# SPDX-License-Identifier: GPL-2.0 # Backward compatibility asflags-y += $(EXTRA_AFLAGS) ccflags-y += $(EXTRA_CFLAGS) cppflags-y += $(EXTRA_CPPFLAGS) ldflags-y += $(EXTRA_LDFLAGS) # flags that take effect in current and sub directories KBUILD_AFLAGS += $(subdir-asflags-y) KBUILD_CFLAGS += $(subdir-ccflags-y) # Figure out what we need to build from the various variables # =========================================================================== # When an object is listed to be built compiled-in and modular, # only build the compiled-in version obj-m := $(filter-out $(obj-y),$(obj-m)) # Libraries are always collected in one lib file. # Filter out objects already built-in lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) # Subdirectories we need to descend into subdir-ym := $(sort $(subdir-y) $(subdir-m) \ $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m)))) # Handle objects in subdirs: # - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and # foo/modules.order # - If we encounter foo/ in $(obj-m), replace it by foo/modules.order # # Generate modules.order to determine modorder. Unfortunately, we don't have # information about ordering between -y and -m subdirs. Just put -y's first. ifdef need-modorder obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m)) else obj-m := $(filter-out %/, $(obj-m)) endif ifdef need-builtin obj-y := $(patsubst %/, %/built-in.a, $(obj-y)) else obj-y := $(filter-out %/, $(obj-y)) endif # Expand $(foo-objs) $(foo-y) etc. by replacing their individuals suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s)))) # List composite targets that are constructed by combining other targets multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m))) # List primitive targets that are compiled from source files real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m)) # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y) multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m) multi-obj-ym := $(multi-obj-y) $(multi-obj-m) # Replace multi-part objects by their individual parts, # including built-in.a from subdirectories real-obj-y := $(call real-search, $(obj-y), .o, -objs -y) real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m) always-y += $(always-m) # hostprogs-always-y += foo # ... is a shorthand for # hostprogs += foo # always-y += foo hostprogs += $(hostprogs-always-y) $(hostprogs-always-m) always-y += $(hostprogs-always-y) $(hostprogs-always-m) # userprogs-always-y is likewise. userprogs += $(userprogs-always-y) $(userprogs-always-m) always-y += $(userprogs-always-y) $(userprogs-always-m) # DTB # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built dtb-$(CONFIG_OF_ALL_DTBS) += $(dtb-) # Composite DTB (i.e. DTB constructed by overlay) multi-dtb-y := $(call multi-search, $(dtb-y), .dtb, -dtbs) # Primitive DTB compiled from *.dts real-dtb-y := $(call real-search, $(dtb-y), .dtb, -dtbs) # Base DTB that overlay is applied onto (each first word of $(*-dtbs) expansion) base-dtb-y := $(foreach m, $(multi-dtb-y), $(firstword $(call suffix-search, $m, .dtb, -dtbs))) always-y += $(dtb-y) # Add subdir path extra-y := $(addprefix $(obj)/,$(extra-y)) always-y := $(addprefix $(obj)/,$(always-y)) targets := $(addprefix $(obj)/,$(targets)) obj-m := $(addprefix $(obj)/,$(obj-m)) lib-y := $(addprefix $(obj)/,$(lib-y)) real-obj-y := $(addprefix $(obj)/,$(real-obj-y)) real-obj-m := $(addprefix $(obj)/,$(real-obj-m)) multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m)) multi-dtb-y := $(addprefix $(obj)/, $(multi-dtb-y)) real-dtb-y := $(addprefix $(obj)/, $(real-dtb-y)) subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) # Finds the multi-part object the current object will be linked into. # If the object belongs to two or more multi-part objects, list them all. modname-multi = $(sort $(foreach m,$(multi-obj-ym),\ $(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=)))) __modname = $(or $(modname-multi),$(basetarget)) modname = $(subst $(space),:,$(__modname)) modfile = $(addprefix $(obj)/,$(__modname)) # target with $(obj)/ and its suffix stripped target-stem = $(basename $(patsubst $(obj)/%,%,$@)) # These flags are needed for modversions and compiling, so we define them here # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will # end up in (or would, if it gets compiled in) name-fix-token = $(subst $(comma),_,$(subst -,_,$1)) name-fix = $(call stringify,$(call name-fix-token,$1)) basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \ -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname)) modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile)) _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \ $(filter-out $(ccflags-remove-y), \ $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \ $(CFLAGS_$(target-stem).o)) _a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \ $(filter-out $(asflags-remove-y), \ $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \ $(AFLAGS_$(target-stem).o)) _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds) # # Enable gcov profiling flags for a file, directory or for all files depending # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL # (in this order) # ifeq ($(CONFIG_GCOV_KERNEL),y) _c_flags += $(if $(patsubst n%,, \ $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \ $(CFLAGS_GCOV)) endif # # Enable address sanitizer flags for kernel except some files or directories # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE) # ifeq ($(CONFIG_KASAN),y) ifneq ($(CONFIG_KASAN_HW_TAGS),y) _c_flags += $(if $(patsubst n%,, \ $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \ $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE)) endif endif ifeq ($(CONFIG_UBSAN),y) _c_flags += $(if $(patsubst n%,, \ $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \ $(CFLAGS_UBSAN)) endif ifeq ($(CONFIG_KCOV),y) _c_flags += $(if $(patsubst n%,, \ $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \ $(CFLAGS_KCOV)) endif # # Enable KCSAN flags except some files or directories we don't want to check # (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE) # ifeq ($(CONFIG_KCSAN),y) _c_flags += $(if $(patsubst n%,, \ $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \ $(CFLAGS_KCSAN)) # Some uninstrumented files provide implied barriers required to avoid false # positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only. _c_flags += $(if $(patsubst n%,, \ $(KCSAN_INSTRUMENT_BARRIERS_$(basetarget).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \ -D__KCSAN_INSTRUMENT_BARRIERS__) endif # $(srctree)/$(src) for including checkin headers from generated source files # $(objtree)/$(obj) for including generated headers from checkin source files ifeq ($(KBUILD_EXTMOD),) ifdef building_out_of_srctree _c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) _a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) _cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj) endif endif part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y) quiet_modtag = $(if $(part-of-module),[M], ) modkern_cflags = \ $(if $(part-of-module), \ $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags)) modkern_aflags = $(if $(part-of-module), \ $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \ $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)) c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ -include $(srctree)/include/linux/compiler_types.h \ $(_c_flags) $(modkern_cflags) \ $(basename_flags) $(modname_flags) a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(_a_flags) $(modkern_aflags) cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(_cpp_flags) ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ $(addprefix -I,$(DTC_INCLUDE)) \ -undef -D__DTS__ ifdef CONFIG_OBJTOOL objtool := $(objtree)/tools/objtool/objtool objtool_args = \ $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \ $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \ $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \ $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ $(if $(CONFIG_UNWINDER_ORC), --orc) \ $(if $(CONFIG_RETPOLINE), --retpoline) \ $(if $(CONFIG_RETHUNK), --rethunk) \ $(if $(CONFIG_SLS), --sls) \ $(if $(CONFIG_STACK_VALIDATION), --stackval) \ $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \ $(if $(CONFIG_HAVE_UACCESS_VALIDATION), --uaccess) \ $(if $(delay-objtool), --link) \ $(if $(part-of-module), --module) \ $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@) cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) endif # CONFIG_OBJTOOL # Useful for describing the dependency of composite objects # Usage: # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) define multi_depend $(foreach m, $1, \ $(eval $m: \ $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3)))) endef # Copy a file # =========================================================================== # 'cp' preserves permissions. If you use it to copy a file in read-only srctree, # the copy would be read-only as well, leading to an error when executing the # rule next time. Use 'cat' instead in order to generate a writable file. quiet_cmd_copy = COPY $@ cmd_copy = cat $< > $@ $(obj)/%: $(src)/%_shipped $(call cmd,copy) # Commands useful for building a boot image # =========================================================================== # # Use as following: # # target: source(s) FORCE # $(if_changed,ld/objcopy/gzip) # # and add target to 'targets' so that we know we have to # read in the saved command line # Linking # --------------------------------------------------------------------------- quiet_cmd_ld = LD $@ cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@ # Archive # --------------------------------------------------------------------------- quiet_cmd_ar = AR $@ cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs) # Objcopy # --------------------------------------------------------------------------- quiet_cmd_objcopy = OBJCOPY $@ cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@ # Gzip # --------------------------------------------------------------------------- quiet_cmd_gzip = GZIP $@ cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@ # DTC # --------------------------------------------------------------------------- DTC ?= $(objtree)/scripts/dtc/dtc DTC_FLAGS += -Wno-interrupt_provider # Disable noisy checks by default ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),) DTC_FLAGS += -Wno-unit_address_vs_reg \ -Wno-avoid_unnecessary_addr_size \ -Wno-alias_paths \ -Wno-graph_child_address \ -Wno-simple_bus_reg \ -Wno-unique_unit_address endif ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),) DTC_FLAGS += -Wnode_name_chars_strict \ -Wproperty_name_chars_strict \ -Winterrupt_provider endif DTC_FLAGS += $(DTC_FLAGS_$(basetarget)) # Set -@ if the target is a base DTB that overlay is applied onto DTC_FLAGS += $(if $(filter $(patsubst $(obj)/%,%,$@), $(base-dtb-y)), -@) # Generate an assembly file to wrap the output of the device tree compiler quiet_cmd_dt_S_dtb= DTB $@ cmd_dt_S_dtb= \ { \ echo '\#include <asm-generic/vmlinux.lds.h>'; \ echo '.section .dtb.init.rodata,"a"'; \ echo '.balign STRUCT_ALIGNMENT'; \ echo '.global __dtb_$(subst -,_,$(*F))_begin'; \ echo '__dtb_$(subst -,_,$(*F))_begin:'; \ echo '.incbin "$<" '; \ echo '__dtb_$(subst -,_,$(*F))_end:'; \ echo '.global __dtb_$(subst -,_,$(*F))_end'; \ echo '.balign STRUCT_ALIGNMENT'; \ } > $@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE $(call if_changed,dt_S_dtb) quiet_cmd_dtc = DTC $@ cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \ $(DTC) -o $@ -b 0 \ $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \ -d $(depfile).dtc.tmp $(dtc-tmp) ; \ cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile) quiet_cmd_fdtoverlay = DTOVL $@ cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs) $(multi-dtb-y): FORCE $(call if_changed,fdtoverlay) $(call multi_depend, $(multi-dtb-y), .dtb, -dtbs) ifneq ($(CHECK_DTBS)$(CHECK_DT_BINDING),) DT_CHECKER ?= dt-validate DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m) DT_BINDING_DIR := Documentation/devicetree/bindings DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json quiet_cmd_dtb_check = CHECK $@ cmd_dtb_check = $(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true endif define rule_dtc $(call cmd_and_fixdep,dtc) $(call cmd,dtb_check) endef $(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE $(call if_changed_rule,dtc) $(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE $(call if_changed_dep,dtc) dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp) # Bzip2 # --------------------------------------------------------------------------- # Bzip2 and LZMA do not include size in file... so we have to fake that; # append the size as a 32-bit littleendian number as gzip does. size_append = printf $(shell \ dec_size=0; \ for F in $(real-prereqs); do \ fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \ dec_size=$$(expr $$dec_size + $$fsize); \ done; \ printf "%08x\n" $$dec_size | \ sed 's/\(..\)/\1 /g' | { \ read ch0 ch1 ch2 ch3; \ for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \ printf '%s%03o' '\\' $$((0x$$ch)); \ done; \ } \ ) quiet_cmd_file_size = GEN $@ cmd_file_size = $(size_append) > $@ quiet_cmd_bzip2 = BZIP2 $@ cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@ quiet_cmd_bzip2_with_size = BZIP2 $@ cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@ # Lzma # --------------------------------------------------------------------------- quiet_cmd_lzma = LZMA $@ cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@ quiet_cmd_lzma_with_size = LZMA $@ cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@ quiet_cmd_lzo = LZO $@ cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@ quiet_cmd_lzo_with_size = LZO $@ cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@ quiet_cmd_lz4 = LZ4 $@ cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@ quiet_cmd_lz4_with_size = LZ4 $@ cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \ $(size_append); } > $@ # U-Boot mkimage # --------------------------------------------------------------------------- MKIMAGE := $(srctree)/scripts/mkuboot.sh # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces # the number of overrides in arch makefiles UIMAGE_ARCH ?= $(SRCARCH) UIMAGE_COMPRESSION ?= $(or $(2),none) UIMAGE_OPTS-y ?= UIMAGE_TYPE ?= kernel UIMAGE_LOADADDR ?= arch_must_set_this UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR) UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)' quiet_cmd_uimage = UIMAGE $@ cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \ -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \ -T $(UIMAGE_TYPE) \ -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \ -n $(UIMAGE_NAME) -d $< $@ # XZ # --------------------------------------------------------------------------- # Use xzkern to compress the kernel image and xzmisc to compress other things. # # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage # of the kernel decompressor. A BCJ filter is used if it is available for # the target architecture. xzkern also appends uncompressed size of the data # using size_append. The .xz format has the size information available at # the end of the file too, but it's in more complex format and it's good to # avoid changing the part of the boot code that reads the uncompressed size. # Note that the bytes added by size_append will make the xz tool think that # the file is corrupt. This is expected. # # xzmisc doesn't use size_append, so it can be used to create normal .xz # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very # big dictionary would increase the memory usage too much in the multi-call # decompression mode. A BCJ filter isn't used either. quiet_cmd_xzkern = XZKERN $@ cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@ quiet_cmd_xzkern_with_size = XZKERN $@ cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \ $(size_append); } > $@ quiet_cmd_xzmisc = XZMISC $@ cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@ # ZSTD # --------------------------------------------------------------------------- # Appends the uncompressed size of the data using size_append. The .zst # format has the size information available at the beginning of the file too, # but it's in a more complex format and it's good to avoid changing the part # of the boot code that reads the uncompressed size. # # Note that the bytes added by size_append will make the zstd tool think that # the file is corrupt. This is expected. # # zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of # 128 MB. zstd22 is used for kernel compression because it is decompressed in a # single pass, so zstd doesn't need to allocate a window buffer. When streaming # decompression is used, like initramfs decompression, zstd22 should likely not # be used because it would require zstd to allocate a 128 MB buffer. quiet_cmd_zstd = ZSTD $@ cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@ quiet_cmd_zstd22 = ZSTD22 $@ cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@ quiet_cmd_zstd22_with_size = ZSTD22 $@ cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@ # ASM offsets # --------------------------------------------------------------------------- # Default sed regexp - multiline due to syntax constraints # # Use [:space:] because LLVM's integrated assembler inserts <tab> around # the .ascii directive whereas GCC keeps the <space> as-is. define sed-offsets 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \ /^->/{s:->#\(.*\):/* \1 */:; \ s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \ s:->::; p;}' endef # Use filechk to avoid rebuilds when a header changes, but the resulting file # does not define filechk_offsets echo "#ifndef $2"; \ echo "#define $2"; \ echo "/*"; \ echo " * DO NOT MODIFY."; \ echo " *"; \ echo " * This file was generated by Kbuild"; \ echo " */"; \ echo ""; \ sed -ne $(sed-offsets) < $<; \ echo ""; \ echo "#endif" endef