xref: /openbmc/linux/Makefile (revision c0d3b831)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 2
4SUBLEVEL = 0
5EXTRAVERSION = -rc5
6NAME = Hurr durr I'ma ninja sloth
7
8# *DOCUMENTATION*
9# To see a list of typical targets execute "make help"
10# More info can be located in ./README
11# Comments in this file are targeted only to the developer, do not
12# expect to learn how to build the kernel reading this file.
13
14ifeq ($(filter undefine,$(.FEATURES)),)
15$(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41ifneq ($(sub_make_done),1)
42
43# Do not use make's built-in rules and variables
44# (this increases performance and avoids hard-to-debug behaviour)
45MAKEFLAGS += -rR
46
47# Avoid funny character set dependencies
48unexport LC_ALL
49LC_COLLATE=C
50LC_NUMERIC=C
51export LC_COLLATE LC_NUMERIC
52
53# Avoid interference with shell env settings
54unexport GREP_OPTIONS
55
56# Beautify output
57# ---------------------------------------------------------------------------
58#
59# Most of build commands in Kbuild start with "cmd_". You can optionally define
60# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
61# that command is printed by default.
62#
63# e.g.)
64#    quiet_cmd_depmod = DEPMOD  $(MODLIB)
65#          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
66#
67# A simple variant is to prefix commands with $(Q) - that's useful
68# for commands that shall be hidden in non-verbose mode.
69#
70#    $(Q)$(MAKE) $(build)=scripts/basic
71#
72# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
73# If KBUILD_VERBOSE equals 1 then the above command is displayed.
74# If KBUILD_VERBOSE equals 2 then give the reason why each target is rebuilt.
75#
76# To put more focus on warnings, be less verbose as default
77# Use 'make V=1' to see the full commands
78
79ifeq ("$(origin V)", "command line")
80  KBUILD_VERBOSE = $(V)
81endif
82ifndef KBUILD_VERBOSE
83  KBUILD_VERBOSE = 0
84endif
85
86ifeq ($(KBUILD_VERBOSE),1)
87  quiet =
88  Q =
89else
90  quiet=quiet_
91  Q = @
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
97
98ifeq ($(filter 3.%,$(MAKE_VERSION)),)
99short-opts := $(firstword -$(MAKEFLAGS))
100else
101short-opts := $(filter-out --%,$(MAKEFLAGS))
102endif
103
104ifneq ($(findstring s,$(short-opts)),)
105quiet=silent_
106KBUILD_VERBOSE = 0
107endif
108
109export quiet Q KBUILD_VERBOSE
110
111# Call a source code checker (by default, "sparse") as part of the
112# C compilation.
113#
114# Use 'make C=1' to enable checking of only re-compiled files.
115# Use 'make C=2' to enable checking of *all* source files, regardless
116# of whether they are re-compiled or not.
117#
118# See the file "Documentation/dev-tools/sparse.rst" for more details,
119# including where to get the "sparse" utility.
120
121ifeq ("$(origin C)", "command line")
122  KBUILD_CHECKSRC = $(C)
123endif
124ifndef KBUILD_CHECKSRC
125  KBUILD_CHECKSRC = 0
126endif
127
128export KBUILD_CHECKSRC
129
130# Enable "clippy" (a linter) as part of the Rust compilation.
131#
132# Use 'make CLIPPY=1' to enable it.
133ifeq ("$(origin CLIPPY)", "command line")
134  KBUILD_CLIPPY := $(CLIPPY)
135endif
136
137export KBUILD_CLIPPY
138
139# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
140# directory of external module to build. Setting M= takes precedence.
141ifeq ("$(origin M)", "command line")
142  KBUILD_EXTMOD := $(M)
143endif
144
145$(if $(word 2, $(KBUILD_EXTMOD)), \
146	$(error building multiple external modules is not supported))
147
148$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
149	$(error module directory path cannot contain '$x')))
150
151# Remove trailing slashes
152ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
153KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
154endif
155
156export KBUILD_EXTMOD
157
158# Kbuild will save output files in the current working directory.
159# This does not need to match to the root of the kernel source tree.
160#
161# For example, you can do this:
162#
163#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
164#
165# If you want to save output files in a different location, there are
166# two syntaxes to specify it.
167#
168# 1) O=
169# Use "make O=dir/to/store/output/files/"
170#
171# 2) Set KBUILD_OUTPUT
172# Set the environment variable KBUILD_OUTPUT to point to the output directory.
173# export KBUILD_OUTPUT=dir/to/store/output/files/; make
174#
175# The O= assignment takes precedence over the KBUILD_OUTPUT environment
176# variable.
177
178# Do we want to change the working directory?
179ifeq ("$(origin O)", "command line")
180  KBUILD_OUTPUT := $(O)
181endif
182
183ifneq ($(KBUILD_OUTPUT),)
184# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
185# expand a shell special character '~'. We use a somewhat tedious way here.
186abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
187$(if $(abs_objtree),, \
188     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
189
190# $(realpath ...) resolves symlinks
191abs_objtree := $(realpath $(abs_objtree))
192else
193abs_objtree := $(CURDIR)
194endif # ifneq ($(KBUILD_OUTPUT),)
195
196ifeq ($(abs_objtree),$(CURDIR))
197# Suppress "Entering directory ..." unless we are changing the work directory.
198MAKEFLAGS += --no-print-directory
199else
200need-sub-make := 1
201endif
202
203this-makefile := $(lastword $(MAKEFILE_LIST))
204abs_srctree := $(realpath $(dir $(this-makefile)))
205
206ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
207$(error source directory cannot contain spaces or colons)
208endif
209
210ifneq ($(abs_srctree),$(abs_objtree))
211# Look for make include files relative to root of kernel src
212#
213# --included-dir is added for backward compatibility, but you should not rely on
214# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
215MAKEFLAGS += --include-dir=$(abs_srctree)
216endif
217
218ifneq ($(filter 3.%,$(MAKE_VERSION)),)
219# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
220# We need to invoke sub-make to avoid implicit rules in the top Makefile.
221need-sub-make := 1
222# Cancel implicit rules for this Makefile.
223$(this-makefile): ;
224endif
225
226export abs_srctree abs_objtree
227export sub_make_done := 1
228
229ifeq ($(need-sub-make),1)
230
231PHONY += $(MAKECMDGOALS) __sub-make
232
233$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
234	@:
235
236# Invoke a second make in the output directory, passing relevant variables
237__sub-make:
238	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
239
240endif # need-sub-make
241endif # sub_make_done
242
243# We process the rest of the Makefile if this is the final invocation of make
244ifeq ($(need-sub-make),)
245
246# Do not print "Entering directory ...",
247# but we want to display it when entering to the output directory
248# so that IDEs/editors are able to understand relative filenames.
249MAKEFLAGS += --no-print-directory
250
251ifeq ($(abs_srctree),$(abs_objtree))
252        # building in the source tree
253        srctree := .
254	building_out_of_srctree :=
255else
256        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
257                # building in a subdirectory of the source tree
258                srctree := ..
259        else
260                srctree := $(abs_srctree)
261        endif
262	building_out_of_srctree := 1
263endif
264
265ifneq ($(KBUILD_ABS_SRCTREE),)
266srctree := $(abs_srctree)
267endif
268
269objtree		:= .
270VPATH		:= $(srctree)
271
272export building_out_of_srctree srctree objtree VPATH
273
274# To make sure we do not include .config for any of the *config targets
275# catch them early, and hand them over to scripts/kconfig/Makefile
276# It is allowed to specify more targets when calling make, including
277# mixing *config targets and build targets.
278# For example 'make oldconfig all'.
279# Detect when mixed targets is specified, and make a second invocation
280# of make so .config is not included in this case either (for *config).
281
282version_h := include/generated/uapi/linux/version.h
283
284clean-targets := %clean mrproper cleandocs
285no-dot-config-targets := $(clean-targets) \
286			 cscope gtags TAGS tags help% %docs check% coccicheck \
287			 $(version_h) headers headers_% archheaders archscripts \
288			 %asm-generic kernelversion %src-pkg dt_binding_check \
289			 outputmakefile rustavailable rustfmt rustfmtcheck
290# Installation targets should not require compiler. Unfortunately, vdso_install
291# is an exception where build artifacts may be updated. This must be fixed.
292no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
293			headers_install modules_install kernelrelease image_name
294no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
295			  image_name
296single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
297
298config-build	:=
299mixed-build	:=
300need-config	:= 1
301need-compiler	:= 1
302may-sync-config	:= 1
303single-build	:=
304
305ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
306	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
307		need-config :=
308	endif
309endif
310
311ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
312	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
313		need-compiler :=
314	endif
315endif
316
317ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
318	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
319		may-sync-config :=
320	endif
321endif
322
323ifneq ($(KBUILD_EXTMOD),)
324	may-sync-config :=
325endif
326
327ifeq ($(KBUILD_EXTMOD),)
328        ifneq ($(filter %config,$(MAKECMDGOALS)),)
329		config-build := 1
330                ifneq ($(words $(MAKECMDGOALS)),1)
331			mixed-build := 1
332                endif
333        endif
334endif
335
336# We cannot build single targets and the others at the same time
337ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
338	single-build := 1
339	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
340		mixed-build := 1
341	endif
342endif
343
344# For "make -j clean all", "make -j mrproper defconfig all", etc.
345ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
346        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
347		mixed-build := 1
348        endif
349endif
350
351# install and modules_install need also be processed one by one
352ifneq ($(filter install,$(MAKECMDGOALS)),)
353        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
354		mixed-build := 1
355        endif
356endif
357
358ifdef mixed-build
359# ===========================================================================
360# We're called with mixed targets (*config and build targets).
361# Handle them one by one.
362
363PHONY += $(MAKECMDGOALS) __build_one_by_one
364
365$(MAKECMDGOALS): __build_one_by_one
366	@:
367
368__build_one_by_one:
369	$(Q)set -e; \
370	for i in $(MAKECMDGOALS); do \
371		$(MAKE) -f $(srctree)/Makefile $$i; \
372	done
373
374else # !mixed-build
375
376include $(srctree)/scripts/Kbuild.include
377
378# Read KERNELRELEASE from include/config/kernel.release (if it exists)
379KERNELRELEASE = $(call read-file, include/config/kernel.release)
380KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
381export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
382
383include $(srctree)/scripts/subarch.include
384
385# Cross compiling and selecting different set of gcc/bin-utils
386# ---------------------------------------------------------------------------
387#
388# When performing cross compilation for other architectures ARCH shall be set
389# to the target architecture. (See arch/* for the possibilities).
390# ARCH can be set during invocation of make:
391# make ARCH=ia64
392# Another way is to have ARCH set in the environment.
393# The default ARCH is the host where make is executed.
394
395# CROSS_COMPILE specify the prefix used for all executables used
396# during compilation. Only gcc and related bin-utils executables
397# are prefixed with $(CROSS_COMPILE).
398# CROSS_COMPILE can be set on the command line
399# make CROSS_COMPILE=ia64-linux-
400# Alternatively CROSS_COMPILE can be set in the environment.
401# Default value for CROSS_COMPILE is not to prefix executables
402# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
403ARCH		?= $(SUBARCH)
404
405# Architecture as present in compile.h
406UTS_MACHINE 	:= $(ARCH)
407SRCARCH 	:= $(ARCH)
408
409# Additional ARCH settings for x86
410ifeq ($(ARCH),i386)
411        SRCARCH := x86
412endif
413ifeq ($(ARCH),x86_64)
414        SRCARCH := x86
415endif
416
417# Additional ARCH settings for sparc
418ifeq ($(ARCH),sparc32)
419       SRCARCH := sparc
420endif
421ifeq ($(ARCH),sparc64)
422       SRCARCH := sparc
423endif
424
425# Additional ARCH settings for parisc
426ifeq ($(ARCH),parisc64)
427       SRCARCH := parisc
428endif
429
430export cross_compiling :=
431ifneq ($(SRCARCH),$(SUBARCH))
432cross_compiling := 1
433endif
434
435KCONFIG_CONFIG	?= .config
436export KCONFIG_CONFIG
437
438# SHELL used by kbuild
439CONFIG_SHELL := sh
440
441HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
442HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
443HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
444
445ifneq ($(LLVM),)
446ifneq ($(filter %/,$(LLVM)),)
447LLVM_PREFIX := $(LLVM)
448else ifneq ($(filter -%,$(LLVM)),)
449LLVM_SUFFIX := $(LLVM)
450endif
451
452HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
453HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
454else
455HOSTCC	= gcc
456HOSTCXX	= g++
457endif
458HOSTRUSTC = rustc
459HOSTPKG_CONFIG	= pkg-config
460
461KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
462			 -O2 -fomit-frame-pointer -std=gnu11 \
463			 -Wdeclaration-after-statement
464KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
465KBUILD_USERLDFLAGS := $(USERLDFLAGS)
466
467# These flags apply to all Rust code in the tree, including the kernel and
468# host programs.
469export rust_common_flags := --edition=2021 \
470			    -Zbinary_dep_depinfo=y \
471			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
472			    -Dunreachable_pub -Dnon_ascii_idents \
473			    -Wmissing_docs \
474			    -Drustdoc::missing_crate_level_docs \
475			    -Dclippy::correctness -Dclippy::style \
476			    -Dclippy::suspicious -Dclippy::complexity \
477			    -Dclippy::perf \
478			    -Dclippy::let_unit_value -Dclippy::mut_mut \
479			    -Dclippy::needless_bitwise_bool \
480			    -Dclippy::needless_continue \
481			    -Wclippy::dbg_macro
482
483KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
484KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
485KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
486			-Zallow-features= $(HOSTRUSTFLAGS)
487KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
488KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
489
490# Make variables (CC, etc...)
491CPP		= $(CC) -E
492ifneq ($(LLVM),)
493CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
494LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
495AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
496NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
497OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
498OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
499READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
500STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
501else
502CC		= $(CROSS_COMPILE)gcc
503LD		= $(CROSS_COMPILE)ld
504AR		= $(CROSS_COMPILE)ar
505NM		= $(CROSS_COMPILE)nm
506OBJCOPY		= $(CROSS_COMPILE)objcopy
507OBJDUMP		= $(CROSS_COMPILE)objdump
508READELF		= $(CROSS_COMPILE)readelf
509STRIP		= $(CROSS_COMPILE)strip
510endif
511RUSTC		= rustc
512RUSTDOC		= rustdoc
513RUSTFMT		= rustfmt
514CLIPPY_DRIVER	= clippy-driver
515BINDGEN		= bindgen
516CARGO		= cargo
517PAHOLE		= pahole
518RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
519LEX		= flex
520YACC		= bison
521AWK		= awk
522INSTALLKERNEL  := installkernel
523DEPMOD		= depmod
524PERL		= perl
525PYTHON3		= python3
526CHECK		= sparse
527BASH		= bash
528KGZIP		= gzip
529KBZIP2		= bzip2
530KLZOP		= lzop
531LZMA		= lzma
532LZ4		= lz4c
533XZ		= xz
534ZSTD		= zstd
535
536PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
537
538CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
539		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
540NOSTDINC_FLAGS :=
541CFLAGS_MODULE   =
542RUSTFLAGS_MODULE =
543AFLAGS_MODULE   =
544LDFLAGS_MODULE  =
545CFLAGS_KERNEL	=
546RUSTFLAGS_KERNEL =
547AFLAGS_KERNEL	=
548LDFLAGS_vmlinux =
549
550# Use USERINCLUDE when you must reference the UAPI directories only.
551USERINCLUDE    := \
552		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
553		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
554		-I$(srctree)/include/uapi \
555		-I$(objtree)/include/generated/uapi \
556                -include $(srctree)/include/linux/compiler-version.h \
557                -include $(srctree)/include/linux/kconfig.h
558
559# Use LINUXINCLUDE when you must reference the include/ directory.
560# Needed to be compatible with the O= option
561LINUXINCLUDE    := \
562		-I$(srctree)/arch/$(SRCARCH)/include \
563		-I$(objtree)/arch/$(SRCARCH)/include/generated \
564		$(if $(building_out_of_srctree),-I$(srctree)/include) \
565		-I$(objtree)/include \
566		$(USERINCLUDE)
567
568KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
569KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
570		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
571		   -Werror=implicit-function-declaration -Werror=implicit-int \
572		   -Werror=return-type -Wno-format-security -funsigned-char \
573		   -std=gnu11
574KBUILD_CPPFLAGS := -D__KERNEL__
575KBUILD_RUSTFLAGS := $(rust_common_flags) \
576		    --target=$(objtree)/rust/target.json \
577		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
578		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
579		    -Csymbol-mangling-version=v0 \
580		    -Crelocation-model=static \
581		    -Zfunction-sections=n \
582		    -Dclippy::float_arithmetic
583
584KBUILD_AFLAGS_KERNEL :=
585KBUILD_CFLAGS_KERNEL :=
586KBUILD_RUSTFLAGS_KERNEL :=
587KBUILD_AFLAGS_MODULE  := -DMODULE
588KBUILD_CFLAGS_MODULE  := -DMODULE
589KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
590KBUILD_LDFLAGS_MODULE :=
591KBUILD_LDFLAGS :=
592CLANG_FLAGS :=
593
594ifeq ($(KBUILD_CLIPPY),1)
595	RUSTC_OR_CLIPPY_QUIET := CLIPPY
596	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
597else
598	RUSTC_OR_CLIPPY_QUIET := RUSTC
599	RUSTC_OR_CLIPPY = $(RUSTC)
600endif
601
602ifdef RUST_LIB_SRC
603	export RUST_LIB_SRC
604endif
605
606# Allows the usage of unstable features in stable compilers.
607export RUSTC_BOOTSTRAP := 1
608
609export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
610export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
611export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
612export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
613export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
614export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
615export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
616export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
617
618export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
619export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
620export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
621export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
622export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
623export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
624export PAHOLE_FLAGS
625
626# Files to ignore in find ... statements
627
628export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
629			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
630			  -prune -o
631export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
632			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
633
634# ===========================================================================
635# Rules shared between *config targets and build targets
636
637# Basic helpers built in scripts/basic/
638PHONY += scripts_basic
639scripts_basic:
640	$(Q)$(MAKE) $(build)=scripts/basic
641
642PHONY += outputmakefile
643ifdef building_out_of_srctree
644# Before starting out-of-tree build, make sure the source tree is clean.
645# outputmakefile generates a Makefile in the output directory, if using a
646# separate output directory. This allows convenient use of make in the
647# output directory.
648# At the same time when output Makefile generated, generate .gitignore to
649# ignore whole output directory
650
651quiet_cmd_makefile = GEN     Makefile
652      cmd_makefile = { \
653	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
654	echo "include $(srctree)/Makefile"; \
655	} > Makefile
656
657outputmakefile:
658	@if [ -f $(srctree)/.config -o \
659		 -d $(srctree)/include/config -o \
660		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
661		echo >&2 "***"; \
662		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
663		echo >&2 "*** in $(abs_srctree)";\
664		echo >&2 "***"; \
665		false; \
666	fi
667	$(Q)ln -fsn $(srctree) source
668	$(call cmd,makefile)
669	$(Q)test -e .gitignore || \
670	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
671endif
672
673# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
674# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
675# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
676# and from include/config/auto.conf.cmd to detect the compiler upgrade.
677CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
678
679ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
680include $(srctree)/scripts/Makefile.clang
681endif
682
683# Include this also for config targets because some architectures need
684# cc-cross-prefix to determine CROSS_COMPILE.
685ifdef need-compiler
686include $(srctree)/scripts/Makefile.compiler
687endif
688
689ifdef config-build
690# ===========================================================================
691# *config targets only - make sure prerequisites are updated, and descend
692# in scripts/kconfig to make the *config target
693
694# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
695# KBUILD_DEFCONFIG may point out an alternative default configuration
696# used for 'make defconfig'
697include $(srctree)/arch/$(SRCARCH)/Makefile
698export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
699
700config: outputmakefile scripts_basic FORCE
701	$(Q)$(MAKE) $(build)=scripts/kconfig $@
702
703%config: outputmakefile scripts_basic FORCE
704	$(Q)$(MAKE) $(build)=scripts/kconfig $@
705
706else #!config-build
707# ===========================================================================
708# Build targets only - this includes vmlinux, arch specific targets, clean
709# targets and others. In general all targets except *config targets.
710
711# If building an external module we do not care about the all: rule
712# but instead __all depend on modules
713PHONY += all
714ifeq ($(KBUILD_EXTMOD),)
715__all: all
716else
717__all: modules
718endif
719
720targets :=
721
722# Decide whether to build built-in, modular, or both.
723# Normally, just do built-in.
724
725KBUILD_MODULES :=
726KBUILD_BUILTIN := 1
727
728# If we have only "make modules", don't compile built-in objects.
729ifeq ($(MAKECMDGOALS),modules)
730  KBUILD_BUILTIN :=
731endif
732
733# If we have "make <whatever> modules", compile modules
734# in addition to whatever we do anyway.
735# Just "make" or "make all" shall build modules as well
736
737ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
738  KBUILD_MODULES := 1
739endif
740
741ifeq ($(MAKECMDGOALS),)
742  KBUILD_MODULES := 1
743endif
744
745export KBUILD_MODULES KBUILD_BUILTIN
746
747ifdef need-config
748include include/config/auto.conf
749endif
750
751ifeq ($(KBUILD_EXTMOD),)
752# Objects we will link into vmlinux / subdirs we need to visit
753core-y		:=
754drivers-y	:=
755libs-y		:= lib/
756endif # KBUILD_EXTMOD
757
758# The all: target is the default when no target is given on the
759# command line.
760# This allow a user to issue only 'make' to build a kernel including modules
761# Defaults to vmlinux, but the arch makefile usually adds further targets
762all: vmlinux
763
764CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
765ifdef CONFIG_CC_IS_GCC
766CFLAGS_GCOV	+= -fno-tree-loop-im
767endif
768export CFLAGS_GCOV
769
770# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
771ifdef CONFIG_FUNCTION_TRACER
772  CC_FLAGS_FTRACE := -pg
773endif
774
775include $(srctree)/arch/$(SRCARCH)/Makefile
776
777ifdef need-config
778ifdef may-sync-config
779# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
780# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
781# because some architectures define CROSS_COMPILE there.
782include include/config/auto.conf.cmd
783
784$(KCONFIG_CONFIG):
785	@echo >&2 '***'
786	@echo >&2 '*** Configuration file "$@" not found!'
787	@echo >&2 '***'
788	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
789	@echo >&2 '*** "make menuconfig" or "make xconfig").'
790	@echo >&2 '***'
791	@/bin/false
792
793# The actual configuration files used during the build are stored in
794# include/generated/ and include/config/. Update them if .config is newer than
795# include/config/auto.conf (which mirrors .config).
796#
797# This exploits the 'multi-target pattern rule' trick.
798# The syncconfig should be executed only once to make all the targets.
799# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
800#
801# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
802# so you cannot notice that Kconfig is waiting for the user input.
803%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
804	$(Q)$(kecho) "  SYNC    $@"
805	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
806else # !may-sync-config
807# External modules and some install targets need include/generated/autoconf.h
808# and include/config/auto.conf but do not care if they are up-to-date.
809# Use auto.conf to trigger the test
810PHONY += include/config/auto.conf
811
812include/config/auto.conf:
813	@test -e include/generated/autoconf.h -a -e $@ || (		\
814	echo >&2;							\
815	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
816	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
817	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
818	echo >&2 ;							\
819	/bin/false)
820
821endif # may-sync-config
822endif # need-config
823
824KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
825KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
826KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
827KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
828KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
829
830ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
831KBUILD_CFLAGS += -O2
832KBUILD_RUSTFLAGS += -Copt-level=2
833else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
834KBUILD_CFLAGS += -Os
835KBUILD_RUSTFLAGS += -Copt-level=s
836endif
837
838# Always set `debug-assertions` and `overflow-checks` because their default
839# depends on `opt-level` and `debug-assertions`, respectively.
840KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
841KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
842
843# Tell gcc to never replace conditional load with a non-conditional one
844ifdef CONFIG_CC_IS_GCC
845# gcc-10 renamed --param=allow-store-data-races=0 to
846# -fno-allow-store-data-races.
847KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
848KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
849endif
850
851ifdef CONFIG_READABLE_ASM
852# Disable optimizations that make assembler listings hard to read.
853# reorder blocks reorders the control in the function
854# ipa clone creates specialized cloned functions
855# partial inlining inlines only parts of functions
856KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
857endif
858
859ifneq ($(CONFIG_FRAME_WARN),0)
860KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
861endif
862
863stackp-flags-y                                    := -fno-stack-protector
864stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
865stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
866
867KBUILD_CFLAGS += $(stackp-flags-y)
868
869KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror
870KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y)
871KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
872
873KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
874KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
875
876ifdef CONFIG_CC_IS_CLANG
877KBUILD_CPPFLAGS += -Qunused-arguments
878# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
879KBUILD_CFLAGS += -Wno-gnu
880else
881
882# gcc inanely warns about local variables called 'main'
883KBUILD_CFLAGS += -Wno-main
884endif
885
886# These warnings generated too much noise in a regular build.
887# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
888KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
889KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
890
891# These result in bogus false positives
892KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
893
894ifdef CONFIG_FRAME_POINTER
895KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
896KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
897else
898# Some targets (ARM with Thumb2, for example), can't be built with frame
899# pointers.  For those, we don't have FUNCTION_TRACER automatically
900# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
901# incompatible with -fomit-frame-pointer with current GCC, so we don't use
902# -fomit-frame-pointer with FUNCTION_TRACER.
903# In the Rust target specification, "frame-pointer" is set explicitly
904# to "may-omit".
905ifndef CONFIG_FUNCTION_TRACER
906KBUILD_CFLAGS	+= -fomit-frame-pointer
907endif
908endif
909
910# Initialize all stack variables with a 0xAA pattern.
911ifdef CONFIG_INIT_STACK_ALL_PATTERN
912KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
913endif
914
915# Initialize all stack variables with a zero value.
916ifdef CONFIG_INIT_STACK_ALL_ZERO
917KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
918ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
919# https://github.com/llvm/llvm-project/issues/44842
920KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
921endif
922endif
923
924# While VLAs have been removed, GCC produces unreachable stack probes
925# for the randomize_kstack_offset feature. Disable it for all compilers.
926KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
927
928# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
929ifdef CONFIG_ZERO_CALL_USED_REGS
930KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
931endif
932
933ifdef CONFIG_FUNCTION_TRACER
934ifdef CONFIG_FTRACE_MCOUNT_USE_CC
935  CC_FLAGS_FTRACE	+= -mrecord-mcount
936  ifdef CONFIG_HAVE_NOP_MCOUNT
937    ifeq ($(call cc-option-yn, -mnop-mcount),y)
938      CC_FLAGS_FTRACE	+= -mnop-mcount
939      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
940    endif
941  endif
942endif
943ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
944  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
945    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
946  endif
947endif
948ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
949  ifdef CONFIG_HAVE_C_RECORDMCOUNT
950    BUILD_C_RECORDMCOUNT := y
951    export BUILD_C_RECORDMCOUNT
952  endif
953endif
954ifdef CONFIG_HAVE_FENTRY
955  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
956  ifeq ($(call cc-option-yn, -mfentry),y)
957    CC_FLAGS_FTRACE	+= -mfentry
958    CC_FLAGS_USING	+= -DCC_USING_FENTRY
959  endif
960endif
961export CC_FLAGS_FTRACE
962KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
963KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
964endif
965
966# We trigger additional mismatches with less inlining
967ifdef CONFIG_DEBUG_SECTION_MISMATCH
968KBUILD_CFLAGS += -fno-inline-functions-called-once
969endif
970
971# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
972ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
973KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
974KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
975LDFLAGS_vmlinux += --gc-sections
976endif
977
978ifdef CONFIG_SHADOW_CALL_STACK
979ifndef CONFIG_DYNAMIC_SCS
980CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
981KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
982endif
983export CC_FLAGS_SCS
984endif
985
986ifdef CONFIG_LTO_CLANG
987ifdef CONFIG_LTO_CLANG_THIN
988CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
989KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
990else
991CC_FLAGS_LTO	:= -flto
992endif
993CC_FLAGS_LTO	+= -fvisibility=hidden
994
995# Limit inlining across translation units to reduce binary size
996KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
997
998# Check for frame size exceeding threshold during prolog/epilog insertion
999# when using lld < 13.0.0.
1000ifneq ($(CONFIG_FRAME_WARN),0)
1001ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
1002KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
1003endif
1004endif
1005endif
1006
1007ifdef CONFIG_LTO
1008KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
1009KBUILD_AFLAGS	+= -fno-lto
1010export CC_FLAGS_LTO
1011endif
1012
1013ifdef CONFIG_CFI_CLANG
1014CC_FLAGS_CFI	:= -fsanitize=kcfi
1015KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1016export CC_FLAGS_CFI
1017endif
1018
1019ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1020KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1021endif
1022
1023# arch Makefile may override CC so keep this after arch Makefile is included
1024NOSTDINC_FLAGS += -nostdinc
1025
1026# warn about C99 declaration after statement
1027KBUILD_CFLAGS += -Wdeclaration-after-statement
1028
1029# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
1030KBUILD_CFLAGS += -Wvla
1031
1032# disable pointer signed / unsigned warnings in gcc 4.0
1033KBUILD_CFLAGS += -Wno-pointer-sign
1034
1035# In order to make sure new function cast mismatches are not introduced
1036# in the kernel (to avoid tripping CFI checking), the kernel should be
1037# globally built with -Wcast-function-type.
1038KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
1039
1040# disable stringop warnings in gcc 8+
1041KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1042
1043# We'll want to enable this eventually, but it's not going away for 5.7 at least
1044KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1045
1046# Another good warning that we'll want to enable eventually
1047KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1048
1049# Enabled with W=2, disabled by default as noisy
1050ifdef CONFIG_CC_IS_GCC
1051KBUILD_CFLAGS += -Wno-maybe-uninitialized
1052endif
1053
1054# The allocators already balk at large sizes, so silence the compiler
1055# warnings for bounds checks involving those possible values. While
1056# -Wno-alloc-size-larger-than would normally be used here, earlier versions
1057# of gcc (<9.1) weirdly don't handle the option correctly when _other_
1058# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
1059# doesn't work (as it is documented to), silently resolving to "0" prior to
1060# version 9.1 (and producing an error more recently). Numeric values larger
1061# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
1062# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
1063# choice, we must perform a versioned check to disable this warning.
1064# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
1065KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
1066KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
1067
1068# disable invalid "can't wrap" optimizations for signed / pointers
1069KBUILD_CFLAGS	+= -fno-strict-overflow
1070
1071# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1072KBUILD_CFLAGS  += -fno-stack-check
1073
1074# conserve stack if available
1075ifdef CONFIG_CC_IS_GCC
1076KBUILD_CFLAGS   += -fconserve-stack
1077endif
1078
1079# Prohibit date/time macros, which would make the build non-deterministic
1080KBUILD_CFLAGS   += -Werror=date-time
1081
1082# enforce correct pointer usage
1083KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1084
1085# Require designated initializers for all marked structures
1086KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1087
1088# change __FILE__ to the relative path from the srctree
1089KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1090
1091# include additional Makefiles when needed
1092include-y			:= scripts/Makefile.extrawarn
1093include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1094include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1095include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1096include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1097include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1098include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1099include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1100include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1101
1102include $(addprefix $(srctree)/, $(include-y))
1103
1104# scripts/Makefile.gcc-plugins is intentionally included last.
1105# Do not add $(call cc-option,...) below this line. When you build the kernel
1106# from the clean source tree, the GCC plugins do not exist at this point.
1107
1108# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1109KBUILD_CPPFLAGS += $(KCPPFLAGS)
1110KBUILD_AFLAGS   += $(KAFLAGS)
1111KBUILD_CFLAGS   += $(KCFLAGS)
1112KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1113
1114KBUILD_LDFLAGS_MODULE += --build-id=sha1
1115LDFLAGS_vmlinux += --build-id=sha1
1116
1117KBUILD_LDFLAGS	+= -z noexecstack
1118ifeq ($(CONFIG_LD_IS_BFD),y)
1119KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1120endif
1121
1122ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1123LDFLAGS_vmlinux	+= -X
1124endif
1125
1126ifeq ($(CONFIG_RELR),y)
1127LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1128endif
1129
1130# We never want expected sections to be placed heuristically by the
1131# linker. All sections should be explicitly named in the linker script.
1132ifdef CONFIG_LD_ORPHAN_WARN
1133LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1134endif
1135
1136# Align the bit size of userspace programs with the kernel
1137KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1138KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1139
1140# make the checker run with the right architecture
1141CHECKFLAGS += --arch=$(ARCH)
1142
1143# insure the checker run with the right endianness
1144CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1145
1146# the checker needs the correct machine size
1147CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1148
1149# Default kernel image to build when no specific target is given.
1150# KBUILD_IMAGE may be overruled on the command line or
1151# set in the environment
1152# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1153# this default value
1154export KBUILD_IMAGE ?= vmlinux
1155
1156#
1157# INSTALL_PATH specifies where to place the updated kernel and system map
1158# images. Default is /boot, but you can set it to other values
1159export	INSTALL_PATH ?= /boot
1160
1161#
1162# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1163# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1164# an argument if needed. Otherwise it defaults to the kernel install path
1165#
1166export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1167
1168#
1169# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1170# relocations required by build roots.  This is not defined in the
1171# makefile but the argument can be passed to make if needed.
1172#
1173
1174MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1175export MODLIB
1176
1177PHONY += prepare0
1178
1179export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1180export MODORDER := $(extmod_prefix)modules.order
1181export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1182
1183ifeq ($(KBUILD_EXTMOD),)
1184
1185build-dir	:= .
1186clean-dirs	:= $(sort . Documentation \
1187		     $(patsubst %/,%,$(filter %/, $(core-) \
1188			$(drivers-) $(libs-))))
1189
1190export ARCH_CORE	:= $(core-y)
1191export ARCH_LIB		:= $(filter %/, $(libs-y))
1192export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1193# Externally visible symbols (used by link-vmlinux.sh)
1194
1195KBUILD_VMLINUX_OBJS := ./built-in.a
1196ifdef CONFIG_MODULES
1197KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1198KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1199else
1200KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1201endif
1202
1203export KBUILD_VMLINUX_LIBS
1204export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1205
1206# Recurse until adjust_autoksyms.sh is satisfied
1207PHONY += autoksyms_recursive
1208ifdef CONFIG_TRIM_UNUSED_KSYMS
1209# For the kernel to actually contain only the needed exported symbols,
1210# we have to build modules as well to determine what those symbols are.
1211# (this can be evaluated only once include/config/auto.conf has been included)
1212KBUILD_MODULES := 1
1213
1214autoksyms_recursive: $(build-dir) modules.order
1215	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1216	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
1217endif
1218
1219autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1220
1221quiet_cmd_autoksyms_h = GEN     $@
1222      cmd_autoksyms_h = mkdir -p $(dir $@); \
1223			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1224
1225$(autoksyms_h):
1226	$(call cmd,autoksyms_h)
1227
1228# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1229quiet_cmd_ar_vmlinux.a = AR      $@
1230      cmd_ar_vmlinux.a = \
1231	rm -f $@; \
1232	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1233	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1234
1235targets += vmlinux.a
1236vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE
1237	$(call if_changed,ar_vmlinux.a)
1238
1239PHONY += vmlinux_o
1240vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1241	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1242
1243vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1244	@:
1245
1246PHONY += vmlinux
1247# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1248# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1249# unrelated; the decompressors just happen to have the same base name,
1250# arch/*/boot/compressed/vmlinux.
1251# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1252#
1253# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1254#   https://savannah.gnu.org/bugs/?61463
1255# For Make > 4.4, the following simple code will work:
1256#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1257vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1258vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1259vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1260	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1261
1262# The actual objects are generated when descending,
1263# make sure no implicit rule kicks in
1264$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1265
1266filechk_kernel.release = \
1267	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1268
1269# Store (new) KERNELRELEASE string in include/config/kernel.release
1270include/config/kernel.release: FORCE
1271	$(call filechk,kernel.release)
1272
1273# Additional helpers built in scripts/
1274# Carefully list dependencies so we do not try to build scripts twice
1275# in parallel
1276PHONY += scripts
1277scripts: scripts_basic scripts_dtc
1278	$(Q)$(MAKE) $(build)=$(@)
1279
1280# Things we need to do before we recursively start building the kernel
1281# or the modules are listed in "prepare".
1282# A multi level approach is used. prepareN is processed before prepareN-1.
1283# archprepare is used in arch Makefiles and when processed asm symlink,
1284# version.h and scripts_basic is processed / created.
1285
1286PHONY += prepare archprepare
1287
1288archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1289	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1290	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1291
1292prepare0: archprepare
1293	$(Q)$(MAKE) $(build)=scripts/mod
1294	$(Q)$(MAKE) $(build)=. prepare
1295
1296# All the preparing..
1297prepare: prepare0
1298ifdef CONFIG_RUST
1299	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v
1300	$(Q)$(MAKE) $(build)=rust
1301endif
1302
1303PHONY += remove-stale-files
1304remove-stale-files:
1305	$(Q)$(srctree)/scripts/remove-stale-files
1306
1307# Support for using generic headers in asm-generic
1308asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1309
1310PHONY += asm-generic uapi-asm-generic
1311asm-generic: uapi-asm-generic
1312	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1313	generic=include/asm-generic
1314uapi-asm-generic:
1315	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1316	generic=include/uapi/asm-generic
1317
1318# Generate some files
1319# ---------------------------------------------------------------------------
1320
1321# KERNELRELEASE can change from a few different places, meaning version.h
1322# needs to be updated, so this check is forced on all builds
1323
1324uts_len := 64
1325define filechk_utsrelease.h
1326	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1327	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1328	  exit 1;                                                         \
1329	fi;                                                               \
1330	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1331endef
1332
1333define filechk_version.h
1334	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1335		echo \#define LINUX_VERSION_CODE $(shell                 \
1336		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1337	else                                                             \
1338		echo \#define LINUX_VERSION_CODE $(shell                 \
1339		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1340	fi;                                                              \
1341	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1342	((c) > 255 ? 255 : (c)))';                                       \
1343	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1344	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1345	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1346endef
1347
1348$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1349$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1350$(version_h): FORCE
1351	$(call filechk,version.h)
1352
1353include/generated/utsrelease.h: include/config/kernel.release FORCE
1354	$(call filechk,utsrelease.h)
1355
1356filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1357	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1358
1359include/generated/compile.h: FORCE
1360	$(call filechk,compile.h)
1361
1362PHONY += headerdep
1363headerdep:
1364	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1365	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1366
1367# ---------------------------------------------------------------------------
1368# Kernel headers
1369
1370#Default location for installed headers
1371export INSTALL_HDR_PATH = $(objtree)/usr
1372
1373quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1374      cmd_headers_install = \
1375	mkdir -p $(INSTALL_HDR_PATH); \
1376	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1377	usr/include $(INSTALL_HDR_PATH)
1378
1379PHONY += headers_install
1380headers_install: headers
1381	$(call cmd,headers_install)
1382
1383PHONY += archheaders archscripts
1384
1385hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1386
1387PHONY += headers
1388headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1389	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1390	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1391	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1392
1393ifdef CONFIG_HEADERS_INSTALL
1394prepare: headers
1395endif
1396
1397PHONY += scripts_unifdef
1398scripts_unifdef: scripts_basic
1399	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1400
1401# ---------------------------------------------------------------------------
1402# Install
1403
1404# Many distributions have the custom install script, /sbin/installkernel.
1405# If DKMS is installed, 'make install' will eventually recurse back
1406# to this Makefile to build and install external modules.
1407# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1408
1409quiet_cmd_install = INSTALL $(INSTALL_PATH)
1410      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1411
1412# ---------------------------------------------------------------------------
1413# Tools
1414
1415ifdef CONFIG_OBJTOOL
1416prepare: tools/objtool
1417endif
1418
1419ifdef CONFIG_BPF
1420ifdef CONFIG_DEBUG_INFO_BTF
1421prepare: tools/bpf/resolve_btfids
1422endif
1423endif
1424
1425PHONY += resolve_btfids_clean
1426
1427resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1428
1429# tools/bpf/resolve_btfids directory might not exist
1430# in output directory, skip its clean in that case
1431resolve_btfids_clean:
1432ifneq ($(wildcard $(resolve_btfids_O)),)
1433	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1434endif
1435
1436# Clear a bunch of variables before executing the submake
1437ifeq ($(quiet),silent_)
1438tools_silent=s
1439endif
1440
1441tools/: FORCE
1442	$(Q)mkdir -p $(objtree)/tools
1443	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1444
1445tools/%: FORCE
1446	$(Q)mkdir -p $(objtree)/tools
1447	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1448
1449# ---------------------------------------------------------------------------
1450# Kernel selftest
1451
1452PHONY += kselftest
1453kselftest: headers
1454	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1455
1456kselftest-%: headers FORCE
1457	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1458
1459PHONY += kselftest-merge
1460kselftest-merge:
1461	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1462	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1463		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1464	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1465
1466# ---------------------------------------------------------------------------
1467# Devicetree files
1468
1469ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1470dtstree := arch/$(SRCARCH)/boot/dts
1471endif
1472
1473ifneq ($(dtstree),)
1474
1475%.dtb: dtbs_prepare
1476	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1477
1478%.dtbo: dtbs_prepare
1479	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1480
1481PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1482dtbs: dtbs_prepare
1483	$(Q)$(MAKE) $(build)=$(dtstree)
1484
1485# include/config/kernel.release is actually needed when installing DTBs because
1486# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1487# dtbs_install depend on it as dtbs_install may run as root.
1488dtbs_prepare: include/config/kernel.release scripts_dtc
1489
1490ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1491export CHECK_DTBS=y
1492dtbs: dt_binding_check
1493endif
1494
1495dtbs_check: dtbs
1496
1497dtbs_install:
1498	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1499
1500ifdef CONFIG_OF_EARLY_FLATTREE
1501all: dtbs
1502endif
1503
1504endif
1505
1506PHONY += scripts_dtc
1507scripts_dtc: scripts_basic
1508	$(Q)$(MAKE) $(build)=scripts/dtc
1509
1510ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1511export CHECK_DT_BINDING=y
1512endif
1513
1514PHONY += dt_binding_check
1515dt_binding_check: scripts_dtc
1516	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1517
1518PHONY += dt_compatible_check
1519dt_compatible_check: dt_binding_check
1520	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1521
1522# ---------------------------------------------------------------------------
1523# Modules
1524
1525ifdef CONFIG_MODULES
1526
1527# By default, build modules as well
1528
1529all: modules
1530
1531# When we're building modules with modversions, we need to consider
1532# the built-in objects during the descend as well, in order to
1533# make sure the checksums are up to date before we record them.
1534ifdef CONFIG_MODVERSIONS
1535  KBUILD_BUILTIN := 1
1536endif
1537
1538# Build modules
1539#
1540
1541# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFOBTF_MODULES
1542# is an exception.
1543ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1544KBUILD_BUILTIN := 1
1545modules: vmlinux
1546endif
1547
1548modules: modules_prepare
1549
1550# Target to prepare building external modules
1551modules_prepare: prepare
1552	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1553
1554export modules_sign_only :=
1555
1556ifeq ($(CONFIG_MODULE_SIG),y)
1557PHONY += modules_sign
1558modules_sign: modules_install
1559	@:
1560
1561# modules_sign is a subset of modules_install.
1562# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1563ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1564modules_sign_only := y
1565endif
1566endif
1567
1568modinst_pre :=
1569ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1570modinst_pre := __modinst_pre
1571endif
1572
1573modules_install: $(modinst_pre)
1574PHONY += __modinst_pre
1575__modinst_pre:
1576	@rm -rf $(MODLIB)/kernel
1577	@rm -f $(MODLIB)/source
1578	@mkdir -p $(MODLIB)/kernel
1579	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1580	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1581		rm -f $(MODLIB)/build ; \
1582		ln -s $(CURDIR) $(MODLIB)/build ; \
1583	fi
1584	@sed 's:^\(.*\)\.o$$:kernel/\1.ko:' modules.order > $(MODLIB)/modules.order
1585	@cp -f modules.builtin $(MODLIB)/
1586	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1587
1588endif # CONFIG_MODULES
1589
1590###
1591# Cleaning is done on three levels.
1592# make clean     Delete most generated files
1593#                Leave enough to build external modules
1594# make mrproper  Delete the current configuration, and all generated files
1595# make distclean Remove editor backup files, patch leftover files and the like
1596
1597# Directories & files removed with 'make clean'
1598CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1599	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1600	       compile_commands.json .thinlto-cache rust/test rust/doc \
1601	       .vmlinux.objs .vmlinux.export.c
1602
1603# Directories & files removed with 'make mrproper'
1604MRPROPER_FILES += include/config include/generated          \
1605		  arch/$(SRCARCH)/include/generated .objdiff \
1606		  debian snap tar-install \
1607		  .config .config.old .version \
1608		  Module.symvers \
1609		  certs/signing_key.pem \
1610		  certs/x509.genkey \
1611		  vmlinux-gdb.py \
1612		  *.spec \
1613		  rust/target.json rust/libmacros.so
1614
1615# clean - Delete most, but leave enough to build external modules
1616#
1617clean: rm-files := $(CLEAN_FILES)
1618
1619PHONY += archclean vmlinuxclean
1620
1621vmlinuxclean:
1622	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1623	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1624
1625clean: archclean vmlinuxclean resolve_btfids_clean
1626
1627# mrproper - Delete all generated files, including .config
1628#
1629mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1630mrproper-dirs      := $(addprefix _mrproper_,scripts)
1631
1632PHONY += $(mrproper-dirs) mrproper
1633$(mrproper-dirs):
1634	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1635
1636mrproper: clean $(mrproper-dirs)
1637	$(call cmd,rmfiles)
1638	@find . $(RCS_FIND_IGNORE) \
1639		\( -name '*.rmeta' \) \
1640		-type f -print | xargs rm -f
1641
1642# distclean
1643#
1644PHONY += distclean
1645
1646distclean: mrproper
1647	@find . $(RCS_FIND_IGNORE) \
1648		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1649		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1650		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1651		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1652		-type f -print | xargs rm -f
1653
1654
1655# Packaging of the kernel to various formats
1656# ---------------------------------------------------------------------------
1657
1658%src-pkg: FORCE
1659	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1660%pkg: include/config/kernel.release FORCE
1661	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1662
1663# Brief documentation of the typical targets used
1664# ---------------------------------------------------------------------------
1665
1666boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1667boards := $(sort $(notdir $(boards)))
1668board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1669board-dirs := $(sort $(notdir $(board-dirs:/=)))
1670
1671PHONY += help
1672help:
1673	@echo  'Cleaning targets:'
1674	@echo  '  clean		  - Remove most generated files but keep the config and'
1675	@echo  '                    enough build support to build external modules'
1676	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1677	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1678	@echo  ''
1679	@echo  'Configuration targets:'
1680	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1681	@echo  ''
1682	@echo  'Other generic targets:'
1683	@echo  '  all		  - Build all targets marked with [*]'
1684	@echo  '* vmlinux	  - Build the bare kernel'
1685	@echo  '* modules	  - Build all modules'
1686	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1687	@echo  '  dir/            - Build all files in dir and below'
1688	@echo  '  dir/file.[ois]  - Build specified target only'
1689	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1690	@echo  '                    (requires compiler support for LLVM assembly generation)'
1691	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1692	@echo  '                    (requires a recent binutils and recent build (System.map))'
1693	@echo  '  dir/file.ko     - Build module including final link'
1694	@echo  '  modules_prepare - Set up for building external modules'
1695	@echo  '  tags/TAGS	  - Generate tags file for editors'
1696	@echo  '  cscope	  - Generate cscope index'
1697	@echo  '  gtags           - Generate GNU GLOBAL index'
1698	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1699	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1700	@echo  '  image_name	  - Output the image name (use with make -s)'
1701	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1702	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1703	 echo  ''
1704	@echo  'Static analysers:'
1705	@echo  '  checkstack      - Generate a list of stack hogs'
1706	@echo  '  versioncheck    - Sanity check on version.h usage'
1707	@echo  '  includecheck    - Check for duplicate included header files'
1708	@echo  '  export_report   - List the usages of all exported symbols'
1709	@echo  '  headerdep       - Detect inclusion cycles in headers'
1710	@echo  '  coccicheck      - Check with Coccinelle'
1711	@echo  '  clang-analyzer  - Check with clang static analyzer'
1712	@echo  '  clang-tidy      - Check with clang-tidy'
1713	@echo  ''
1714	@echo  'Tools:'
1715	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1716	@echo  ''
1717	@echo  'Kernel selftest:'
1718	@echo  '  kselftest         - Build and run kernel selftest'
1719	@echo  '                      Build, install, and boot kernel before'
1720	@echo  '                      running kselftest on it'
1721	@echo  '                      Run as root for full coverage'
1722	@echo  '  kselftest-all     - Build kernel selftest'
1723	@echo  '  kselftest-install - Build and install kernel selftest'
1724	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1725	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1726	@echo  '		      kselftest to existing .config.'
1727	@echo  ''
1728	@echo  'Rust targets:'
1729	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1730	@echo  '		    available and, if not, explains why.'
1731	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1732	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1733	@echo  '		    is formatted, printing a diff otherwise.'
1734	@echo  '  rustdoc	  - Generate Rust documentation'
1735	@echo  '		    (requires kernel .config)'
1736	@echo  '  rusttest        - Runs the Rust tests'
1737	@echo  '                    (requires kernel .config; downloads external repos)'
1738	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1739	@echo  '		    (requires kernel .config)'
1740	@echo  '  dir/file.[os]   - Build specified target only'
1741	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1742	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1743	@echo  '                    The output is not intended to be compilable.'
1744	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1745	@echo  ''
1746	@$(if $(dtstree), \
1747		echo 'Devicetree:'; \
1748		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1749		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1750		echo '  dt_binding_check - Validate device tree binding documents'; \
1751		echo '  dtbs_check       - Validate device tree source files';\
1752		echo '')
1753
1754	@echo 'Userspace tools targets:'
1755	@echo '  use "make tools/help"'
1756	@echo '  or  "cd tools; make help"'
1757	@echo  ''
1758	@echo  'Kernel packaging:'
1759	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1760	@echo  ''
1761	@echo  'Documentation targets:'
1762	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1763	@echo  ''
1764	@echo  'Architecture specific targets ($(SRCARCH)):'
1765	@$(or $(archhelp),\
1766		echo '  No architecture specific help defined for $(SRCARCH)')
1767	@echo  ''
1768	@$(if $(boards), \
1769		$(foreach b, $(boards), \
1770		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1771		echo '')
1772	@$(if $(board-dirs), \
1773		$(foreach b, $(board-dirs), \
1774		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1775		printf "  %-16s - Show all of the above\\n" help-boards; \
1776		echo '')
1777
1778	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1779	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1780	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1781	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1782	@echo  '                       (sparse by default)'
1783	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1784	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1785	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1786	@echo  '		1: warnings which may be relevant and do not occur too often'
1787	@echo  '		2: warnings which occur quite often but may still be relevant'
1788	@echo  '		3: more obscure warnings, can most likely be ignored'
1789	@echo  '		e: warnings are being treated as errors'
1790	@echo  '		Multiple levels can be combined with W=12 or W=123'
1791	@echo  ''
1792	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1793	@echo  'For further info see the ./README file'
1794
1795
1796help-board-dirs := $(addprefix help-,$(board-dirs))
1797
1798help-boards: $(help-board-dirs)
1799
1800boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1801
1802$(help-board-dirs): help-%:
1803	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1804	@$(if $(boards-per-dir), \
1805		$(foreach b, $(boards-per-dir), \
1806		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1807		echo '')
1808
1809
1810# Documentation targets
1811# ---------------------------------------------------------------------------
1812DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1813	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1814PHONY += $(DOC_TARGETS)
1815$(DOC_TARGETS):
1816	$(Q)$(MAKE) $(build)=Documentation $@
1817
1818
1819# Rust targets
1820# ---------------------------------------------------------------------------
1821
1822# "Is Rust available?" target
1823PHONY += rustavailable
1824rustavailable:
1825	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v && echo "Rust is available!"
1826
1827# Documentation target
1828#
1829# Using the singular to avoid running afoul of `no-dot-config-targets`.
1830PHONY += rustdoc
1831rustdoc: prepare
1832	$(Q)$(MAKE) $(build)=rust $@
1833
1834# Testing target
1835PHONY += rusttest
1836rusttest: prepare
1837	$(Q)$(MAKE) $(build)=rust $@
1838
1839# Formatting targets
1840PHONY += rustfmt rustfmtcheck
1841
1842# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1843#
1844# We match using absolute paths since `find` does not resolve them
1845# when matching, which is a problem when e.g. `srctree` is `..`.
1846# We `grep` afterwards in order to remove the directory entry itself.
1847rustfmt:
1848	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1849		-o -path $(abs_srctree)/rust/alloc -prune \
1850		-o -path $(abs_objtree)/rust/test -prune \
1851		| grep -Fv $(abs_srctree)/rust/alloc \
1852		| grep -Fv $(abs_objtree)/rust/test \
1853		| grep -Fv generated \
1854		| xargs $(RUSTFMT) $(rustfmt_flags)
1855
1856rustfmtcheck: rustfmt_flags = --check
1857rustfmtcheck: rustfmt
1858
1859# IDE support targets
1860PHONY += rust-analyzer
1861rust-analyzer:
1862	$(Q)$(MAKE) $(build)=rust $@
1863
1864# Misc
1865# ---------------------------------------------------------------------------
1866
1867PHONY += scripts_gdb
1868scripts_gdb: prepare0
1869	$(Q)$(MAKE) $(build)=scripts/gdb
1870	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1871
1872ifdef CONFIG_GDB_SCRIPTS
1873all: scripts_gdb
1874endif
1875
1876else # KBUILD_EXTMOD
1877
1878###
1879# External module support.
1880# When building external modules the kernel used as basis is considered
1881# read-only, and no consistency checks are made and the make
1882# system is not used on the basis kernel. If updates are required
1883# in the basis kernel ordinary make commands (without M=...) must be used.
1884
1885# We are always building only modules.
1886KBUILD_BUILTIN :=
1887KBUILD_MODULES := 1
1888
1889build-dir := $(KBUILD_EXTMOD)
1890
1891compile_commands.json: $(extmod_prefix)compile_commands.json
1892PHONY += compile_commands.json
1893
1894clean-dirs := $(KBUILD_EXTMOD)
1895clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1896	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1897
1898PHONY += prepare
1899# now expand this into a simple variable to reduce the cost of shell evaluations
1900prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1901prepare:
1902	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1903		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1904		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1905		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1906	fi
1907
1908PHONY += help
1909help:
1910	@echo  '  Building external modules.'
1911	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1912	@echo  ''
1913	@echo  '  modules         - default target, build the module(s)'
1914	@echo  '  modules_install - install the module'
1915	@echo  '  clean           - remove generated files in module directory only'
1916	@echo  ''
1917
1918endif # KBUILD_EXTMOD
1919
1920# ---------------------------------------------------------------------------
1921# Modules
1922
1923PHONY += modules modules_install modules_prepare
1924
1925ifdef CONFIG_MODULES
1926
1927$(MODORDER): $(build-dir)
1928	@:
1929
1930# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1931# This is solely useful to speed up test compiles.
1932modules: modpost
1933ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1934	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1935endif
1936
1937PHONY += modules_check
1938modules_check: $(MODORDER)
1939	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1940
1941quiet_cmd_depmod = DEPMOD  $(MODLIB)
1942      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1943                   $(KERNELRELEASE)
1944
1945modules_install:
1946	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1947	$(call cmd,depmod)
1948
1949else # CONFIG_MODULES
1950
1951# Modules not configured
1952# ---------------------------------------------------------------------------
1953
1954modules modules_install:
1955	@echo >&2 '***'
1956	@echo >&2 '*** The present kernel configuration has modules disabled.'
1957	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1958	@echo >&2 '*** to enable CONFIG_MODULES.'
1959	@echo >&2 '***'
1960	@exit 1
1961
1962KBUILD_MODULES :=
1963
1964endif # CONFIG_MODULES
1965
1966PHONY += modpost
1967modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1968	 $(if $(KBUILD_MODULES), modules_check)
1969	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1970
1971# Single targets
1972# ---------------------------------------------------------------------------
1973# To build individual files in subdirectories, you can do like this:
1974#
1975#   make foo/bar/baz.s
1976#
1977# The supported suffixes for single-target are listed in 'single-targets'
1978#
1979# To build only under specific subdirectories, you can do like this:
1980#
1981#   make foo/bar/baz/
1982
1983ifdef single-build
1984
1985# .ko is special because modpost is needed
1986single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1987single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1988		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1989
1990$(single-ko): single_modules
1991	@:
1992$(single-no-ko): $(build-dir)
1993	@:
1994
1995# Remove MODORDER when done because it is not the real one.
1996PHONY += single_modules
1997single_modules: $(single-no-ko) modules_prepare
1998	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1999	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
2000ifneq ($(KBUILD_MODPOST_NOFINAL),1)
2001	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
2002endif
2003	$(Q)rm -f $(MODORDER)
2004
2005single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
2006
2007KBUILD_MODULES := 1
2008
2009endif
2010
2011# Preset locale variables to speed up the build process. Limit locale
2012# tweaks to this spot to avoid wrong language settings when running
2013# make menuconfig etc.
2014# Error messages still appears in the original language
2015PHONY += $(build-dir)
2016$(build-dir): prepare
2017	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
2018
2019clean-dirs := $(addprefix _clean_, $(clean-dirs))
2020PHONY += $(clean-dirs) clean
2021$(clean-dirs):
2022	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2023
2024clean: $(clean-dirs)
2025	$(call cmd,rmfiles)
2026	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
2027		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2028		-o -name '*.ko.*' \
2029		-o -name '*.dtb' -o -name '*.dtbo' \
2030		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2031		-o -name '*.dt.yaml' \
2032		-o -name '*.dwo' -o -name '*.lst' \
2033		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
2034		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2035		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2036		-o -name '*.asn1.[ch]' \
2037		-o -name '*.symtypes' -o -name 'modules.order' \
2038		-o -name '.tmp_*' \
2039		-o -name '*.c.[012]*.*' \
2040		-o -name '*.ll' \
2041		-o -name '*.gcno' \
2042		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
2043
2044# Generate tags for editors
2045# ---------------------------------------------------------------------------
2046quiet_cmd_tags = GEN     $@
2047      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2048
2049tags TAGS cscope gtags: FORCE
2050	$(call cmd,tags)
2051
2052# Script to generate missing namespace dependencies
2053# ---------------------------------------------------------------------------
2054
2055PHONY += nsdeps
2056nsdeps: export KBUILD_NSDEPS=1
2057nsdeps: modules
2058	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2059
2060# Clang Tooling
2061# ---------------------------------------------------------------------------
2062
2063quiet_cmd_gen_compile_commands = GEN     $@
2064      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2065
2066$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
2067	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2068	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2069	$(call if_changed,gen_compile_commands)
2070
2071targets += $(extmod_prefix)compile_commands.json
2072
2073PHONY += clang-tidy clang-analyzer
2074
2075ifdef CONFIG_CC_IS_CLANG
2076quiet_cmd_clang_tools = CHECK   $<
2077      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2078
2079clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2080	$(call cmd,clang_tools)
2081else
2082clang-tidy clang-analyzer:
2083	@echo "$@ requires CC=clang" >&2
2084	@false
2085endif
2086
2087# Scripts to check various things for consistency
2088# ---------------------------------------------------------------------------
2089
2090PHONY += includecheck versioncheck coccicheck export_report
2091
2092includecheck:
2093	find $(srctree)/* $(RCS_FIND_IGNORE) \
2094		-name '*.[hcS]' -type f -print | sort \
2095		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2096
2097versioncheck:
2098	find $(srctree)/* $(RCS_FIND_IGNORE) \
2099		-name '*.[hcS]' -type f -print | sort \
2100		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2101
2102coccicheck:
2103	$(Q)$(BASH) $(srctree)/scripts/$@
2104
2105export_report:
2106	$(PERL) $(srctree)/scripts/export_report.pl
2107
2108PHONY += checkstack kernelrelease kernelversion image_name
2109
2110# UML needs a little special treatment here.  It wants to use the host
2111# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2112# else wants $(ARCH), including people doing cross-builds, which means
2113# that $(SUBARCH) doesn't work here.
2114ifeq ($(ARCH), um)
2115CHECKSTACK_ARCH := $(SUBARCH)
2116else
2117CHECKSTACK_ARCH := $(ARCH)
2118endif
2119checkstack:
2120	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2121	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2122
2123kernelrelease:
2124	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
2125
2126kernelversion:
2127	@echo $(KERNELVERSION)
2128
2129image_name:
2130	@echo $(KBUILD_IMAGE)
2131
2132quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2133      cmd_rmfiles = rm -rf $(rm-files)
2134
2135# read saved command lines for existing targets
2136existing-targets := $(wildcard $(sort $(targets)))
2137
2138-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2139
2140endif # config-build
2141endif # mixed-build
2142endif # need-sub-make
2143
2144PHONY += FORCE
2145FORCE:
2146
2147# Declare the contents of the PHONY variable as phony.  We keep that
2148# information in a variable so we can use it in if_changed and friends.
2149.PHONY: $(PHONY)
2150