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