#

  # (C) Copyright 2000-2013

  # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  #

  # SPDX-License-Identifier:	GPL-2.0+

  #

  #########################################################################

  # Set shell to bash if possible, otherwise fall back to sh
  SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
  	else if [ -x /bin/bash ]; then echo /bin/bash; \
  	else echo sh; fi; fi)
  
  export	SHELL

  ifeq ($(CURDIR),$(SRCTREE))

  dir :=

  else
  dir := $(subst $(SRCTREE)/,,$(CURDIR))
  endif

  ifneq ($(OBJTREE),$(SRCTREE))
  # Create object files for SPL in a separate directory
  ifeq ($(CONFIG_SPL_BUILD),y)

  ifeq ($(CONFIG_TPL_BUILD),y)
  obj := $(if $(dir),$(TPLTREE)/$(dir)/,$(TPLTREE)/)
  else

  obj := $(if $(dir),$(SPLTREE)/$(dir)/,$(SPLTREE)/)

  endif

  else

  obj := $(if $(dir),$(OBJTREE)/$(dir)/,$(OBJTREE)/)

  endif

  src := $(if $(dir),$(SRCTREE)/$(dir)/,$(SRCTREE)/)
  
  $(shell mkdir -p $(obj))
  else

  # Create object files for SPL in a separate directory
  ifeq ($(CONFIG_SPL_BUILD),y)

  ifeq ($(CONFIG_TPL_BUILD),y)
  obj := $(if $(dir),$(TPLTREE)/$(dir)/,$(TPLTREE)/)
  else

  obj := $(if $(dir),$(SPLTREE)/$(dir)/,$(SPLTREE)/)

  endif

  $(shell mkdir -p $(obj))
  else

  obj :=

  endif

  src :=
  endif

  # clean the slate ...
  PLATFORM_RELFLAGS =
  PLATFORM_CPPFLAGS =
  PLATFORM_LDFLAGS =

  #########################################################################

  HOSTCFLAGS	= -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer \
  		  $(HOSTCPPFLAGS)
  HOSTSTRIP	= strip
  
  #
  # Mac OS X / Darwin's C preprocessor is Apple specific.  It
  # generates numerous errors and warnings.  We want to bypass it

  # and use GNU C's cpp.	To do this we pass the -traditional-cpp

  # option to the compiler.  Note that the -traditional-cpp flag
  # DOES NOT have the same semantics as GNU C's flag, all it does
  # is invoke the GNU preprocessor in stock ANSI/ISO C fashion.
  #
  # Apple's linker is similar, thanks to the new 2 stage linking
  # multiple symbol definitions are treated as errors, hence the
  # -multiply_defined suppress option to turn off this error.
  #

  ifeq ($(HOSTOS),darwin)

  # get major and minor product version (e.g. '10' and '6' for Snow Leopard)
  DARWIN_MAJOR_VERSION	= $(shell sw_vers -productVersion | cut -f 1 -d '.')
  DARWIN_MINOR_VERSION	= $(shell sw_vers -productVersion | cut -f 2 -d '.')

  os_x_before	= $(shell if [ $(DARWIN_MAJOR_VERSION) -le $(1) -a \
  	$(DARWIN_MINOR_VERSION) -le $(2) ] ; then echo "$(3)"; else echo "$(4)"; fi ;)

  
  # Snow Leopards build environment has no longer restrictions as described above

  HOSTCC		 = $(call os_x_before, 10, 5, "cc", "gcc")
  HOSTCFLAGS	+= $(call os_x_before, 10, 4, "-traditional-cpp")
  HOSTLDFLAGS	+= $(call os_x_before, 10, 5, "-multiply_defined suppress")

  else
  HOSTCC		= gcc
  endif

  
  ifeq ($(HOSTOS),cygwin)
  HOSTCFLAGS	+= -ansi
  endif
  
  # We build some files with extra pedantic flags to try to minimize things
  # that won't build on some weird host compiler -- though there are lots of
  # exceptions for files that aren't complaint.
  
  HOSTCFLAGS_NOPED = $(filter-out -pedantic,$(HOSTCFLAGS))
  HOSTCFLAGS	+= -pedantic

  
  #########################################################################

  #

  # Option checker, gcc version (courtesy linux kernel) to ensure

  # only supported compiler options are used
  #

  CC_OPTIONS_CACHE_FILE := $(OBJTREE)/include/generated/cc_options.mk

  CC_TEST_OFILE := $(OBJTREE)/include/generated/cc_test_file.o

  
  -include $(CC_OPTIONS_CACHE_FILE)

  cc-option-sys = $(shell mkdir -p $(dir $(CC_TEST_OFILE)); \
  		if $(CC) $(CFLAGS) $(1) -S -xc /dev/null -o $(CC_TEST_OFILE) \

  		> /dev/null 2>&1; then \
  		echo 'CC_OPTIONS += $(strip $1)' >> $(CC_OPTIONS_CACHE_FILE); \
  		echo "$(1)"; fi)
  
  ifeq ($(CONFIG_CC_OPT_CACHE_DISABLE),y)
  cc-option = $(strip $(if $(call cc-option-sys,$1),$1,$2))
  else
  cc-option = $(strip $(if $(findstring $1,$(CC_OPTIONS)),$1,\
  		$(if $(call cc-option-sys,$1),$1,$2)))
  endif

  # cc-version
  # Usage gcc-ver := $(call cc-version)

  cc-version = $(shell $(SHELL) $(SRCTREE)/scripts/gcc-version.sh $(CC))
  binutils-version = $(shell $(SHELL) $(SRCTREE)/scripts/binutils-version.sh $(AS))
  dtc-version = $(shell $(SHELL) $(SRCTREE)/scripts/dtc-version.sh $(DTC))

  #
  # Include the make variables (CC, etc...)
  #
  AS	= $(CROSS_COMPILE)as

  
  # Always use GNU ld
  LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
  		then echo "$(CROSS_COMPILE)ld.bfd"; else echo "$(CROSS_COMPILE)ld"; fi;)

  CC	= $(CROSS_COMPILE)gcc
  CPP	= $(CC) -E
  AR	= $(CROSS_COMPILE)ar
  NM	= $(CROSS_COMPILE)nm

  LDR	= $(CROSS_COMPILE)ldr

  STRIP	= $(CROSS_COMPILE)strip
  OBJCOPY = $(CROSS_COMPILE)objcopy
  OBJDUMP = $(CROSS_COMPILE)objdump
  RANLIB	= $(CROSS_COMPILE)RANLIB

  DTC	= dtc

  CHECK	= sparse

  #########################################################################
  
  # Load generated board configuration

  ifeq ($(CONFIG_TPL_BUILD),y)
  # Include TPL autoconf
  sinclude $(OBJTREE)/include/tpl-autoconf.mk
  else

  ifeq ($(CONFIG_SPL_BUILD),y)
  # Include SPL autoconf
  sinclude $(OBJTREE)/include/spl-autoconf.mk
  else
  # Include normal autoconf

  sinclude $(OBJTREE)/include/autoconf.mk

  endif

  endif

  sinclude $(OBJTREE)/include/config.mk

  # Some architecture config.mk files need to know what CPUDIR is set to,
  # so calculate CPUDIR before including ARCH/SOC/CPU config.mk files.

  # Check if arch/$ARCH/cpu/$CPU exists, otherwise assume arch/$ARCH/cpu contains
  # CPU-specific code.
  CPUDIR=arch/$(ARCH)/cpu/$(CPU)
  ifneq ($(SRCTREE)/$(CPUDIR),$(wildcard $(SRCTREE)/$(CPUDIR)))
  CPUDIR=arch/$(ARCH)/cpu
  endif

  sinclude $(TOPDIR)/arch/$(ARCH)/config.mk	# include architecture dependend rules

  sinclude $(TOPDIR)/$(CPUDIR)/config.mk		# include  CPU	specific rules

  ifdef	SOC

  sinclude $(TOPDIR)/$(CPUDIR)/$(SOC)/config.mk	# include  SoC	specific rules

  endif
  ifdef	VENDOR
  BOARDDIR = $(VENDOR)/$(BOARD)
  else
  BOARDDIR = $(BOARD)
  endif
  ifdef	BOARD
  sinclude $(TOPDIR)/board/$(BOARDDIR)/config.mk	# include board specific rules
  endif
  
  #########################################################################

  # We don't actually use $(ARFLAGS) anywhere anymore, so catch people
  # who are porting old code to latest mainline but not updating $(AR).
  ARFLAGS = $(error update your Makefile to use cmd_link_o_target and not AR)

  RELFLAGS= $(PLATFORM_RELFLAGS)

  DBGFLAGS= -g # -DDEBUG

  OPTFLAGS= -Os #-fomit-frame-pointer

  OBJCFLAGS += --gap-fill=0xff

  gccincdir := $(shell $(CC) -print-file-name=include)

  CPPFLAGS := $(DBGFLAGS) $(OPTFLAGS) $(RELFLAGS)		\

  	-D__KERNEL__

  
  # Enable garbage collection of un-used sections for SPL
  ifeq ($(CONFIG_SPL_BUILD),y)
  CPPFLAGS += -ffunction-sections -fdata-sections
  LDFLAGS_FINAL += --gc-sections
  endif

  # TODO(sjg@chromium.org): Is this correct on Mac OS?

  
  # MXSImage needs LibSSL
  ifneq ($(CONFIG_MX23)$(CONFIG_MX28),)
  HOSTLIBS	+= -lssl -lcrypto
  # Add CONFIG_MXS into host CFLAGS, so we can check whether or not register
  # the mxsimage support within tools/mxsimage.c .
  HOSTCFLAGS	+= -DCONFIG_MXS
  endif

  ifdef CONFIG_FIT_SIGNATURE
  HOSTLIBS	+= -lssl -lcrypto

  
  # This affects include/image.h, but including the board config file
  # is tricky, so manually define this options here.
  HOSTCFLAGS	+= -DCONFIG_FIT_SIGNATURE

  endif

  ifneq ($(CONFIG_SYS_TEXT_BASE),)
  CPPFLAGS += -DCONFIG_SYS_TEXT_BASE=$(CONFIG_SYS_TEXT_BASE)

  endif

  ifeq ($(CONFIG_SPL_BUILD),y)
  CPPFLAGS += -DCONFIG_SPL_BUILD

  ifeq ($(CONFIG_TPL_BUILD),y)
  CPPFLAGS += -DCONFIG_TPL_BUILD
  endif

  endif

  # Does this architecture support generic board init?
  ifeq ($(__HAVE_ARCH_GENERIC_BOARD),)
  ifneq ($(CONFIG_SYS_GENERIC_BOARD),)

  CHECK_GENERIC_BOARD = $(error Your architecture does not support generic board. \
  Please undefined CONFIG_SYS_GENERIC_BOARD in your board config file)

  endif
  endif

  ifneq ($(OBJTREE),$(SRCTREE))

  CPPFLAGS += -I$(OBJTREE)/include

  endif

  CPPFLAGS += -I$(TOPDIR)/include -I$(SRCTREE)/arch/$(ARCH)/include

  CPPFLAGS += -fno-builtin -ffreestanding -nostdinc	\

  	-isystem $(gccincdir) -pipe $(PLATFORM_CPPFLAGS)

  CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes

  
  ifdef BUILD_TAG
  CFLAGS += -DBUILD_TAG='"$(BUILD_TAG)"'

  endif

  CFLAGS_SSP := $(call cc-option,-fno-stack-protector)
  CFLAGS += $(CFLAGS_SSP)

  # Some toolchains enable security related warning flags by default,
  # but they don't make much sense in the u-boot world, so disable them.

  CFLAGS_WARN := $(call cc-option,-Wno-format-nonliteral) \
  	       $(call cc-option,-Wno-format-security)
  CFLAGS += $(CFLAGS_WARN)

  # Report stack usage if supported
  CFLAGS_STACK := $(call cc-option,-fstack-usage)
  CFLAGS += $(CFLAGS_STACK)

  BCURDIR = $(subst $(SRCTREE)/,,$(CURDIR:$(obj)%=%))
  
  ifeq ($(findstring examples/,$(BCURDIR)),)
  ifeq ($(CONFIG_SPL_BUILD),)
  ifdef FTRACE
  CFLAGS += -finstrument-functions -DFTRACE
  endif
  endif
  endif

  # $(CPPFLAGS) sets -g, which causes gcc to pass a suitable -g<format>
  # option to the assembler.
  AFLAGS_DEBUG :=

  # turn jbsr into jsr for m68k
  ifeq ($(ARCH),m68k)
  ifeq ($(findstring 3.4,$(shell $(CC) --version)),3.4)
  AFLAGS_DEBUG := -Wa,-gstabs,-S
  endif

  endif

  AFLAGS := $(AFLAGS_DEBUG) -D__ASSEMBLY__ $(CPPFLAGS)

  LDFLAGS += $(PLATFORM_LDFLAGS)

  LDFLAGS_FINAL += -Bstatic

  LDFLAGS_u-boot += -T $(obj)u-boot.lds $(LDFLAGS_FINAL)

  ifneq ($(CONFIG_SYS_TEXT_BASE),)

  LDFLAGS_u-boot += -Ttext $(CONFIG_SYS_TEXT_BASE)

  endif

  LDFLAGS_$(SPL_BIN) += -T $(obj)u-boot-spl.lds $(LDFLAGS_FINAL)

  ifneq ($(CONFIG_SPL_TEXT_BASE),)

  LDFLAGS_$(SPL_BIN) += -Ttext $(CONFIG_SPL_TEXT_BASE)

  endif

  # Linus' kernel sanity checking tool
  CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \

  		  -Wbitwise -Wno-return-void -D__CHECK_ENDIAN__ $(CF)

  # Location of a usable BFD library, where we define "usable" as
  # "built for ${HOST}, supports ${TARGET}".  Sensible values are
  # - When cross-compiling: the root of the cross-environment
  # - Linux/ppc (native): /usr
  # - NetBSD/ppc (native): you lose ... (must extract these from the
  #   binutils build directory, plus the native and U-Boot include
  #   files don't like each other)
  #
  # So far, this is used only by tools/gdb/Makefile.

  ifeq ($(HOSTOS),darwin)

  BFD_ROOT_DIR =		/usr/local/tools
  else

  ifeq ($(HOSTARCH),$(ARCH))
  # native
  BFD_ROOT_DIR =		/usr
  else

  #BFD_ROOT_DIR =		/LinuxPPC/CDK		# Linux/i386
  #BFD_ROOT_DIR =		/usr/pkg/cross		# NetBSD/i386

  BFD_ROOT_DIR =		/opt/powerpc
  endif

  endif

  
  #########################################################################

  export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE \

  	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE

  export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS CPPFLAGS CFLAGS AFLAGS

  
  #########################################################################

  # Allow boards to use custom optimize flags on a per dir/file basis

  ALL_AFLAGS = $(AFLAGS) $(AFLAGS_$(BCURDIR)/$(@F)) $(AFLAGS_$(BCURDIR))
  ALL_CFLAGS = $(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR))

  EXTRA_CPPFLAGS = $(CPPFLAGS_$(BCURDIR)/$(@F)) $(CPPFLAGS_$(BCURDIR))
  ALL_CFLAGS += $(EXTRA_CPPFLAGS)
  
  # The _DEP version uses the $< file target (for dependency generation)
  # See rules.mk
  EXTRA_CPPFLAGS_DEP = $(CPPFLAGS_$(BCURDIR)/$(addsuffix .o,$(basename $<))) \
  		$(CPPFLAGS_$(BCURDIR))

  $(obj)%.s:	%.S

  	$(CPP) $(ALL_AFLAGS) -o $@ $<

  $(obj)%.o:	%.S

  	$(CC)  $(ALL_AFLAGS) -o $@ $< -c

  $(obj)%.o:	%.c

  ifneq ($(CHECKSRC),0)
  	$(CHECK) $(CHECKFLAGS) $(ALL_CFLAGS) $<
  endif

  	$(CC)  $(ALL_CFLAGS) -o $@ $< -c

  $(obj)%.i:	%.c

  	$(CPP) $(ALL_CFLAGS) -o $@ $< -c

  $(obj)%.s:	%.c

  	$(CC)  $(ALL_CFLAGS) -o $@ $< -c -S

  #########################################################################

  
  # If the list of objects to link is empty, just create an empty built-in.o
  cmd_link_o_target = $(if $(strip $1),\

  		      $(LD) $(LDFLAGS) -r -o $@ $1,\

  		      rm -f $@; $(AR) rcs $@ )

  
  #########################################################################