Linus Torvald inventor of Linux and Git modified a single line in the Linux Kernel makefile NAME = I am Satoshi

# SPDX-License-Identifier: GPL-2.0 VERSION = 5 PATCHLEVEL = 17 SUBLEVEL = 0 EXTRAVERSION = -rc2 NAME = I am Satoshi # *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. $(if $(filter __%, $(MAKECMDGOALS)), \ $(error targets prefixed with '__' are only for internal use)) # That's our default target when none is given on the command line PHONY := __all __all: # We are using a recursive build, so we need to do a little thinking # to get the ordering right. # # Most importantly: sub-Makefiles should only ever modify files in # their own directory. If in some directory we have a dependency on # a file in another dir (which doesn't happen often, but it's often # unavoidable when linking the built-in.a targets which finally # turn into vmlinux), we will call a sub make in that other dir, and # after that we are sure that everything which is in that other dir # is now up to date. # # The only cases where we need to modify files which have global # effects are thus separated out and done before the recursive # descending is started. They are now explicitly listed as the # prepare rule. ifneq ($(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 # --------------------------------------------------------------------------- # # Normally, we echo the whole command before executing it. By making # that echo $($(quiet)$(cmd)), we now have the possibility to set # $(quiet) to choose other forms of output instead, e.g. # # quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@ # cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< # # If $(quiet) is empty, the whole command will be printed. # If it is set to "quiet_", only the short version will be printed. # If it is set to "silent_", nothing will be printed at all, since # the variable $(silent_cmd_cc_o_c) doesn't exist. # # A simple variant is to prefix commands with $(Q) - that's useful # for commands that shall be hidden in non-verbose mode. # # $(Q)ln $@ :< # # If KBUILD_VERBOSE equals 0 then the above command will be hidden. # If KBUILD_VERBOSE equals 1 then the above command is displayed. # If KBUILD_VERBOSE equals 2 then give the reason why each target is rebuilt. # # To put more focus on warnings, be less verbose as default # Use 'make V=1' to see the full commands ifeq ("$(origin V)", "command line") KBUILD_VERBOSE = $(V) endif ifndef KBUILD_VERBOSE KBUILD_VERBOSE = 0 endif ifeq ($(KBUILD_VERBOSE),1) quiet = Q = else quiet=quiet_ Q = @ endif # If the user is running make -s (silent mode), suppress echoing of # commands ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) quiet=silent_ KBUILD_VERBOSE = 0 endif export quiet Q KBUILD_VERBOSE # Call a source code checker (by default, "sparse") as part of the # C compilation. # # Use 'make C=1' to enable checking of only re-compiled files. # Use 'make C=2' to enable checking of *all* source files, regardless # of whether they are re-compiled or not. # # See the file "Documentation/dev-tools/sparse.rst" for more details, # including where to get the "sparse" utility. ifeq ("$(origin C)", "command line") KBUILD_CHECKSRC = $(C) endif ifndef KBUILD_CHECKSRC KBUILD_CHECKSRC = 0 endif export KBUILD_CHECKSRC # Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the # directory of external module to build. Setting M= takes precedence. ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif $(if $(word 2, $(KBUILD_EXTMOD)), \ $(error building multiple external modules is not supported)) # Remove trailing slashes ifneq ($(filter %/, $(KBUILD_EXTMOD)),) KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).) endif export KBUILD_EXTMOD # Kbuild will save output files in the current working directory. # This does not need to match to the root of the kernel source tree. # # For example, you can do this: # # cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile # # If you want to save output files in a different location, there are # two syntaxes to specify it. # # 1) O= # Use "make O=dir/to/store/output/files/" # # 2) Set KBUILD_OUTPUT # Set the environment variable KBUILD_OUTPUT to point to the output directory. # export KBUILD_OUTPUT=dir/to/store/output/files/; make # # The O= assignment takes precedence over the KBUILD_OUTPUT environment # variable. # Do we want to change the working directory? ifeq ("$(origin O)", "command line") KBUILD_OUTPUT := $(O) endif ifneq ($(KBUILD_OUTPUT),) # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot # expand a shell special character '~'. We use a somewhat tedious way here. abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd) $(if $(abs_objtree),, \ $(error failed to create output directory "$(KBUILD_OUTPUT)")) # $(realpath ...) resolves symlinks abs_objtree := $(realpath $(abs_objtree)) else abs_objtree := $(CURDIR) endif # ifneq ($(KBUILD_OUTPUT),) ifeq ($(abs_objtree),$(CURDIR)) # Suppress "Entering directory ..." unless we are changing the work directory. MAKEFLAGS += --no-print-directory else need-sub-make := 1 endif this-makefile := $(lastword $(MAKEFILE_LIST)) abs_srctree := $(realpath $(dir $(this-makefile))) ifneq ($(words $(subst :, ,$(abs_srctree))), 1) $(error source directory cannot contain spaces or colons) endif ifneq ($(abs_srctree),$(abs_objtree)) # Look for make include files relative to root of kernel src # # --included-dir is added for backward compatibility, but you should not rely on # it. Please add $(srctree)/ prefix to include Makefiles in the source tree. MAKEFLAGS += --include-dir=$(abs_srctree) endif ifneq ($(filter 3.%,$(MAKE_VERSION)),) # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x # We need to invoke sub-make to avoid implicit rules in the top Makefile. need-sub-make := 1 # Cancel implicit rules for this Makefile. $(this-makefile): ; endif export abs_srctree abs_objtree export sub_make_done := 1 ifeq ($(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) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS) endif # need-sub-make endif # sub_make_done # We process the rest of the Makefile if this is the final invocation of make ifeq ($(need-sub-make),) # Do not print "Entering directory ...", # but we want to display it when entering to the output directory # so that IDEs/editors are able to understand relative filenames. MAKEFLAGS += --no-print-directory 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 := $(srctree) 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 # Installation targets should not require compiler. Unfortunately, vdso_install # is an exception where build artifacts may be updated. This must be fixed. no-compiler-targets := $(no-dot-config-targets) install dtbs_install \ headers_install modules_install kernelrelease image_name no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \ image_name single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/ config-build := mixed-build := need-config := 1 need-compiler := 1 may-sync-config := 1 single-build := ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) need-config := endif endif ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),) ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),) need-compiler := endif endif ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),) ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),) may-sync-config := endif endif ifneq ($(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 = $(shell cat include/config/kernel.release 2> /dev/null) 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=ia64 # 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=ia64-linux- # 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),) HOSTCC = clang HOSTCXX = clang++ else HOSTCC = gcc HOSTCXX = g++ endif export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ -O2 -fomit-frame-pointer -std=gnu89 export KBUILD_USERLDFLAGS := KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS) KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS) # Make variables (CC, etc...) CPP = $(CC) -E ifneq ($(LLVM),) CC = clang LD = ld.lld AR = llvm-ar NM = llvm-nm OBJCOPY = llvm-objcopy OBJDUMP = llvm-objdump READELF = llvm-readelf STRIP = llvm-strip 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 PAHOLE = pahole RESOLVE_BTFIDS = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids LEX = flex YACC = bison AWK = awk INSTALLKERNEL := installkernel DEPMOD = depmod PERL = perl PYTHON3 = python3 CHECK = sparse BASH = bash KGZIP = gzip KBZIP2 = bzip2 KLZOP = lzop LZMA = lzma LZ4 = lz4c XZ = xz ZSTD = zstd PAHOLE_FLAGS = $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh) CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF) NOSTDINC_FLAGS := CFLAGS_MODULE = AFLAGS_MODULE = LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = LDFLAGS_vmlinux = # Use USERINCLUDE when you must reference the UAPI directories only. USERINCLUDE := \ -I$(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 := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \ -Werror=implicit-function-declaration -Werror=implicit-int \ -Werror=return-type -Wno-format-security \ -std=gnu89 KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_AFLAGS_KERNEL := KBUILD_CFLAGS_KERNEL := KBUILD_AFLAGS_MODULE := -DMODULE KBUILD_CFLAGS_MODULE := -DMODULE KBUILD_LDFLAGS_MODULE := KBUILD_LDFLAGS := CLANG_FLAGS := export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC 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_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL export PAHOLE_FLAGS # 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 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \ --exclude CVS --exclude .pc --exclude .hg --exclude .git # =========================================================================== # 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: $(Q)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 is referenced from Kconfig (so it needs export), # and from include/config/auto.conf.cmd to detect the compiler upgrade. CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1)) ifneq ($(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 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 # 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 ($(MAKECMDGOALS),modules) KBUILD_BUILTIN := endif # If we have "make <whatever> modules", compile modules # in addition to whatever we do anyway. # Just "make" or "make all" shall build modules as well ifneq ($(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 ($(KBUILD_EXTMOD),) # Objects we will link into vmlinux / subdirs we need to visit core-y := init/ usr/ arch/$(SRCARCH)/ drivers-y := drivers/ sound/ drivers-$(CONFIG_SAMPLES) += samples/ drivers-$(CONFIG_NET) += net/ drivers-y += virt/ 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: $(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: $(Q)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 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE KBUILD_CFLAGS += -O2 else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 KBUILD_CFLAGS += -O3 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE KBUILD_CFLAGS += -Os endif # 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 += $(call cc-option,-fno-allow-store-data-races) endif ifdef CONFIG_READABLE_ASM # Disable optimizations that make assembler listings hard to read. # reorder blocks reorders the control in the function # ipa clone creates specialized cloned functions # partial inlining inlines only parts of functions KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining endif ifneq ($(CONFIG_FRAME_WARN),0) KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN) endif stackp-flags-y := -fno-stack-protector stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong KBUILD_CFLAGS += $(stackp-flags-y) KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH) ifdef CONFIG_CC_IS_CLANG KBUILD_CPPFLAGS += -Qunused-arguments # The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable. KBUILD_CFLAGS += -Wno-gnu # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the # source of a reference will be _MergedGlobals and not on of the whitelisted names. # See modpost pattern 2 KBUILD_CFLAGS += -mno-global-merge else # gcc inanely warns about local variables called 'main' KBUILD_CFLAGS += -Wno-main endif # These warnings generated too much noise in a regular build. # Use make W=1 to enable them (see scripts/Makefile.extrawarn) KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls 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. 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_IS_CLANG # https://bugs.llvm.org/show_bug.cgi?id=45497 KBUILD_CFLAGS += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang 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 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT 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 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections LDFLAGS_vmlinux += --gc-sections endif ifdef CONFIG_SHADOW_CALL_STACK CC_FLAGS_SCS := -fsanitize=shadow-call-stack KBUILD_CFLAGS += $(CC_FLAGS_SCS) export CC_FLAGS_SCS endif ifdef CONFIG_LTO_CLANG ifdef CONFIG_LTO_CLANG_THIN CC_FLAGS_LTO := -flto=thin -fsplit-lto-unit KBUILD_LDFLAGS += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache 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 # Check for frame size exceeding threshold during prolog/epilog insertion # when using lld < 13.0.0. ifneq ($(CONFIG_FRAME_WARN),0) ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0) KBUILD_LDFLAGS += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN) endif endif 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=cfi \ -fsanitize-cfi-cross-dso \ -fno-sanitize-cfi-canonical-jump-tables \ -fno-sanitize-trap=cfi \ -fno-sanitize-blacklist ifdef CONFIG_CFI_PERMISSIVE CC_FLAGS_CFI += -fsanitize-recover=cfi endif # If LTO flags are filtered out, we must also filter out CFI. CC_FLAGS_LTO += $(CC_FLAGS_CFI) KBUILD_CFLAGS += $(CC_FLAGS_CFI) export CC_FLAGS_CFI endif ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B KBUILD_CFLAGS += -falign-functions=64 endif # arch Makefile may override CC so keep this after arch Makefile is included NOSTDINC_FLAGS += -nostdinc # warn about C99 declaration after statement KBUILD_CFLAGS += -Wdeclaration-after-statement # Variable Length Arrays (VLAs) should not be used anywhere in the kernel KBUILD_CFLAGS += -Wvla # disable pointer signed / unsigned warnings in gcc 4.0 KBUILD_CFLAGS += -Wno-pointer-sign # In order to make sure new function cast mismatches are not introduced # in the kernel (to avoid tripping CFI checking), the kernel should be # globally built with -Wcast-function-type. KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type) # disable stringop warnings in gcc 8+ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) # We'll want to enable this eventually, but it's not going away for 5.7 at least KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds) KBUILD_CFLAGS += -Wno-array-bounds KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) # Another good warning that we'll want to enable eventually KBUILD_CFLAGS += $(call cc-disable-warning, restrict) # Enabled with W=2, disabled by default as noisy ifdef CONFIG_CC_IS_GCC KBUILD_CFLAGS += -Wno-maybe-uninitialized endif ifdef CONFIG_CC_IS_GCC # The allocators already balk at large sizes, so silence the compiler # warnings for bounds checks involving those possible values. While # -Wno-alloc-size-larger-than would normally be used here, earlier versions # of gcc (<9.1) weirdly don't handle the option correctly when _other_ # warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX # doesn't work (as it is documented to), silently resolving to "0" prior to # version 9.1 (and producing an error more recently). Numeric values larger # than PTRDIFF_MAX also don't work prior to version 9.1, which are silently # ignored, continuing to default to PTRDIFF_MAX. So, left with no other # choice, we must perform a versioned check to disable this warning. # https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than) endif # 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 # Prohibit date/time macros, which would make the build non-deterministic KBUILD_CFLAGS += -Werror=date-time # enforce correct pointer usage KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types) # Require designated initializers for all marked structures KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init) # 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_KASAN) += scripts/Makefile.kasan include-$(CONFIG_KCSAN) += scripts/Makefile.kcsan include-$(CONFIG_UBSAN) += scripts/Makefile.ubsan include-$(CONFIG_KCOV) += scripts/Makefile.kcov 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 and CFLAGS as the last assignments KBUILD_CPPFLAGS += $(KCPPFLAGS) KBUILD_AFLAGS += $(KAFLAGS) KBUILD_CFLAGS += $(KCFLAGS) KBUILD_LDFLAGS_MODULE += --build-id=sha1 LDFLAGS_vmlinux += --build-id=sha1 ifeq ($(CONFIG_STRIP_ASM_SYMS),y) LDFLAGS_vmlinux += $(call ld-option, -X,) endif ifeq ($(CONFIG_RELR),y) LDFLAGS_vmlinux += --pack-dyn-relocs=relr --use-android-relr-tags 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=warn 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),) core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ core-$(CONFIG_BLOCK) += block/ vmlinux-dirs := $(patsubst %/,%,$(filter %/, \ $(core-y) $(core-m) $(drivers-y) $(drivers-m) \ $(libs-y) $(libs-m))) vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \ $(patsubst %/,%,$(filter %/, $(core-) \ $(drivers-) $(libs-)))) subdir-modorder := $(addsuffix modules.order,$(filter %/, \ $(core-y) $(core-m) $(libs-y) $(libs-m) \ $(drivers-y) $(drivers-m))) build-dirs := $(vmlinux-dirs) clean-dirs := $(vmlinux-alldirs) # Externally visible symbols (used by link-vmlinux.sh) KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y)) KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y))) 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 KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y)) export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds # used by scripts/Makefile.package export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools) vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) # Recurse until adjust_autoksyms.sh is satisfied PHONY += autoksyms_recursive 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. # (this can be evaluated only once include/config/auto.conf has been included) KBUILD_MODULES := 1 autoksyms_recursive: descend modules.order $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \ "$(MAKE) -f $(srctree)/Makefile vmlinux" endif autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h) quiet_cmd_autoksyms_h = GEN $@ cmd_autoksyms_h = mkdir -p $(dir $@); \ $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@ $(autoksyms_h): $(call cmd,autoksyms_h) ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink) # Final link of vmlinux with optional arch pass after final link cmd_link-vmlinux = \ $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)"; \ $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE +$(call if_changed_dep,link-vmlinux) targets := vmlinux # The actual objects are generated when descending, # make sure no implicit rule kicks in $(sort $(vmlinux-deps) $(subdir-modorder)): descend ; filechk_kernel.release = \ echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))" # 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) $(autoksyms_h) include/generated/utsrelease.h \ include/generated/autoconf.h remove-stale-files prepare0: archprepare $(Q)$(MAKE) $(build)=scripts/mod $(Q)$(MAKE) $(build)=. # All the preparing.. prepare: prepare0 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-generic 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): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0) $(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0) $(version_h): FORCE $(call filechk,version.h) include/generated/utsrelease.h: include/config/kernel.release FORCE $(call filechk,utsrelease.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 $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \ $(error Headers not exportable for the $(SRCARCH) architecture)) $(Q)$(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 recuses back # to the this Makefile to build and install external modules. # Cancel sub_make_done so that options such as M=, V=, etc. are parsed. install: sub_make_done := # --------------------------------------------------------------------------- # Tools ifdef CONFIG_STACK_VALIDATION prepare: tools/objtool endif ifdef CONFIG_BPF ifdef CONFIG_DEBUG_INFO_BTF prepare: tools/bpf/resolve_btfids endif endif 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: $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests kselftest-%: 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 | \ xargs $(srctree)/scripts/kconfig/merge_config.sh -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: include/config/kernel.release scripts_dtc $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ %.dtbo: include/config/kernel.release scripts_dtc $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ PHONY += dtbs dtbs_install dtbs_check dtbs: include/config/kernel.release scripts_dtc $(Q)$(MAKE) $(build)=$(dtstree) ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),) export CHECK_DTBS=y dtbs: dt_binding_check endif dtbs_check: dtbs dtbs_install: $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH) 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_DT_BINDING=y endif PHONY += dt_binding_check dt_binding_check: scripts_dtc $(Q)$(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 # # A module can be listed more than once in obj-m resulting in # duplicate lines in modules.order files. Those are removed # using awk while concatenating to the final file. PHONY += modules modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@ modules.order: $(subdir-modorder) FORCE $(call if_changed,modules_order) targets += modules.order # Target to prepare building external modules PHONY += modules_prepare modules_prepare: prepare $(Q)$(MAKE) $(build)=scripts scripts/module.lds export modules_sign_only := ifeq ($(CONFIG_MODULE_SIG),y) PHONY += modules_sign modules_sign: modules_install @: # modules_sign is a subset of modules_install. # 'make modules_install modules_sign' is equivalent to 'make modules_install'. ifeq ($(filter modules_install,$(MAKECMDGOALS)),) modules_sign_only := y endif endif modinst_pre := ifneq ($(filter modules_install,$(MAKECMDGOALS)),) modinst_pre := __modinst_pre endif modules_install: $(modinst_pre) PHONY += __modinst_pre __modinst_pre: @rm -rf $(MODLIB)/kernel @rm -f $(MODLIB)/source @mkdir -p $(MODLIB)/kernel @ln -s $(abspath $(srctree)) $(MODLIB)/source @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \ rm -f $(MODLIB)/build ; \ ln -s $(CURDIR) $(MODLIB)/build ; \ fi @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order @cp -f modules.builtin $(MODLIB)/ @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/ endif # CONFIG_MODULES ### # Cleaning is done on three levels. # make clean Delete most generated files # Leave enough to build external modules # make mrproper Delete the current configuration, and all generated files # make distclean Remove editor backup files, patch leftover files and the like # Directories & files removed with 'make clean' CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \ modules.builtin modules.builtin.modinfo modules.nsdeps \ compile_commands.json .thinlto-cache # Directories & files removed with 'make mrproper' MRPROPER_FILES += include/config include/generated \ arch/$(SRCARCH)/include/generated .tmp_objdiff \ debian snap tar-install \ .config .config.old .version \ Module.symvers \ certs/signing_key.pem \ certs/x509.genkey \ vmlinux-gdb.py \ *.spec # clean - Delete most, but leave enough to build external modules # clean: 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: rm-files := $(wildcard $(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) # 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 $(board-dirs:/=))) PHONY += help help: @echo 'Cleaning targets:' @echo ' clean - Remove most generated files but keep the config and' @echo ' enough build support to build external modules' @echo ' mrproper - Remove all generated files + config + various backup files' @echo ' distclean - mrproper + remove editor backup and patch files' @echo '' @echo 'Configuration targets:' @$(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 ' 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: $(INSTALL_HDR_PATH))'; \ echo '' @echo 'Static analysers:' @echo ' checkstack - Generate a list of stack hogs' @echo ' versioncheck - Sanity check on version.h usage' @echo ' includecheck - Check for duplicate included header files' @echo ' export_report - List the usages of all exported symbols' @echo ' headerdep - Detect inclusion cycles in headers' @echo ' coccicheck - Check with Coccinelle' @echo ' clang-analyzer - Check with clang static analyzer' @echo ' clang-tidy - Check with clang-tidy' @echo '' @echo 'Tools:' @echo ' nsdeps - Generate missing symbol namespace dependencies' @echo '' @echo 'Kernel selftest:' @echo ' kselftest - Build and run kernel selftest' @echo ' Build, install, and boot kernel before' @echo ' running kselftest on it' @echo ' Run as root for full coverage' @echo ' kselftest-all - Build kernel selftest' @echo ' kselftest-install - Build and install kernel selftest' @echo ' kselftest-clean - Remove all generated kselftest files' @echo ' kselftest-merge - Merge all the config dependencies of' @echo ' kselftest to existing .config.' @echo '' @$(if $(dtstree), \ echo 'Devicetree:'; \ echo '* dtbs - Build device tree blobs for enabled boards'; \ echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \ echo ' dt_binding_check - Validate device tree binding documents'; \ echo ' dtbs_check - Validate device tree source files';\ echo '') @echo 'Userspace tools targets:' @echo ' use "make tools/help"' @echo ' or "cd tools; make help"' @echo '' @echo 'Kernel packaging:' @$(MAKE) -f $(srctree)/scripts/Makefile.package help @echo '' @echo 'Documentation targets:' @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp @echo '' @echo 'Architecture specific targets ($(SRCARCH)):' @$(if $(archhelp),$(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=0|1 [targets] 0 => quiet build (default), 1 => verbose build' @echo ' make V=2 [targets] 2 => give reason for rebuild of target' @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 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 ' Multiple levels can be combined with W=12 or W=123' @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 PHONY += $(DOC_TARGETS) $(DOC_TARGETS): $(Q)$(MAKE) $(build)=Documentation $@ # Misc # --------------------------------------------------------------------------- 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 ### # 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-dirs := $(KBUILD_EXTMOD) $(MODORDER): descend @: compile_commands.json: $(extmod_prefix)compile_commands.json PHONY += compile_commands.json clean-dirs := $(KBUILD_EXTMOD) clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \ $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache 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 '' # no-op for external module builds PHONY += modules_prepare endif # KBUILD_EXTMOD # --------------------------------------------------------------------------- # Modules PHONY += modules modules_install ifdef CONFIG_MODULES modules: modules_check $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost PHONY += modules_check modules_check: $(MODORDER) $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $< quiet_cmd_depmod = DEPMOD $(MODLIB) cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \ $(KERNELRELEASE) modules_install: $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst $(call cmd,depmod) else # CONFIG_MODULES # Modules not configured # --------------------------------------------------------------------------- modules modules_install: @echo >&2 '***' @echo >&2 '*** The present kernel configuration has modules disabled.' @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.' @echo >&2 '*** to enable CONFIG_MODULES.' @echo >&2 '***' @exit 1 endif # CONFIG_MODULES # 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 := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS))) $(single-ko): single_modpost @: $(single-no-ko): descend @: ifeq ($(KBUILD_EXTMOD),) # For the single build of in-tree modules, use a temporary file to avoid # the situation of modules_install installing an invalid modules.order. MODORDER := .modules.tmp endif PHONY += single_modpost single_modpost: $(single-no-ko) modules_prepare $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER) $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost KBUILD_MODULES := 1 export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko)) # trim unrelated directories build-dirs := $(foreach d, $(build-dirs), \ $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d))) endif ifndef CONFIG_MODULES KBUILD_MODULES := endif # Handle descending into subdirectories listed in $(build-dirs) # 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 += descend $(build-dirs) descend: $(build-dirs) $(build-dirs): prepare $(Q)$(MAKE) $(build)=$@ \ single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \ need-builtin=1 need-modorder=1 clean-dirs := $(addprefix _clean_, $(clean-dirs)) PHONY += $(clean-dirs) clean $(clean-dirs): $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@) clean: $(clean-dirs) $(call cmd,rmfiles) @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \ \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \ -o -name '*.ko.*' \ -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \ -o -name '*.dwo' -o -name '*.lst' \ -o -name '*.su' -o -name '*.mod' \ -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ -o -name '*.lex.c' -o -name '*.tab.[ch]' \ -o -name '*.asn1.[ch]' \ -o -name '*.symtypes' -o -name 'modules.order' \ -o -name '.tmp_*.o.*' \ -o -name '*.c.[012]*.*' \ -o -name '*.ll' \ -o -name '*.gcno' \ -o -name '*.*.symversions' \) -type f -print | xargs rm -f # Generate tags for editors # --------------------------------------------------------------------------- quiet_cmd_tags = GEN $@ cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@ tags TAGS cscope gtags: FORCE $(call cmd,tags) # 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: scripts/clang-tools/gen_compile_commands.py \ $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(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 checkstack: $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \ $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) kernelrelease: @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))" kernelversion: @echo $(KERNELVERSION) image_name: @echo $(KBUILD_IMAGE) 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)