Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:
src := $(obj)
When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.
This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.
To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.
Going forward, the variables used in Makefiles will have the following
meanings:
$(obj) - directory in the object tree
$(src) - directory in the source tree (changed by this commit)
$(objtree) - the top of the kernel object tree
$(srctree) - the top of the kernel source tree
Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
When using a custom location for kernel config files this merge config
command fails as it doesn't use the configuration set with
KCONFIG_CONFIG.
Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
KCONFIG_WARN_UNKNOWN_SYMBOLS=1 and KCONFIG_WERROR=1 are descriptive
and suitable in scripting, but typing them from the command line can
be tedious.
Associate them with KBUILD_EXTRA_WARN (and the W= shorthand).
Support a new letter 'c' to enable extra checks in Kconfig. You can
still manage compiler warnings (W=1) and Kconfig warnings (W=c)
independently.
Reuse the letter 'e' to turn Kconfig warnings into errors.
As usual, you can combine multiple letters in KCONFIG_EXTRA_WARN.
$ KCONFIG_WARN_UNKNOWN_SYMBOLS=1 KCONFIG_WERROR=1 make defconfig
can be shortened to:
$ KBUILD_EXTRA_WARN=ce make defconfig
or, even shorter:
$ make W=ce defconfig
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Currently the Kconfig fragments in kernel/configs and arch/*/configs
that aren't used internally aren't discoverable through "make help",
which consists of hard-coded lists of config fragments. Instead, list
all the fragment targets that have a "# Help: " comment prefix so the
targets can be generated dynamically.
Add logic to the Makefile to search for and display the fragment and
comment. Add comments to fragments that are intended to be direct targets.
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently qconf-cfg.sh is the only script that touches the "-bin"
target, even though all of the conf_cfg rules declare that they do.
Make the recipe unconditionally touch all declared targets to avoid
incompatibilities with upcoming versions of GNU make:
https://lists.gnu.org/archive/html/info-gnu/2022-10/msg00008.html
e.g.
scripts/kconfig/Makefile:215: warning: pattern recipe did not update peer target 'scripts/kconfig/nconf-bin'.
scripts/kconfig/Makefile:215: warning: pattern recipe did not update peer target 'scripts/kconfig/mconf-bin'.
scripts/kconfig/Makefile:215: warning: pattern recipe did not update peer target 'scripts/kconfig/gconf-bin'.
Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Refactor Makefile and use read-file macro. For Make >= 4.2, it can read
out a file by using the built-in function.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
When converting a modular kernel to a monolithic kernel, once the kernel
works without loading any modules, this helps to quickly disable all the
modules before turning off module support entirely.
Refactor conf_rewrite_mod_or_yes to a more general
conf_rewrite_tristates that accepts an old and new state.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Björn Töpel <bjorn@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When the .config file is missing, 'make config', 'make menuconfig', etc.
uses a file listed in DEFCONFIG_LIST, if found, as base configuration.
Ususally, /boot/config-$(uname -r) exists, and is used as default.
However, when you are cross-compiling the kernel, it does not make
sense to use /boot/config-* on the build host. It should default to
arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG).
UML previously did not use DEFCONFIG_LIST at all, but it should be
able to use arch/um/configs/$(KBUILD_DEFCONFIG) as a base config file.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
allnoconfig_y is an ugly hack that sets a symbol to 'y' by allnoconfig.
allnoconfig does not mean a minimal set of CONFIG options because a
bunch of prompts are hidden by 'if EMBEDDED' or 'if EXPERT', but I do
not like to hack Kconfig this way.
Use the pre-existing feature, KCONFIG_ALLCONFIG, to provide a one
liner config fragment. CONFIG_EMBEDDED=y is still forced when
allnoconfig is invoked as a part of tinyconfig.
No change in the .config file produced by 'make tinyconfig'.
The output of 'make allnoconfig' will be changed; we will get
CONFIG_EMBEDDED=n because allnoconfig literally sets all symbols to n.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This is a partial revert of commit 2a86f66121 ("kbuild: use
KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST").
Now that the reference to $(DEFCONFIG_LIST) was removed from
init/Kconfig, the default KBUILD_DEFCONFIG can go back home.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
"defconfig_list" is a weird option that defines a static symbol that
declares the list of base config files in case the .config does not
exist yet.
This is quite different from other normal symbols; we just abused the
"string" type and the "default" properties to list out the input files.
They must be fixed values since these are searched for and loaded in
the parse stage.
It is an ugly hack, and should not exist in the first place. Providing
this feature as an environment variable is a saner approach.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Unify the similar build rules.
This supports 'make build_config', which builds scripts/kconfig/conf
but does not invoke it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
scripts/kconfig/conf.c line 39 defines the default of input_mode as
oldaskconfig. Hence, 'make config' works in the same way even without
the --oldaskconfig option given. Note this in the help message.
This will be helpful to unify build rules in Makefile in the next
commit.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Some targets (localyesconfig, localmodconfig, defconfig) hide the
command running, but the others do not.
Users know which Kconfig flavor they are running, so it is OK to hide
the command. Add $(Q) to all commands consistently. If you want to see
the full command running, pass V=1 from the command line.
syncconfig is the exceptional case, which occurs without explicit
command invocation by the user. Display the Kbuild-style log for it.
The ugly bare log will go away.
[Before]
scripts/kconfig/conf --syncconfig Kconfig
[After]
SYNC include/config/auto.conf
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, qconf.moc is included from qconf.cc but they can be compiled
independently.
When you modify qconf.cc, qconf.moc does not need recompiling.
Rename qconf.moc to qconf-moc.cc, and split it out as an independent
compilation unit.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Regenerate qconf.moc when the moc command is changed.
This also allows 'make mrproper' to clean it up. Previously, it was
not cleaned up because 'clean-files += qconf.moc' was missing.
Now 'make mrproper' correctly cleans it up because files listed in
'targets' are cleaned.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
kvmconfig' is a shorthand for kvm_guest.config to save 7 character typing.
xenconfig' is a shorthand for xen.config to save 1 character typing.
There is nothing more than that.
There are more files in kernel/configs/, so it is not maintainable
to wire-up every config fragment to the Kconfig Makefile. Hence,
we should not do this at all.
These will be removed after Linux 5.10. Meanwhile, the following
warning message will be displayed if they are used.
WARNING: 'make kvmconfig' will be removed after Linux 5.10
Please use 'make kvm_guest.config' instead.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Sometimes it is useful to preserve batches of configs when making
localmodconfig. For example, I usually don't want any usb and fs
modules to be disabled. Now we can do it by:
$ make LMC_KEEP="drivers/usb:fs" localmodconfig
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Most of the Kconfig commands (except defconfig and all*config) read
the .config file as a base set of CONFIG options.
When it does not exist, the files in DEFCONFIG_LIST are searched in
this order and loaded if found.
I do not see much sense in the last two lines in DEFCONFIG_LIST.
[1] ARCH_DEFCONFIG
The entry for DEFCONFIG_LIST is guarded by 'depends on !UML'. So, the
ARCH_DEFCONFIG definition in arch/x86/um/Kconfig is meaningless.
arch/{sh,sparc,x86}/Kconfig define ARCH_DEFCONFIG depending on 32 or
64 bit variant symbols. This is a little bit strange; ARCH_DEFCONFIG
should be a fixed string because the base config file is loaded before
the symbol evaluation stage.
Using KBUILD_DEFCONFIG makes more sense because it is fixed before
Kconfig is invoked. Fortunately, arch/{sh,sparc,x86}/Makefile define it
in the same way, and it works as expected. Hence, replace ARCH_DEFCONFIG
with "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)".
[2] arch/$(ARCH)/defconfig
This file path is no longer valid. The defconfig files are always located
in the arch configs/ directories.
$ find arch -name defconfig | sort
arch/alpha/configs/defconfig
arch/arm64/configs/defconfig
arch/csky/configs/defconfig
arch/nds32/configs/defconfig
arch/riscv/configs/defconfig
arch/s390/configs/defconfig
arch/unicore32/configs/defconfig
The path arch/*/configs/defconfig is already covered by
"arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)". So, this file path is
not necessary.
I moved the default KBUILD_DEFCONFIG to the top Makefile. Otherwise,
the 7 architectures listed above would end up with endless loop of
syncconfig.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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>
Since kernel configs provided by syzbot are close to "make allyesconfig",
it takes long time to rebuild. This is especially waste of time when we
need to rebuild for many times (e.g. doing manual printk() inspection,
bisect operations).
We can save time if we can exclude modules which are irrelevant to each
problem. But "make localmodconfig" cannot exclude modules which are built
into vmlinux because /sbin/lsmod output is used as the source of modules.
Therefore, this patch adds "make yes2modconfig" which converts from =y
to =m if possible. After confirming that the interested problem is still
reproducible, we can try "make localmodconfig" (and/or manually tune
based on "Modules linked in:" line) in order to exclude modules which are
irrelevant to the interested problem. While we are at it, this patch also
adds "make mod2yesconfig" which converts from =m to =y in case someone
wants to convert from =m to =y after "make localmodconfig".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
