1# SPDX-License-Identifier: GPL-2.0 2# Backward compatibility 3asflags-y += $(EXTRA_AFLAGS) 4ccflags-y += $(EXTRA_CFLAGS) 5cppflags-y += $(EXTRA_CPPFLAGS) 6ldflags-y += $(EXTRA_LDFLAGS) 7ifneq ($(always),) 8$(warning 'always' is deprecated. Please use 'always-y' instead) 9always-y += $(always) 10endif 11ifneq ($(hostprogs-y),) 12$(warning 'hostprogs-y' is deprecated. Please use 'hostprogs' instead) 13hostprogs += $(hostprogs-y) 14endif 15ifneq ($(hostprogs-m),) 16$(warning 'hostprogs-m' is deprecated. Please use 'hostprogs' instead) 17hostprogs += $(hostprogs-m) 18endif 19 20# flags that take effect in current and sub directories 21KBUILD_AFLAGS += $(subdir-asflags-y) 22KBUILD_CFLAGS += $(subdir-ccflags-y) 23 24# Figure out what we need to build from the various variables 25# =========================================================================== 26 27# When an object is listed to be built compiled-in and modular, 28# only build the compiled-in version 29obj-m := $(filter-out $(obj-y),$(obj-m)) 30 31# Libraries are always collected in one lib file. 32# Filter out objects already built-in 33lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) 34 35# Subdirectories we need to descend into 36subdir-ym := $(sort $(subdir-y) $(subdir-m) \ 37 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m)))) 38 39# Handle objects in subdirs: 40# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and 41# foo/modules.order 42# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order 43# 44# Generate modules.order to determine modorder. Unfortunately, we don't have 45# information about ordering between -y and -m subdirs. Just put -y's first. 46 47ifdef need-modorder 48obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m)) 49else 50obj-m := $(filter-out %/, $(obj-m)) 51endif 52 53ifdef need-builtin 54obj-y := $(patsubst %/, %/built-in.a, $(obj-y)) 55else 56obj-y := $(filter-out %/, $(obj-y)) 57endif 58 59# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object 60multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))), $(m)))) 61multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))), $(m)))) 62multi-used := $(multi-used-y) $(multi-used-m) 63 64# Replace multi-part objects by their individual parts, 65# including built-in.a from subdirectories 66real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) 67real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m))) 68 69always-y += $(always-m) 70 71# hostprogs-always-y += foo 72# ... is a shorthand for 73# hostprogs += foo 74# always-y += foo 75hostprogs += $(hostprogs-always-y) $(hostprogs-always-m) 76always-y += $(hostprogs-always-y) $(hostprogs-always-m) 77 78# userprogs-always-y is likewise. 79userprogs += $(userprogs-always-y) $(userprogs-always-m) 80always-y += $(userprogs-always-y) $(userprogs-always-m) 81 82# DTB 83# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built 84extra-y += $(dtb-y) 85extra-$(CONFIG_OF_ALL_DTBS) += $(dtb-) 86 87ifneq ($(CHECK_DTBS),) 88extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y)) 89extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-)) 90endif 91 92# Add subdir path 93 94extra-y := $(addprefix $(obj)/,$(extra-y)) 95always-y := $(addprefix $(obj)/,$(always-y)) 96targets := $(addprefix $(obj)/,$(targets)) 97obj-m := $(addprefix $(obj)/,$(obj-m)) 98lib-y := $(addprefix $(obj)/,$(lib-y)) 99real-obj-y := $(addprefix $(obj)/,$(real-obj-y)) 100real-obj-m := $(addprefix $(obj)/,$(real-obj-m)) 101multi-used-m := $(addprefix $(obj)/,$(multi-used-m)) 102subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) 103 104# Finds the multi-part object the current object will be linked into. 105# If the object belongs to two or more multi-part objects, list them all. 106modname-multi = $(sort $(foreach m,$(multi-used),\ 107 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=)))) 108 109__modname = $(if $(modname-multi),$(modname-multi),$(basetarget)) 110 111modname = $(subst $(space),:,$(__modname)) 112modfile = $(addprefix $(obj)/,$(__modname)) 113 114# target with $(obj)/ and its suffix stripped 115target-stem = $(basename $(patsubst $(obj)/%,%,$@)) 116 117# These flags are needed for modversions and compiling, so we define them here 118# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will 119# end up in (or would, if it gets compiled in) 120name-fix = $(call stringify,$(subst $(comma),_,$(subst -,_,$1))) 121basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) 122modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) 123modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile)) 124 125_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \ 126 $(filter-out $(ccflags-remove-y), \ 127 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \ 128 $(CFLAGS_$(target-stem).o)) 129_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \ 130 $(filter-out $(asflags-remove-y), \ 131 $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \ 132 $(AFLAGS_$(target-stem).o)) 133_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds) 134 135# 136# Enable gcov profiling flags for a file, directory or for all files depending 137# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL 138# (in this order) 139# 140ifeq ($(CONFIG_GCOV_KERNEL),y) 141_c_flags += $(if $(patsubst n%,, \ 142 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \ 143 $(CFLAGS_GCOV)) 144endif 145 146# 147# Enable address sanitizer flags for kernel except some files or directories 148# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE) 149# 150ifeq ($(CONFIG_KASAN),y) 151_c_flags += $(if $(patsubst n%,, \ 152 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \ 153 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE)) 154endif 155 156ifeq ($(CONFIG_UBSAN),y) 157_c_flags += $(if $(patsubst n%,, \ 158 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \ 159 $(CFLAGS_UBSAN)) 160endif 161 162ifeq ($(CONFIG_KCOV),y) 163_c_flags += $(if $(patsubst n%,, \ 164 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \ 165 $(CFLAGS_KCOV)) 166endif 167 168# 169# Enable KCSAN flags except some files or directories we don't want to check 170# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE) 171# 172ifeq ($(CONFIG_KCSAN),y) 173_c_flags += $(if $(patsubst n%,, \ 174 $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \ 175 $(CFLAGS_KCSAN)) 176endif 177 178# $(srctree)/$(src) for including checkin headers from generated source files 179# $(objtree)/$(obj) for including generated headers from checkin source files 180ifeq ($(KBUILD_EXTMOD),) 181ifdef building_out_of_srctree 182_c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) 183_a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) 184_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) 185endif 186endif 187 188part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y) 189quiet_modtag = $(if $(part-of-module),[M], ) 190 191modkern_cflags = \ 192 $(if $(part-of-module), \ 193 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 194 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags)) 195 196modkern_aflags = $(if $(part-of-module), \ 197 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \ 198 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)) 199 200c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 201 -include $(srctree)/include/linux/compiler_types.h \ 202 $(_c_flags) $(modkern_cflags) \ 203 $(basename_flags) $(modname_flags) 204 205a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 206 $(_a_flags) $(modkern_aflags) 207 208cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 209 $(_cpp_flags) 210 211ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) 212 213DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes 214 215dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ 216 $(addprefix -I,$(DTC_INCLUDE)) \ 217 -undef -D__DTS__ 218 219# Useful for describing the dependency of composite objects 220# Usage: 221# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) 222define multi_depend 223$(foreach m, $(notdir $1), \ 224 $(eval $(obj)/$m: \ 225 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s))))))) 226endef 227 228quiet_cmd_copy = COPY $@ 229 cmd_copy = cp $< $@ 230 231# Shipped files 232# =========================================================================== 233 234quiet_cmd_shipped = SHIPPED $@ 235cmd_shipped = cat $< > $@ 236 237$(obj)/%: $(src)/%_shipped 238 $(call cmd,shipped) 239 240# Commands useful for building a boot image 241# =========================================================================== 242# 243# Use as following: 244# 245# target: source(s) FORCE 246# $(if_changed,ld/objcopy/gzip) 247# 248# and add target to extra-y so that we know we have to 249# read in the saved command line 250 251# Linking 252# --------------------------------------------------------------------------- 253 254quiet_cmd_ld = LD $@ 255 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@ 256 257# Archive 258# --------------------------------------------------------------------------- 259 260quiet_cmd_ar = AR $@ 261 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs) 262 263# Objcopy 264# --------------------------------------------------------------------------- 265 266quiet_cmd_objcopy = OBJCOPY $@ 267cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@ 268 269# Gzip 270# --------------------------------------------------------------------------- 271 272quiet_cmd_gzip = GZIP $@ 273 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@ 274 275# DTC 276# --------------------------------------------------------------------------- 277DTC ?= $(objtree)/scripts/dtc/dtc 278DTC_FLAGS += -Wno-interrupt_provider 279 280# Disable noisy checks by default 281ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),) 282DTC_FLAGS += -Wno-unit_address_vs_reg \ 283 -Wno-unit_address_format \ 284 -Wno-avoid_unnecessary_addr_size \ 285 -Wno-alias_paths \ 286 -Wno-graph_child_address \ 287 -Wno-simple_bus_reg \ 288 -Wno-unique_unit_address \ 289 -Wno-pci_device_reg 290endif 291 292ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),) 293DTC_FLAGS += -Wnode_name_chars_strict \ 294 -Wproperty_name_chars_strict \ 295 -Winterrupt_provider 296endif 297 298DTC_FLAGS += $(DTC_FLAGS_$(basetarget)) 299 300# Generate an assembly file to wrap the output of the device tree compiler 301quiet_cmd_dt_S_dtb= DTB $@ 302cmd_dt_S_dtb= \ 303{ \ 304 echo '\#include <asm-generic/vmlinux.lds.h>'; \ 305 echo '.section .dtb.init.rodata,"a"'; \ 306 echo '.balign STRUCT_ALIGNMENT'; \ 307 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \ 308 echo '__dtb_$(subst -,_,$(*F))_begin:'; \ 309 echo '.incbin "$<" '; \ 310 echo '__dtb_$(subst -,_,$(*F))_end:'; \ 311 echo '.global __dtb_$(subst -,_,$(*F))_end'; \ 312 echo '.balign STRUCT_ALIGNMENT'; \ 313} > $@ 314 315$(obj)/%.dtb.S: $(obj)/%.dtb FORCE 316 $(call if_changed,dt_S_dtb) 317 318quiet_cmd_dtc = DTC $@ 319cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \ 320 $(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \ 321 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \ 322 -d $(depfile).dtc.tmp $(dtc-tmp) ; \ 323 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile) 324 325$(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE 326 $(call if_changed_dep,dtc) 327 328DT_CHECKER ?= dt-validate 329DT_BINDING_DIR := Documentation/devicetree/bindings 330# DT_TMP_SCHEMA may be overridden from Documentation/devicetree/bindings/Makefile 331DT_TMP_SCHEMA ?= $(objtree)/$(DT_BINDING_DIR)/processed-schema.json 332 333quiet_cmd_dtb_check = CHECK $@ 334 cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ 335 336define rule_dtc 337 $(call cmd_and_fixdep,dtc) 338 $(call cmd,dtb_check) 339endef 340 341$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE 342 $(call if_changed_rule,dtc,yaml) 343 344dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp) 345 346# Bzip2 347# --------------------------------------------------------------------------- 348 349# Bzip2 and LZMA do not include size in file... so we have to fake that; 350# append the size as a 32-bit littleendian number as gzip does. 351size_append = printf $(shell \ 352dec_size=0; \ 353for F in $(real-prereqs); do \ 354 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \ 355 dec_size=$$(expr $$dec_size + $$fsize); \ 356done; \ 357printf "%08x\n" $$dec_size | \ 358 sed 's/\(..\)/\1 /g' | { \ 359 read ch0 ch1 ch2 ch3; \ 360 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \ 361 printf '%s%03o' '\\' $$((0x$$ch)); \ 362 done; \ 363 } \ 364) 365 366quiet_cmd_bzip2 = BZIP2 $@ 367 cmd_bzip2 = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@ 368 369# Lzma 370# --------------------------------------------------------------------------- 371 372quiet_cmd_lzma = LZMA $@ 373 cmd_lzma = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@ 374 375quiet_cmd_lzo = LZO $@ 376 cmd_lzo = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@ 377 378quiet_cmd_lz4 = LZ4 $@ 379 cmd_lz4 = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \ 380 $(size_append); } > $@ 381 382# U-Boot mkimage 383# --------------------------------------------------------------------------- 384 385MKIMAGE := $(srctree)/scripts/mkuboot.sh 386 387# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces 388# the number of overrides in arch makefiles 389UIMAGE_ARCH ?= $(SRCARCH) 390UIMAGE_COMPRESSION ?= $(if $(2),$(2),none) 391UIMAGE_OPTS-y ?= 392UIMAGE_TYPE ?= kernel 393UIMAGE_LOADADDR ?= arch_must_set_this 394UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR) 395UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)' 396 397quiet_cmd_uimage = UIMAGE $@ 398 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \ 399 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \ 400 -T $(UIMAGE_TYPE) \ 401 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \ 402 -n $(UIMAGE_NAME) -d $< $@ 403 404# XZ 405# --------------------------------------------------------------------------- 406# Use xzkern to compress the kernel image and xzmisc to compress other things. 407# 408# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage 409# of the kernel decompressor. A BCJ filter is used if it is available for 410# the target architecture. xzkern also appends uncompressed size of the data 411# using size_append. The .xz format has the size information available at 412# the end of the file too, but it's in more complex format and it's good to 413# avoid changing the part of the boot code that reads the uncompressed size. 414# Note that the bytes added by size_append will make the xz tool think that 415# the file is corrupt. This is expected. 416# 417# xzmisc doesn't use size_append, so it can be used to create normal .xz 418# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very 419# big dictionary would increase the memory usage too much in the multi-call 420# decompression mode. A BCJ filter isn't used either. 421quiet_cmd_xzkern = XZKERN $@ 422 cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \ 423 $(size_append); } > $@ 424 425quiet_cmd_xzmisc = XZMISC $@ 426 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@ 427 428# ZSTD 429# --------------------------------------------------------------------------- 430# Appends the uncompressed size of the data using size_append. The .zst 431# format has the size information available at the beginning of the file too, 432# but it's in a more complex format and it's good to avoid changing the part 433# of the boot code that reads the uncompressed size. 434# 435# Note that the bytes added by size_append will make the zstd tool think that 436# the file is corrupt. This is expected. 437# 438# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of 439# 128 MB. zstd22 is used for kernel compression because it is decompressed in a 440# single pass, so zstd doesn't need to allocate a window buffer. When streaming 441# decompression is used, like initramfs decompression, zstd22 should likely not 442# be used because it would require zstd to allocate a 128 MB buffer. 443 444quiet_cmd_zstd = ZSTD $@ 445 cmd_zstd = { cat $(real-prereqs) | $(ZSTD) -19; $(size_append); } > $@ 446 447quiet_cmd_zstd22 = ZSTD22 $@ 448 cmd_zstd22 = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@ 449 450# ASM offsets 451# --------------------------------------------------------------------------- 452 453# Default sed regexp - multiline due to syntax constraints 454# 455# Use [:space:] because LLVM's integrated assembler inserts <tab> around 456# the .ascii directive whereas GCC keeps the <space> as-is. 457define sed-offsets 458 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \ 459 /^->/{s:->#\(.*\):/* \1 */:; \ 460 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \ 461 s:->::; p;}' 462endef 463 464# Use filechk to avoid rebuilds when a header changes, but the resulting file 465# does not 466define filechk_offsets 467 echo "#ifndef $2"; \ 468 echo "#define $2"; \ 469 echo "/*"; \ 470 echo " * DO NOT MODIFY."; \ 471 echo " *"; \ 472 echo " * This file was generated by Kbuild"; \ 473 echo " */"; \ 474 echo ""; \ 475 sed -ne $(sed-offsets) < $<; \ 476 echo ""; \ 477 echo "#endif" 478endef 479