# 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)

  ifneq ($(CHECK_DTBS),)

  always-y += $(patsubst %.dtb,%.dt.yaml, $(real-dtb-y))
  always-y += $(patsubst %.dtbo,%.dt.yaml, $(real-dtb-y))

  endif

  # 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 = $(if $(modname-multi),$(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))
  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__

  ifeq ($(CONFIG_LTO_CLANG),y)
  # With CONFIG_LTO_CLANG, .o files in modules might be LLVM bitcode, so we
  # need to run LTO to compile them into native code (.lto.o) before further
  # processing.
  mod-prelink-ext := .lto
  endif

  # 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, $(notdir $1), \
  	$(eval $(obj)/$m: \
  	$(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
  endef

  quiet_cmd_copy = COPY    $@
        cmd_copy = cp $< $@

  # Shipped files
  # ===========================================================================

  # '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_shipped = SHIPPED $@
  cmd_shipped = cat $< > $@

  $(obj)/%: $(src)/%_shipped

  	$(call cmd,shipped)
  
  # 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-unit_address_format \

  	-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)

  $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE

  	$(call if_changed_dep,dtc)

  $(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE
  	$(call if_changed_dep,dtc)

  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)

  DT_CHECKER ?= dt-validate

  DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),,-m)

  DT_BINDING_DIR := Documentation/devicetree/bindings

  # DT_TMP_SCHEMA may be overridden from Documentation/devicetree/bindings/Makefile

  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) $@

  define rule_dtc

  	$(call cmd_and_fixdep,dtc)

  	$(call cmd,dtb_check)

  endef
  
  $(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE

  	$(call if_changed_rule,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
  " $$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_bzip2 = BZIP2   $@

        cmd_bzip2 = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@

  
  # Lzma
  # ---------------------------------------------------------------------------
  
  quiet_cmd_lzma = LZMA    $@

        cmd_lzma = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@

  quiet_cmd_lzo = LZO     $@

        cmd_lzo = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@

  quiet_cmd_lz4 = LZ4     $@

        cmd_lz4 = { 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 ?= $(if $(2),$(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; \

                       $(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; $(size_append); } > $@
  
  quiet_cmd_zstd22 = ZSTD22  $@
        cmd_zstd22 = { 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