Merge branch 'for-next/module'

Merge branch 'for-next/misc'

Merge branch 'for-next/kbuild'

Release v2020.07.0 ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Makefile: Initialize and export KBUILD variables ...

Initialize and export KBUILD KERNEL and MODULE variables. Otherwise,
appending to them elsewhere in the srctree will not be seen by the build
commands in Makefile.lib

Signed-off-by: David Dgien <dgienda125@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add infrastructure to build userspace programs ...

Import Linux commit 7f3a59d

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add -Wmissing-prototypes and -std=gnu89 to KBUILD_HOSTCFLAGS ...

Align with Linux kernel.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: remove package targets ...

This hunk is already out of sync from upstream Linux.

Barebox does not support package targets, so let's delete this
rotten code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: remove AS variable ...

The assembler files in the barebox are *.S instead of *.s, so they must
be preprocessed. Since 'as' of GNU binutils is not able to preprocess,
we always use $(CC) as an assembler driver.

Remove AS variable.

Linux also removed AS. See Linux commits:

 aa824e0c962b ("kbuild: remove AS variable")
 1ca0c2f61211 ("kbuild: remove unused AS assignment")

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/kbuild'

Release v2020.06.0 ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: switch over to thin archive ...

Starting v4.13, Linux always uses thin archive instead of relocatable
ELF to combine builtin objects.

The thin archive is basically a text file that only contains paths to
object files.

As Linux commit 98ced886dd79 mentioned, this has a lot of benefits:

 - save disk space for builds

 - speed-up building a little

 - fix some issues when liking a giant executable (for example,
   allyesconfig on ARM Linux)

 - work better with dead code elimination

The last one is important for barebox because pbl highly relies on the
dead code elimination (-f{function,data}-sections and --gc-sections)
dropping symbols that are unreachable from the linker's entry point.
The dead code elimination does not work if the same symbol names are
used in the pevious incremental link mechanism because the same name
symbols all go into the same section.

Commit a83c97f2a406 ("ARM: socfpga: generate smaller images when
multiple boards are selected") worked around it by giving a dedicate
section to each of the same name symbols. This workaround can go away.

built-in.o was renamed to built-in.a since it is now an archive.
built-in-pbl.o was renamed to built-in.pbl.a for consistency.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: build modules by 'make' ...

In Linux, 'make' and 'make all' work equivalently; it builds both
vmlinux and modules.

In barebox, strangely, 'make all' builds both barebox and modules,
but 'make' builds only barebox because KBUILD_MODULES is unset.

The check for 'ifeq ($(MAKECMDGOALS),)' is missing since the day-one.

Fixes: b02e0966412c ("add additional linking stage for modules")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add -std=gnu89 to KBUILD_CFLAGS ...

Barebox imports lots of code from Linux, so should use the same
language standard as Linux.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/kbuild'

Release v2020.05.0 ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: resync top Makefile, mkmakefile, tags.sh with Linux 5.7-rc4 ...

The prologue of the build system is not specific to Linux or Barebox.
Paritially resync with Linux 5.7-rc4

- In Linux, $(objtree) is always '.', and $(srctree) might be relative.
  I am keeping both absolute for now to avoid unexpected breakage.

- I did not resync single target for now. We need to touch
  Makefile.build a lot if we want to resync it.

- 'export CDPATH=' is Barebox-only code, which was added by
  commit 6cc8d0544658 ("Makefile: disable CDPATH"). Keep it.

- KBUILD_SRC no longer exists in the upstream Linux. I replaced it
  with building_out_of_srctree.

- scripts/mkmakefile does not contain anything specific to Linux or
  Barebox. Resync it with Linux 5.7-rc4

- scripts/tags was imported from Linux 3.6 with some cherry-picks on
  top of that. Resync it with Linux 5.7-rc4

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add -Wall to KBUILD_HOSTCXXFLAGS ...

[ Linux commit 735aab1 ]

Add -Wall to catch more warnings for C++ host programs.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add -Werror={strict-prototypes, implicit-int} to KBUILD_CFLAGS ...

- Turn Wstrict-prototypes into an error
- Add -Werror=implicit-int
- Use the standard form -Werror=... for implicit-function-declaration

This commit imports the following Linux commits. They should work for
barebox too.

80970472179a Makefile: enable -Werror=implicit-int and -Werror=strict-prototypes by default
eeb5687a7139 kbuild: add -Werror=strict-prototypes flag unconditionally
61a0902a06d6 kbuild: add -Werror=implicit-int flag unconditionally
b89f25ea7892 kbuild: use -Werror=implicit-... instead of -Werror-implicit-...

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: sync if_changed and friends with Linux 5.7-rc2 ...

Resync cmd, if_change, if_changed_dep, and if_changed_rule.

Clean up the users of if_changed_rule.

I deleted the modversions rule. It is dead code because barebox
does not define CONFIG_MODVERSIONS. It does not work without
scripts/genksyms/ anyway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: sync filechk rule with Linux 5.7-rc2 ...

The 'filechk' in the latest Linux works more simply, reliably.

- Do not show CHK every time
- Delete the *.tmp file when the filechk_$(1) fails
- Do not open the first prerequisite. This is unneeded in most cases.

I deleted pointeless dependency on Makefile.

Also delete the meaningless assignment to 'targets' because filechk
does not generate .cmd file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: do not delete $@ explicitly on failure ...

The .DELETE_ON_ERROR special target is specified in scripts/Kbuild.include

You do not need to delete $@ explicitly when the command fails.
GNU Make automatically does it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ppc: rename arch/ppc/ to arch/powerpc/ ...

In old days, Linux supported PowerPC with two arch directories,
arch/ppc/ and arch/ppc64/.

Linux commit 564ee7a5668e ("[PATCH] powerpc: Move arch/ppc*/kernel/vecemu.c
to arch/powerpc") started the migration to arch/powerpc/, and
commit 917f0af9e5a9 ("powerpc: Remove arch/ppc and include/asm-ppc")
finished it.

This commit aligns the directory name with the current Linux.

I did 'git mv arch/ppc/ arch/powerpc/', and fixed up some hard-coded
arch/ppc paths.

Barebox has stuck to arch/ppc/ for a long time. To keep the backward
compatibility, I added the following to the top Makefile.

  # Support ARCH=ppc for backward compatibility
  ifeq ($(ARCH),ppc)
         SRCARCH := powerpc
  endif

Both ARCH=ppc and ARCH=powerpc work in the same way.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: set SRCARCH=arm when ARCH=arm64 ...

In Linux, ARCH can be passed from the command line or the environment.
In barebox, "ARCH=arm64 make" works, but "make ARCH=arm64" does not.

Instead of overriding ARCH, use SRCARCH properly.

This is what Linux does for biarch directories (x86, sh, sparc).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: use $(SRCARCH) to point to the arch directory ...

A couple of arch directories in Linux are biarch, that is, a single
arch/*/ directory supports both 32-bit and 64-bit.

In old days of Linux, they started as separated directories.
arm/arm64 is the exceptional case, but the other architectures were
unified.

e.g.)

  arch/i386, arch/x86_64    ->  arch/x86
  arch/sh, arch/sh64        ->  arch/sh
  arch/sparc, arch/sparc64  ->  arch/sparc

Linux commit 6752ed90da03 ("Kbuild: allow arch/xxx to use a different
source path") introduced SRCARCH to point to the arch directory, still
allowing to pass in the former ARCH=i386 or ARCH=x86_64.

The top Makefile in Linux converts ARCH to SRCARCH as follows:

  # Additional ARCH settings for x86
  ifeq ($(ARCH),i386)
          SRCARCH := x86
  endif
  ifeq ($(ARCH),x86_64)
          SRCARCH := x86
  endif

So, if you follow the upstream Kbuild convention, using arch/$(SRCARCH)
is the correct way to point to the arch directory.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: swap the include order of arch Makefile and auto.conf.cmd ...

Include

  include/config/auto.conf
  arch/$(ARCH)/Makefile
  include/config/auto.conf.cmd

in this order, which is the same as the current Linux does.

auto.conf.cmd contains the environment variables that were referenced
from Kconfig files. If an environment variable defined in arch Makefile
is referenced from Kconfig files, Kbuild would end up with eternal
synconfig loop.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: remove meaningless headers_check from help target ...

This is never shown because include/asm-$(ARCH)/Kbuild does not exist.

headers_check does not make any sense for barebox.

Linux also deprecated headers_check by commit 7ecaf069da52 ("kbuild:
move headers_check rule to usr/include/Makefile").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kconfig: update to Linux 5.7-rc2 ...

The previous sync was Linux 5.5. This updates Kconfig to Linux 5.7-rc2.

Highlights:

 - add yes2modconfig and mod2yesconfig, which are useful for coping with
   syzbot configs in Linux

 - remove include/config/tristate.conf

 - show more precise help

 - fix various issues of 'make xconfig'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: prefix compiler flag variables with KBUILD_ ...

In old days, Linux also used to use well-known variables such CFLAGS,
CPPFLAGS, etc.

They were prefixed with KBUILD_ presumably for preventing users from
overriding them accidentally.

Rename as follows:
  CFLAGS          ->  KBUILD_CFLAGS
  AFLAGS          ->  KBUILD_AFLAGS
  CPPFLAGS        ->  KBUILD_CPPFLAGS
  LDFLAGS         ->  KBUILD_LDFLAGS
  HOSTCFLAGS      ->  KBUILD_HOSTCFLAGS
  HOSTCXXFLAGS    ->  KBUILD_HOSTCXXFLAGS
  HOSTLDFLAGS     ->  KBUILD_HOSTLDFLAGS
  HOST_LOADLIBES  ->  KBUILD_HOSTLDLIBS

HOSTCFLAGS, HOSTCXXFLAGS, HOSTLDFLAGS, HOSTLDLIBS are re-used to allow
users to pass-in additional flags to the host compiler.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/arm'