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>

scripts: bareboximd: fix write_file error handling ...

write will never return 0 on POSIX conformant systems. Remove this error
path.
Also, close the file on error.

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

kbuild: sync scripts/Kbuild.include with Linux 5.7-rc2 ...

More random cherry-picks for scripts/Kbuild.include

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: add $(always-y) to 'targets' ...

I missed to sync this line in commit 421108c51da4 ("kbuild: rename
hostprogs-y/always to hostprogs/always-y").

Since then, the files in always(-y) are needlessly rebuilt.

Fixes: 421108c51da4 ("kbuild: rename hostprogs-y/always to hostprogs/always-y")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: imd: fix uninitialized variable read ...

Errors are propagated in the loop and ret is never set. Remove it.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: kconfig-lint.py: extend for undefined symbol detection ...

Extend the script by some code from the official list_undefined.py example[1]
to further detect symbols we are using, but haven't defined anywhere.

[1]: https://github.com/ulfalizer/Kconfiglib/blob/35a60b7/examples/list_undefined.py

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: import Zephyr scripts/kconfig/lint.py into barebox ...

This kconfig linter can do some useful analysis to find problems
in our Kconfig files. Import it into barebox source tree with the
changes necessary to be usable.

The results of running it should be taken with a grain of salt and
verified with grep.

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
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>

modpost: sync mk_elfconfig.c with Linux 5.7-rc2 ...

Just get rid of the argument $(ARCH), then hardcode MODULE_SYMBOL_PREFIX.
This should have no impact because none of v850, h8300, blackfin is
supported by barebox.

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>

kbuild: support ccflags-y, asflags-y, cppflags-y, and ldflags-y ...

Some Makefiles use ccflags-y, but it is not actually supported.
Support ccflags-y, asflags-y, cppflags-y, and ldflags-y like Linux.

Remove the workaround in drivers/pci/Makefile.

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

treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

dtc: remove redundant YYLOC global declaration ...

Same as the upstream fix for building dtc with gcc 10.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/zynq'

fixdep: update to Linux 5.7-rc1 ...

scripts/basic/ works for barebox as drop-in.

Update scripts/basic/ to Linux 5.7-rc1.

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

kbuild: update flex and bison rules to Linux 5.7-rc1 ...

Import the following commits from Linux, and re-sync.

- 6ba7dc6616ce
  "kbuild: make bison create C file and header in a single pattern rule"

- cf8dfd15e5fb
  "kbuild: move flex and bison rules to Makefile.host"

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

kbuild: rename hostprogs-y/always to hostprogs/always-y ...

[ Linux commit 5f2fb52 ]

In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.

It is typically useful in scripts/Makefile because it allows Kbuild to
selectively compile host programs based on the kernel configuration.

This commit renames like follows:

  always       ->  always-y
  hostprogs-y  ->  hostprogs

So, scripts/Makefile will look like this:

  always-$(CONFIG_BUILD_BIN2C) += ...
  always-$(CONFIG_KALLSYMS)    += ...
      ...
  hostprogs := $(always-y) $(always-m)

I think this makes more sense because a host program is always a host
program, irrespective of the kernel configuration. We want to specify
which ones to compile by CONFIG options, so always-y will be handier.

The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
compatibility for a while.

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

checkpatch.pl: Update DT vendor prefix check ...

In commit 796af3473b82 ("dts: update to v5.2-rc1")
vendor-prefixes.txt has been converted to a DT schema.
Update the checkpatch.pl DT check to extract vendor prefixes from the new
vendor-prefixes.yaml file.

Based on this linux kernel commit 852d095d16a6
("checkpatch.pl: Update DT vendor prefix check").

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: zynq_mkimage: remove compiler warning ...

Fixes a warning while compiling zynq_mkimage.c
scripts/zynq_mkimage.c:312:2: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
fread returns the number bytes read, if it is not equal to st_size some error has happend

Signed-off-by: Michael Graichen <michael.graichen@hotmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kconfig: update to Linux 5.5 ...

The previous sync was Linux 5.3-rc3. This updates Kconfig to Linux 5.5.

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

kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj) ...

[ Linux commit 54b8ae6 ]

Kbuild provides per-file compiler flag addition/removal:

  CFLAGS_<basetarget>.o
  CFLAGS_REMOVE_<basetarget>.o
  AFLAGS_<basetarget>.o
  AFLAGS_REMOVE_<basetarget>.o
  CPPFLAGS_<basetarget>.lds
  HOSTCFLAGS_<basetarget>.o
  HOSTCXXFLAGS_<basetarget>.o

The <basetarget> is the filename of the target with its directory and
suffix stripped.

This syntax comes into a trouble when two files with the same basename
appear in one Makefile, for example:

  obj-y += foo.o
  obj-y += dir/foo.o
  CFLAGS_foo.o := <some-flags>

Here, the <some-flags> applies to both foo.o and dir/foo.o

The real world problem is:

  scripts/kconfig/util.c
  scripts/kconfig/lxdialog/util.c

Both files are compiled into scripts/kconfig/mconf, but only the
latter should be given with the ncurses flags.

It is more sensible to use the relative path to the Makefile, like this:

  obj-y += foo.o
  CFLAGS_foo.o := <some-flags>
  obj-y += dir/foo.o
  CFLAGS_dir/foo.o := <other-flags>

At first, I attempted to replace $(basetarget) with $*. The $* variable
is replaced with the stem ('%') part in a pattern rule. This works with
most of cases, but does not for explicit rules.

For example, arch/ia64/lib/Makefile reuses rule_as_o_S in its own
explicit rules, so $* will be empty, resulting in ignoring the per-file
AFLAGS.

I introduced a new variable, target-stem, which can be used also from
explicit rules.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: remove clean-dirs syntax ...

[ Linux comit 1634f2b ]

The only the difference between clean-files and clean-dirs is the -r
option passed to the 'rm' command.

You can always pass -r, and then remove the clean-dirs syntax.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/misc'

Merge branch 'for-next/imx'

scripts/bareboximd: add mode argument to open call ...

Newer gcc complain about missing mode argument when a new file is
created. This is an extract of man-pages:

 "The mode argument specifies the file mode bits be applied when
 a new file is created.  This argument must be supplied when
 O_CREAT or O_TMPFILE is specified in flags"

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: imx-usb-loader: Fix i.MX8MM ...

Most things valid for the i.MX8MQ are needed for the i.MX8MM as well, so
add a common macro which returns true for both SoCs and use it where
appropriate. Also we have to search for the i.MX header in a bigger area
as it is at offset 33KiB.

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

scripts: imd: remove duplicate macro definitions ...

include/scripts/linux/kernel.h included via #include <linux/kernel.h>
later on already defines these three macros. Remove them here to avoid
the warnings about the duplicate macro definition.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>