67 KiB
SPDX-License-Identifier: GPL-2.0
VERSION = 6 PATCHLEVEL = 12 SUBLEVEL = 0 EXTRAVERSION = NAME = Baby Opossum Posse
DOCUMENTATION
To see a list of typical targets execute "make help"
More info can be located in ./README
Comments in this file are targeted only to the developer, do not
expect to learn how to build the kernel reading this file.
ifeq ($(filter output-sync,$(.FEATURES)),) $(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION)) endif
$(if $(filter %, $(MAKECMDGOALS)),
$(error targets prefixed with '' are only for internal use))
That's our default target when none is given on the command line
PHONY := __all __all:
We are using a recursive build, so we need to do a little thinking
to get the ordering right.
Most importantly: sub-Makefiles should only ever modify files in
their own directory. If in some directory we have a dependency on
a file in another dir (which doesn't happen often, but it's often
unavoidable when linking the built-in.a targets which finally
turn into vmlinux), we will call a sub make in that other dir, and
after that we are sure that everything which is in that other dir
is now up to date.
The only cases where we need to modify files which have global
effects are thus separated out and done before the recursive
descending is started. They are now explicitly listed as the
prepare rule.
this-makefile := $(lastword $(MAKEFILE_LIST)) abs_srctree := $(realpath $(dir $(this-makefile))) abs_objtree := $(CURDIR)
ifneq ($(sub_make_done),1)
Do not use make's built-in rules and variables
(this increases performance and avoids hard-to-debug behaviour)
MAKEFLAGS += -rR
Avoid funny character set dependencies
unexport LC_ALL LC_COLLATE=C LC_NUMERIC=C export LC_COLLATE LC_NUMERIC
Avoid interference with shell env settings
unexport GREP_OPTIONS
Beautify output
---------------------------------------------------------------------------
Most of build commands in Kbuild start with "cmd_". You can optionally define
"quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
that command is printed by default.
e.g.)
quiet_cmd_depmod = DEPMOD $(MODLIB)
cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
A simple variant is to prefix commands with $(Q) - that's useful
for commands that shall be hidden in non-verbose mode.
$(Q)$(MAKE) $(build)=scripts/basic
If KBUILD_VERBOSE contains 1, the whole command is echoed.
If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
To put more focus on warnings, be less verbose as default
Use 'make V=1' to see the full commands
ifeq ("$(origin V)", "command line") KBUILD_VERBOSE = $(V) endif
quiet = quiet_ Q = @
ifneq ($(findstring 1, $(KBUILD_VERBOSE)),) quiet = Q = endif
If the user is running make -s (silent mode), suppress echoing of
commands
ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),) quiet=silent_ override KBUILD_VERBOSE := endif
export quiet Q KBUILD_VERBOSE
Call a source code checker (by default, "sparse") as part of the
C compilation.
Use 'make C=1' to enable checking of only re-compiled files.
Use 'make C=2' to enable checking of all source files, regardless
of whether they are re-compiled or not.
See the file "Documentation/dev-tools/sparse.rst" for more details,
including where to get the "sparse" utility.
ifeq ("$(origin C)", "command line") KBUILD_CHECKSRC = $(C) endif ifndef KBUILD_CHECKSRC KBUILD_CHECKSRC = 0 endif
export KBUILD_CHECKSRC
Enable "clippy" (a linter) as part of the Rust compilation.
Use 'make CLIPPY=1' to enable it.
ifeq ("$(origin CLIPPY)", "command line") KBUILD_CLIPPY := $(CLIPPY) endif
export KBUILD_CLIPPY
Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
directory of external module to build. Setting M= takes precedence.
ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif
$(if $(word 2, $(KBUILD_EXTMOD)),
$(error building multiple external modules is not supported))
$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)),
$(error module directory path cannot contain '$x')))
Remove trailing slashes
ifneq ($(filter %/, $(KBUILD_EXTMOD)),) KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).) endif
export KBUILD_EXTMOD
backward compatibility
KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
ifeq ("$(origin W)", "command line") KBUILD_EXTRA_WARN := $(W) endif
export KBUILD_EXTRA_WARN
Kbuild will save output files in the current working directory.
This does not need to match to the root of the kernel source tree.
For example, you can do this:
cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
If you want to save output files in a different location, there are
two syntaxes to specify it.
1) O=
Use "make O=dir/to/store/output/files/"
2) Set KBUILD_OUTPUT
Set the environment variable KBUILD_OUTPUT to point to the output directory.
export KBUILD_OUTPUT=dir/to/store/output/files/; make
The O= assignment takes precedence over the KBUILD_OUTPUT environment
variable.
Do we want to change the working directory?
ifeq ("$(origin O)", "command line") KBUILD_OUTPUT := $(O) endif
ifneq ($(KBUILD_OUTPUT),)
$(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
$(shell mkdir -p "$(KBUILD_OUTPUT)")
$(realpath ...) resolves symlinks
abs_objtree := $(realpath $(KBUILD_OUTPUT)) $(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)")) endif # ifneq ($(KBUILD_OUTPUT),)
ifneq ($(words $(subst :, ,$(abs_srctree))), 1) $(error source directory cannot contain spaces or colons) endif
export sub_make_done := 1
endif # sub_make_done
ifeq ($(abs_objtree),$(CURDIR))
Suppress "Entering directory ..." if we are at the final work directory.
no-print-directory := --no-print-directory else
Recursion to show "Entering directory ..."
need-sub-make := 1 endif
ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
If --no-print-directory is unset, recurse once again to set it.
You may end up recursing into __sub-make twice. This is needed due to the
behavior change in GNU Make 4.4.1.
need-sub-make := 1 endif
ifeq ($(need-sub-make),1)
PHONY += $(MAKECMDGOALS) __sub-make
$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make @:
Invoke a second make in the output directory, passing relevant variables
__sub-make:
$(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree)
-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
else # need-sub-make
We process the rest of the Makefile if this is the final invocation of make
ifeq ($(abs_srctree),$(abs_objtree)) # building in the source tree srctree := . building_out_of_srctree := else ifeq ($(abs_srctree)/,$(dir $(abs_objtree))) # building in a subdirectory of the source tree srctree := .. else srctree := $(abs_srctree) endif building_out_of_srctree := 1 endif
ifneq ($(KBUILD_ABS_SRCTREE),) srctree := $(abs_srctree) endif
objtree := .
VPATH :=
ifeq ($(KBUILD_EXTMOD),) ifdef building_out_of_srctree VPATH := $(srctree) endif endif
export building_out_of_srctree srctree objtree VPATH
To make sure we do not include .config for any of the *config targets
catch them early, and hand them over to scripts/kconfig/Makefile
It is allowed to specify more targets when calling make, including
mixing *config targets and build targets.
For example 'make oldconfig all'.
Detect when mixed targets is specified, and make a second invocation
of make so .config is not included in this case either (for *config).
version_h := include/generated/uapi/linux/version.h
clean-targets := %clean mrproper cleandocs
no-dot-config-targets := $(clean-targets)
cscope gtags TAGS tags help% %docs check% coccicheck
$(version_h) headers headers_% archheaders archscripts
%asm-generic kernelversion %src-pkg dt_binding_check
outputmakefile rustavailable rustfmt rustfmtcheck
no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease
image_name
single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
config-build := mixed-build := need-config := 1 may-sync-config := 1 single-build :=
ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) need-config := endif endif
ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),) ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),) may-sync-config := endif endif
need-compiler := $(may-sync-config)
ifneq ($(KBUILD_EXTMOD),) may-sync-config := endif
ifeq ($(KBUILD_EXTMOD),) ifneq ($(filter %config,$(MAKECMDGOALS)),) config-build := 1 ifneq ($(words $(MAKECMDGOALS)),1) mixed-build := 1 endif endif endif
We cannot build single targets and the others at the same time
ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),) single-build := 1 ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),) mixed-build := 1 endif endif
For "make -j clean all", "make -j mrproper defconfig all", etc.
ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),) ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),) mixed-build := 1 endif endif
install and modules_install need also be processed one by one
ifneq ($(filter install,$(MAKECMDGOALS)),) ifneq ($(filter modules_install,$(MAKECMDGOALS)),) mixed-build := 1 endif endif
ifdef mixed-build
===========================================================================
We're called with mixed targets (*config and build targets).
Handle them one by one.
PHONY += $(MAKECMDGOALS) __build_one_by_one
$(MAKECMDGOALS): __build_one_by_one @:
__build_one_by_one:
$(Q)set -e;
for i in $(MAKECMDGOALS); do
$(MAKE) -f $(srctree)/Makefile $$i;
done
else # !mixed-build
include $(srctree)/scripts/Kbuild.include
Read KERNELRELEASE from include/config/kernel.release (if it exists)
KERNELRELEASE = $(call read-file, include/config/kernel.release) KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION) export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
include $(srctree)/scripts/subarch.include
Cross compiling and selecting different set of gcc/bin-utils
---------------------------------------------------------------------------
When performing cross compilation for other architectures ARCH shall be set
to the target architecture. (See arch/* for the possibilities).
ARCH can be set during invocation of make:
make ARCH=arm64
Another way is to have ARCH set in the environment.
The default ARCH is the host where make is executed.
CROSS_COMPILE specify the prefix used for all executables used
during compilation. Only gcc and related bin-utils executables
are prefixed with $(CROSS_COMPILE).
CROSS_COMPILE can be set on the command line
make CROSS_COMPILE=aarch64-linux-gnu-
Alternatively CROSS_COMPILE can be set in the environment.
Default value for CROSS_COMPILE is not to prefix executables
Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
ARCH ?= $(SUBARCH)
Architecture as present in compile.h
UTS_MACHINE := $(ARCH) SRCARCH := $(ARCH)
Additional ARCH settings for x86
ifeq ($(ARCH),i386) SRCARCH := x86 endif ifeq ($(ARCH),x86_64) SRCARCH := x86 endif
Additional ARCH settings for sparc
ifeq ($(ARCH),sparc32) SRCARCH := sparc endif ifeq ($(ARCH),sparc64) SRCARCH := sparc endif
Additional ARCH settings for parisc
ifeq ($(ARCH),parisc64) SRCARCH := parisc endif
export cross_compiling := ifneq ($(SRCARCH),$(SUBARCH)) cross_compiling := 1 endif
KCONFIG_CONFIG ?= .config export KCONFIG_CONFIG
SHELL used by kbuild
CONFIG_SHELL := sh
HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null) HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null) HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
ifneq ($(LLVM),) ifneq ($(filter %/,$(LLVM)),) LLVM_PREFIX := $(LLVM) else ifneq ($(filter -%,$(LLVM)),) LLVM_SUFFIX := $(LLVM) endif
HOSTCC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX) HOSTCXX = $(LLVM_PREFIX)clang++$(LLVM_SUFFIX) else HOSTCC = gcc HOSTCXX = g++ endif HOSTRUSTC = rustc HOSTPKG_CONFIG = pkg-config
KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes
-O2 -fomit-frame-pointer -std=gnu11
KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
KBUILD_USERLDFLAGS := $(USERLDFLAGS)
These flags apply to all Rust code in the tree, including the kernel and
host programs.
export rust_common_flags := --edition=2021
-Zbinary_dep_depinfo=y
-Astable_features
-Dunsafe_op_in_unsafe_fn
-Dnon_ascii_idents
-Wrust_2018_idioms
-Wunreachable_pub
-Wmissing_docs
-Wrustdoc::missing_crate_level_docs
-Wclippy::all
-Wclippy::mut_mut
-Wclippy::needless_bitwise_bool
-Wclippy::needless_continue
-Wclippy::no_mangle_with_rust_abi
-Wclippy::dbg_macro
KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS)
$(HOSTCFLAGS) -I $(srctree)/scripts/include
KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
-I $(srctree)/scripts/include
KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo
-Zallow-features= $(HOSTRUSTFLAGS)
KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
Make variables (CC, etc...)
CPP = $(CC) -E ifneq ($(LLVM),) CC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX) LD = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX) AR = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX) NM = $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX) OBJCOPY = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX) OBJDUMP = $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX) READELF = $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX) STRIP = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX) else CC = $(CROSS_COMPILE)gcc LD = $(CROSS_COMPILE)ld AR = $(CROSS_COMPILE)ar NM = $(CROSS_COMPILE)nm OBJCOPY = $(CROSS_COMPILE)objcopy OBJDUMP = $(CROSS_COMPILE)objdump READELF = $(CROSS_COMPILE)readelf STRIP = $(CROSS_COMPILE)strip endif RUSTC = rustc RUSTDOC = rustdoc RUSTFMT = rustfmt CLIPPY_DRIVER = clippy-driver BINDGEN = bindgen PAHOLE = pahole RESOLVE_BTFIDS = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids LEX = flex YACC = bison AWK = awk INSTALLKERNEL := installkernel PERL = perl PYTHON3 = python3 CHECK = sparse BASH = bash KGZIP = gzip KBZIP2 = bzip2 KLZOP = lzop LZMA = lzma LZ4 = lz4c XZ = xz ZSTD = zstd
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__
-Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
NOSTDINC_FLAGS :=
CFLAGS_MODULE =
RUSTFLAGS_MODULE =
AFLAGS_MODULE =
LDFLAGS_MODULE =
CFLAGS_KERNEL =
RUSTFLAGS_KERNEL =
AFLAGS_KERNEL =
LDFLAGS_vmlinux =
Use USERINCLUDE when you must reference the UAPI directories only.
USERINCLUDE :=
-I$(srctree)/arch/$(SRCARCH)/include/uapi
-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi
-I$(srctree)/include/uapi
-I$(objtree)/include/generated/uapi
-include $(srctree)/include/linux/compiler-version.h
-include $(srctree)/include/linux/kconfig.h
Use LINUXINCLUDE when you must reference the include/ directory.
Needed to be compatible with the O= option
LINUXINCLUDE :=
-I$(srctree)/arch/$(SRCARCH)/include
-I$(objtree)/arch/$(SRCARCH)/include/generated
$(if $(building_out_of_srctree),-I$(srctree)/include)
-I$(objtree)/include
$(USERINCLUDE)
KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
KBUILD_CFLAGS := KBUILD_CFLAGS += -std=gnu11 KBUILD_CFLAGS += -fshort-wchar KBUILD_CFLAGS += -funsigned-char KBUILD_CFLAGS += -fno-common KBUILD_CFLAGS += -fno-PIE KBUILD_CFLAGS += -fno-strict-aliasing
KBUILD_CPPFLAGS := -D__KERNEL__
KBUILD_RUSTFLAGS := $(rust_common_flags)
-Cpanic=abort -Cembed-bitcode=n -Clto=n
-Cforce-unwind-tables=n -Ccodegen-units=1
-Csymbol-mangling-version=v0
-Crelocation-model=static
-Zfunction-sections=n
-Wclippy::float_arithmetic
KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := KBUILD_RUSTFLAGS_KERNEL := KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE KBUILD_RUSTFLAGS_MODULE := --cfg MODULE KBUILD_LDFLAGS_MODULE := KBUILD_LDFLAGS := CLANG_FLAGS :=
ifeq ($(KBUILD_CLIPPY),1) RUSTC_OR_CLIPPY_QUIET := CLIPPY RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER) else RUSTC_OR_CLIPPY_QUIET := RUSTC RUSTC_OR_CLIPPY = $(RUSTC) endif
Allows the usage of unstable features in stable compilers.
export RUSTC_BOOTSTRAP := 1
export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN export HOSTRUSTC KBUILD_HOSTRUSTFLAGS export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
Files to ignore in find ... statements
export RCS_FIND_IGNORE := ( -name SCCS -o -name BitKeeper -o -name .svn -o
-name CVS -o -name .pc -o -name .hg -o -name .git )
-prune -o
===========================================================================
Rules shared between *config targets and build targets
Basic helpers built in scripts/basic/
PHONY += scripts_basic scripts_basic: $(Q)$(MAKE) $(build)=scripts/basic
PHONY += outputmakefile ifdef building_out_of_srctree
Before starting out-of-tree build, make sure the source tree is clean.
outputmakefile generates a Makefile in the output directory, if using a
separate output directory. This allows convenient use of make in the
output directory.
At the same time when output Makefile generated, generate .gitignore to
ignore whole output directory
quiet_cmd_makefile = GEN Makefile
cmd_makefile = {
echo "# Automatically generated by $(srctree)/Makefile: don't edit";
echo "include $(srctree)/Makefile";
} > Makefile
outputmakefile:
@if [ -f $(srctree)/.config -o
-d $(srctree)/include/config -o
-d $(srctree)/arch/$(SRCARCH)/include/generated ]; then
echo >&2 "";
echo >&2 " The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'";
echo >&2 "*** in $(abs_srctree)";
echo >&2 "**";
false;
fi
$(Q)ln -fsn $(srctree) source
$(call cmd,makefile)
$(Q)test -e .gitignore ||
{ echo "# this is build directory, ignore it"; echo ""; } > .gitignore
endif
The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they
need export), and from include/config/auto.conf.cmd to detect the compiler
upgrade.
CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1)) RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
ifneq ($(findstring clang,$(CC_VERSION_TEXT)),) include $(srctree)/scripts/Makefile.clang endif
Include this also for config targets because some architectures need
cc-cross-prefix to determine CROSS_COMPILE.
ifdef need-compiler include $(srctree)/scripts/Makefile.compiler endif
ifdef config-build
===========================================================================
*config targets only - make sure prerequisites are updated, and descend
in scripts/kconfig to make the *config target
Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
KBUILD_DEFCONFIG may point out an alternative default configuration
used for 'make defconfig'
include $(srctree)/arch/$(SRCARCH)/Makefile export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
config: outputmakefile scripts_basic FORCE $(Q)$(MAKE) $(build)=scripts/kconfig $@
%config: outputmakefile scripts_basic FORCE $(Q)$(MAKE) $(build)=scripts/kconfig $@
else #!config-build
===========================================================================
Build targets only - this includes vmlinux, arch-specific targets, clean
targets and others. In general all targets except *config targets.
If building an external module we do not care about the all: rule
but instead __all depend on modules
PHONY += all ifeq ($(KBUILD_EXTMOD),) __all: all else __all: modules endif
targets :=
Decide whether to build built-in, modular, or both.
Normally, just do built-in.
KBUILD_MODULES := KBUILD_BUILTIN := 1
If we have only "make modules", don't compile built-in objects.
ifeq ($(MAKECMDGOALS),modules) KBUILD_BUILTIN := endif
If we have "make modules", compile modules
in addition to whatever we do anyway.
Just "make" or "make all" shall build modules as well
ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),) KBUILD_MODULES := 1 endif
ifeq ($(MAKECMDGOALS),) KBUILD_MODULES := 1 endif
export KBUILD_MODULES KBUILD_BUILTIN
ifdef need-config include include/config/auto.conf endif
ifeq ($(KBUILD_EXTMOD),)
Objects we will link into vmlinux / subdirs we need to visit
core-y := drivers-y := libs-y := lib/ endif # KBUILD_EXTMOD
The all: target is the default when no target is given on the
command line.
This allow a user to issue only 'make' to build a kernel including modules
Defaults to vmlinux, but the arch makefile usually adds further targets
all: vmlinux
CFLAGS_GCOV := -fprofile-arcs -ftest-coverage ifdef CONFIG_CC_IS_GCC CFLAGS_GCOV += -fno-tree-loop-im endif export CFLAGS_GCOV
The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
ifdef CONFIG_FUNCTION_TRACER CC_FLAGS_FTRACE := -pg endif
include $(srctree)/arch/$(SRCARCH)/Makefile
ifdef need-config ifdef may-sync-config
Read in dependencies to all Kconfig* files, make sure to run syncconfig if
changes are detected. This should be included after arch/$(SRCARCH)/Makefile
because some architectures define CROSS_COMPILE there.
include include/config/auto.conf.cmd
$(KCONFIG_CONFIG): @echo >&2 '' @echo >&2 ' Configuration file "$@" not found!' @echo >&2 '' @echo >&2 ' Please run some configurator (e.g. "make oldconfig" or' @echo >&2 '*** "make menuconfig" or "make xconfig").' @echo >&2 '***' @/bin/false
The actual configuration files used during the build are stored in
include/generated/ and include/config/. Update them if .config is newer than
include/config/auto.conf (which mirrors .config).
This exploits the 'multi-target pattern rule' trick.
The syncconfig should be executed only once to make all the targets.
(Note: use the grouped target '&:' when we bump to GNU Make 4.3)
Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
so you cannot notice that Kconfig is waiting for the user input.
%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG) $(Q)$(kecho) " SYNC $@" $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig else # !may-sync-config
External modules and some install targets need include/generated/autoconf.h
and include/config/auto.conf but do not care if they are up-to-date.
Use auto.conf to trigger the test
PHONY += include/config/auto.conf
include/config/auto.conf:
@test -e include/generated/autoconf.h -a -e $@ || (
echo >&2;
echo >&2 " ERROR: Kernel configuration is invalid.";
echo >&2 " include/generated/autoconf.h or $@ are missing.";
echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it.";
echo >&2 ;
/bin/false)
endif # may-sync-config endif # need-config
KBUILD_CFLAGS += -fno-delete-null-pointer-checks
ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE KBUILD_CFLAGS += -O2 KBUILD_RUSTFLAGS += -Copt-level=2 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE KBUILD_CFLAGS += -Os KBUILD_RUSTFLAGS += -Copt-level=s endif
Always set debug-assertions and overflow-checks because their default
depends on opt-level and debug-assertions, respectively.
KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n) KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
Tell gcc to never replace conditional load with a non-conditional one
ifdef CONFIG_CC_IS_GCC
gcc-10 renamed --param=allow-store-data-races=0 to
-fno-allow-store-data-races.
KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races) endif
ifdef CONFIG_READABLE_ASM
Disable optimizations that make assembler listings hard to read.
reorder blocks reorders the control in the function
ipa clone creates specialized cloned functions
partial inlining inlines only parts of functions
KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining endif
stackp-flags-y := -fno-stack-protector stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
KBUILD_CFLAGS += $(stackp-flags-y)
KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y else
Some targets (ARM with Thumb2, for example), can't be built with frame
pointers. For those, we don't have FUNCTION_TRACER automatically
select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
incompatible with -fomit-frame-pointer with current GCC, so we don't use
-fomit-frame-pointer with FUNCTION_TRACER.
In the Rust target specification, "frame-pointer" is set explicitly
to "may-omit".
ifndef CONFIG_FUNCTION_TRACER KBUILD_CFLAGS += -fomit-frame-pointer endif endif
Initialize all stack variables with a 0xAA pattern.
ifdef CONFIG_INIT_STACK_ALL_PATTERN KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern endif
Initialize all stack variables with a zero value.
ifdef CONFIG_INIT_STACK_ALL_ZERO KBUILD_CFLAGS += -ftrivial-auto-var-init=zero ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
https://github.com/llvm/llvm-project/issues/44842
CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang export CC_AUTO_VAR_INIT_ZERO_ENABLER KBUILD_CFLAGS += $(CC_AUTO_VAR_INIT_ZERO_ENABLER) endif endif
While VLAs have been removed, GCC produces unreachable stack probes
for the randomize_kstack_offset feature. Disable it for all compilers.
KBUILD_CFLAGS += $(call cc-option, -fno-stack-clash-protection)
Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
ifdef CONFIG_ZERO_CALL_USED_REGS KBUILD_CFLAGS += -fzero-call-used-regs=used-gpr endif
ifdef CONFIG_FUNCTION_TRACER ifdef CONFIG_FTRACE_MCOUNT_USE_CC CC_FLAGS_FTRACE += -mrecord-mcount ifdef CONFIG_HAVE_NOP_MCOUNT ifeq ($(call cc-option-yn, -mnop-mcount),y) CC_FLAGS_FTRACE += -mnop-mcount CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT endif endif endif ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT endif endif ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT ifdef CONFIG_HAVE_C_RECORDMCOUNT BUILD_C_RECORDMCOUNT := y export BUILD_C_RECORDMCOUNT endif endif ifdef CONFIG_HAVE_FENTRY
s390-linux-gnu-gcc did not support -mfentry until gcc-9.
ifeq ($(call cc-option-yn, -mfentry),y) CC_FLAGS_FTRACE += -mfentry CC_FLAGS_USING += -DCC_USING_FENTRY endif endif export CC_FLAGS_FTRACE KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING) KBUILD_AFLAGS += $(CC_FLAGS_USING) endif
We trigger additional mismatches with less inlining
ifdef CONFIG_DEBUG_SECTION_MISMATCH KBUILD_CFLAGS += -fno-inline-functions-called-once endif
rustc's -Zfunction-sections applies to data too (as of 1.59.0).
ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y LDFLAGS_vmlinux += --gc-sections endif
ifdef CONFIG_SHADOW_CALL_STACK ifndef CONFIG_DYNAMIC_SCS CC_FLAGS_SCS := -fsanitize=shadow-call-stack KBUILD_CFLAGS += $(CC_FLAGS_SCS) KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack endif export CC_FLAGS_SCS endif
ifdef CONFIG_LTO_CLANG ifdef CONFIG_LTO_CLANG_THIN CC_FLAGS_LTO := -flto=thin -fsplit-lto-unit else CC_FLAGS_LTO := -flto endif CC_FLAGS_LTO += -fvisibility=hidden
Limit inlining across translation units to reduce binary size
KBUILD_LDFLAGS += -mllvm -import-instr-limit=5 endif
ifdef CONFIG_LTO KBUILD_CFLAGS += -fno-lto $(CC_FLAGS_LTO) KBUILD_AFLAGS += -fno-lto export CC_FLAGS_LTO endif
ifdef CONFIG_CFI_CLANG CC_FLAGS_CFI := -fsanitize=kcfi ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS CC_FLAGS_CFI += -fsanitize-cfi-icall-experimental-normalize-integers endif ifdef CONFIG_RUST # Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects # CONFIG_CFI_ICALL_NORMALIZE_INTEGERS. RUSTC_FLAGS_CFI := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI) export RUSTC_FLAGS_CFI endif KBUILD_CFLAGS += $(CC_FLAGS_CFI) export CC_FLAGS_CFI endif
Architectures can define flags to add/remove for floating-point support
CC_FLAGS_FPU += -D_LINUX_FPU_COMPILATION_UNIT export CC_FLAGS_FPU export CC_FLAGS_NO_FPU
ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
Set the minimal function alignment. Use the newer GCC option
-fmin-function-alignment if it is available, or fall back to -falign-funtions.
See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT) else KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT) endif endif
arch Makefile may override CC so keep this after arch Makefile is included
NOSTDINC_FLAGS += -nostdinc
To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
the kernel uses only C99 flexible arrays for dynamically sized trailing
arrays. Enforce this for everything that may examine structure sizes and
perform bounds checking.
KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
#Currently, disable -Wstringop-overflow for GCC 11, globally. KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow) KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += -fno-strict-overflow
Make sure -fstack-check isn't enabled (like gentoo apparently did)
KBUILD_CFLAGS += -fno-stack-check
conserve stack if available
ifdef CONFIG_CC_IS_GCC KBUILD_CFLAGS += -fconserve-stack endif
change FILE to the relative path from the srctree
KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
include additional Makefiles when needed
include-y := scripts/Makefile.extrawarn include-$(CONFIG_DEBUG_INFO) += scripts/Makefile.debug include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf include-$(CONFIG_KASAN) += scripts/Makefile.kasan include-$(CONFIG_KCSAN) += scripts/Makefile.kcsan include-$(CONFIG_KMSAN) += scripts/Makefile.kmsan include-$(CONFIG_UBSAN) += scripts/Makefile.ubsan include-$(CONFIG_KCOV) += scripts/Makefile.kcov include-$(CONFIG_RANDSTRUCT) += scripts/Makefile.randstruct include-$(CONFIG_GCC_PLUGINS) += scripts/Makefile.gcc-plugins
include $(addprefix $(srctree)/, $(include-y))
scripts/Makefile.gcc-plugins is intentionally included last.
Do not add $(call cc-option,...) below this line. When you build the kernel
from the clean source tree, the GCC plugins do not exist at this point.
Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
KBUILD_CPPFLAGS += $(KCPPFLAGS) KBUILD_AFLAGS += $(KAFLAGS) KBUILD_CFLAGS += $(KCFLAGS) KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
KBUILD_LDFLAGS_MODULE += --build-id=sha1 LDFLAGS_vmlinux += --build-id=sha1
KBUILD_LDFLAGS += -z noexecstack ifeq ($(CONFIG_LD_IS_BFD),y) KBUILD_LDFLAGS += $(call ld-option,--no-warn-rwx-segments) endif
ifeq ($(CONFIG_STRIP_ASM_SYMS),y) LDFLAGS_vmlinux += -X endif
ifeq ($(CONFIG_RELR),y)
ld.lld before 15 did not support -z pack-relative-relocs.
LDFLAGS_vmlinux += $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs) endif
We never want expected sections to be placed heuristically by the
linker. All sections should be explicitly named in the linker script.
ifdef CONFIG_LD_ORPHAN_WARN LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) endif
Align the bit size of userspace programs with the kernel
KBUILD_USERCFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS)) KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
make the checker run with the right architecture
CHECKFLAGS += --arch=$(ARCH)
insure the checker run with the right endianness
CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
the checker needs the correct machine size
CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
Default kernel image to build when no specific target is given.
KBUILD_IMAGE may be overruled on the command line or
set in the environment
Also any assignments in arch/$(ARCH)/Makefile take precedence over
this default value
export KBUILD_IMAGE ?= vmlinux
INSTALL_PATH specifies where to place the updated kernel and system map
images. Default is /boot, but you can set it to other values
export INSTALL_PATH ?= /boot
INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
an argument if needed. Otherwise it defaults to the kernel install path
export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
relocations required by build roots. This is not defined in the
makefile but the argument can be passed to make if needed.
MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) export MODLIB
PHONY += prepare0
export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) export MODORDER := $(extmod_prefix)modules.order export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
ifeq ($(KBUILD_EXTMOD),)
build-dir := .
clean-dirs := $(sort . Documentation
$(patsubst %/,%,$(filter %/, $(core-)
$(drivers-) $(libs-))))
export ARCH_CORE := $(core-y) export ARCH_LIB := $(filter %/, $(libs-y)) export ARCH_DRIVERS := $(drivers-y) $(drivers-m)
Externally visible symbols (used by link-vmlinux.sh)
KBUILD_VMLINUX_OBJS := ./built-in.a ifdef CONFIG_MODULES KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y))) KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y)) else KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y)) endif
export KBUILD_VMLINUX_LIBS export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
ifdef CONFIG_TRIM_UNUSED_KSYMS
For the kernel to actually contain only the needed exported symbols,
we have to build modules as well to determine what those symbols are.
KBUILD_MODULES := 1 endif
'$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
quiet_cmd_ar_vmlinux.a = AR $@
cmd_ar_vmlinux.a =
rm -f $@;
$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS);
$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
targets += vmlinux.a vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE $(call if_changed,ar_vmlinux.a)
PHONY += vmlinux_o vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS) $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o @:
PHONY += vmlinux
LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
unrelated; the decompressors just happen to have the same base name,
arch/*/boot/compressed/vmlinux.
Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
_LDFLAGS_vmlinux is a workaround for the 'private export' bug:
https://savannah.gnu.org/bugs/?61463
For Make > 4.4, the following simple code will work:
vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux) vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux) vmlinux: vmlinux.o $(KBUILD_LDS) modpost $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
The actual objects are generated when descending,
make sure no implicit rule kicks in
$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
ifeq ($(origin KERNELRELEASE),file) filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree) else filechk_kernel.release = echo $(KERNELRELEASE) endif
Store (new) KERNELRELEASE string in include/config/kernel.release
include/config/kernel.release: FORCE $(call filechk,kernel.release)
Additional helpers built in scripts/
Carefully list dependencies so we do not try to build scripts twice
in parallel
PHONY += scripts scripts: scripts_basic scripts_dtc $(Q)$(MAKE) $(build)=$(@)
Things we need to do before we recursively start building the kernel
or the modules are listed in "prepare".
A multi level approach is used. prepareN is processed before prepareN-1.
archprepare is used in arch Makefiles and when processed asm symlink,
version.h and scripts_basic is processed / created.
PHONY += prepare archprepare
archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release
asm-generic $(version_h) include/generated/utsrelease.h
include/generated/compile.h include/generated/autoconf.h remove-stale-files
prepare0: archprepare $(Q)$(MAKE) $(build)=scripts/mod $(Q)$(MAKE) $(build)=. prepare
All the preparing..
prepare: prepare0 ifdef CONFIG_RUST +$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh $(Q)$(MAKE) $(build)=rust endif
PHONY += remove-stale-files remove-stale-files: $(Q)$(srctree)/scripts/remove-stale-files
Support for using generic headers in asm-generic
asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
PHONY += asm-generic uapi-asm-generic
asm-generic: uapi-asm-generic
$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm
generic=include/asm-generic
uapi-asm-generic:
$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm
generic=include/uapi/asm-generic
Generate some files
---------------------------------------------------------------------------
KERNELRELEASE can change from a few different places, meaning version.h
needs to be updated, so this check is forced on all builds
uts_len := 64
define filechk_utsrelease.h
if [ echo -n "$(KERNELRELEASE)" | wc -c -gt $(uts_len) ]; then
echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;
exit 1;
fi;
echo #define UTS_RELEASE "$(KERNELRELEASE)"
endef
define filechk_version.h
if [ $(SUBLEVEL) -gt 255 ]; then
echo #define LINUX_VERSION_CODE $(shell
expr $(VERSION) * 65536 + $(PATCHLEVEL) * 256 + 255);
else
echo #define LINUX_VERSION_CODE $(shell
expr $(VERSION) * 65536 + $(PATCHLEVEL) * 256 + $(SUBLEVEL));
fi;
echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +
((c) > 255 ? 255 : (c)))';
echo #define LINUX_VERSION_MAJOR $(VERSION);
echo #define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);
echo #define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
endef
$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0) $(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0) $(version_h): FORCE $(call filechk,version.h)
include/generated/utsrelease.h: include/config/kernel.release FORCE $(call filechk,utsrelease.h)
filechk_compile.h = $(srctree)/scripts/mkcompile_h
"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
include/generated/compile.h: FORCE $(call filechk,compile.h)
PHONY += headerdep
headerdep:
$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1
$(srctree)/scripts/headerdep.pl -I$(srctree)/include
---------------------------------------------------------------------------
Kernel headers
#Default location for installed headers export INSTALL_HDR_PATH = $(objtree)/usr
quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
cmd_headers_install =
mkdir -p $(INSTALL_HDR_PATH);
rsync -mrl --include='/' --include='.h' --exclude='*'
usr/include $(INSTALL_HDR_PATH)
PHONY += headers_install headers_install: headers $(call cmd,headers_install)
PHONY += archheaders archscripts
hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
PHONY += headers headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts $(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML)) $(Q)$(MAKE) $(hdr-inst)=include/uapi $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
ifdef CONFIG_HEADERS_INSTALL prepare: headers endif
PHONY += scripts_unifdef scripts_unifdef: scripts_basic $(Q)$(MAKE) $(build)=scripts scripts/unifdef
---------------------------------------------------------------------------
Install
Many distributions have the custom install script, /sbin/installkernel.
If DKMS is installed, 'make install' will eventually recurse back
to this Makefile to build and install external modules.
Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
quiet_cmd_install = INSTALL $(INSTALL_PATH) cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
---------------------------------------------------------------------------
vDSO install
PHONY += vdso_install vdso_install: export INSTALL_FILES = $(vdso-install-y) vdso_install: $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
---------------------------------------------------------------------------
Tools
ifdef CONFIG_OBJTOOL prepare: tools/objtool endif
ifdef CONFIG_BPF ifdef CONFIG_DEBUG_INFO_BTF prepare: tools/bpf/resolve_btfids endif endif
The tools build system is not a part of Kbuild and tends to introduce
its own unique issues. If you need to integrate a new tool into Kbuild,
please consider locating that tool outside the tools/ tree and using the
standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
here. See Documentation/kbuild/makefiles.rst for details.
PHONY += resolve_btfids_clean
resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
tools/bpf/resolve_btfids directory might not exist
in output directory, skip its clean in that case
resolve_btfids_clean: ifneq ($(wildcard $(resolve_btfids_O)),) $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean endif
Clear a bunch of variables before executing the submake
ifeq ($(quiet),silent_) tools_silent=s endif
tools/: FORCE $(Q)mkdir -p $(objtree)/tools $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
tools/%: FORCE $(Q)mkdir -p $(objtree)/tools $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
---------------------------------------------------------------------------
Kernel selftest
PHONY += kselftest kselftest: headers $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
kselftest-%: headers FORCE $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
PHONY += kselftest-merge
kselftest-merge:
$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) |
xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
---------------------------------------------------------------------------
Devicetree files
ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),) dtstree := arch/$(SRCARCH)/boot/dts endif
ifneq ($(dtstree),)
%.dtb: dtbs_prepare $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
%.dtbo: dtbs_prepare $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
PHONY += dtbs dtbs_prepare dtbs_install dtbs_check dtbs: dtbs_prepare $(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
include/config/kernel.release is actually needed when installing DTBs because
INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
dtbs_install depend on it as dtbs_install may run as root.
dtbs_prepare: include/config/kernel.release scripts_dtc
ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),) export CHECK_DTBS=y endif
ifneq ($(CHECK_DTBS),) dtbs_prepare: dt_binding_schemas endif
dtbs_check: dtbs
dtbs_install: $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
ifdef CONFIG_OF_EARLY_FLATTREE all: dtbs endif
endif
PHONY += scripts_dtc scripts_dtc: scripts_basic $(Q)$(MAKE) $(build)=scripts/dtc
ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),) export CHECK_DTBS=y endif
PHONY += dt_binding_check dt_binding_schemas dt_binding_check: dt_binding_schemas scripts_dtc $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
dt_binding_schemas: $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
PHONY += dt_compatible_check dt_compatible_check: dt_binding_schemas $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
---------------------------------------------------------------------------
Modules
ifdef CONFIG_MODULES
By default, build modules as well
all: modules
When we're building modules with modversions, we need to consider
the built-in objects during the descend as well, in order to
make sure the checksums are up to date before we record them.
ifdef CONFIG_MODVERSIONS KBUILD_BUILTIN := 1 endif
Build modules
*.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
is an exception.
ifdef CONFIG_DEBUG_INFO_BTF_MODULES KBUILD_BUILTIN := 1 modules: vmlinux endif
modules: modules_prepare
Target to prepare building external modules
modules_prepare: prepare $(Q)$(MAKE) $(build)=scripts scripts/module.lds
endif # CONFIG_MODULES
Cleaning is done on three levels.
make clean Delete most generated files
Leave enough to build external modules
make mrproper Delete the current configuration, and all generated files
make distclean Remove editor backup files, patch leftover files and the like
Directories & files removed with 'make clean'
CLEAN_FILES += vmlinux.symvers modules-only.symvers
modules.builtin modules.builtin.modinfo modules.nsdeps
modules.builtin.ranges vmlinux.o.map
compile_commands.json rust/test
rust-project.json .vmlinux.objs .vmlinux.export.c
Directories & files removed with 'make mrproper'
MRPROPER_FILES += include/config include/generated
arch/$(SRCARCH)/include/generated .objdiff
debian snap tar-install PKGBUILD pacman
.config .config.old .version
Module.symvers
certs/signing_key.pem
certs/x509.genkey
vmlinux-gdb.py
rpmbuild
rust/libmacros.so
clean - Delete most, but leave enough to build external modules
clean: private rm-files := $(CLEAN_FILES)
PHONY += archclean vmlinuxclean
vmlinuxclean: $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
clean: archclean vmlinuxclean resolve_btfids_clean
mrproper - Delete all generated files, including .config
mrproper: private rm-files := $(MRPROPER_FILES) mrproper-dirs := $(addprefix mrproper,scripts)
PHONY += $(mrproper-dirs) mrproper $(mrproper-dirs): $(Q)$(MAKE) $(clean)=$(patsubst mrproper%,%,$@)
mrproper: clean $(mrproper-dirs)
$(call cmd,rmfiles)
@find . $(RCS_FIND_IGNORE)
-name '*.rmeta'
-type f -print | xargs rm -f
distclean
PHONY += distclean
distclean: mrproper
@find . $(RCS_FIND_IGNORE)
( -name '.orig' -o -name '.rej' -o -name '~'
-o -name '.bak' -o -name '##' -o -name '%'
-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*'
-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS )
-type f -print | xargs rm -f
Packaging of the kernel to various formats
---------------------------------------------------------------------------
%src-pkg: FORCE $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@ %pkg: include/config/kernel.release FORCE $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
Brief documentation of the typical targets used
---------------------------------------------------------------------------
boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/_defconfig) boards := $(sort $(notdir $(boards))) board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs//*_defconfig)) board-dirs := $(sort $(notdir $(board-dirs:/=)))
PHONY += help
help:
@echo 'Cleaning targets:'
@echo ' clean - Remove most generated files but keep the config and'
@echo ' enough build support to build external modules'
@echo ' mrproper - Remove all generated files + config + various backup files'
@echo ' distclean - mrproper + remove editor backup and patch files'
@echo ''
@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
@echo ''
@echo 'Other generic targets:'
@echo ' all - Build all targets marked with []'
@echo ' vmlinux - Build the bare kernel'
@echo '* modules - Build all modules'
@echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
@echo ' vdso_install - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
@echo ' dir/ - Build all files in dir and below'
@echo ' dir/file.[ois] - Build specified target only'
@echo ' dir/file.ll - Build the LLVM assembly file'
@echo ' (requires compiler support for LLVM assembly generation)'
@echo ' dir/file.lst - Build specified mixed source/assembly target only'
@echo ' (requires a recent binutils and recent build (System.map))'
@echo ' dir/file.ko - Build module including final link'
@echo ' modules_prepare - Set up for building external modules'
@echo ' tags/TAGS - Generate tags file for editors'
@echo ' cscope - Generate cscope index'
@echo ' gtags - Generate GNU GLOBAL index'
@echo ' kernelrelease - Output the release version string (use with make -s)'
@echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
@echo ' image_name - Output the image name (use with make -s)'
@echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH';
echo ' (default: $(INSTALL_HDR_PATH))';
echo ''
@echo 'Static analysers:'
@echo ' checkstack - Generate a list of stack hogs and consider all functions'
@echo ' with a stack size larger than MINSTACKSIZE (default: 100)'
@echo ' versioncheck - Sanity check on version.h usage'
@echo ' includecheck - Check for duplicate included header files'
@echo ' export_report - List the usages of all exported symbols'
@echo ' headerdep - Detect inclusion cycles in headers'
@echo ' coccicheck - Check with Coccinelle'
@echo ' clang-analyzer - Check with clang static analyzer'
@echo ' clang-tidy - Check with clang-tidy'
@echo ''
@echo 'Tools:'
@echo ' nsdeps - Generate missing symbol namespace dependencies'
@echo ''
@echo 'Kernel selftest:'
@echo ' kselftest - Build and run kernel selftest'
@echo ' Build, install, and boot kernel before'
@echo ' running kselftest on it'
@echo ' Run as root for full coverage'
@echo ' kselftest-all - Build kernel selftest'
@echo ' kselftest-install - Build and install kernel selftest'
@echo ' kselftest-clean - Remove all generated kselftest files'
@echo ' kselftest-merge - Merge all the config dependencies of'
@echo ' kselftest to existing .config.'
@echo ''
@echo 'Rust targets:'
@echo ' rustavailable - Checks whether the Rust toolchain is'
@echo ' available and, if not, explains why.'
@echo ' rustfmt - Reformat all the Rust code in the kernel'
@echo ' rustfmtcheck - Checks if all the Rust code in the kernel'
@echo ' is formatted, printing a diff otherwise.'
@echo ' rustdoc - Generate Rust documentation'
@echo ' (requires kernel .config)'
@echo ' rusttest - Runs the Rust tests'
@echo ' (requires kernel .config; downloads external repos)'
@echo ' rust-analyzer - Generate rust-project.json rust-analyzer support file'
@echo ' (requires kernel .config)'
@echo ' dir/file.[os] - Build specified target only'
@echo ' dir/file.rsi - Build macro expanded source, similar to C preprocessing.'
@echo ' Run with RUSTFMT=n to skip reformatting if needed.'
@echo ' The output is not intended to be compilable.'
@echo ' dir/file.ll - Build the LLVM assembly file'
@echo ''
@$(if $(dtstree),
echo 'Devicetree:';
echo '* dtbs - Build device tree blobs for enabled boards';
echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)';
echo ' dt_binding_check - Validate device tree binding documents and examples';
echo ' dt_binding_schemas - Build processed device tree binding schemas';
echo ' dtbs_check - Validate device tree source files';
echo '')
@echo 'Userspace tools targets:'
@echo ' use "make tools/help"'
@echo ' or "cd tools; make help"'
@echo ''
@echo 'Kernel packaging:'
@$(MAKE) -f $(srctree)/scripts/Makefile.package help
@echo ''
@echo 'Documentation targets:'
@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
@echo ''
@echo 'Architecture-specific targets ($(SRCARCH)):'
@$(or $(archhelp),\
echo ' No architecture-specific help defined for $(SRCARCH)')
@echo ''
@$(if $(boards), \
$(foreach b, $(boards), \
printf " %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
echo '')
@$(if $(board-dirs), \
$(foreach b, $(board-dirs), \
printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
printf " %-16s - Show all of the above\\n" help-boards; \
echo '')
@echo ' make V=n [targets] 1: verbose build'
@echo ' 2: give reason for rebuild of target'
@echo ' V=1 and V=2 can be combined with V=12'
@echo ' make O=dir [targets] Locate all output files in "dir", including .config'
@echo ' make C=1 [targets] Check re-compiled c source with $$CHECK'
@echo ' (sparse by default)'
@echo ' make C=2 [targets] Force check of all c source with $$CHECK'
@echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
@echo ' make W=n [targets] Enable extra build checks, n=1,2,3,c,e where'
@echo ' 1: warnings which may be relevant and do not occur too often'
@echo ' 2: warnings which occur quite often but may still be relevant'
@echo ' 3: more obscure warnings, can most likely be ignored'
@echo ' c: extra checks in the configuration stage (Kconfig)'
@echo ' e: warnings are being treated as errors'
@echo ' Multiple levels can be combined with W=12 or W=123'
@$(if $(dtstree), \
echo ' make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
echo ' This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
)
@echo ''
@echo 'Execute "make" or "make all" to build all targets marked with [*] '
@echo 'For further info see the ./README file'
help-board-dirs := $(addprefix help-,$(board-dirs))
help-boards: $(help-board-dirs)
boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$/_defconfig)))
$(help-board-dirs): help-%:
@echo 'Architecture-specific targets ($(SRCARCH) $):'
@$(if $(boards-per-dir),
$(foreach b, $(boards-per-dir),
printf " %-24s - Build for %s\n" $/$(b) $(subst _defconfig,,$(b));)
echo '')
Documentation targets
---------------------------------------------------------------------------
DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs
linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
PHONY += $(DOC_TARGETS)
$(DOC_TARGETS):
$(Q)$(MAKE) $(build)=Documentation $@
Rust targets
---------------------------------------------------------------------------
"Is Rust available?" target
PHONY += rustavailable rustavailable: +$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
Documentation target
Using the singular to avoid running afoul of no-dot-config-targets.
PHONY += rustdoc rustdoc: prepare $(Q)$(MAKE) $(build)=rust $@
Testing target
PHONY += rusttest rusttest: prepare $(Q)$(MAKE) $(build)=rust $@
Formatting targets
PHONY += rustfmt rustfmtcheck
We skip rust/alloc since we want to minimize the diff w.r.t. upstream.
We match using absolute paths since find does not resolve them
when matching, which is a problem when e.g. srctree is ...
We grep afterwards in order to remove the directory entry itself.
rustfmt:
$(Q)find $(abs_srctree) -type f -name '*.rs'
-o -path $(abs_srctree)/rust/alloc -prune
-o -path $(abs_objtree)/rust/test -prune
| grep -Fv $(abs_srctree)/rust/alloc
| grep -Fv $(abs_objtree)/rust/test
| grep -Fv generated
| xargs $(RUSTFMT) $(rustfmt_flags)
rustfmtcheck: rustfmt_flags = --check rustfmtcheck: rustfmt
Misc
---------------------------------------------------------------------------
PHONY += misc-check misc-check: $(Q)$(srctree)/scripts/misc-check
all: misc-check
PHONY += scripts_gdb scripts_gdb: prepare0 $(Q)$(MAKE) $(build)=scripts/gdb $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
ifdef CONFIG_GDB_SCRIPTS all: scripts_gdb endif
else # KBUILD_EXTMOD
filechk_kernel.release = echo $(KERNELRELEASE)
External module support.
When building external modules the kernel used as basis is considered
read-only, and no consistency checks are made and the make
system is not used on the basis kernel. If updates are required
in the basis kernel ordinary make commands (without M=...) must be used.
We are always building only modules.
KBUILD_BUILTIN := KBUILD_MODULES := 1
build-dir := $(KBUILD_EXTMOD)
compile_commands.json: $(extmod_prefix)compile_commands.json PHONY += compile_commands.json
clean-dirs := $(KBUILD_EXTMOD)
clean: private rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps
$(KBUILD_EXTMOD)/compile_commands.json
PHONY += prepare
now expand this into a simple variable to reduce the cost of shell evaluations
prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
prepare:
@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then
echo >&2 "warning: the compiler differs from the one used to build the kernel";
echo >&2 " The kernel was built by: $(CONFIG_CC_VERSION_TEXT)";
echo >&2 " You are using: $(CC_VERSION_TEXT)";
fi
PHONY += help help: @echo ' Building external modules.' @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target' @echo '' @echo ' modules - default target, build the module(s)' @echo ' modules_install - install the module' @echo ' clean - remove generated files in module directory only' @echo ' rust-analyzer - generate rust-project.json rust-analyzer support file' @echo ''
ifndef CONFIG_MODULES modules modules_install: __external_modules_error __external_modules_error: @echo >&2 '' @echo >&2 ' The present kernel disabled CONFIG_MODULES.' @echo >&2 '*** You cannot build or install external modules.' @echo >&2 '***' @false endif
endif # KBUILD_EXTMOD
---------------------------------------------------------------------------
Modules
PHONY += modules modules_install modules_sign modules_prepare
modules_install:
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
ifeq ($(CONFIG_MODULE_SIG),y)
modules_sign is a subset of modules_install.
'make modules_install modules_sign' is equivalent to 'make modules_install'.
modules_sign: modules_install @: else modules_sign: @echo >&2 '' @echo >&2 ' CONFIG_MODULE_SIG is disabled. You cannot sign modules.' @echo >&2 '***' @false endif
ifdef CONFIG_MODULES
$(MODORDER): $(build-dir) @:
KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
This is solely useful to speed up test compiles.
modules: modpost ifneq ($(KBUILD_MODPOST_NOFINAL),1) $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal endif
PHONY += modules_check modules_check: $(MODORDER) $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
else # CONFIG_MODULES
modules: @:
KBUILD_MODULES :=
endif # CONFIG_MODULES
PHONY += modpost
modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o))
$(if $(KBUILD_MODULES), modules_check)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
Single targets
---------------------------------------------------------------------------
To build individual files in subdirectories, you can do like this:
make foo/bar/baz.s
The supported suffixes for single-target are listed in 'single-targets'
To build only under specific subdirectories, you can do like this:
make foo/bar/baz/
ifdef single-build
.ko is special because modpost is needed
single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS))
$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
$(single-ko): single_modules @: $(single-no-ko): $(build-dir) @:
Remove MODORDER when done because it is not the real one.
PHONY += single_modules single_modules: $(single-no-ko) modules_prepare $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER) $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost ifneq ($(KBUILD_MODPOST_NOFINAL),1) $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal endif $(Q)rm -f $(MODORDER)
single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
KBUILD_MODULES := 1
endif
Preset locale variables to speed up the build process. Limit locale
tweaks to this spot to avoid wrong language settings when running
make menuconfig etc.
Error messages still appears in the original language
PHONY += $(build-dir) $(build-dir): prepare $(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
clean-dirs := $(addprefix clean, $(clean-dirs)) PHONY += $(clean-dirs) clean $(clean-dirs): $(Q)$(MAKE) $(clean)=$(patsubst clean%,%,$@)
clean: $(clean-dirs)
$(call cmd,rmfiles)
@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE)
( -name '.[aios]' -o -name '.rsi' -o -name '.ko' -o -name '..cmd'
-o -name '.ko.'
-o -name '.dtb' -o -name '.dtbo'
-o -name '.dtb.S' -o -name '.dtbo.S'
-o -name '.dt.yaml' -o -name 'dtbs-list'
-o -name '.dwo' -o -name '.lst'
-o -name '.su' -o -name '.mod'
-o -name '..d' -o -name '..tmp' -o -name '.mod.c'
-o -name '.lex.c' -o -name '.tab.[ch]'
-o -name '.asn1.[ch]'
-o -name '.symtypes' -o -name 'modules.order'
-o -name '.c.[012].'
-o -name '.ll'
-o -name '.gcno'
) -type f -print
-o -name '.tmp_' -print
| xargs rm -rf
Generate tags for editors
---------------------------------------------------------------------------
quiet_cmd_tags = GEN $@ cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
tags TAGS cscope gtags: FORCE $(call cmd,tags)
Generate rust-project.json (a file that describes the structure of non-Cargo
Rust projects) for rust-analyzer (an implementation of the Language Server
Protocol).
PHONY += rust-analyzer rust-analyzer: +$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh $(Q)$(MAKE) $(build)=rust $@
Script to generate missing namespace dependencies
---------------------------------------------------------------------------
PHONY += nsdeps nsdeps: export KBUILD_NSDEPS=1 nsdeps: modules $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
Clang Tooling
---------------------------------------------------------------------------
quiet_cmd_gen_compile_commands = GEN $@ cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
$(extmod_prefix)compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py
$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS))
$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
$(call if_changed,gen_compile_commands)
targets += $(extmod_prefix)compile_commands.json
PHONY += clang-tidy clang-analyzer
ifdef CONFIG_CC_IS_CLANG quiet_cmd_clang_tools = CHECK $< cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json $(call cmd,clang_tools) else clang-tidy clang-analyzer: @echo "$@ requires CC=clang" >&2 @false endif
Scripts to check various things for consistency
---------------------------------------------------------------------------
PHONY += includecheck versioncheck coccicheck export_report
includecheck:
find $(srctree)/* $(RCS_FIND_IGNORE)
-name '*.[hcS]' -type f -print | sort
| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
versioncheck:
find $(srctree)/* $(RCS_FIND_IGNORE)
-name '*.[hcS]' -type f -print | sort
| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
coccicheck: $(Q)$(BASH) $(srctree)/scripts/$@
export_report: $(PERL) $(srctree)/scripts/export_report.pl
PHONY += checkstack kernelrelease kernelversion image_name
UML needs a little special treatment here. It wants to use the host
toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
else wants $(ARCH), including people doing cross-builds, which means
that $(SUBARCH) doesn't work here.
ifeq ($(ARCH), um)
CHECKSTACK_ARCH := $(SUBARCH)
else
CHECKSTACK_ARCH := $(ARCH)
endif
MINSTACKSIZE ?= 100
checkstack:
$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') |
$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
kernelrelease: @$(filechk_kernel.release)
kernelversion: @echo $(KERNELVERSION)
image_name: @echo $(KBUILD_IMAGE)
PHONY += run-command run-command: $(Q)$(KBUILD_RUN_COMMAND)
quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))) cmd_rmfiles = rm -rf $(rm-files)
read saved command lines for existing targets
existing-targets := $(wildcard $(sort $(targets)))
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
endif # config-build endif # mixed-build endif # need-sub-make
PHONY += FORCE FORCE:
Declare the contents of the PHONY variable as phony. We keep that
information in a variable so we can use it in if_changed and friends.
.PHONY: $(PHONY)