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