfig: switch to single .config configuration

2015-02-24T22:06:23+00:00

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 
Reviewed-by: Simon Glass

kbuild: sync misc scripts with Linux 3.18-rc1

2014-11-07T21:27:07+00:00

This commit imports some updates in misc scripts from Linux 3.18-rc1.

[1] commit cbb4d3e6510b99522719c5ef0 by Horia Geanta
scripts/kernel-doc: handle object-like macros

[2] commit 164f0d2efaaef83 by Michal Marek
kbuild: Fix handling of backslashes in *.cmd files

[3] commit 270a00963cd367214e by Randy Dunlap
scripts/kernel-doc: recognize __meminit

[4] commit a4954fd7724c0f55361eb5 by Masahiro Yamada
  kbuild: remove obj-n and lib-n handling

[5] commit 5b2389b45d1a9c12b9f by Masahiro Yamada
kbuild: simplify build, clean, modbuiltin shorthands

Signed-off-by: Horia Geanta 
Signed-off-by: Michal Marek 
Signed-off-by: Randy Dunlap 
Signed-off-by: Masahiro Yamada

kbuild: improve multi-objs dependency and cleanups

2014-11-07T21:27:06+00:00

Since Linux 3.18-rc1, Kbuild is able to handle multi-objs
dependency correctly, which also allows us futher cleanups
of some makefiles.

This commit imports those commits:

[1] commit c8589d1e9e01 by Masahiro Yamada
kbuild: handle multi-objs dependency appropriately

[2] commit 97e3226e6e98 by Masahiro Yamada
kbuild: handle the dependency of multi-objs hostprogs appropriately

[3] commit 022af62d0190 by Masahiro Yamada
kbuild: refactor script/kconfig/Makefile

[4] commit 221ecca6cafe by Masahiro Yamada
kbuild: remove redundant clean-files from scripts/kconfig/Makefile

Signed-off-by: Masahiro Yamada

kbuild: move extra gcc checks to scripts/Makefile.extrawarn

2014-08-21T16:01:11+00:00

This commit was imported from Linux Kernel:
commit a86fe353 written by me.

W=... provides extra gcc checks.

Having such code in scripts/Makefile.build results in the same flags
being added to KBUILD_CFLAGS multiple times becuase
scripts/Makefile.build is invoked every time Kbuild descends into
the subdirectories.

Since the top Makefile is already too cluttered, this commit moves
all of extra gcc check stuff to a new file scripts/Makefile.extrawarn,
which is included from the top Makefile.

Signed-off-by: Masahiro Yamada

kconfig: switch to Kconfig

2014-07-30T12:48:03+00:00

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 _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:

  /

Here,  is either 'spl' or 'tpl'
       is 'config', 'menuconfig', 'xconfig', etc.

When the configuration is done, run "make".
(Or "make _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 
Acked-by: Simon Glass