Loading...
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 9
4SUBLEVEL = 4
5EXTRAVERSION =
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
41this-makefile := $(lastword $(MAKEFILE_LIST))
42abs_srctree := $(realpath $(dir $(this-makefile)))
43abs_objtree := $(CURDIR)
44
45ifneq ($(sub_make_done),1)
46
47# Do not use make's built-in rules and variables
48# (this increases performance and avoids hard-to-debug behaviour)
49MAKEFLAGS += -rR
50
51# Avoid funny character set dependencies
52unexport LC_ALL
53LC_COLLATE=C
54LC_NUMERIC=C
55export LC_COLLATE LC_NUMERIC
56
57# Avoid interference with shell env settings
58unexport GREP_OPTIONS
59
60# Beautify output
61# ---------------------------------------------------------------------------
62#
63# Most of build commands in Kbuild start with "cmd_". You can optionally define
64# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
65# that command is printed by default.
66#
67# e.g.)
68# quiet_cmd_depmod = DEPMOD $(MODLIB)
69# cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
70#
71# A simple variant is to prefix commands with $(Q) - that's useful
72# for commands that shall be hidden in non-verbose mode.
73#
74# $(Q)$(MAKE) $(build)=scripts/basic
75#
76# If KBUILD_VERBOSE contains 1, the whole command is echoed.
77# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
78#
79# To put more focus on warnings, be less verbose as default
80# Use 'make V=1' to see the full commands
81
82ifeq ("$(origin V)", "command line")
83 KBUILD_VERBOSE = $(V)
84endif
85
86quiet = quiet_
87Q = @
88
89ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
90 quiet =
91 Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
97
98ifeq ($(filter 3.%,$(MAKE_VERSION)),)
99short-opts := $(firstword -$(MAKEFLAGS))
100else
101short-opts := $(filter-out --%,$(MAKEFLAGS))
102endif
103
104ifneq ($(findstring s,$(short-opts)),)
105quiet=silent_
106override KBUILD_VERBOSE :=
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# backward compatibility
159KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
160
161ifeq ("$(origin W)", "command line")
162 KBUILD_EXTRA_WARN := $(W)
163endif
164
165export KBUILD_EXTRA_WARN
166
167# Kbuild will save output files in the current working directory.
168# This does not need to match to the root of the kernel source tree.
169#
170# For example, you can do this:
171#
172# cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
173#
174# If you want to save output files in a different location, there are
175# two syntaxes to specify it.
176#
177# 1) O=
178# Use "make O=dir/to/store/output/files/"
179#
180# 2) Set KBUILD_OUTPUT
181# Set the environment variable KBUILD_OUTPUT to point to the output directory.
182# export KBUILD_OUTPUT=dir/to/store/output/files/; make
183#
184# The O= assignment takes precedence over the KBUILD_OUTPUT environment
185# variable.
186
187# Do we want to change the working directory?
188ifeq ("$(origin O)", "command line")
189 KBUILD_OUTPUT := $(O)
190endif
191
192ifneq ($(KBUILD_OUTPUT),)
193# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
194$(shell mkdir -p "$(KBUILD_OUTPUT)")
195# $(realpath ...) resolves symlinks
196abs_objtree := $(realpath $(KBUILD_OUTPUT))
197$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)"))
198endif # ifneq ($(KBUILD_OUTPUT),)
199
200ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
201$(error source directory cannot contain spaces or colons)
202endif
203
204ifneq ($(filter 3.%,$(MAKE_VERSION)),)
205# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
206# We need to invoke sub-make to avoid implicit rules in the top Makefile.
207need-sub-make := 1
208# Cancel implicit rules for this Makefile.
209$(this-makefile): ;
210endif
211
212export sub_make_done := 1
213
214endif # sub_make_done
215
216ifeq ($(abs_objtree),$(CURDIR))
217# Suppress "Entering directory ..." if we are at the final work directory.
218no-print-directory := --no-print-directory
219else
220# Recursion to show "Entering directory ..."
221need-sub-make := 1
222endif
223
224ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
225# If --no-print-directory is unset, recurse once again to set it.
226# You may end up recursing into __sub-make twice. This is needed due to the
227# behavior change in GNU Make 4.4.1.
228need-sub-make := 1
229endif
230
231ifeq ($(need-sub-make),1)
232
233PHONY += $(MAKECMDGOALS) __sub-make
234
235$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
236 @:
237
238# Invoke a second make in the output directory, passing relevant variables
239__sub-make:
240 $(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
241 -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
242
243else # need-sub-make
244
245# We process the rest of the Makefile if this is the final invocation of make
246
247ifeq ($(abs_srctree),$(abs_objtree))
248 # building in the source tree
249 srctree := .
250 building_out_of_srctree :=
251else
252 ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
253 # building in a subdirectory of the source tree
254 srctree := ..
255 else
256 srctree := $(abs_srctree)
257 endif
258 building_out_of_srctree := 1
259endif
260
261ifneq ($(KBUILD_ABS_SRCTREE),)
262srctree := $(abs_srctree)
263endif
264
265objtree := .
266VPATH := $(srctree)
267
268export building_out_of_srctree srctree objtree VPATH
269
270# To make sure we do not include .config for any of the *config targets
271# catch them early, and hand them over to scripts/kconfig/Makefile
272# It is allowed to specify more targets when calling make, including
273# mixing *config targets and build targets.
274# For example 'make oldconfig all'.
275# Detect when mixed targets is specified, and make a second invocation
276# of make so .config is not included in this case either (for *config).
277
278version_h := include/generated/uapi/linux/version.h
279
280clean-targets := %clean mrproper cleandocs
281no-dot-config-targets := $(clean-targets) \
282 cscope gtags TAGS tags help% %docs check% coccicheck \
283 $(version_h) headers headers_% archheaders archscripts \
284 %asm-generic kernelversion %src-pkg dt_binding_check \
285 outputmakefile rustavailable rustfmt rustfmtcheck
286no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
287 image_name
288single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
289
290config-build :=
291mixed-build :=
292need-config := 1
293may-sync-config := 1
294single-build :=
295
296ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
297 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
298 need-config :=
299 endif
300endif
301
302ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
303 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
304 may-sync-config :=
305 endif
306endif
307
308need-compiler := $(may-sync-config)
309
310ifneq ($(KBUILD_EXTMOD),)
311 may-sync-config :=
312endif
313
314ifeq ($(KBUILD_EXTMOD),)
315 ifneq ($(filter %config,$(MAKECMDGOALS)),)
316 config-build := 1
317 ifneq ($(words $(MAKECMDGOALS)),1)
318 mixed-build := 1
319 endif
320 endif
321endif
322
323# We cannot build single targets and the others at the same time
324ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
325 single-build := 1
326 ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
327 mixed-build := 1
328 endif
329endif
330
331# For "make -j clean all", "make -j mrproper defconfig all", etc.
332ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
333 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
334 mixed-build := 1
335 endif
336endif
337
338# install and modules_install need also be processed one by one
339ifneq ($(filter install,$(MAKECMDGOALS)),)
340 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
341 mixed-build := 1
342 endif
343endif
344
345ifdef mixed-build
346# ===========================================================================
347# We're called with mixed targets (*config and build targets).
348# Handle them one by one.
349
350PHONY += $(MAKECMDGOALS) __build_one_by_one
351
352$(MAKECMDGOALS): __build_one_by_one
353 @:
354
355__build_one_by_one:
356 $(Q)set -e; \
357 for i in $(MAKECMDGOALS); do \
358 $(MAKE) -f $(srctree)/Makefile $$i; \
359 done
360
361else # !mixed-build
362
363include $(srctree)/scripts/Kbuild.include
364
365# Read KERNELRELEASE from include/config/kernel.release (if it exists)
366KERNELRELEASE = $(call read-file, include/config/kernel.release)
367KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
368export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
369
370include $(srctree)/scripts/subarch.include
371
372# Cross compiling and selecting different set of gcc/bin-utils
373# ---------------------------------------------------------------------------
374#
375# When performing cross compilation for other architectures ARCH shall be set
376# to the target architecture. (See arch/* for the possibilities).
377# ARCH can be set during invocation of make:
378# make ARCH=arm64
379# Another way is to have ARCH set in the environment.
380# The default ARCH is the host where make is executed.
381
382# CROSS_COMPILE specify the prefix used for all executables used
383# during compilation. Only gcc and related bin-utils executables
384# are prefixed with $(CROSS_COMPILE).
385# CROSS_COMPILE can be set on the command line
386# make CROSS_COMPILE=aarch64-linux-gnu-
387# Alternatively CROSS_COMPILE can be set in the environment.
388# Default value for CROSS_COMPILE is not to prefix executables
389# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
390ARCH ?= $(SUBARCH)
391
392# Architecture as present in compile.h
393UTS_MACHINE := $(ARCH)
394SRCARCH := $(ARCH)
395
396# Additional ARCH settings for x86
397ifeq ($(ARCH),i386)
398 SRCARCH := x86
399endif
400ifeq ($(ARCH),x86_64)
401 SRCARCH := x86
402endif
403
404# Additional ARCH settings for sparc
405ifeq ($(ARCH),sparc32)
406 SRCARCH := sparc
407endif
408ifeq ($(ARCH),sparc64)
409 SRCARCH := sparc
410endif
411
412# Additional ARCH settings for parisc
413ifeq ($(ARCH),parisc64)
414 SRCARCH := parisc
415endif
416
417export cross_compiling :=
418ifneq ($(SRCARCH),$(SUBARCH))
419cross_compiling := 1
420endif
421
422KCONFIG_CONFIG ?= .config
423export KCONFIG_CONFIG
424
425# SHELL used by kbuild
426CONFIG_SHELL := sh
427
428HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
429HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
430HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
431
432ifneq ($(LLVM),)
433ifneq ($(filter %/,$(LLVM)),)
434LLVM_PREFIX := $(LLVM)
435else ifneq ($(filter -%,$(LLVM)),)
436LLVM_SUFFIX := $(LLVM)
437endif
438
439HOSTCC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
440HOSTCXX = $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
441else
442HOSTCC = gcc
443HOSTCXX = g++
444endif
445HOSTRUSTC = rustc
446HOSTPKG_CONFIG = pkg-config
447
448KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
449 -O2 -fomit-frame-pointer -std=gnu11
450KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
451KBUILD_USERLDFLAGS := $(USERLDFLAGS)
452
453# These flags apply to all Rust code in the tree, including the kernel and
454# host programs.
455export rust_common_flags := --edition=2021 \
456 -Zbinary_dep_depinfo=y \
457 -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
458 -Dunreachable_pub -Dnon_ascii_idents \
459 -Wmissing_docs \
460 -Drustdoc::missing_crate_level_docs \
461 -Dclippy::correctness -Dclippy::style \
462 -Dclippy::suspicious -Dclippy::complexity \
463 -Dclippy::perf \
464 -Dclippy::let_unit_value -Dclippy::mut_mut \
465 -Dclippy::needless_bitwise_bool \
466 -Dclippy::needless_continue \
467 -Dclippy::no_mangle_with_rust_abi \
468 -Wclippy::dbg_macro
469
470KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
471KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
472KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
473 -Zallow-features= $(HOSTRUSTFLAGS)
474KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
475KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
476
477# Make variables (CC, etc...)
478CPP = $(CC) -E
479ifneq ($(LLVM),)
480CC = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
481LD = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
482AR = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
483NM = $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
484OBJCOPY = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
485OBJDUMP = $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
486READELF = $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
487STRIP = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
488else
489CC = $(CROSS_COMPILE)gcc
490LD = $(CROSS_COMPILE)ld
491AR = $(CROSS_COMPILE)ar
492NM = $(CROSS_COMPILE)nm
493OBJCOPY = $(CROSS_COMPILE)objcopy
494OBJDUMP = $(CROSS_COMPILE)objdump
495READELF = $(CROSS_COMPILE)readelf
496STRIP = $(CROSS_COMPILE)strip
497endif
498RUSTC = rustc
499RUSTDOC = rustdoc
500RUSTFMT = rustfmt
501CLIPPY_DRIVER = clippy-driver
502BINDGEN = bindgen
503CARGO = cargo
504PAHOLE = pahole
505RESOLVE_BTFIDS = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
506LEX = flex
507YACC = bison
508AWK = awk
509INSTALLKERNEL := installkernel
510PERL = perl
511PYTHON3 = python3
512CHECK = sparse
513BASH = bash
514KGZIP = gzip
515KBZIP2 = bzip2
516KLZOP = lzop
517LZMA = lzma
518LZ4 = lz4c
519XZ = xz
520ZSTD = zstd
521
522CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
523 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
524NOSTDINC_FLAGS :=
525CFLAGS_MODULE =
526RUSTFLAGS_MODULE =
527AFLAGS_MODULE =
528LDFLAGS_MODULE =
529CFLAGS_KERNEL =
530RUSTFLAGS_KERNEL =
531AFLAGS_KERNEL =
532LDFLAGS_vmlinux =
533
534# Use USERINCLUDE when you must reference the UAPI directories only.
535USERINCLUDE := \
536 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
537 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
538 -I$(srctree)/include/uapi \
539 -I$(objtree)/include/generated/uapi \
540 -include $(srctree)/include/linux/compiler-version.h \
541 -include $(srctree)/include/linux/kconfig.h
542
543# Use LINUXINCLUDE when you must reference the include directory.
544# Needed to be compatible with the O= option
545LINUXINCLUDE := \
546 -I$(srctree)/arch/$(SRCARCH)/include \
547 -I$(objtree)/arch/$(SRCARCH)/include/generated \
548 $(if $(building_out_of_srctree),-I$(srctree)/include) \
549 -I$(objtree)/include \
550 $(USERINCLUDE)
551
552KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
553
554KBUILD_CFLAGS :=
555KBUILD_CFLAGS += -std=gnu11
556KBUILD_CFLAGS += -fshort-wchar
557KBUILD_CFLAGS += -funsigned-char
558KBUILD_CFLAGS += -fno-common
559KBUILD_CFLAGS += -fno-PIE
560KBUILD_CFLAGS += -fno-strict-aliasing
561
562KBUILD_CPPFLAGS := -D__KERNEL__
563KBUILD_RUSTFLAGS := $(rust_common_flags) \
564 -Cpanic=abort -Cembed-bitcode=n -Clto=n \
565 -Cforce-unwind-tables=n -Ccodegen-units=1 \
566 -Csymbol-mangling-version=v0 \
567 -Crelocation-model=static \
568 -Zfunction-sections=n \
569 -Dclippy::float_arithmetic
570
571KBUILD_AFLAGS_KERNEL :=
572KBUILD_CFLAGS_KERNEL :=
573KBUILD_RUSTFLAGS_KERNEL :=
574KBUILD_AFLAGS_MODULE := -DMODULE
575KBUILD_CFLAGS_MODULE := -DMODULE
576KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
577KBUILD_LDFLAGS_MODULE :=
578KBUILD_LDFLAGS :=
579CLANG_FLAGS :=
580
581ifeq ($(KBUILD_CLIPPY),1)
582 RUSTC_OR_CLIPPY_QUIET := CLIPPY
583 RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
584else
585 RUSTC_OR_CLIPPY_QUIET := RUSTC
586 RUSTC_OR_CLIPPY = $(RUSTC)
587endif
588
589ifdef RUST_LIB_SRC
590 export RUST_LIB_SRC
591endif
592
593# Allows the usage of unstable features in stable compilers.
594export RUSTC_BOOTSTRAP := 1
595
596export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
597export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
598export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
599export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
600export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
601export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
602export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
603export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
604
605export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
606export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
607export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
608export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
609export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
610export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
611
612# Files to ignore in find ... statements
613
614export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
615 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
616 -prune -o
617
618# ===========================================================================
619# Rules shared between *config targets and build targets
620
621# Basic helpers built in scripts/basic
622PHONY += scripts_basic
623scripts_basic:
624 $(Q)$(MAKE) $(build)=scripts/basic
625
626PHONY += outputmakefile
627ifdef building_out_of_srctree
628# Before starting out-of-tree build, make sure the source tree is clean.
629# outputmakefile generates a Makefile in the output directory, if using a
630# separate output directory. This allows convenient use of make in the
631# output directory.
632# At the same time when output Makefile generated, generate .gitignore to
633# ignore whole output directory
634
635quiet_cmd_makefile = GEN Makefile
636 cmd_makefile = { \
637 echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
638 echo "include $(srctree)/Makefile"; \
639 } > Makefile
640
641outputmakefile:
642 @if [ -f $(srctree)/.config -o \
643 -d $(srctree)/include/config -o \
644 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
645 echo >&2 "***"; \
646 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
647 echo >&2 "*** in $(abs_srctree)";\
648 echo >&2 "***"; \
649 false; \
650 fi
651 $(Q)ln -fsn $(srctree) source
652 $(call cmd,makefile)
653 $(Q)test -e .gitignore || \
654 { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
655endif
656
657# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
658# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
659# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
660# and from include/config/auto.conf.cmd to detect the compiler upgrade.
661CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
662
663ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
664include $(srctree)/scripts/Makefile.clang
665endif
666
667# Include this also for config targets because some architectures need
668# cc-cross-prefix to determine CROSS_COMPILE.
669ifdef need-compiler
670include $(srctree)/scripts/Makefile.compiler
671endif
672
673ifdef config-build
674# ===========================================================================
675# *config targets only - make sure prerequisites are updated, and descend
676# in scripts/kconfig to make the *config target
677
678# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
679# KBUILD_DEFCONFIG may point out an alternative default configuration
680# used for 'make defconfig'
681include $(srctree)/arch/$(SRCARCH)/Makefile
682export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
683
684config: outputmakefile scripts_basic FORCE
685 $(Q)$(MAKE) $(build)=scripts/kconfig $@
686
687%config: outputmakefile scripts_basic FORCE
688 $(Q)$(MAKE) $(build)=scripts/kconfig $@
689
690else #!config-build
691# ===========================================================================
692# Build targets only - this includes vmlinux, arch-specific targets, clean
693# targets and others. In general all targets except *config targets.
694
695# If building an external module we do not care about the all: rule
696# but instead __all depend on modules
697PHONY += all
698ifeq ($(KBUILD_EXTMOD),)
699__all: all
700else
701__all: modules
702endif
703
704targets :=
705
706# Decide whether to build built-in, modular, or both.
707# Normally, just do built-in.
708
709KBUILD_MODULES :=
710KBUILD_BUILTIN := 1
711
712# If we have only "make modules", don't compile built-in objects.
713ifeq ($(MAKECMDGOALS),modules)
714 KBUILD_BUILTIN :=
715endif
716
717# If we have "make <whatever> modules", compile modules
718# in addition to whatever we do anyway.
719# Just "make" or "make all" shall build modules as well
720
721ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
722 KBUILD_MODULES := 1
723endif
724
725ifeq ($(MAKECMDGOALS),)
726 KBUILD_MODULES := 1
727endif
728
729export KBUILD_MODULES KBUILD_BUILTIN
730
731ifdef need-config
732include include/config/auto.conf
733endif
734
735ifeq ($(KBUILD_EXTMOD),)
736# Objects we will link into vmlinux / subdirs we need to visit
737core-y :=
738drivers-y :=
739libs-y := lib
740endif # KBUILD_EXTMOD
741
742# The all: target is the default when no target is given on the
743# command line.
744# This allow a user to issue only 'make' to build a kernel including modules
745# Defaults to vmlinux, but the arch makefile usually adds further targets
746all: vmlinux
747
748CFLAGS_GCOV := -fprofile-arcs -ftest-coverage
749ifdef CONFIG_CC_IS_GCC
750CFLAGS_GCOV += -fno-tree-loop-im
751endif
752export CFLAGS_GCOV
753
754# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
755ifdef CONFIG_FUNCTION_TRACER
756 CC_FLAGS_FTRACE := -pg
757endif
758
759include $(srctree)/arch/$(SRCARCH)/Makefile
760
761ifdef need-config
762ifdef may-sync-config
763# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
764# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
765# because some architectures define CROSS_COMPILE there.
766include include/config/auto.conf.cmd
767
768$(KCONFIG_CONFIG):
769 @echo >&2 '***'
770 @echo >&2 '*** Configuration file "$@" not found!'
771 @echo >&2 '***'
772 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
773 @echo >&2 '*** "make menuconfig" or "make xconfig").'
774 @echo >&2 '***'
775 @/bin/false
776
777# The actual configuration files used during the build are stored in
778# include/generated/ and include/config/. Update them if .config is newer than
779# include/config/auto.conf (which mirrors .config).
780#
781# This exploits the 'multi-target pattern rule' trick.
782# The syncconfig should be executed only once to make all the targets.
783# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
784#
785# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
786# so you cannot notice that Kconfig is waiting for the user input.
787%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
788 $(Q)$(kecho) " SYNC $@"
789 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
790else # !may-sync-config
791# External modules and some install targets need include/generated/autoconf.h
792# and include/config/auto.conf but do not care if they are up-to-date.
793# Use auto.conf to trigger the test
794PHONY += include/config/auto.conf
795
796include/config/auto.conf:
797 @test -e include/generated/autoconf.h -a -e $@ || ( \
798 echo >&2; \
799 echo >&2 " ERROR: Kernel configuration is invalid."; \
800 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
801 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
802 echo >&2 ; \
803 /bin/false)
804
805endif # may-sync-config
806endif # need-config
807
808KBUILD_CFLAGS += -fno-delete-null-pointer-checks
809
810ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
811KBUILD_CFLAGS += -O2
812KBUILD_RUSTFLAGS += -Copt-level=2
813else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
814KBUILD_CFLAGS += -Os
815KBUILD_RUSTFLAGS += -Copt-level=s
816endif
817
818# Always set `debug-assertions` and `overflow-checks` because their default
819# depends on `opt-level` and `debug-assertions`, respectively.
820KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
821KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
822
823# Tell gcc to never replace conditional load with a non-conditional one
824ifdef CONFIG_CC_IS_GCC
825# gcc-10 renamed --param=allow-store-data-races=0 to
826# -fno-allow-store-data-races.
827KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
828KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races)
829endif
830
831ifdef CONFIG_READABLE_ASM
832# Disable optimizations that make assembler listings hard to read.
833# reorder blocks reorders the control in the function
834# ipa clone creates specialized cloned functions
835# partial inlining inlines only parts of functions
836KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
837endif
838
839stackp-flags-y := -fno-stack-protector
840stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
841stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
842
843KBUILD_CFLAGS += $(stackp-flags-y)
844
845KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
846KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
847
848ifdef CONFIG_FRAME_POINTER
849KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
850KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
851else
852# Some targets (ARM with Thumb2, for example), can't be built with frame
853# pointers. For those, we don't have FUNCTION_TRACER automatically
854# select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
855# incompatible with -fomit-frame-pointer with current GCC, so we don't use
856# -fomit-frame-pointer with FUNCTION_TRACER.
857# In the Rust target specification, "frame-pointer" is set explicitly
858# to "may-omit".
859ifndef CONFIG_FUNCTION_TRACER
860KBUILD_CFLAGS += -fomit-frame-pointer
861endif
862endif
863
864# Initialize all stack variables with a 0xAA pattern.
865ifdef CONFIG_INIT_STACK_ALL_PATTERN
866KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern
867endif
868
869# Initialize all stack variables with a zero value.
870ifdef CONFIG_INIT_STACK_ALL_ZERO
871KBUILD_CFLAGS += -ftrivial-auto-var-init=zero
872ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
873# https://github.com/llvm/llvm-project/issues/44842
874CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
875export CC_AUTO_VAR_INIT_ZERO_ENABLER
876KBUILD_CFLAGS += $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
877endif
878endif
879
880# While VLAs have been removed, GCC produces unreachable stack probes
881# for the randomize_kstack_offset feature. Disable it for all compilers.
882KBUILD_CFLAGS += $(call cc-option, -fno-stack-clash-protection)
883
884# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
885ifdef CONFIG_ZERO_CALL_USED_REGS
886KBUILD_CFLAGS += -fzero-call-used-regs=used-gpr
887endif
888
889ifdef CONFIG_FUNCTION_TRACER
890ifdef CONFIG_FTRACE_MCOUNT_USE_CC
891 CC_FLAGS_FTRACE += -mrecord-mcount
892 ifdef CONFIG_HAVE_NOP_MCOUNT
893 ifeq ($(call cc-option-yn, -mnop-mcount),y)
894 CC_FLAGS_FTRACE += -mnop-mcount
895 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
896 endif
897 endif
898endif
899ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
900 ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
901 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
902 endif
903endif
904ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
905 ifdef CONFIG_HAVE_C_RECORDMCOUNT
906 BUILD_C_RECORDMCOUNT := y
907 export BUILD_C_RECORDMCOUNT
908 endif
909endif
910ifdef CONFIG_HAVE_FENTRY
911 # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
912 ifeq ($(call cc-option-yn, -mfentry),y)
913 CC_FLAGS_FTRACE += -mfentry
914 CC_FLAGS_USING += -DCC_USING_FENTRY
915 endif
916endif
917export CC_FLAGS_FTRACE
918KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
919KBUILD_AFLAGS += $(CC_FLAGS_USING)
920endif
921
922# We trigger additional mismatches with less inlining
923ifdef CONFIG_DEBUG_SECTION_MISMATCH
924KBUILD_CFLAGS += -fno-inline-functions-called-once
925endif
926
927# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
928ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
929KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
930KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
931LDFLAGS_vmlinux += --gc-sections
932endif
933
934ifdef CONFIG_SHADOW_CALL_STACK
935ifndef CONFIG_DYNAMIC_SCS
936CC_FLAGS_SCS := -fsanitize=shadow-call-stack
937KBUILD_CFLAGS += $(CC_FLAGS_SCS)
938endif
939export CC_FLAGS_SCS
940endif
941
942ifdef CONFIG_LTO_CLANG
943ifdef CONFIG_LTO_CLANG_THIN
944CC_FLAGS_LTO := -flto=thin -fsplit-lto-unit
945KBUILD_LDFLAGS += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
946else
947CC_FLAGS_LTO := -flto
948endif
949CC_FLAGS_LTO += -fvisibility=hidden
950
951# Limit inlining across translation units to reduce binary size
952KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
953endif
954
955ifdef CONFIG_LTO
956KBUILD_CFLAGS += -fno-lto $(CC_FLAGS_LTO)
957KBUILD_AFLAGS += -fno-lto
958export CC_FLAGS_LTO
959endif
960
961ifdef CONFIG_CFI_CLANG
962CC_FLAGS_CFI := -fsanitize=kcfi
963KBUILD_CFLAGS += $(CC_FLAGS_CFI)
964export CC_FLAGS_CFI
965endif
966
967ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
968# Set the minimal function alignment. Use the newer GCC option
969# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
970# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
971ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
972KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
973else
974KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
975endif
976endif
977
978# arch Makefile may override CC so keep this after arch Makefile is included
979NOSTDINC_FLAGS += -nostdinc
980
981# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
982# the kernel uses only C99 flexible arrays for dynamically sized trailing
983# arrays. Enforce this for everything that may examine structure sizes and
984# perform bounds checking.
985KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
986
987#Currently, disable -Wstringop-overflow for GCC 11, globally.
988KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
989KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
990
991# disable invalid "can't wrap" optimizations for signed / pointers
992KBUILD_CFLAGS += -fno-strict-overflow
993
994# Make sure -fstack-check isn't enabled (like gentoo apparently did)
995KBUILD_CFLAGS += -fno-stack-check
996
997# conserve stack if available
998ifdef CONFIG_CC_IS_GCC
999KBUILD_CFLAGS += -fconserve-stack
1000endif
1001
1002# change __FILE__ to the relative path from the srctree
1003KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1004
1005# include additional Makefiles when needed
1006include-y := scripts/Makefile.extrawarn
1007include-$(CONFIG_DEBUG_INFO) += scripts/Makefile.debug
1008include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1009include-$(CONFIG_KASAN) += scripts/Makefile.kasan
1010include-$(CONFIG_KCSAN) += scripts/Makefile.kcsan
1011include-$(CONFIG_KMSAN) += scripts/Makefile.kmsan
1012include-$(CONFIG_UBSAN) += scripts/Makefile.ubsan
1013include-$(CONFIG_KCOV) += scripts/Makefile.kcov
1014include-$(CONFIG_RANDSTRUCT) += scripts/Makefile.randstruct
1015include-$(CONFIG_GCC_PLUGINS) += scripts/Makefile.gcc-plugins
1016
1017include $(addprefix $(srctree)/, $(include-y))
1018
1019# scripts/Makefile.gcc-plugins is intentionally included last.
1020# Do not add $(call cc-option,...) below this line. When you build the kernel
1021# from the clean source tree, the GCC plugins do not exist at this point.
1022
1023# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1024KBUILD_CPPFLAGS += $(KCPPFLAGS)
1025KBUILD_AFLAGS += $(KAFLAGS)
1026KBUILD_CFLAGS += $(KCFLAGS)
1027KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1028
1029KBUILD_LDFLAGS_MODULE += --build-id=sha1
1030LDFLAGS_vmlinux += --build-id=sha1
1031
1032KBUILD_LDFLAGS += -z noexecstack
1033ifeq ($(CONFIG_LD_IS_BFD),y)
1034KBUILD_LDFLAGS += $(call ld-option,--no-warn-rwx-segments)
1035endif
1036
1037ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1038LDFLAGS_vmlinux += -X
1039endif
1040
1041ifeq ($(CONFIG_RELR),y)
1042# ld.lld before 15 did not support -z pack-relative-relocs.
1043LDFLAGS_vmlinux += $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1044endif
1045
1046# We never want expected sections to be placed heuristically by the
1047# linker. All sections should be explicitly named in the linker script.
1048ifdef CONFIG_LD_ORPHAN_WARN
1049LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1050endif
1051
1052# Align the bit size of userspace programs with the kernel
1053KBUILD_USERCFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1054KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1055
1056# make the checker run with the right architecture
1057CHECKFLAGS += --arch=$(ARCH)
1058
1059# insure the checker run with the right endianness
1060CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1061
1062# the checker needs the correct machine size
1063CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1064
1065# Default kernel image to build when no specific target is given.
1066# KBUILD_IMAGE may be overruled on the command line or
1067# set in the environment
1068# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1069# this default value
1070export KBUILD_IMAGE ?= vmlinux
1071
1072#
1073# INSTALL_PATH specifies where to place the updated kernel and system map
1074# images. Default is /boot, but you can set it to other values
1075export INSTALL_PATH ?= /boot
1076
1077#
1078# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1079# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1080# an argument if needed. Otherwise it defaults to the kernel install path
1081#
1082export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1083
1084#
1085# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1086# relocations required by build roots. This is not defined in the
1087# makefile but the argument can be passed to make if needed.
1088#
1089
1090MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1091export MODLIB
1092
1093PHONY += prepare0
1094
1095export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1096export MODORDER := $(extmod_prefix)modules.order
1097export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1098
1099ifeq ($(KBUILD_EXTMOD),)
1100
1101build-dir := .
1102clean-dirs := $(sort . Documentation \
1103 $(patsubst %/,%,$(filter %/, $(core-) \
1104 $(drivers-) $(libs-))))
1105
1106export ARCH_CORE := $(core-y)
1107export ARCH_LIB := $(filter %/, $(libs-y))
1108export ARCH_DRIVERS := $(drivers-y) $(drivers-m)
1109# Externally visible symbols (used by link-vmlinux.sh)
1110
1111KBUILD_VMLINUX_OBJS := ./built-in.a
1112ifdef CONFIG_MODULES
1113KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1114KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1115else
1116KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1117endif
1118
1119export KBUILD_VMLINUX_LIBS
1120export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1121
1122ifdef CONFIG_TRIM_UNUSED_KSYMS
1123# For the kernel to actually contain only the needed exported symbols,
1124# we have to build modules as well to determine what those symbols are.
1125KBUILD_MODULES := 1
1126endif
1127
1128# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1129quiet_cmd_ar_vmlinux.a = AR $@
1130 cmd_ar_vmlinux.a = \
1131 rm -f $@; \
1132 $(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1133 $(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1134
1135targets += vmlinux.a
1136vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1137 $(call if_changed,ar_vmlinux.a)
1138
1139PHONY += vmlinux_o
1140vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1141 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1142
1143vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1144 @:
1145
1146PHONY += vmlinux
1147# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1148# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1149# unrelated; the decompressors just happen to have the same base name,
1150# arch/*/boot/compressed/vmlinux.
1151# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1152#
1153# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1154# https://savannah.gnu.org/bugs/?61463
1155# For Make > 4.4, the following simple code will work:
1156# vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1157vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1158vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1159vmlinux: __KEEPMAKEFILEO__C.o $(KBUILD_LDS) modpost
1160 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1161
1162# The actual objects are generated when descending,
1163# make sure no implicit rule kicks in
1164$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1165
1166ifeq ($(origin KERNELRELEASE),file)
1167filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1168else
1169filechk_kernel.release = echo $(KERNELRELEASE)
1170endif
1171
1172# Store (new) KERNELRELEASE string in include/config/kernel.release
1173include/config/kernel.release: FORCE
1174 $(call filechk,kernel.release)
1175
1176# Additional helpers built in scripts
1177# Carefully list dependencies so we do not try to build scripts twice
1178# in parallel
1179PHONY += scripts
1180scripts: scripts_basic scripts_dtc
1181 $(Q)$(MAKE) $(build)=$(@)
1182
1183# Things we need to do before we recursively start building the kernel
1184# or the modules are listed in "prepare".
1185# A multi level approach is used. prepareN is processed before prepareN-1.
1186# archprepare is used in arch Makefiles and when processed asm symlink,
1187# version.h and scripts_basic is processed / created.
1188
1189PHONY += prepare archprepare
1190
1191archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1192 asm-generic $(version_h) include/generated/utsrelease.h \
1193 include/generated/compile.h include/generated/autoconf.h remove-stale-files
1194
1195prepare0: archprepare
1196 $(Q)$(MAKE) $(build)=scripts/mod
1197 $(Q)$(MAKE) $(build)=. prepare
1198
1199# All the preparing..
1200prepare: prepare0
1201ifdef CONFIG_RUST
1202 +$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1203 $(Q)$(MAKE) $(build)=rust
1204endif
1205
1206PHONY += remove-stale-files
1207remove-stale-files:
1208 $(Q)$(srctree)/scripts/remove-stale-files
1209
1210# Support for using generic headers in asm-generic
1211asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1212
1213PHONY += asm-generic uapi-asm-generic
1214asm-generic: uapi-asm-generic
1215 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1216 generic=include/asm-generic
1217uapi-asm-generic:
1218 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1219 generic=include/uapi/asm-generic
1220
1221# Generate some files
1222# ---------------------------------------------------------------------------
1223
1224# KERNELRELEASE can change from a few different places, meaning version.h
1225# needs to be updated, so this check is forced on all builds
1226
1227uts_len := 64
1228define filechk_utsrelease.h
1229 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1230 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1231 exit 1; \
1232 fi; \
1233 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1234endef
1235
1236define filechk_version.h
1237 if [ $(SUBLEVEL) -gt 255 ]; then \
1238 echo \#define LINUX_VERSION_CODE $(shell \
1239 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1240 else \
1241 echo \#define LINUX_VERSION_CODE $(shell \
1242 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1243 fi; \
1244 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + \
1245 ((c) > 255 ? 255 : (c)))'; \
1246 echo \#define LINUX_VERSION_MAJOR $(VERSION); \
1247 echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL); \
1248 echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1249endef
1250
1251$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1252$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1253$(version_h): FORCE
1254 $(call filechk,version.h)
1255
1256include/generated/utsrelease.h: include/config/kernel.release FORCE
1257 $(call filechk,utsrelease.h)
1258
1259filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1260 "$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1261
1262include/generated/compile.h: FORCE
1263 $(call filechk,compile.h)
1264
1265PHONY += headerdep
1266headerdep:
1267 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1268 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1269
1270# ---------------------------------------------------------------------------
1271# Kernel headers
1272
1273#Default location for installed headers
1274export INSTALL_HDR_PATH = $(objtree)/usr
1275
1276quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1277 cmd_headers_install = \
1278 mkdir -p $(INSTALL_HDR_PATH); \
1279 rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1280 usr/include $(INSTALL_HDR_PATH)
1281
1282PHONY += headers_install
1283headers_install: headers
1284 $(call cmd,headers_install)
1285
1286PHONY += archheaders archscripts
1287
1288hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1289
1290PHONY += headers
1291headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1292 $(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1293 $(Q)$(MAKE) $(hdr-inst)=include/uapi
1294 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1295
1296ifdef CONFIG_HEADERS_INSTALL
1297prepare: headers
1298endif
1299
1300PHONY += scripts_unifdef
1301scripts_unifdef: scripts_basic
1302 $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1303
1304# ---------------------------------------------------------------------------
1305# Install
1306
1307# Many distributions have the custom install script, /sbin/installkernel.
1308# If DKMS is installed, 'make install' will eventually recurse back
1309# to this Makefile to build and install external modules.
1310# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1311
1312quiet_cmd_install = INSTALL $(INSTALL_PATH)
1313 cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1314
1315# ---------------------------------------------------------------------------
1316# vDSO install
1317
1318PHONY += vdso_install
1319vdso_install: export INSTALL_FILES = $(vdso-install-y)
1320vdso_install:
1321 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1322
1323# ---------------------------------------------------------------------------
1324# Tools
1325
1326ifdef CONFIG_OBJTOOL
1327prepare: tools/objtool
1328endif
1329
1330ifdef CONFIG_BPF
1331ifdef CONFIG_DEBUG_INFO_BTF
1332prepare: tools/bpf/resolve_btfids
1333endif
1334endif
1335
1336PHONY += resolve_btfids_clean
1337
1338resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1339
1340# tools/bpf/resolve_btfids directory might not exist
1341# in output directory, skip its clean in that case
1342resolve_btfids_clean:
1343ifneq ($(wildcard $(resolve_btfids_O)),)
1344 $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1345endif
1346
1347# Clear a bunch of variables before executing the submake
1348ifeq ($(quiet),silent_)
1349tools_silent=s
1350endif
1351
1352tools/: FORCE
1353 $(Q)mkdir -p $(objtree)/tools
1354 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1355
1356tools/%: FORCE
1357 $(Q)mkdir -p $(objtree)/tools
1358 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1359
1360# ---------------------------------------------------------------------------
1361# Kernel selftest
1362
1363PHONY += kselftest
1364kselftest: headers
1365 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1366
1367kselftest-%: headers FORCE
1368 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1369
1370PHONY += kselftest-merge
1371kselftest-merge:
1372 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1373 $(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1374 xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1375 $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1376
1377# ---------------------------------------------------------------------------
1378# Devicetree files
1379
1380ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1381dtstree := arch/$(SRCARCH)/boot/dts
1382endif
1383
1384ifneq ($(dtstree),)
1385
1386%.dtb: dtbs_prepare
1387 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1388
1389%.dtbo: dtbs_prepare
1390 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1391
1392PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1393dtbs: dtbs_prepare
1394 $(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1395
1396# include/config/kernel.release is actually needed when installing DTBs because
1397# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1398# dtbs_install depend on it as dtbs_install may run as root.
1399dtbs_prepare: include/config/kernel.release scripts_dtc
1400
1401ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1402export CHECK_DTBS=y
1403endif
1404
1405ifneq ($(CHECK_DTBS),)
1406dtbs_prepare: dt_binding_check
1407endif
1408
1409dtbs_check: dtbs
1410
1411dtbs_install:
1412 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1413
1414ifdef CONFIG_OF_EARLY_FLATTREE
1415all: dtbs
1416endif
1417
1418endif
1419
1420PHONY += scripts_dtc
1421scripts_dtc: scripts_basic
1422 $(Q)$(MAKE) $(build)=scripts/dtc
1423
1424ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1425export CHECK_DT_BINDING=y
1426endif
1427
1428PHONY += dt_binding_check
1429dt_binding_check: scripts_dtc
1430 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1431
1432PHONY += dt_compatible_check
1433dt_compatible_check: dt_binding_check
1434 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1435
1436# ---------------------------------------------------------------------------
1437# Modules
1438
1439ifdef CONFIG_MODULES
1440
1441# By default, build modules as well
1442
1443all: modules
1444
1445# When we're building modules with modversions, we need to consider
1446# the built-in objects during the descend as well, in order to
1447# make sure the checksums are up to date before we record them.
1448ifdef CONFIG_MODVERSIONS
1449 KBUILD_BUILTIN := 1
1450endif
1451
1452# Build modules
1453#
1454
1455# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1456# is an exception.
1457ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1458KBUILD_BUILTIN := 1
1459modules: vmlinux
1460endif
1461
1462modules: modules_prepare
1463
1464# Target to prepare building external modules
1465modules_prepare: prepare
1466 $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1467
1468endif # CONFIG_MODULES
1469
1470###
1471# Cleaning is done on three levels.
1472# make clean Delete most generated files
1473# Leave enough to build external modules
1474# make mrproper Delete the current configuration, and all generated files
1475# make distclean Remove editor backup files, patch leftover files and the like
1476
1477# Directories & files removed with 'make clean'
1478CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1479 modules.builtin modules.builtin.modinfo modules.nsdeps \
1480 compile_commands.json .thinlto-cache rust/test \
1481 rust-project.json .vmlinux.objs .vmlinux.export.c
1482
1483# Directories & files removed with 'make mrproper'
1484MRPROPER_FILES += include/config include/generated \
1485 arch/$(SRCARCH)/include/generated .objdiff \
1486 debian snap tar-install \
1487 .config .config.old .version \
1488 Module.symvers \
1489 certs/signing_key.pem \
1490 certs/x509.genkey \
1491 vmlinux-gdb.py \
1492 rpmbuild \
1493 rust/libmacros.so
1494
1495# clean - Delete most, but leave enough to build external modules
1496#
1497clean: rm-files := $(CLEAN_FILES)
1498
1499PHONY += archclean vmlinuxclean
1500
1501vmlinuxclean:
1502 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1503 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1504
1505clean: archclean vmlinuxclean resolve_btfids_clean
1506
1507# mrproper - Delete all generated files, including .config
1508#
1509mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1510mrproper-dirs := $(addprefix _mrproper_,scripts)
1511
1512PHONY += $(mrproper-dirs) mrproper
1513$(mrproper-dirs):
1514 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1515
1516mrproper: clean $(mrproper-dirs)
1517 $(call cmd,rmfiles)
1518 @find . $(RCS_FIND_IGNORE) \
1519 \( -name '*.rmeta' \) \
1520 -type f -print | xargs rm -f
1521
1522# distclean
1523#
1524PHONY += distclean
1525
1526distclean: mrproper
1527 @find . $(RCS_FIND_IGNORE) \
1528 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1529 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1530 -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1531 -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1532 -type f -print | xargs rm -f
1533
1534
1535# Packaging of the kernel to various formats
1536# ---------------------------------------------------------------------------
1537
1538%src-pkg: FORCE
1539 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1540%pkg: include/config/kernel.release FORCE
1541 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1542
1543# Brief documentation of the typical targets used
1544# ---------------------------------------------------------------------------
1545
1546boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1547boards := $(sort $(notdir $(boards)))
1548board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1549board-dirs := $(sort $(notdir $(board-dirs:/=)))
1550
1551PHONY += help
1552help:
1553 @echo 'Cleaning targets:'
1554 @echo ' clean - Remove most generated files but keep the config and'
1555 @echo ' enough build support to build external modules'
1556 @echo ' mrproper - Remove all generated files + config + various backup files'
1557 @echo ' distclean - mrproper + remove editor backup and patch files'
1558 @echo ''
1559 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1560 @echo ''
1561 @echo 'Other generic targets:'
1562 @echo ' all - Build all targets marked with [*]'
1563 @echo '* vmlinux - Build the bare kernel'
1564 @echo '* modules - Build all modules'
1565 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1566 @echo ' vdso_install - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1567 @echo ' dir/ - Build all files in dir and below'
1568 @echo ' dir/file.[ois] - Build specified target only'
1569 @echo ' dir/file.ll - Build the LLVM assembly file'
1570 @echo ' (requires compiler support for LLVM assembly generation)'
1571 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1572 @echo ' (requires a recent binutils and recent build (System.map))'
1573 @echo ' dir/file.ko - Build module including final link'
1574 @echo ' modules_prepare - Set up for building external modules'
1575 @echo ' tags/TAGS - Generate tags file for editors'
1576 @echo ' cscope - Generate cscope index'
1577 @echo ' gtags - Generate GNU GLOBAL index'
1578 @echo ' kernelrelease - Output the release version string (use with make -s)'
1579 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1580 @echo ' image_name - Output the image name (use with make -s)'
1581 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1582 echo ' (default: $(INSTALL_HDR_PATH))'; \
1583 echo ''
1584 @echo 'Static analysers:'
1585 @echo ' checkstack - Generate a list of stack hogs and consider all functions'
1586 @echo ' with a stack size larger than MINSTACKSIZE (default: 100)'
1587 @echo ' versioncheck - Sanity check on version.h usage'
1588 @echo ' includecheck - Check for duplicate included header files'
1589 @echo ' export_report - List the usages of all exported symbols'
1590 @echo ' headerdep - Detect inclusion cycles in headers'
1591 @echo ' coccicheck - Check with Coccinelle'
1592 @echo ' clang-analyzer - Check with clang static analyzer'
1593 @echo ' clang-tidy - Check with clang-tidy'
1594 @echo ''
1595 @echo 'Tools:'
1596 @echo ' nsdeps - Generate missing symbol namespace dependencies'
1597 @echo ''
1598 @echo 'Kernel selftest:'
1599 @echo ' kselftest - Build and run kernel selftest'
1600 @echo ' Build, install, and boot kernel before'
1601 @echo ' running kselftest on it'
1602 @echo ' Run as root for full coverage'
1603 @echo ' kselftest-all - Build kernel selftest'
1604 @echo ' kselftest-install - Build and install kernel selftest'
1605 @echo ' kselftest-clean - Remove all generated kselftest files'
1606 @echo ' kselftest-merge - Merge all the config dependencies of'
1607 @echo ' kselftest to existing .config.'
1608 @echo ''
1609 @echo 'Rust targets:'
1610 @echo ' rustavailable - Checks whether the Rust toolchain is'
1611 @echo ' available and, if not, explains why.'
1612 @echo ' rustfmt - Reformat all the Rust code in the kernel'
1613 @echo ' rustfmtcheck - Checks if all the Rust code in the kernel'
1614 @echo ' is formatted, printing a diff otherwise.'
1615 @echo ' rustdoc - Generate Rust documentation'
1616 @echo ' (requires kernel .config)'
1617 @echo ' rusttest - Runs the Rust tests'
1618 @echo ' (requires kernel .config; downloads external repos)'
1619 @echo ' rust-analyzer - Generate rust-project.json rust-analyzer support file'
1620 @echo ' (requires kernel .config)'
1621 @echo ' dir/file.[os] - Build specified target only'
1622 @echo ' dir/file.rsi - Build macro expanded source, similar to C preprocessing.'
1623 @echo ' Run with RUSTFMT=n to skip reformatting if needed.'
1624 @echo ' The output is not intended to be compilable.'
1625 @echo ' dir/file.ll - Build the LLVM assembly file'
1626 @echo ''
1627 @$(if $(dtstree), \
1628 echo 'Devicetree:'; \
1629 echo '* dtbs - Build device tree blobs for enabled boards'; \
1630 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1631 echo ' dt_binding_check - Validate device tree binding documents'; \
1632 echo ' dtbs_check - Validate device tree source files';\
1633 echo '')
1634
1635 @echo 'Userspace tools targets:'
1636 @echo ' use "make tools/help"'
1637 @echo ' or "cd tools; make help"'
1638 @echo ''
1639 @echo 'Kernel packaging:'
1640 @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1641 @echo ''
1642 @echo 'Documentation targets:'
1643 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1644 @echo ''
1645 @echo 'Architecture-specific targets ($(SRCARCH)):'
1646 @$(or $(archhelp),\
1647 echo ' No architecture-specific help defined for $(SRCARCH)')
1648 @echo ''
1649 @$(if $(boards), \
1650 $(foreach b, $(boards), \
1651 printf " %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1652 echo '')
1653 @$(if $(board-dirs), \
1654 $(foreach b, $(board-dirs), \
1655 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1656 printf " %-16s - Show all of the above\\n" help-boards; \
1657 echo '')
1658
1659 @echo ' make V=n [targets] 1: verbose build'
1660 @echo ' 2: give reason for rebuild of target'
1661 @echo ' V=1 and V=2 can be combined with V=12'
1662 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1663 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK'
1664 @echo ' (sparse by default)'
1665 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1666 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1667 @echo ' make W=n [targets] Enable extra build checks, n=1,2,3,c,e where'
1668 @echo ' 1: warnings which may be relevant and do not occur too often'
1669 @echo ' 2: warnings which occur quite often but may still be relevant'
1670 @echo ' 3: more obscure warnings, can most likely be ignored'
1671 @echo ' c: extra checks in the configuration stage (Kconfig)'
1672 @echo ' e: warnings are being treated as errors'
1673 @echo ' Multiple levels can be combined with W=12 or W=123'
1674 @$(if $(dtstree), \
1675 echo ' make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1676 echo ' This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1677 )
1678 @echo ''
1679 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1680 @echo 'For further info see the ./README file'
1681
1682
1683help-board-dirs := $(addprefix help-,$(board-dirs))
1684
1685help-boards: $(help-board-dirs)
1686
1687boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1688
1689$(help-board-dirs): help-%:
1690 @echo 'Architecture-specific targets ($(SRCARCH) $*):'
1691 @$(if $(boards-per-dir), \
1692 $(foreach b, $(boards-per-dir), \
1693 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1694 echo '')
1695
1696
1697# Documentation targets
1698# ---------------------------------------------------------------------------
1699DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1700 linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1701PHONY += $(DOC_TARGETS)
1702$(DOC_TARGETS):
1703 $(Q)$(MAKE) $(build)=Documentation $@
1704
1705
1706# Rust targets
1707# ---------------------------------------------------------------------------
1708
1709# "Is Rust available?" target
1710PHONY += rustavailable
1711rustavailable:
1712 +$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1713
1714# Documentation target
1715#
1716# Using the singular to avoid running afoul of `no-dot-config-targets`.
1717PHONY += rustdoc
1718rustdoc: prepare
1719 $(Q)$(MAKE) $(build)=rust $@
1720
1721# Testing target
1722PHONY += rusttest
1723rusttest: prepare
1724 $(Q)$(MAKE) $(build)=rust $@
1725
1726# Formatting targets
1727PHONY += rustfmt rustfmtcheck
1728
1729# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1730#
1731# We match using absolute paths since `find` does not resolve them
1732# when matching, which is a problem when e.g. `srctree` is `..`.
1733# We `grep` afterwards in order to remove the directory entry itself.
1734rustfmt:
1735 $(Q)find $(abs_srctree) -type f -name '*.rs' \
1736 -o -path $(abs_srctree)/rust/alloc -prune \
1737 -o -path $(abs_objtree)/rust/test -prune \
1738 | grep -Fv $(abs_srctree)/rust/alloc \
1739 | grep -Fv $(abs_objtree)/rust/test \
1740 | grep -Fv generated \
1741 | xargs $(RUSTFMT) $(rustfmt_flags)
1742
1743rustfmtcheck: rustfmt_flags = --check
1744rustfmtcheck: rustfmt
1745
1746# Misc
1747# ---------------------------------------------------------------------------
1748
1749PHONY += misc-check
1750misc-check:
1751 $(Q)$(srctree)/scripts/misc-check
1752
1753all: misc-check
1754
1755PHONY += scripts_gdb
1756scripts_gdb: prepare0
1757 $(Q)$(MAKE) $(build)=scripts/gdb
1758 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1759
1760ifdef CONFIG_GDB_SCRIPTS
1761all: scripts_gdb
1762endif
1763
1764else # KBUILD_EXTMOD
1765
1766filechk_kernel.release = echo $(KERNELRELEASE)
1767
1768###
1769# External module support.
1770# When building external modules the kernel used as basis is considered
1771# read-only, and no consistency checks are made and the make
1772# system is not used on the basis kernel. If updates are required
1773# in the basis kernel ordinary make commands (without M=...) must be used.
1774
1775# We are always building only modules.
1776KBUILD_BUILTIN :=
1777KBUILD_MODULES := 1
1778
1779build-dir := $(KBUILD_EXTMOD)
1780
1781compile_commands.json: $(extmod_prefix)compile_commands.json
1782PHONY += compile_commands.json
1783
1784clean-dirs := $(KBUILD_EXTMOD)
1785clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1786 $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1787
1788PHONY += prepare
1789# now expand this into a simple variable to reduce the cost of shell evaluations
1790prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1791prepare:
1792 @if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1793 echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1794 echo >&2 " The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1795 echo >&2 " You are using: $(CC_VERSION_TEXT)"; \
1796 fi
1797
1798PHONY += help
1799help:
1800 @echo ' Building external modules.'
1801 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1802 @echo ''
1803 @echo ' modules - default target, build the module(s)'
1804 @echo ' modules_install - install the module'
1805 @echo ' clean - remove generated files in module directory only'
1806 @echo ' rust-analyzer - generate rust-project.json rust-analyzer support file'
1807 @echo ''
1808
1809ifndef CONFIG_MODULES
1810modules modules_install: __external_modules_error
1811__external_modules_error:
1812 @echo >&2 '***'
1813 @echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1814 @echo >&2 '*** You cannot build or install external modules.'
1815 @echo >&2 '***'
1816 @false
1817endif
1818
1819endif # KBUILD_EXTMOD
1820
1821# ---------------------------------------------------------------------------
1822# Modules
1823
1824PHONY += modules modules_install modules_sign modules_prepare
1825
1826modules_install:
1827 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1828 sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1829
1830ifeq ($(CONFIG_MODULE_SIG),y)
1831# modules_sign is a subset of modules_install.
1832# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1833modules_sign: modules_install
1834 @:
1835else
1836modules_sign:
1837 @echo >&2 '***'
1838 @echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1839 @echo >&2 '***'
1840 @false
1841endif
1842
1843ifdef CONFIG_MODULES
1844
1845$(MODORDER): $(build-dir)
1846 @:
1847
1848# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1849# This is solely useful to speed up test compiles.
1850modules: modpost
1851ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1852 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1853endif
1854
1855PHONY += modules_check
1856modules_check: $(MODORDER)
1857 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1858
1859else # CONFIG_MODULES
1860
1861modules:
1862 @:
1863
1864KBUILD_MODULES :=
1865
1866endif # CONFIG_MODULES
1867
1868PHONY += modpost
1869modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1870 $(if $(KBUILD_MODULES), modules_check)
1871 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1872
1873# Single targets
1874# ---------------------------------------------------------------------------
1875# To build individual files in subdirectories, you can do like this:
1876#
1877# make foo/bar/baz.s
1878#
1879# The supported suffixes for single-target are listed in 'single-targets'
1880#
1881# To build only under specific subdirectories, you can do like this:
1882#
1883# make foo/bar/baz/
1884
1885ifdef single-build
1886
1887# .ko is special because modpost is needed
1888single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1889single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1890 $(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1891
1892$(single-ko): single_modules
1893 @:
1894$(single-no-ko): $(build-dir)
1895 @:
1896
1897# Remove MODORDER when done because it is not the real one.
1898PHONY += single_modules
1899single_modules: $(single-no-ko) modules_prepare
1900 $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1901 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1902ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1903 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1904endif
1905 $(Q)rm -f $(MODORDER)
1906
1907single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1908
1909KBUILD_MODULES := 1
1910
1911endif
1912
1913# Preset locale variables to speed up the build process. Limit locale
1914# tweaks to this spot to avoid wrong language settings when running
1915# make menuconfig etc.
1916# Error messages still appears in the original language
1917PHONY += $(build-dir)
1918$(build-dir): prepare
1919 $(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1920
1921clean-dirs := $(addprefix _clean_, $(clean-dirs))
1922PHONY += $(clean-dirs) clean
1923$(clean-dirs):
1924 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1925
1926clean: $(clean-dirs)
1927 $(call cmd,rmfiles)
1928 @find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1929 \( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
1930 -o -name '*.ko.*' \
1931 -o -name '*.dtb' -o -name '*.dtbo' \
1932 -o -name '*.dtb.S' -o -name '*.dtbo.S' \
1933 -o -name '*.dt.yaml' -o -name 'dtbs-list' \
1934 -o -name '*.dwo' -o -name '*.lst' \
1935 -o -name '*.su' -o -name '*.mod' \
1936 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1937 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1938 -o -name '*.asn1.[ch]' \
1939 -o -name '*.symtypes' -o -name 'modules.order' \
1940 -o -name '*.c.[012]*.*' \
1941 -o -name '*.ll' \
1942 -o -name '*.gcno' \
1943 -o -name '*.*.symversions' \) -type f -print \
1944 -o -name '.tmp_*' -print \
1945 | xargs rm -rf
1946
1947# Generate tags for editors
1948# ---------------------------------------------------------------------------
1949quiet_cmd_tags = GEN $@
1950 cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1951
1952tags TAGS cscope gtags: FORCE
1953 $(call cmd,tags)
1954
1955# IDE support targets
1956PHONY += rust-analyzer
1957rust-analyzer:
1958 $(Q)$(MAKE) $(build)=rust $@
1959
1960# Script to generate missing namespace dependencies
1961# ---------------------------------------------------------------------------
1962
1963PHONY += nsdeps
1964nsdeps: export KBUILD_NSDEPS=1
1965nsdeps: modules
1966 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1967
1968# Clang Tooling
1969# ---------------------------------------------------------------------------
1970
1971quiet_cmd_gen_compile_commands = GEN $@
1972 cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1973
1974$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1975 $(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
1976 $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1977 $(call if_changed,gen_compile_commands)
1978
1979targets += $(extmod_prefix)compile_commands.json
1980
1981PHONY += clang-tidy clang-analyzer
1982
1983ifdef CONFIG_CC_IS_CLANG
1984quiet_cmd_clang_tools = CHECK $<
1985 cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1986
1987clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1988 $(call cmd,clang_tools)
1989else
1990clang-tidy clang-analyzer:
1991 @echo "$@ requires CC=clang" >&2
1992 @false
1993endif
1994
1995# Scripts to check various things for consistency
1996# ---------------------------------------------------------------------------
1997
1998PHONY += includecheck versioncheck coccicheck export_report
1999
2000includecheck:
2001 find $(srctree)/* $(RCS_FIND_IGNORE) \
2002 -name '*.[hcS]' -type f -print | sort \
2003 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2004
2005versioncheck:
2006 find $(srctree)/* $(RCS_FIND_IGNORE) \
2007 -name '*.[hcS]' -type f -print | sort \
2008 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2009
2010coccicheck:
2011 $(Q)$(BASH) $(srctree)/scripts/$@
2012
2013export_report:
2014 $(PERL) $(srctree)/scripts/export_report.pl
2015
2016PHONY += checkstack kernelrelease kernelversion image_name
2017
2018# UML needs a little special treatment here. It wants to use the host
2019# toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
2020# else wants $(ARCH), including people doing cross-builds, which means
2021# that $(SUBARCH) doesn't work here.
2022ifeq ($(ARCH), um)
2023CHECKSTACK_ARCH := $(SUBARCH)
2024else
2025CHECKSTACK_ARCH := $(ARCH)
2026endif
2027MINSTACKSIZE ?= 100
2028checkstack:
2029 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2030 $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2031
2032kernelrelease:
2033 @$(filechk_kernel.release)
2034
2035kernelversion:
2036 @echo $(KERNELVERSION)
2037
2038image_name:
2039 @echo $(KBUILD_IMAGE)
2040
2041PHONY += run-command
2042run-command:
2043 $(Q)$(KBUILD_RUN_COMMAND)
2044
2045quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
2046 cmd_rmfiles = rm -rf $(rm-files)
2047
2048# read saved command lines for existing targets
2049existing-targets := $(wildcard $(sort $(targets)))
2050
2051-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2052
2053endif # config-build
2054endif # mixed-build
2055endif # need-sub-make
2056
2057PHONY += FORCE
2058FORCE:
2059
2060# Declare the contents of the PHONY variable as phony. We keep that
2061# information in a variable so we can use it in if_changed and friends.
2062.PHONY: $(PHONY)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 4
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Kleptomaniac Octopus
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
14# That's our default target when none is given on the command line
15PHONY := _all
16_all:
17
18# We are using a recursive build, so we need to do a little thinking
19# to get the ordering right.
20#
21# Most importantly: sub-Makefiles should only ever modify files in
22# their own directory. If in some directory we have a dependency on
23# a file in another dir (which doesn't happen often, but it's often
24# unavoidable when linking the built-in.a targets which finally
25# turn into vmlinux), we will call a sub make in that other dir, and
26# after that we are sure that everything which is in that other dir
27# is now up to date.
28#
29# The only cases where we need to modify files which have global
30# effects are thus separated out and done before the recursive
31# descending is started. They are now explicitly listed as the
32# prepare rule.
33
34ifneq ($(sub_make_done),1)
35
36# Do not use make's built-in rules and variables
37# (this increases performance and avoids hard-to-debug behaviour)
38MAKEFLAGS += -rR
39
40# Avoid funny character set dependencies
41unexport LC_ALL
42LC_COLLATE=C
43LC_NUMERIC=C
44export LC_COLLATE LC_NUMERIC
45
46# Avoid interference with shell env settings
47unexport GREP_OPTIONS
48
49# Beautify output
50# ---------------------------------------------------------------------------
51#
52# Normally, we echo the whole command before executing it. By making
53# that echo $($(quiet)$(cmd)), we now have the possibility to set
54# $(quiet) to choose other forms of output instead, e.g.
55#
56# quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
57# cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
58#
59# If $(quiet) is empty, the whole command will be printed.
60# If it is set to "quiet_", only the short version will be printed.
61# If it is set to "silent_", nothing will be printed at all, since
62# the variable $(silent_cmd_cc_o_c) doesn't exist.
63#
64# A simple variant is to prefix commands with $(Q) - that's useful
65# for commands that shall be hidden in non-verbose mode.
66#
67# $(Q)ln $@ :<
68#
69# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
70# If KBUILD_VERBOSE equals 1 then the above command is displayed.
71#
72# To put more focus on warnings, be less verbose as default
73# Use 'make V=1' to see the full commands
74
75ifeq ("$(origin V)", "command line")
76 KBUILD_VERBOSE = $(V)
77endif
78ifndef KBUILD_VERBOSE
79 KBUILD_VERBOSE = 0
80endif
81
82ifeq ($(KBUILD_VERBOSE),1)
83 quiet =
84 Q =
85else
86 quiet=quiet_
87 Q = @
88endif
89
90# If the user is running make -s (silent mode), suppress echoing of
91# commands
92
93ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
94 quiet=silent_
95endif
96
97export quiet Q KBUILD_VERBOSE
98
99# Kbuild will save output files in the current working directory.
100# This does not need to match to the root of the kernel source tree.
101#
102# For example, you can do this:
103#
104# cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
105#
106# If you want to save output files in a different location, there are
107# two syntaxes to specify it.
108#
109# 1) O=
110# Use "make O=dir/to/store/output/files/"
111#
112# 2) Set KBUILD_OUTPUT
113# Set the environment variable KBUILD_OUTPUT to point to the output directory.
114# export KBUILD_OUTPUT=dir/to/store/output/files/; make
115#
116# The O= assignment takes precedence over the KBUILD_OUTPUT environment
117# variable.
118
119# Do we want to change the working directory?
120ifeq ("$(origin O)", "command line")
121 KBUILD_OUTPUT := $(O)
122endif
123
124ifneq ($(KBUILD_OUTPUT),)
125# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
126# expand a shell special character '~'. We use a somewhat tedious way here.
127abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
128$(if $(abs_objtree),, \
129 $(error failed to create output directory "$(KBUILD_OUTPUT)"))
130
131# $(realpath ...) resolves symlinks
132abs_objtree := $(realpath $(abs_objtree))
133else
134abs_objtree := $(CURDIR)
135endif # ifneq ($(KBUILD_OUTPUT),)
136
137ifeq ($(abs_objtree),$(CURDIR))
138# Suppress "Entering directory ..." unless we are changing the work directory.
139MAKEFLAGS += --no-print-directory
140else
141need-sub-make := 1
142endif
143
144abs_srctree := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
145
146ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
147$(error source directory cannot contain spaces or colons)
148endif
149
150ifneq ($(abs_srctree),$(abs_objtree))
151# Look for make include files relative to root of kernel src
152#
153# This does not become effective immediately because MAKEFLAGS is re-parsed
154# once after the Makefile is read. We need to invoke sub-make.
155MAKEFLAGS += --include-dir=$(abs_srctree)
156need-sub-make := 1
157endif
158
159ifneq ($(filter 3.%,$(MAKE_VERSION)),)
160# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
161# We need to invoke sub-make to avoid implicit rules in the top Makefile.
162need-sub-make := 1
163# Cancel implicit rules for this Makefile.
164$(lastword $(MAKEFILE_LIST)): ;
165endif
166
167export abs_srctree abs_objtree
168export sub_make_done := 1
169
170ifeq ($(need-sub-make),1)
171
172PHONY += $(MAKECMDGOALS) sub-make
173
174$(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all: sub-make
175 @:
176
177# Invoke a second make in the output directory, passing relevant variables
178sub-make:
179 $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
180
181endif # need-sub-make
182endif # sub_make_done
183
184# We process the rest of the Makefile if this is the final invocation of make
185ifeq ($(need-sub-make),)
186
187# Do not print "Entering directory ...",
188# but we want to display it when entering to the output directory
189# so that IDEs/editors are able to understand relative filenames.
190MAKEFLAGS += --no-print-directory
191
192# Call a source code checker (by default, "sparse") as part of the
193# C compilation.
194#
195# Use 'make C=1' to enable checking of only re-compiled files.
196# Use 'make C=2' to enable checking of *all* source files, regardless
197# of whether they are re-compiled or not.
198#
199# See the file "Documentation/dev-tools/sparse.rst" for more details,
200# including where to get the "sparse" utility.
201
202ifeq ("$(origin C)", "command line")
203 KBUILD_CHECKSRC = $(C)
204endif
205ifndef KBUILD_CHECKSRC
206 KBUILD_CHECKSRC = 0
207endif
208
209# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
210# directory of external module to build. Setting M= takes precedence.
211ifeq ("$(origin M)", "command line")
212 KBUILD_EXTMOD := $(M)
213endif
214
215export KBUILD_CHECKSRC KBUILD_EXTMOD
216
217extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
218
219ifeq ($(abs_srctree),$(abs_objtree))
220 # building in the source tree
221 srctree := .
222 building_out_of_srctree :=
223else
224 ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
225 # building in a subdirectory of the source tree
226 srctree := ..
227 else
228 srctree := $(abs_srctree)
229 endif
230 building_out_of_srctree := 1
231endif
232
233ifneq ($(KBUILD_ABS_SRCTREE),)
234srctree := $(abs_srctree)
235endif
236
237objtree := .
238VPATH := $(srctree)
239
240export building_out_of_srctree srctree objtree VPATH
241
242# To make sure we do not include .config for any of the *config targets
243# catch them early, and hand them over to scripts/kconfig/Makefile
244# It is allowed to specify more targets when calling make, including
245# mixing *config targets and build targets.
246# For example 'make oldconfig all'.
247# Detect when mixed targets is specified, and make a second invocation
248# of make so .config is not included in this case either (for *config).
249
250version_h := include/generated/uapi/linux/version.h
251old_version_h := include/linux/version.h
252
253clean-targets := %clean mrproper cleandocs
254no-dot-config-targets := $(clean-targets) \
255 cscope gtags TAGS tags help% %docs check% coccicheck \
256 $(version_h) headers headers_% archheaders archscripts \
257 %asm-generic kernelversion %src-pkg
258no-sync-config-targets := $(no-dot-config-targets) install %install \
259 kernelrelease
260single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
261
262config-build :=
263mixed-build :=
264need-config := 1
265may-sync-config := 1
266single-build :=
267
268ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
269 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
270 need-config :=
271 endif
272endif
273
274ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
275 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
276 may-sync-config :=
277 endif
278endif
279
280ifneq ($(KBUILD_EXTMOD),)
281 may-sync-config :=
282endif
283
284ifeq ($(KBUILD_EXTMOD),)
285 ifneq ($(filter config %config,$(MAKECMDGOALS)),)
286 config-build := 1
287 ifneq ($(words $(MAKECMDGOALS)),1)
288 mixed-build := 1
289 endif
290 endif
291endif
292
293# We cannot build single targets and the others at the same time
294ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
295 single-build := 1
296 ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
297 mixed-build := 1
298 endif
299endif
300
301# For "make -j clean all", "make -j mrproper defconfig all", etc.
302ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
303 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
304 mixed-build := 1
305 endif
306endif
307
308# install and modules_install need also be processed one by one
309ifneq ($(filter install,$(MAKECMDGOALS)),)
310 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
311 mixed-build := 1
312 endif
313endif
314
315ifdef mixed-build
316# ===========================================================================
317# We're called with mixed targets (*config and build targets).
318# Handle them one by one.
319
320PHONY += $(MAKECMDGOALS) __build_one_by_one
321
322$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
323 @:
324
325__build_one_by_one:
326 $(Q)set -e; \
327 for i in $(MAKECMDGOALS); do \
328 $(MAKE) -f $(srctree)/Makefile $$i; \
329 done
330
331else # !mixed-build
332
333include scripts/Kbuild.include
334
335# Read KERNELRELEASE from include/config/kernel.release (if it exists)
336KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
337KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
338export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
339
340include scripts/subarch.include
341
342# Cross compiling and selecting different set of gcc/bin-utils
343# ---------------------------------------------------------------------------
344#
345# When performing cross compilation for other architectures ARCH shall be set
346# to the target architecture. (See arch/* for the possibilities).
347# ARCH can be set during invocation of make:
348# make ARCH=ia64
349# Another way is to have ARCH set in the environment.
350# The default ARCH is the host where make is executed.
351
352# CROSS_COMPILE specify the prefix used for all executables used
353# during compilation. Only gcc and related bin-utils executables
354# are prefixed with $(CROSS_COMPILE).
355# CROSS_COMPILE can be set on the command line
356# make CROSS_COMPILE=ia64-linux-
357# Alternatively CROSS_COMPILE can be set in the environment.
358# Default value for CROSS_COMPILE is not to prefix executables
359# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
360ARCH ?= $(SUBARCH)
361
362# Architecture as present in compile.h
363UTS_MACHINE := $(ARCH)
364SRCARCH := $(ARCH)
365
366# Additional ARCH settings for x86
367ifeq ($(ARCH),i386)
368 SRCARCH := x86
369endif
370ifeq ($(ARCH),x86_64)
371 SRCARCH := x86
372endif
373
374# Additional ARCH settings for sparc
375ifeq ($(ARCH),sparc32)
376 SRCARCH := sparc
377endif
378ifeq ($(ARCH),sparc64)
379 SRCARCH := sparc
380endif
381
382# Additional ARCH settings for sh
383ifeq ($(ARCH),sh64)
384 SRCARCH := sh
385endif
386
387KCONFIG_CONFIG ?= .config
388export KCONFIG_CONFIG
389
390# SHELL used by kbuild
391CONFIG_SHELL := sh
392
393HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
394HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
395HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
396
397HOSTCC = gcc
398HOSTCXX = g++
399KBUILD_HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 \
400 -fomit-frame-pointer -std=gnu89 $(HOST_LFS_CFLAGS) \
401 $(HOSTCFLAGS)
402KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
403KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
404KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
405
406# Make variables (CC, etc...)
407AS = $(CROSS_COMPILE)as
408LD = $(CROSS_COMPILE)ld
409CC = $(CROSS_COMPILE)gcc
410CPP = $(CC) -E
411AR = $(CROSS_COMPILE)ar
412NM = $(CROSS_COMPILE)nm
413STRIP = $(CROSS_COMPILE)strip
414OBJCOPY = $(CROSS_COMPILE)objcopy
415OBJDUMP = $(CROSS_COMPILE)objdump
416OBJSIZE = $(CROSS_COMPILE)size
417PAHOLE = pahole
418LEX = flex
419YACC = bison
420AWK = awk
421INSTALLKERNEL := installkernel
422DEPMOD = /sbin/depmod
423PERL = perl
424PYTHON = python
425PYTHON2 = python2
426PYTHON3 = python3
427CHECK = sparse
428BASH = bash
429
430CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
431 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
432NOSTDINC_FLAGS :=
433CFLAGS_MODULE =
434AFLAGS_MODULE =
435LDFLAGS_MODULE =
436CFLAGS_KERNEL =
437AFLAGS_KERNEL =
438LDFLAGS_vmlinux =
439
440# Use USERINCLUDE when you must reference the UAPI directories only.
441USERINCLUDE := \
442 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
443 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
444 -I$(srctree)/include/uapi \
445 -I$(objtree)/include/generated/uapi \
446 -include $(srctree)/include/linux/kconfig.h
447
448# Use LINUXINCLUDE when you must reference the include directory.
449# Needed to be compatible with the O= option
450LINUXINCLUDE := \
451 -I$(srctree)/arch/$(SRCARCH)/include \
452 -I$(objtree)/arch/$(SRCARCH)/include/generated \
453 $(if $(building_out_of_srctree),-I$(srctree)/include) \
454 -I$(objtree)/include \
455 $(USERINCLUDE)
456
457KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
458KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
459 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
460 -Werror=implicit-function-declaration -Werror=implicit-int \
461 -Wno-format-security \
462 -std=gnu89
463KBUILD_CPPFLAGS := -D__KERNEL__
464KBUILD_AFLAGS_KERNEL :=
465KBUILD_CFLAGS_KERNEL :=
466KBUILD_AFLAGS_MODULE := -DMODULE
467KBUILD_CFLAGS_MODULE := -DMODULE
468KBUILD_LDFLAGS_MODULE :=
469export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
470KBUILD_LDFLAGS :=
471GCC_PLUGINS_CFLAGS :=
472CLANG_FLAGS :=
473
474export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
475export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE PAHOLE LEX YACC AWK INSTALLKERNEL
476export PERL PYTHON PYTHON2 PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
477export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
478
479export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
480export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
481export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
482export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
483export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
484export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
485
486# Files to ignore in find ... statements
487
488export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
489 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
490 -prune -o
491export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
492 --exclude CVS --exclude .pc --exclude .hg --exclude .git
493
494# ===========================================================================
495# Rules shared between *config targets and build targets
496
497# Basic helpers built in scripts/basic
498PHONY += scripts_basic
499scripts_basic:
500 $(Q)$(MAKE) $(build)=scripts/basic
501 $(Q)rm -f .tmp_quiet_recordmcount
502
503PHONY += outputmakefile
504# Before starting out-of-tree build, make sure the source tree is clean.
505# outputmakefile generates a Makefile in the output directory, if using a
506# separate output directory. This allows convenient use of make in the
507# output directory.
508# At the same time when output Makefile generated, generate .gitignore to
509# ignore whole output directory
510outputmakefile:
511ifdef building_out_of_srctree
512 $(Q)if [ -f $(srctree)/.config -o \
513 -d $(srctree)/include/config -o \
514 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
515 echo >&2 "***"; \
516 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
517 echo >&2 "*** in $(abs_srctree)";\
518 echo >&2 "***"; \
519 false; \
520 fi
521 $(Q)ln -fsn $(srctree) source
522 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
523 $(Q)test -e .gitignore || \
524 { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
525endif
526
527ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
528ifneq ($(CROSS_COMPILE),)
529CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
530GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
531CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)
532GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
533endif
534ifneq ($(GCC_TOOLCHAIN),)
535CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
536endif
537ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
538CLANG_FLAGS += -no-integrated-as
539endif
540CLANG_FLAGS += -Werror=unknown-warning-option
541KBUILD_CFLAGS += $(CLANG_FLAGS)
542KBUILD_AFLAGS += $(CLANG_FLAGS)
543export CLANG_FLAGS
544endif
545
546# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
547# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
548# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
549# and from include/config/auto.conf.cmd to detect the compiler upgrade.
550CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)
551
552ifdef config-build
553# ===========================================================================
554# *config targets only - make sure prerequisites are updated, and descend
555# in scripts/kconfig to make the *config target
556
557# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
558# KBUILD_DEFCONFIG may point out an alternative default configuration
559# used for 'make defconfig'
560include arch/$(SRCARCH)/Makefile
561export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
562
563config: outputmakefile scripts_basic FORCE
564 $(Q)$(MAKE) $(build)=scripts/kconfig $@
565
566%config: outputmakefile scripts_basic FORCE
567 $(Q)$(MAKE) $(build)=scripts/kconfig $@
568
569else #!config-build
570# ===========================================================================
571# Build targets only - this includes vmlinux, arch specific targets, clean
572# targets and others. In general all targets except *config targets.
573
574# If building an external module we do not care about the all: rule
575# but instead _all depend on modules
576PHONY += all
577ifeq ($(KBUILD_EXTMOD),)
578_all: all
579else
580_all: modules
581endif
582
583# Decide whether to build built-in, modular, or both.
584# Normally, just do built-in.
585
586KBUILD_MODULES :=
587KBUILD_BUILTIN := 1
588
589# If we have only "make modules", don't compile built-in objects.
590# When we're building modules with modversions, we need to consider
591# the built-in objects during the descend as well, in order to
592# make sure the checksums are up to date before we record them.
593
594ifeq ($(MAKECMDGOALS),modules)
595 KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
596endif
597
598# If we have "make <whatever> modules", compile modules
599# in addition to whatever we do anyway.
600# Just "make" or "make all" shall build modules as well
601
602ifneq ($(filter all _all modules nsdeps,$(MAKECMDGOALS)),)
603 KBUILD_MODULES := 1
604endif
605
606ifeq ($(MAKECMDGOALS),)
607 KBUILD_MODULES := 1
608endif
609
610export KBUILD_MODULES KBUILD_BUILTIN
611
612ifdef need-config
613include include/config/auto.conf
614endif
615
616ifeq ($(KBUILD_EXTMOD),)
617# Objects we will link into vmlinux / subdirs we need to visit
618init-y := init
619drivers-y := drivers sound
620drivers-$(CONFIG_SAMPLES) += samples
621drivers-$(CONFIG_KERNEL_HEADER_TEST) += include/
622net-y := net
623libs-y := lib
624core-y := usr
625virt-y := virt
626endif # KBUILD_EXTMOD
627
628# The all: target is the default when no target is given on the
629# command line.
630# This allow a user to issue only 'make' to build a kernel including modules
631# Defaults to vmlinux, but the arch makefile usually adds further targets
632all: vmlinux
633
634CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
635 $(call cc-option,-fno-tree-loop-im) \
636 $(call cc-disable-warning,maybe-uninitialized,)
637export CFLAGS_GCOV
638
639# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
640ifdef CONFIG_FUNCTION_TRACER
641 CC_FLAGS_FTRACE := -pg
642endif
643
644RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
645RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
646RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
647RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
648RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
649RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
650export RETPOLINE_CFLAGS
651export RETPOLINE_VDSO_CFLAGS
652
653include arch/$(SRCARCH)/Makefile
654
655ifdef need-config
656ifdef may-sync-config
657# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
658# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
659# because some architectures define CROSS_COMPILE there.
660include include/config/auto.conf.cmd
661
662$(KCONFIG_CONFIG):
663 @echo >&2 '***'
664 @echo >&2 '*** Configuration file "$@" not found!'
665 @echo >&2 '***'
666 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
667 @echo >&2 '*** "make menuconfig" or "make xconfig").'
668 @echo >&2 '***'
669 @/bin/false
670
671# The actual configuration files used during the build are stored in
672# include/generated/ and include/config/. Update them if .config is newer than
673# include/config/auto.conf (which mirrors .config).
674#
675# This exploits the 'multi-target pattern rule' trick.
676# The syncconfig should be executed only once to make all the targets.
677%/auto.conf %/auto.conf.cmd %/tristate.conf: $(KCONFIG_CONFIG)
678 $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
679else # !may-sync-config
680# External modules and some install targets need include/generated/autoconf.h
681# and include/config/auto.conf but do not care if they are up-to-date.
682# Use auto.conf to trigger the test
683PHONY += include/config/auto.conf
684
685include/config/auto.conf:
686 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
687 echo >&2; \
688 echo >&2 " ERROR: Kernel configuration is invalid."; \
689 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
690 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
691 echo >&2 ; \
692 /bin/false)
693
694endif # may-sync-config
695endif # need-config
696
697KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
698KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
699KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
700KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
701KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
702
703ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
704KBUILD_CFLAGS += -O2
705else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
706KBUILD_CFLAGS += -O3
707else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
708KBUILD_CFLAGS += -Os
709endif
710
711ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
712KBUILD_CFLAGS += -Wno-maybe-uninitialized
713endif
714
715# Tell gcc to never replace conditional load with a non-conditional one
716KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
717
718include scripts/Makefile.kcov
719include scripts/Makefile.gcc-plugins
720
721ifdef CONFIG_READABLE_ASM
722# Disable optimizations that make assembler listings hard to read.
723# reorder blocks reorders the control in the function
724# ipa clone creates specialized cloned functions
725# partial inlining inlines only parts of functions
726KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
727 $(call cc-option,-fno-ipa-cp-clone,) \
728 $(call cc-option,-fno-partial-inlining)
729endif
730
731ifneq ($(CONFIG_FRAME_WARN),0)
732KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
733endif
734
735stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
736stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
737stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
738
739KBUILD_CFLAGS += $(stackp-flags-y)
740
741ifdef CONFIG_CC_IS_CLANG
742KBUILD_CPPFLAGS += -Qunused-arguments
743KBUILD_CFLAGS += -Wno-format-invalid-specifier
744KBUILD_CFLAGS += -Wno-gnu
745# Quiet clang warning: comparison of unsigned expression < 0 is always false
746KBUILD_CFLAGS += -Wno-tautological-compare
747# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
748# source of a reference will be _MergedGlobals and not on of the whitelisted names.
749# See modpost pattern 2
750KBUILD_CFLAGS += -mno-global-merge
751else
752
753# These warnings generated too much noise in a regular build.
754# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
755KBUILD_CFLAGS += -Wno-unused-but-set-variable
756
757# Warn about unmarked fall-throughs in switch statement.
758# Disabled for clang while comment to attribute conversion happens and
759# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
760KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
761endif
762
763KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
764ifdef CONFIG_FRAME_POINTER
765KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
766else
767# Some targets (ARM with Thumb2, for example), can't be built with frame
768# pointers. For those, we don't have FUNCTION_TRACER automatically
769# select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
770# incompatible with -fomit-frame-pointer with current GCC, so we don't use
771# -fomit-frame-pointer with FUNCTION_TRACER.
772ifndef CONFIG_FUNCTION_TRACER
773KBUILD_CFLAGS += -fomit-frame-pointer
774endif
775endif
776
777# Initialize all stack variables with a pattern, if desired.
778ifdef CONFIG_INIT_STACK_ALL
779KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern
780endif
781
782DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments)
783
784ifdef CONFIG_DEBUG_INFO
785ifdef CONFIG_DEBUG_INFO_SPLIT
786DEBUG_CFLAGS += -gsplit-dwarf
787else
788DEBUG_CFLAGS += -g
789endif
790KBUILD_AFLAGS += -Wa,-gdwarf-2
791endif
792ifdef CONFIG_DEBUG_INFO_DWARF4
793DEBUG_CFLAGS += -gdwarf-4
794endif
795
796ifdef CONFIG_DEBUG_INFO_REDUCED
797DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
798 $(call cc-option,-fno-var-tracking)
799endif
800
801KBUILD_CFLAGS += $(DEBUG_CFLAGS)
802export DEBUG_CFLAGS
803
804ifdef CONFIG_FUNCTION_TRACER
805ifdef CONFIG_FTRACE_MCOUNT_RECORD
806 # gcc 5 supports generating the mcount tables directly
807 ifeq ($(call cc-option-yn,-mrecord-mcount),y)
808 CC_FLAGS_FTRACE += -mrecord-mcount
809 export CC_USING_RECORD_MCOUNT := 1
810 endif
811 ifdef CONFIG_HAVE_NOP_MCOUNT
812 ifeq ($(call cc-option-yn, -mnop-mcount),y)
813 CC_FLAGS_FTRACE += -mnop-mcount
814 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
815 endif
816 endif
817endif
818ifdef CONFIG_HAVE_FENTRY
819 ifeq ($(call cc-option-yn, -mfentry),y)
820 CC_FLAGS_FTRACE += -mfentry
821 CC_FLAGS_USING += -DCC_USING_FENTRY
822 endif
823endif
824export CC_FLAGS_FTRACE
825KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
826KBUILD_AFLAGS += $(CC_FLAGS_USING)
827ifdef CONFIG_DYNAMIC_FTRACE
828 ifdef CONFIG_HAVE_C_RECORDMCOUNT
829 BUILD_C_RECORDMCOUNT := y
830 export BUILD_C_RECORDMCOUNT
831 endif
832endif
833endif
834
835# We trigger additional mismatches with less inlining
836ifdef CONFIG_DEBUG_SECTION_MISMATCH
837KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
838endif
839
840ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
841KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
842LDFLAGS_vmlinux += --gc-sections
843endif
844
845ifdef CONFIG_LIVEPATCH
846KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone)
847endif
848
849# arch Makefile may override CC so keep this after arch Makefile is included
850NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
851
852# warn about C99 declaration after statement
853KBUILD_CFLAGS += -Wdeclaration-after-statement
854
855# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
856KBUILD_CFLAGS += -Wvla
857
858# disable pointer signed / unsigned warnings in gcc 4.0
859KBUILD_CFLAGS += -Wno-pointer-sign
860
861# disable stringop warnings in gcc 8+
862KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
863
864# disable invalid "can't wrap" optimizations for signed / pointers
865KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
866
867# clang sets -fmerge-all-constants by default as optimization, but this
868# is non-conforming behavior for C and in fact breaks the kernel, so we
869# need to disable it here generally.
870KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants)
871
872# for gcc -fno-merge-all-constants disables everything, but it is fine
873# to have actual conforming behavior enabled.
874KBUILD_CFLAGS += $(call cc-option,-fmerge-constants)
875
876# Make sure -fstack-check isn't enabled (like gentoo apparently did)
877KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,)
878
879# conserve stack if available
880KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
881
882# Prohibit date/time macros, which would make the build non-deterministic
883KBUILD_CFLAGS += $(call cc-option,-Werror=date-time)
884
885# enforce correct pointer usage
886KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
887
888# Require designated initializers for all marked structures
889KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
890
891# change __FILE__ to the relative path from the srctree
892KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
893
894# ensure -fcf-protection is disabled when using retpoline as it is
895# incompatible with -mindirect-branch=thunk-extern
896ifdef CONFIG_RETPOLINE
897KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
898endif
899
900include scripts/Makefile.kasan
901include scripts/Makefile.extrawarn
902include scripts/Makefile.ubsan
903
904# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
905KBUILD_CPPFLAGS += $(KCPPFLAGS)
906KBUILD_AFLAGS += $(KAFLAGS)
907KBUILD_CFLAGS += $(KCFLAGS)
908
909KBUILD_LDFLAGS_MODULE += --build-id
910LDFLAGS_vmlinux += --build-id
911
912ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
913LDFLAGS_vmlinux += $(call ld-option, -X,)
914endif
915
916ifeq ($(CONFIG_RELR),y)
917LDFLAGS_vmlinux += --pack-dyn-relocs=relr
918endif
919
920# make the checker run with the right architecture
921CHECKFLAGS += --arch=$(ARCH)
922
923# insure the checker run with the right endianness
924CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
925
926# the checker needs the correct machine size
927CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
928
929# Default kernel image to build when no specific target is given.
930# KBUILD_IMAGE may be overruled on the command line or
931# set in the environment
932# Also any assignments in arch/$(ARCH)/Makefile take precedence over
933# this default value
934export KBUILD_IMAGE ?= vmlinux
935
936#
937# INSTALL_PATH specifies where to place the updated kernel and system map
938# images. Default is /boot, but you can set it to other values
939export INSTALL_PATH ?= /boot
940
941#
942# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
943# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
944# an argument if needed. Otherwise it defaults to the kernel install path
945#
946export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
947
948#
949# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
950# relocations required by build roots. This is not defined in the
951# makefile but the argument can be passed to make if needed.
952#
953
954MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
955export MODLIB
956
957#
958# INSTALL_MOD_STRIP, if defined, will cause modules to be
959# stripped after they are installed. If INSTALL_MOD_STRIP is '1', then
960# the default option --strip-debug will be used. Otherwise,
961# INSTALL_MOD_STRIP value will be used as the options to the strip command.
962
963ifdef INSTALL_MOD_STRIP
964ifeq ($(INSTALL_MOD_STRIP),1)
965mod_strip_cmd = $(STRIP) --strip-debug
966else
967mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
968endif # INSTALL_MOD_STRIP=1
969else
970mod_strip_cmd = true
971endif # INSTALL_MOD_STRIP
972export mod_strip_cmd
973
974# CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
975# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
976# or CONFIG_MODULE_COMPRESS_XZ.
977
978mod_compress_cmd = true
979ifdef CONFIG_MODULE_COMPRESS
980 ifdef CONFIG_MODULE_COMPRESS_GZIP
981 mod_compress_cmd = gzip -n -f
982 endif # CONFIG_MODULE_COMPRESS_GZIP
983 ifdef CONFIG_MODULE_COMPRESS_XZ
984 mod_compress_cmd = xz -f
985 endif # CONFIG_MODULE_COMPRESS_XZ
986endif # CONFIG_MODULE_COMPRESS
987export mod_compress_cmd
988
989ifdef CONFIG_MODULE_SIG_ALL
990$(eval $(call config_filename,MODULE_SIG_KEY))
991
992mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
993else
994mod_sign_cmd = true
995endif
996export mod_sign_cmd
997
998HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
999
1000ifdef CONFIG_STACK_VALIDATION
1001 has_libelf := $(call try-run,\
1002 echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1003 ifeq ($(has_libelf),1)
1004 objtool_target := tools/objtool FORCE
1005 else
1006 SKIP_STACK_VALIDATION := 1
1007 export SKIP_STACK_VALIDATION
1008 endif
1009endif
1010
1011PHONY += prepare0
1012
1013export MODORDER := $(extmod-prefix)modules.order
1014
1015ifeq ($(KBUILD_EXTMOD),)
1016core-y += kernel certs mm fs ipc security crypto block
1017
1018vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
1019 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1020 $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
1021
1022vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1023 $(patsubst %/,%,$(filter %/, $(init-) $(core-) \
1024 $(drivers-) $(net-) $(libs-) $(virt-))))
1025
1026build-dirs := $(vmlinux-dirs)
1027clean-dirs := $(vmlinux-alldirs)
1028
1029init-y := $(patsubst %/, %/built-in.a, $(init-y))
1030core-y := $(patsubst %/, %/built-in.a, $(core-y))
1031drivers-y := $(patsubst %/, %/built-in.a, $(drivers-y))
1032net-y := $(patsubst %/, %/built-in.a, $(net-y))
1033libs-y1 := $(patsubst %/, %/lib.a, $(libs-y))
1034libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
1035virt-y := $(patsubst %/, %/built-in.a, $(virt-y))
1036
1037# Externally visible symbols (used by link-vmlinux.sh)
1038export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
1039 $(drivers-y) $(net-y) $(virt-y)
1040export KBUILD_VMLINUX_LIBS := $(libs-y1)
1041export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1042export LDFLAGS_vmlinux
1043# used by scripts/Makefile.package
1044export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1045
1046vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1047
1048# Recurse until adjust_autoksyms.sh is satisfied
1049PHONY += autoksyms_recursive
1050ifdef CONFIG_TRIM_UNUSED_KSYMS
1051autoksyms_recursive: descend modules.order
1052 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1053 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1054endif
1055
1056# For the kernel to actually contain only the needed exported symbols,
1057# we have to build modules as well to determine what those symbols are.
1058# (this can be evaluated only once include/config/auto.conf has been included)
1059ifdef CONFIG_TRIM_UNUSED_KSYMS
1060 KBUILD_MODULES := 1
1061endif
1062
1063autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1064
1065$(autoksyms_h):
1066 $(Q)mkdir -p $(dir $@)
1067 $(Q)touch $@
1068
1069ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1070
1071# Final link of vmlinux with optional arch pass after final link
1072cmd_link-vmlinux = \
1073 $(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ; \
1074 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1075
1076vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1077 +$(call if_changed,link-vmlinux)
1078
1079targets := vmlinux
1080
1081# The actual objects are generated when descending,
1082# make sure no implicit rule kicks in
1083$(sort $(vmlinux-deps)): descend ;
1084
1085filechk_kernel.release = \
1086 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1087
1088# Store (new) KERNELRELEASE string in include/config/kernel.release
1089include/config/kernel.release: FORCE
1090 $(call filechk,kernel.release)
1091
1092# Additional helpers built in scripts
1093# Carefully list dependencies so we do not try to build scripts twice
1094# in parallel
1095PHONY += scripts
1096scripts: scripts_basic scripts_dtc
1097 $(Q)$(MAKE) $(build)=$(@)
1098
1099# Things we need to do before we recursively start building the kernel
1100# or the modules are listed in "prepare".
1101# A multi level approach is used. prepareN is processed before prepareN-1.
1102# archprepare is used in arch Makefiles and when processed asm symlink,
1103# version.h and scripts_basic is processed / created.
1104
1105PHONY += prepare archprepare
1106
1107archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1108 asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h
1109
1110prepare0: archprepare
1111 $(Q)$(MAKE) $(build)=scripts/mod
1112 $(Q)$(MAKE) $(build)=.
1113
1114# All the preparing..
1115prepare: prepare0 prepare-objtool
1116
1117# Support for using generic headers in asm-generic
1118asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1119
1120PHONY += asm-generic uapi-asm-generic
1121asm-generic: uapi-asm-generic
1122 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1123 generic=include/asm-generic
1124uapi-asm-generic:
1125 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1126 generic=include/uapi/asm-generic
1127
1128PHONY += prepare-objtool
1129prepare-objtool: $(objtool_target)
1130ifeq ($(SKIP_STACK_VALIDATION),1)
1131ifdef CONFIG_UNWINDER_ORC
1132 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1133 @false
1134else
1135 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1136endif
1137endif
1138
1139# Generate some files
1140# ---------------------------------------------------------------------------
1141
1142# KERNELRELEASE can change from a few different places, meaning version.h
1143# needs to be updated, so this check is forced on all builds
1144
1145uts_len := 64
1146define filechk_utsrelease.h
1147 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1148 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1149 exit 1; \
1150 fi; \
1151 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1152endef
1153
1154define filechk_version.h
1155 echo \#define LINUX_VERSION_CODE $(shell \
1156 expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1157 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1158endef
1159
1160$(version_h): FORCE
1161 $(call filechk,version.h)
1162 $(Q)rm -f $(old_version_h)
1163
1164include/generated/utsrelease.h: include/config/kernel.release FORCE
1165 $(call filechk,utsrelease.h)
1166
1167PHONY += headerdep
1168headerdep:
1169 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1170 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1171
1172# ---------------------------------------------------------------------------
1173# Kernel headers
1174
1175#Default location for installed headers
1176export INSTALL_HDR_PATH = $(objtree)/usr
1177
1178quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1179 cmd_headers_install = \
1180 mkdir -p $(INSTALL_HDR_PATH); \
1181 rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1182 usr/include $(INSTALL_HDR_PATH)
1183
1184PHONY += headers_install
1185headers_install: headers
1186 $(call cmd,headers_install)
1187
1188PHONY += archheaders archscripts
1189
1190hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1191
1192PHONY += headers
1193headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1194 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1195 $(error Headers not exportable for the $(SRCARCH) architecture))
1196 $(Q)$(MAKE) $(hdr-inst)=include/uapi
1197 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1198
1199PHONY += headers_check
1200headers_check: headers
1201 $(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
1202 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi HDRCHECK=1
1203
1204ifdef CONFIG_HEADERS_INSTALL
1205prepare: headers
1206endif
1207
1208ifdef CONFIG_HEADERS_CHECK
1209all: headers_check
1210endif
1211
1212PHONY += scripts_unifdef
1213scripts_unifdef: scripts_basic
1214 $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1215
1216# ---------------------------------------------------------------------------
1217# Kernel selftest
1218
1219PHONY += kselftest
1220kselftest:
1221 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1222
1223kselftest-%: FORCE
1224 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1225
1226PHONY += kselftest-merge
1227kselftest-merge:
1228 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1229 $(Q)find $(srctree)/tools/testing/selftests -name config | \
1230 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1231 $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1232
1233# ---------------------------------------------------------------------------
1234# Devicetree files
1235
1236ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1237dtstree := arch/$(SRCARCH)/boot/dts
1238endif
1239
1240ifneq ($(dtstree),)
1241
1242%.dtb: include/config/kernel.release scripts_dtc
1243 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1244
1245PHONY += dtbs dtbs_install dt_binding_check
1246dtbs dtbs_check: include/config/kernel.release scripts_dtc
1247 $(Q)$(MAKE) $(build)=$(dtstree)
1248
1249dtbs_check: export CHECK_DTBS=1
1250dtbs_check: dt_binding_check
1251
1252dtbs_install:
1253 $(Q)$(MAKE) $(dtbinst)=$(dtstree)
1254
1255ifdef CONFIG_OF_EARLY_FLATTREE
1256all: dtbs
1257endif
1258
1259endif
1260
1261PHONY += scripts_dtc
1262scripts_dtc: scripts_basic
1263 $(Q)$(MAKE) $(build)=scripts/dtc
1264
1265dt_binding_check: scripts_dtc
1266 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1267
1268# ---------------------------------------------------------------------------
1269# Modules
1270
1271ifdef CONFIG_MODULES
1272
1273# By default, build modules as well
1274
1275all: modules
1276
1277# Build modules
1278#
1279# A module can be listed more than once in obj-m resulting in
1280# duplicate lines in modules.order files. Those are removed
1281# using awk while concatenating to the final file.
1282
1283PHONY += modules
1284modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
1285 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1286 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
1287
1288modules.order: descend
1289 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1290
1291modbuiltin-dirs := $(addprefix _modbuiltin_, $(build-dirs))
1292
1293modules.builtin: $(modbuiltin-dirs)
1294 $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@
1295
1296PHONY += $(modbuiltin-dirs)
1297# tristate.conf is not included from this Makefile. Add it as a prerequisite
1298# here to make it self-healing in case somebody accidentally removes it.
1299$(modbuiltin-dirs): include/config/tristate.conf
1300 $(Q)$(MAKE) $(modbuiltin)=$(patsubst _modbuiltin_%,%,$@)
1301
1302# Target to prepare building external modules
1303PHONY += modules_prepare
1304modules_prepare: prepare
1305
1306# Target to install modules
1307PHONY += modules_install
1308modules_install: _modinst_ _modinst_post
1309
1310PHONY += _modinst_
1311_modinst_:
1312 @rm -rf $(MODLIB)/kernel
1313 @rm -f $(MODLIB)/source
1314 @mkdir -p $(MODLIB)/kernel
1315 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1316 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1317 rm -f $(MODLIB)/build ; \
1318 ln -s $(CURDIR) $(MODLIB)/build ; \
1319 fi
1320 @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1321 @sed 's:^:kernel/:' modules.builtin > $(MODLIB)/modules.builtin
1322 @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1323 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1324
1325# This depmod is only for convenience to give the initial
1326# boot a modules.dep even before / is mounted read-write. However the
1327# boot script depmod is the master version.
1328PHONY += _modinst_post
1329_modinst_post: _modinst_
1330 $(call cmd,depmod)
1331
1332ifeq ($(CONFIG_MODULE_SIG), y)
1333PHONY += modules_sign
1334modules_sign:
1335 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1336endif
1337
1338else # CONFIG_MODULES
1339
1340# Modules not configured
1341# ---------------------------------------------------------------------------
1342
1343PHONY += modules modules_install
1344modules modules_install:
1345 @echo >&2
1346 @echo >&2 "The present kernel configuration has modules disabled."
1347 @echo >&2 "Type 'make config' and enable loadable module support."
1348 @echo >&2 "Then build a kernel with module support enabled."
1349 @echo >&2
1350 @exit 1
1351
1352endif # CONFIG_MODULES
1353
1354###
1355# Cleaning is done on three levels.
1356# make clean Delete most generated files
1357# Leave enough to build external modules
1358# make mrproper Delete the current configuration, and all generated files
1359# make distclean Remove editor backup files, patch leftover files and the like
1360
1361# Directories & files removed with 'make clean'
1362CLEAN_DIRS += include/ksym
1363CLEAN_FILES += modules.builtin.modinfo
1364
1365# Directories & files removed with 'make mrproper'
1366MRPROPER_DIRS += include/config include/generated \
1367 arch/$(SRCARCH)/include/generated .tmp_objdiff \
1368 debian/ snap/ tar-install/
1369MRPROPER_FILES += .config .config.old .version \
1370 Module.symvers \
1371 signing_key.pem signing_key.priv signing_key.x509 \
1372 x509.genkey extra_certificates signing_key.x509.keyid \
1373 signing_key.x509.signer vmlinux-gdb.py \
1374 *.spec
1375
1376# Directories & files removed with 'make distclean'
1377DISTCLEAN_DIRS +=
1378DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1379
1380# clean - Delete most, but leave enough to build external modules
1381#
1382clean: rm-dirs := $(CLEAN_DIRS)
1383clean: rm-files := $(CLEAN_FILES)
1384
1385PHONY += archclean vmlinuxclean
1386
1387vmlinuxclean:
1388 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1389 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1390
1391clean: archclean vmlinuxclean
1392
1393# mrproper - Delete all generated files, including .config
1394#
1395mrproper: rm-dirs := $(wildcard $(MRPROPER_DIRS))
1396mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1397mrproper-dirs := $(addprefix _mrproper_,scripts)
1398
1399PHONY += $(mrproper-dirs) mrproper
1400$(mrproper-dirs):
1401 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1402
1403mrproper: clean $(mrproper-dirs)
1404 $(call cmd,rmdirs)
1405 $(call cmd,rmfiles)
1406
1407# distclean
1408#
1409distclean: rm-dirs := $(wildcard $(DISTCLEAN_DIRS))
1410distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1411
1412PHONY += distclean
1413
1414distclean: mrproper
1415 $(call cmd,rmdirs)
1416 $(call cmd,rmfiles)
1417 @find $(srctree) $(RCS_FIND_IGNORE) \
1418 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1419 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1420 -o -name 'core' \) \
1421 -type f -print | xargs rm -f
1422
1423
1424# Packaging of the kernel to various formats
1425# ---------------------------------------------------------------------------
1426
1427%src-pkg: FORCE
1428 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1429%pkg: include/config/kernel.release FORCE
1430 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1431
1432# Brief documentation of the typical targets used
1433# ---------------------------------------------------------------------------
1434
1435boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1436boards := $(sort $(notdir $(boards)))
1437board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1438board-dirs := $(sort $(notdir $(board-dirs:/=)))
1439
1440PHONY += help
1441help:
1442 @echo 'Cleaning targets:'
1443 @echo ' clean - Remove most generated files but keep the config and'
1444 @echo ' enough build support to build external modules'
1445 @echo ' mrproper - Remove all generated files + config + various backup files'
1446 @echo ' distclean - mrproper + remove editor backup and patch files'
1447 @echo ''
1448 @echo 'Configuration targets:'
1449 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1450 @echo ''
1451 @echo 'Other generic targets:'
1452 @echo ' all - Build all targets marked with [*]'
1453 @echo '* vmlinux - Build the bare kernel'
1454 @echo '* modules - Build all modules'
1455 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1456 @echo ' dir/ - Build all files in dir and below'
1457 @echo ' dir/file.[ois] - Build specified target only'
1458 @echo ' dir/file.ll - Build the LLVM assembly file'
1459 @echo ' (requires compiler support for LLVM assembly generation)'
1460 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1461 @echo ' (requires a recent binutils and recent build (System.map))'
1462 @echo ' dir/file.ko - Build module including final link'
1463 @echo ' modules_prepare - Set up for building external modules'
1464 @echo ' tags/TAGS - Generate tags file for editors'
1465 @echo ' cscope - Generate cscope index'
1466 @echo ' gtags - Generate GNU GLOBAL index'
1467 @echo ' kernelrelease - Output the release version string (use with make -s)'
1468 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1469 @echo ' image_name - Output the image name (use with make -s)'
1470 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1471 echo ' (default: $(INSTALL_HDR_PATH))'; \
1472 echo ''
1473 @echo 'Static analysers:'
1474 @echo ' checkstack - Generate a list of stack hogs'
1475 @echo ' namespacecheck - Name space analysis on compiled kernel'
1476 @echo ' versioncheck - Sanity check on version.h usage'
1477 @echo ' includecheck - Check for duplicate included header files'
1478 @echo ' export_report - List the usages of all exported symbols'
1479 @echo ' headers_check - Sanity check on exported headers'
1480 @echo ' headerdep - Detect inclusion cycles in headers'
1481 @echo ' coccicheck - Check with Coccinelle'
1482 @echo ''
1483 @echo 'Tools:'
1484 @echo ' nsdeps - Generate missing symbol namespace dependencies'
1485 @echo ''
1486 @echo 'Kernel selftest:'
1487 @echo ' kselftest - Build and run kernel selftest (run as root)'
1488 @echo ' Build, install, and boot kernel before'
1489 @echo ' running kselftest on it'
1490 @echo ' kselftest-clean - Remove all generated kselftest files'
1491 @echo ' kselftest-merge - Merge all the config dependencies of kselftest to existing'
1492 @echo ' .config.'
1493 @echo ''
1494 @$(if $(dtstree), \
1495 echo 'Devicetree:'; \
1496 echo '* dtbs - Build device tree blobs for enabled boards'; \
1497 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1498 echo ' dt_binding_check - Validate device tree binding documents'; \
1499 echo ' dtbs_check - Validate device tree source files';\
1500 echo '')
1501
1502 @echo 'Userspace tools targets:'
1503 @echo ' use "make tools/help"'
1504 @echo ' or "cd tools; make help"'
1505 @echo ''
1506 @echo 'Kernel packaging:'
1507 @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1508 @echo ''
1509 @echo 'Documentation targets:'
1510 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1511 @echo ''
1512 @echo 'Architecture specific targets ($(SRCARCH)):'
1513 @$(if $(archhelp),$(archhelp),\
1514 echo ' No architecture specific help defined for $(SRCARCH)')
1515 @echo ''
1516 @$(if $(boards), \
1517 $(foreach b, $(boards), \
1518 printf " %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1519 echo '')
1520 @$(if $(board-dirs), \
1521 $(foreach b, $(board-dirs), \
1522 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1523 printf " %-16s - Show all of the above\\n" help-boards; \
1524 echo '')
1525
1526 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1527 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1528 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1529 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK (sparse by default)'
1530 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1531 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1532 @echo ' make W=n [targets] Enable extra build checks, n=1,2,3 where'
1533 @echo ' 1: warnings which may be relevant and do not occur too often'
1534 @echo ' 2: warnings which occur quite often but may still be relevant'
1535 @echo ' 3: more obscure warnings, can most likely be ignored'
1536 @echo ' Multiple levels can be combined with W=12 or W=123'
1537 @echo ''
1538 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1539 @echo 'For further info see the ./README file'
1540
1541
1542help-board-dirs := $(addprefix help-,$(board-dirs))
1543
1544help-boards: $(help-board-dirs)
1545
1546boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1547
1548$(help-board-dirs): help-%:
1549 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1550 @$(if $(boards-per-dir), \
1551 $(foreach b, $(boards-per-dir), \
1552 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1553 echo '')
1554
1555
1556# Documentation targets
1557# ---------------------------------------------------------------------------
1558DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1559 linkcheckdocs dochelp refcheckdocs
1560PHONY += $(DOC_TARGETS)
1561$(DOC_TARGETS):
1562 $(Q)$(MAKE) $(build)=Documentation $@
1563
1564# Misc
1565# ---------------------------------------------------------------------------
1566
1567PHONY += scripts_gdb
1568scripts_gdb: prepare0
1569 $(Q)$(MAKE) $(build)=scripts/gdb
1570 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1571
1572ifdef CONFIG_GDB_SCRIPTS
1573all: scripts_gdb
1574endif
1575
1576else # KBUILD_EXTMOD
1577
1578###
1579# External module support.
1580# When building external modules the kernel used as basis is considered
1581# read-only, and no consistency checks are made and the make
1582# system is not used on the basis kernel. If updates are required
1583# in the basis kernel ordinary make commands (without M=...) must
1584# be used.
1585#
1586# The following are the only valid targets when building external
1587# modules.
1588# make M=dir clean Delete all automatically generated files
1589# make M=dir modules Make all modules in specified dir
1590# make M=dir Same as 'make M=dir modules'
1591# make M=dir modules_install
1592# Install the modules built in the module directory
1593# Assumes install directory is already created
1594
1595# We are always building modules
1596KBUILD_MODULES := 1
1597
1598PHONY += $(objtree)/Module.symvers
1599$(objtree)/Module.symvers:
1600 @test -e $(objtree)/Module.symvers || ( \
1601 echo; \
1602 echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1603 echo " is missing; modules will have no dependencies and modversions."; \
1604 echo )
1605
1606build-dirs := $(KBUILD_EXTMOD)
1607PHONY += modules
1608modules: descend $(objtree)/Module.symvers
1609 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1610
1611PHONY += modules_install
1612modules_install: _emodinst_ _emodinst_post
1613
1614install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1615PHONY += _emodinst_
1616_emodinst_:
1617 $(Q)mkdir -p $(MODLIB)/$(install-dir)
1618 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1619
1620PHONY += _emodinst_post
1621_emodinst_post: _emodinst_
1622 $(call cmd,depmod)
1623
1624clean-dirs := $(KBUILD_EXTMOD)
1625clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1626
1627PHONY += /
1628/:
1629 @echo >&2 '"$(MAKE) /" is no longer supported. Please use "$(MAKE) ./" instead.'
1630
1631PHONY += help
1632help:
1633 @echo ' Building external modules.'
1634 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1635 @echo ''
1636 @echo ' modules - default target, build the module(s)'
1637 @echo ' modules_install - install the module'
1638 @echo ' clean - remove generated files in module directory only'
1639 @echo ''
1640
1641PHONY += prepare
1642endif # KBUILD_EXTMOD
1643
1644# Handle descending into subdirectories listed in $(build-dirs)
1645# Preset locale variables to speed up the build process. Limit locale
1646# tweaks to this spot to avoid wrong language settings when running
1647# make menuconfig etc.
1648# Error messages still appears in the original language
1649PHONY += descend $(build-dirs)
1650descend: $(build-dirs)
1651$(build-dirs): prepare
1652 $(Q)$(MAKE) $(build)=$@ single-build=$(single-build) need-builtin=1 need-modorder=1
1653
1654clean-dirs := $(addprefix _clean_, $(clean-dirs))
1655PHONY += $(clean-dirs) clean
1656$(clean-dirs):
1657 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1658
1659clean: $(clean-dirs)
1660 $(call cmd,rmdirs)
1661 $(call cmd,rmfiles)
1662 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1663 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1664 -o -name '*.ko.*' \
1665 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1666 -o -name '*.dwo' -o -name '*.lst' \
1667 -o -name '*.su' -o -name '*.mod' -o -name '*.ns_deps' \
1668 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1669 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1670 -o -name '*.asn1.[ch]' \
1671 -o -name '*.symtypes' -o -name 'modules.order' \
1672 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1673 -o -name '*.c.[012]*.*' \
1674 -o -name '*.ll' \
1675 -o -name '*.gcno' \) -type f -print | xargs rm -f
1676
1677# Generate tags for editors
1678# ---------------------------------------------------------------------------
1679quiet_cmd_tags = GEN $@
1680 cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1681
1682tags TAGS cscope gtags: FORCE
1683 $(call cmd,tags)
1684
1685# Script to generate missing namespace dependencies
1686# ---------------------------------------------------------------------------
1687
1688PHONY += nsdeps
1689
1690nsdeps: modules
1691 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps
1692 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1693
1694# Scripts to check various things for consistency
1695# ---------------------------------------------------------------------------
1696
1697PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1698
1699includecheck:
1700 find $(srctree)/* $(RCS_FIND_IGNORE) \
1701 -name '*.[hcS]' -type f -print | sort \
1702 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1703
1704versioncheck:
1705 find $(srctree)/* $(RCS_FIND_IGNORE) \
1706 -name '*.[hcS]' -type f -print | sort \
1707 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1708
1709coccicheck:
1710 $(Q)$(BASH) $(srctree)/scripts/$@
1711
1712namespacecheck:
1713 $(PERL) $(srctree)/scripts/namespace.pl
1714
1715export_report:
1716 $(PERL) $(srctree)/scripts/export_report.pl
1717
1718PHONY += checkstack kernelrelease kernelversion image_name
1719
1720# UML needs a little special treatment here. It wants to use the host
1721# toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1722# else wants $(ARCH), including people doing cross-builds, which means
1723# that $(SUBARCH) doesn't work here.
1724ifeq ($(ARCH), um)
1725CHECKSTACK_ARCH := $(SUBARCH)
1726else
1727CHECKSTACK_ARCH := $(ARCH)
1728endif
1729checkstack:
1730 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1731 $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1732
1733kernelrelease:
1734 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1735
1736kernelversion:
1737 @echo $(KERNELVERSION)
1738
1739image_name:
1740 @echo $(KBUILD_IMAGE)
1741
1742# Clear a bunch of variables before executing the submake
1743
1744ifeq ($(quiet),silent_)
1745tools_silent=s
1746endif
1747
1748tools/: FORCE
1749 $(Q)mkdir -p $(objtree)/tools
1750 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1751
1752tools/%: FORCE
1753 $(Q)mkdir -p $(objtree)/tools
1754 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1755
1756# Single targets
1757# ---------------------------------------------------------------------------
1758# To build individual files in subdirectories, you can do like this:
1759#
1760# make foo/bar/baz.s
1761#
1762# The supported suffixes for single-target are listed in 'single-targets'
1763#
1764# To build only under specific subdirectories, you can do like this:
1765#
1766# make foo/bar/baz/
1767
1768ifdef single-build
1769
1770single-all := $(filter $(single-targets), $(MAKECMDGOALS))
1771
1772# .ko is special because modpost is needed
1773single-ko := $(sort $(filter %.ko, $(single-all)))
1774single-no-ko := $(sort $(patsubst %.ko,%.mod, $(single-all)))
1775
1776$(single-ko): single_modpost
1777 @:
1778$(single-no-ko): descend
1779 @:
1780
1781ifeq ($(KBUILD_EXTMOD),)
1782# For the single build of in-tree modules, use a temporary file to avoid
1783# the situation of modules_install installing an invalid modules.order.
1784MODORDER := .modules.tmp
1785endif
1786
1787PHONY += single_modpost
1788single_modpost: $(single-no-ko)
1789 $(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
1790 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1791
1792KBUILD_MODULES := 1
1793
1794export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
1795
1796single-build = $(if $(filter-out $@/, $(single-no-ko)),1)
1797
1798endif
1799
1800# FIXME Should go into a make.lib or something
1801# ===========================================================================
1802
1803quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN $(wildcard $(rm-dirs)))
1804 cmd_rmdirs = rm -rf $(rm-dirs)
1805
1806quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1807 cmd_rmfiles = rm -f $(rm-files)
1808
1809# Run depmod only if we have System.map and depmod is executable
1810quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
1811 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1812 $(KERNELRELEASE)
1813
1814# read saved command lines for existing targets
1815existing-targets := $(wildcard $(sort $(targets)))
1816
1817-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1818
1819endif # config-targets
1820endif # mixed-build
1821endif # need-sub-make
1822
1823PHONY += FORCE
1824FORCE:
1825
1826# Declare the contents of the PHONY variable as phony. We keep that
1827# information in a variable so we can use it in if_changed and friends.
1828.PHONY: $(PHONY)