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) 7 8# 9# flags that take effect in sub directories 10export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y) 11export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y) 12 13# Figure out what we need to build from the various variables 14# =========================================================================== 15 16# When an object is listed to be built compiled-in and modular, 17# only build the compiled-in version 18 19obj-m := $(filter-out $(obj-y),$(obj-m)) 20 21# Libraries are always collected in one lib file. 22# Filter out objects already built-in 23 24lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) 25 26 27# Handle objects in subdirs 28# --------------------------------------------------------------------------- 29# o if we encounter foo/ in $(obj-y), replace it by foo/built-in.o 30# and add the directory to the list of dirs to descend into: $(subdir-y) 31# o if we encounter foo/ in $(obj-m), remove it from $(obj-m) 32# and add the directory to the list of dirs to descend into: $(subdir-m) 33 34# Determine modorder. 35# Unfortunately, we don't have information about ordering between -y 36# and -m subdirs. Just put -y's first. 37modorder := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko)) 38 39__subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y))) 40subdir-y += $(__subdir-y) 41__subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m))) 42subdir-m += $(__subdir-m) 43obj-y := $(patsubst %/, %/built-in.o, $(obj-y)) 44obj-m := $(filter-out %/, $(obj-m)) 45 46# Subdirectories we need to descend into 47 48subdir-ym := $(sort $(subdir-y) $(subdir-m)) 49 50# if $(foo-objs) exists, foo.o is a composite object 51multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m)))) 52multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))), $(m)))) 53multi-used := $(multi-used-y) $(multi-used-m) 54single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m))) 55 56# Build list of the parts of our composite objects, our composite 57# objects depend on those (obviously) 58multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y))) 59multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y))) 60multi-objs := $(multi-objs-y) $(multi-objs-m) 61 62# $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to 63# tell kbuild to descend 64subdir-obj-y := $(filter %/built-in.o, $(obj-y)) 65 66# $(obj-dirs) is a list of directories that contain object files 67obj-dirs := $(dir $(multi-objs) $(obj-y)) 68 69# Replace multi-part objects by their individual parts, look at local dir only 70real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) $(extra-y) 71real-objs-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m))) 72 73# Add subdir path 74 75extra-y := $(addprefix $(obj)/,$(extra-y)) 76always := $(addprefix $(obj)/,$(always)) 77targets := $(addprefix $(obj)/,$(targets)) 78modorder := $(addprefix $(obj)/,$(modorder)) 79obj-y := $(addprefix $(obj)/,$(obj-y)) 80obj-m := $(addprefix $(obj)/,$(obj-m)) 81lib-y := $(addprefix $(obj)/,$(lib-y)) 82subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y)) 83real-objs-y := $(addprefix $(obj)/,$(real-objs-y)) 84real-objs-m := $(addprefix $(obj)/,$(real-objs-m)) 85single-used-m := $(addprefix $(obj)/,$(single-used-m)) 86multi-used-y := $(addprefix $(obj)/,$(multi-used-y)) 87multi-used-m := $(addprefix $(obj)/,$(multi-used-m)) 88multi-objs-y := $(addprefix $(obj)/,$(multi-objs-y)) 89multi-objs-m := $(addprefix $(obj)/,$(multi-objs-m)) 90subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) 91obj-dirs := $(addprefix $(obj)/,$(obj-dirs)) 92 93# These flags are needed for modversions and compiling, so we define them here 94# already 95# $(modname_flags) #defines KBUILD_MODNAME as the name of the module it will 96# end up in (or would, if it gets compiled in) 97# Note: Files that end up in two or more modules are compiled without the 98# KBUILD_MODNAME definition. The reason is that any made-up name would 99# differ in different configs. 100name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote) 101basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) 102modname_flags = $(if $(filter 1,$(words $(modname))),\ 103 -DKBUILD_MODNAME=$(call name-fix,$(modname))) 104 105orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \ 106 $(ccflags-y) $(CFLAGS_$(basetarget).o) 107_c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags)) 108orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \ 109 $(asflags-y) $(AFLAGS_$(basetarget).o) 110_a_flags = $(filter-out $(AFLAGS_REMOVE_$(basetarget).o), $(orig_a_flags)) 111_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F)) 112 113# 114# Enable gcov profiling flags for a file, directory or for all files depending 115# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL 116# (in this order) 117# 118ifeq ($(CONFIG_GCOV_KERNEL),y) 119_c_flags += $(if $(patsubst n%,, \ 120 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \ 121 $(CFLAGS_GCOV)) 122endif 123 124# 125# Enable address sanitizer flags for kernel except some files or directories 126# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE) 127# 128ifeq ($(CONFIG_KASAN),y) 129_c_flags += $(if $(patsubst n%,, \ 130 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \ 131 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE)) 132endif 133 134ifeq ($(CONFIG_UBSAN),y) 135_c_flags += $(if $(patsubst n%,, \ 136 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \ 137 $(CFLAGS_UBSAN)) 138endif 139 140ifeq ($(CONFIG_KCOV),y) 141_c_flags += $(if $(patsubst n%,, \ 142 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \ 143 $(CFLAGS_KCOV)) 144endif 145 146# If building the kernel in a separate objtree expand all occurrences 147# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/'). 148 149ifeq ($(KBUILD_SRC),) 150__c_flags = $(_c_flags) 151__a_flags = $(_a_flags) 152__cpp_flags = $(_cpp_flags) 153else 154 155# -I$(obj) locates generated .h files 156# $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files 157# and locates generated .h files 158# FIXME: Replace both with specific CFLAGS* statements in the makefiles 159__c_flags = $(if $(obj),$(call addtree,-I$(src)) -I$(obj)) \ 160 $(call flags,_c_flags) 161__a_flags = $(call flags,_a_flags) 162__cpp_flags = $(call flags,_cpp_flags) 163endif 164 165c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 166 $(__c_flags) $(modkern_cflags) \ 167 $(basename_flags) $(modname_flags) 168 169a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 170 $(__a_flags) $(modkern_aflags) 171 172cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 173 $(__cpp_flags) 174 175ld_flags = $(LDFLAGS) $(ldflags-y) 176 177DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes 178 179dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \ 180 $(addprefix -I,$(DTC_INCLUDE)) \ 181 -undef -D__DTS__ 182 183# Finds the multi-part object the current object will be linked into 184modname-multi = $(sort $(foreach m,$(multi-used),\ 185 $(if $(filter $(subst $(obj)/,,$*.o), $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=)))) 186 187# Useful for describing the dependency of composite objects 188# Usage: 189# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) 190define multi_depend 191$(foreach m, $(notdir $1), \ 192 $(eval $(obj)/$m: \ 193 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s))))))) 194endef 195 196ifdef REGENERATE_PARSERS 197 198# LEX 199# --------------------------------------------------------------------------- 200LEX_PREFIX = $(if $(LEX_PREFIX_${baseprereq}),$(LEX_PREFIX_${baseprereq}),yy) 201 202quiet_cmd_flex = LEX $@ 203 cmd_flex = flex -o$@ -L -P $(LEX_PREFIX) $< 204 205.PRECIOUS: $(src)/%.lex.c_shipped 206$(src)/%.lex.c_shipped: $(src)/%.l 207 $(call cmd,flex) 208 209# YACC 210# --------------------------------------------------------------------------- 211YACC_PREFIX = $(if $(YACC_PREFIX_${baseprereq}),$(YACC_PREFIX_${baseprereq}),yy) 212 213quiet_cmd_bison = YACC $@ 214 cmd_bison = bison -o$@ -t -l -p $(YACC_PREFIX) $< 215 216.PRECIOUS: $(src)/%.tab.c_shipped 217$(src)/%.tab.c_shipped: $(src)/%.y 218 $(call cmd,bison) 219 220quiet_cmd_bison_h = YACC $@ 221 cmd_bison_h = bison -o/dev/null --defines=$@ -t -l -p $(YACC_PREFIX) $< 222 223.PRECIOUS: $(src)/%.tab.h_shipped 224$(src)/%.tab.h_shipped: $(src)/%.y 225 $(call cmd,bison_h) 226 227endif 228 229# Shipped files 230# =========================================================================== 231 232quiet_cmd_shipped = SHIPPED $@ 233cmd_shipped = cat $< > $@ 234 235$(obj)/%: $(src)/%_shipped 236 $(call cmd,shipped) 237 238# Commands useful for building a boot image 239# =========================================================================== 240# 241# Use as following: 242# 243# target: source(s) FORCE 244# $(if_changed,ld/objcopy/gzip) 245# 246# and add target to extra-y so that we know we have to 247# read in the saved command line 248 249# Linking 250# --------------------------------------------------------------------------- 251 252quiet_cmd_ld = LD $@ 253cmd_ld = $(LD) $(LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) \ 254 $(filter-out FORCE,$^) -o $@ 255 256# Objcopy 257# --------------------------------------------------------------------------- 258 259quiet_cmd_objcopy = OBJCOPY $@ 260cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@ 261 262# Gzip 263# --------------------------------------------------------------------------- 264 265quiet_cmd_gzip = GZIP $@ 266cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \ 267 (rm -f $@ ; false) 268 269# DTC 270# --------------------------------------------------------------------------- 271DTC ?= $(objtree)/scripts/dtc/dtc 272 273# Disable noisy checks by default 274ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),) 275DTC_FLAGS += -Wno-unit_address_vs_reg \ 276 -Wno-simple_bus_reg \ 277 -Wno-unit_address_format \ 278 -Wno-pci_bridge \ 279 -Wno-pci_device_bus_num \ 280 -Wno-pci_device_reg 281endif 282 283ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),2) 284DTC_FLAGS += -Wnode_name_chars_strict \ 285 -Wproperty_name_chars_strict 286endif 287 288DTC_FLAGS += $(DTC_FLAGS_$(basetarget)) 289 290# Generate an assembly file to wrap the output of the device tree compiler 291quiet_cmd_dt_S_dtb= DTB $@ 292cmd_dt_S_dtb= \ 293( \ 294 echo '\#include <asm-generic/vmlinux.lds.h>'; \ 295 echo '.section .dtb.init.rodata,"a"'; \ 296 echo '.balign STRUCT_ALIGNMENT'; \ 297 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \ 298 echo '__dtb_$(subst -,_,$(*F))_begin:'; \ 299 echo '.incbin "$<" '; \ 300 echo '__dtb_$(subst -,_,$(*F))_end:'; \ 301 echo '.global __dtb_$(subst -,_,$(*F))_end'; \ 302 echo '.balign STRUCT_ALIGNMENT'; \ 303) > $@ 304 305$(obj)/%.dtb.S: $(obj)/%.dtb 306 $(call cmd,dt_S_dtb) 307 308quiet_cmd_dtc = DTC $@ 309cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \ 310 $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \ 311 $(DTC) -O dtb -o $@ -b 0 \ 312 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \ 313 -d $(depfile).dtc.tmp $(dtc-tmp) ; \ 314 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile) 315 316$(obj)/%.dtb: $(src)/%.dts FORCE 317 $(call if_changed_dep,dtc) 318 319dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp) 320 321# cat 322# --------------------------------------------------------------------------- 323# Concatentate multiple files together 324quiet_cmd_cat = CAT $@ 325cmd_cat = (cat $(filter-out FORCE,$^) > $@) || (rm -f $@; false) 326 327# Bzip2 328# --------------------------------------------------------------------------- 329 330# Bzip2 and LZMA do not include size in file... so we have to fake that; 331# append the size as a 32-bit littleendian number as gzip does. 332size_append = printf $(shell \ 333dec_size=0; \ 334for F in $1; do \ 335 fsize=$$(stat -c "%s" $$F); \ 336 dec_size=$$(expr $$dec_size + $$fsize); \ 337done; \ 338printf "%08x\n" $$dec_size | \ 339 sed 's/\(..\)/\1 /g' | { \ 340 read ch0 ch1 ch2 ch3; \ 341 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \ 342 printf '%s%03o' '\\' $$((0x$$ch)); \ 343 done; \ 344 } \ 345) 346 347quiet_cmd_bzip2 = BZIP2 $@ 348cmd_bzip2 = (cat $(filter-out FORCE,$^) | \ 349 bzip2 -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ 350 (rm -f $@ ; false) 351 352# Lzma 353# --------------------------------------------------------------------------- 354 355quiet_cmd_lzma = LZMA $@ 356cmd_lzma = (cat $(filter-out FORCE,$^) | \ 357 lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ 358 (rm -f $@ ; false) 359 360quiet_cmd_lzo = LZO $@ 361cmd_lzo = (cat $(filter-out FORCE,$^) | \ 362 lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ 363 (rm -f $@ ; false) 364 365quiet_cmd_lz4 = LZ4 $@ 366cmd_lz4 = (cat $(filter-out FORCE,$^) | \ 367 lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \ 368 (rm -f $@ ; false) 369 370# U-Boot mkimage 371# --------------------------------------------------------------------------- 372 373MKIMAGE := $(srctree)/scripts/mkuboot.sh 374 375# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces 376# the number of overrides in arch makefiles 377UIMAGE_ARCH ?= $(SRCARCH) 378UIMAGE_COMPRESSION ?= $(if $(2),$(2),none) 379UIMAGE_OPTS-y ?= 380UIMAGE_TYPE ?= kernel 381UIMAGE_LOADADDR ?= arch_must_set_this 382UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR) 383UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)' 384UIMAGE_IN ?= $< 385UIMAGE_OUT ?= $@ 386 387quiet_cmd_uimage = UIMAGE $(UIMAGE_OUT) 388 cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \ 389 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \ 390 -T $(UIMAGE_TYPE) \ 391 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \ 392 -n $(UIMAGE_NAME) -d $(UIMAGE_IN) $(UIMAGE_OUT) 393 394# XZ 395# --------------------------------------------------------------------------- 396# Use xzkern to compress the kernel image and xzmisc to compress other things. 397# 398# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage 399# of the kernel decompressor. A BCJ filter is used if it is available for 400# the target architecture. xzkern also appends uncompressed size of the data 401# using size_append. The .xz format has the size information available at 402# the end of the file too, but it's in more complex format and it's good to 403# avoid changing the part of the boot code that reads the uncompressed size. 404# Note that the bytes added by size_append will make the xz tool think that 405# the file is corrupt. This is expected. 406# 407# xzmisc doesn't use size_append, so it can be used to create normal .xz 408# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very 409# big dictionary would increase the memory usage too much in the multi-call 410# decompression mode. A BCJ filter isn't used either. 411quiet_cmd_xzkern = XZKERN $@ 412cmd_xzkern = (cat $(filter-out FORCE,$^) | \ 413 sh $(srctree)/scripts/xz_wrap.sh && \ 414 $(call size_append, $(filter-out FORCE,$^))) > $@ || \ 415 (rm -f $@ ; false) 416 417quiet_cmd_xzmisc = XZMISC $@ 418cmd_xzmisc = (cat $(filter-out FORCE,$^) | \ 419 xz --check=crc32 --lzma2=dict=1MiB) > $@ || \ 420 (rm -f $@ ; false) 421 422# ASM offsets 423# --------------------------------------------------------------------------- 424 425# Default sed regexp - multiline due to syntax constraints 426# 427# Use [:space:] because LLVM's integrated assembler inserts <tab> around 428# the .ascii directive whereas GCC keeps the <space> as-is. 429define sed-offsets 430 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \ 431 /^->/{s:->#\(.*\):/* \1 */:; \ 432 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \ 433 s:->::; p;}' 434endef 435 436# Use filechk to avoid rebuilds when a header changes, but the resulting file 437# does not 438define filechk_offsets 439 (set -e; \ 440 echo "#ifndef $2"; \ 441 echo "#define $2"; \ 442 echo "/*"; \ 443 echo " * DO NOT MODIFY."; \ 444 echo " *"; \ 445 echo " * This file was generated by Kbuild"; \ 446 echo " */"; \ 447 echo ""; \ 448 sed -ne $(sed-offsets); \ 449 echo ""; \ 450 echo "#endif" ) 451endef 452