Makefile

# SPDX-License-Identifier: GPL-2.0+

VERSION = 2020
PATCHLEVEL = 10
SUBLEVEL =
EXTRAVERSION = -rc4
NAME =

# *DOCUMENTATION*
# To see a list of typical targets execute "make help"
# More info can be located in ./README
# Comments in this file are targeted only to the developer, do not
# expect to learn how to build the kernel reading this file.

# o Do not use make's built-in rules and variables
#   (this increases performance and avoids hard-to-debug behaviour);
# o Look for make include files relative to root of kernel src
MAKEFLAGS += -rR --include-dir=$(CURDIR)

# Determine host architecture
include include/host_arch.h
MK_ARCH="${shell uname -m}"
unexport HOST_ARCH
ifeq ("x86_64", $(MK_ARCH))
  export HOST_ARCH=$(HOST_ARCH_X86_64)
else ifneq (,$(findstring $(MK_ARCH), "i386" "i486" "i586" "i686"))
  export HOST_ARCH=$(HOST_ARCH_X86)
else ifneq (,$(findstring $(MK_ARCH), "aarch64" "armv8l"))
  export HOST_ARCH=$(HOST_ARCH_AARCH64)
else ifeq ("armv7l", $(MK_ARCH))
  export HOST_ARCH=$(HOST_ARCH_ARM)
else ifeq ("riscv32", $(MK_ARCH))
  export HOST_ARCH=$(HOST_ARCH_RISCV32)
else ifeq ("riscv64", $(MK_ARCH))
  export HOST_ARCH=$(HOST_ARCH_RISCV64)
endif
undefine MK_ARCH

# Avoid funny character set dependencies
unexport LC_ALL
LC_COLLATE=C
LC_NUMERIC=C
export LC_COLLATE LC_NUMERIC

# Avoid interference with shell env settings
unexport GREP_OPTIONS

# We are using a recursive build, so we need to do a little thinking
# to get the ordering right.
#
# Most importantly: sub-Makefiles should only ever modify files in
# their own directory. If in some directory we have a dependency on
# a file in another dir (which doesn't happen often, but it's often
# unavoidable when linking the built-in.o targets which finally
# turn into vmlinux), we will call a sub make in that other dir, and
# after that we are sure that everything which is in that other dir
# is now up to date.
#
# The only cases where we need to modify files which have global
# effects are thus separated out and done before the recursive
# descending is started. They are now explicitly listed as the
# prepare rule.

# Beautify output
# ---------------------------------------------------------------------------
#
# Normally, we echo the whole command before executing it. By making
# that echo $($(quiet)$(cmd)), we now have the possibility to set
# $(quiet) to choose other forms of output instead, e.g.
#
#         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
#         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
#
# If $(quiet) is empty, the whole command will be printed.
# If it is set to "quiet_", only the short version will be printed.
# If it is set to "silent_", nothing will be printed at all, since
# the variable $(silent_cmd_cc_o_c) doesn't exist.
#
# A simple variant is to prefix commands with $(Q) - that's useful
# for commands that shall be hidden in non-verbose mode.
#
#	$(Q)ln $@ :<
#
# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
# If KBUILD_VERBOSE equals 1 then the above command is displayed.
#
# To put more focus on warnings, be less verbose as default
# Use 'make V=1' to see the full commands

ifeq ("$(origin V)", "command line")
  KBUILD_VERBOSE = $(V)
endif
ifndef KBUILD_VERBOSE
  KBUILD_VERBOSE = 0
endif

ifeq ($(KBUILD_VERBOSE),1)
  quiet =
  Q =
else
  quiet=quiet_
  Q = @
endif

# If the user is running make -s (silent mode), suppress echoing of
# commands

ifneq ($(filter 4.%,$(MAKE_VERSION)),)	# make-4
ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),)
  quiet=silent_
endif
else					# make-3.8x
ifneq ($(filter s% -s%,$(MAKEFLAGS)),)
  quiet=silent_
endif
endif

export quiet Q KBUILD_VERBOSE

# kbuild supports saving output files in a separate directory.
# To locate output files in a separate directory two syntaxes are supported.
# In both cases the working directory must be the root of the kernel src.
# 1) O=
# Use "make O=dir/to/store/output/files/"
#
# 2) Set KBUILD_OUTPUT
# Set the environment variable KBUILD_OUTPUT to point to the directory
# where the output files shall be placed.
# export KBUILD_OUTPUT=dir/to/store/output/files/
# make
#
# The O= assignment takes precedence over the KBUILD_OUTPUT environment
# variable.

# KBUILD_SRC is set on invocation of make in OBJ directory
# KBUILD_SRC is not intended to be used by the regular user (for now)
ifeq ($(KBUILD_SRC),)

# OK, Make called in directory where kernel src resides
# Do we want to locate output files in a separate directory?
ifeq ("$(origin O)", "command line")
  KBUILD_OUTPUT := $(O)
endif

# That's our default target when none is given on the command line
PHONY := _all
_all:

# Cancel implicit rules on top Makefile
$(CURDIR)/Makefile Makefile: ;

ifneq ($(KBUILD_OUTPUT),)
# Invoke a second make in the output directory, passing relevant variables
# check that the output directory actually exists
saved-output := $(KBUILD_OUTPUT)
KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
								&& /bin/pwd)
$(if $(KBUILD_OUTPUT),, \
     $(error failed to create output directory "$(saved-output)"))

PHONY += $(MAKECMDGOALS) sub-make

$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
	@:

sub-make: FORCE
	$(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
	-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))

# Leave processing to above invocation of make
skip-makefile := 1
endif # ifneq ($(KBUILD_OUTPUT),)
endif # ifeq ($(KBUILD_SRC),)

# We process the rest of the Makefile if this is the final invocation of make
ifeq ($(skip-makefile),)

# Do not print "Entering directory ...",
# but we want to display it when entering to the output directory
# so that IDEs/editors are able to understand relative filenames.
MAKEFLAGS += --no-print-directory

# Call a source code checker (by default, "sparse") as part of the
# C compilation.
#
# Use 'make C=1' to enable checking of only re-compiled files.
# Use 'make C=2' to enable checking of *all* source files, regardless
# of whether they are re-compiled or not.
#
# See the file "doc/sparse.txt" for more details, including
# where to get the "sparse" utility.

ifeq ("$(origin C)", "command line")
  KBUILD_CHECKSRC = $(C)
endif
ifndef KBUILD_CHECKSRC
  KBUILD_CHECKSRC = 0
endif

# Use make M=dir to specify directory of external module to build
# Old syntax make ... SUBDIRS=$PWD is still supported
# Setting the environment variable KBUILD_EXTMOD take precedence
ifdef SUBDIRS
  KBUILD_EXTMOD ?= $(SUBDIRS)
endif

ifeq ("$(origin M)", "command line")
  KBUILD_EXTMOD := $(M)
endif

# If building an external module we do not care about the all: rule
# but instead _all depend on modules
PHONY += all
ifeq ($(KBUILD_EXTMOD),)
_all: all
else
_all: modules
endif

ifeq ($(KBUILD_SRC),)
        # building in the source tree
        srctree := .
else
        ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
                # building in a subdirectory of the source tree
                srctree := ..
        else
                srctree := $(KBUILD_SRC)
        endif
endif
objtree		:= .
src		:= $(srctree)
obj		:= $(objtree)

VPATH		:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))

export srctree objtree VPATH

# Make sure CDPATH settings don't interfere
unexport CDPATH

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

HOSTARCH := $(shell uname -m | \
	sed -e s/i.86/x86/ \
	    -e s/sun4u/sparc64/ \
	    -e s/arm.*/arm/ \
	    -e s/sa110/arm/ \
	    -e s/ppc64/powerpc/ \
	    -e s/ppc/powerpc/ \
	    -e s/macppc/powerpc/\
	    -e s/sh.*/sh/)

HOSTOS := $(shell uname -s | tr '[:upper:]' '[:lower:]' | \
	    sed -e 's/\(cygwin\).*/cygwin/')

export	HOSTARCH HOSTOS

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

# set default to nothing for native builds
ifeq ($(HOSTARCH),$(ARCH))
CROSS_COMPILE ?=
endif

KCONFIG_CONFIG	?= .config
export KCONFIG_CONFIG

# SHELL used by kbuild
CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
	  else if [ -x /bin/bash ]; then echo /bin/bash; \
	  else echo sh; fi ; fi)

HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)

HOSTCC       = cc
HOSTCXX      = c++
KBUILD_HOSTCFLAGS   := -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer \
		$(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)

# With the move to GCC 6, we have implicitly upgraded our language
# standard to GNU11 (see https://gcc.gnu.org/gcc-5/porting_to.html).
# Some Linux distributions (including RHEL7, SLES13, Debian 8) still
# have older compilers as their default, so we make it explicit for
# these that our host tools are GNU11 (i.e. C11 w/ GNU extensions).
CSTD_FLAG := -std=gnu11
ifeq ($(HOSTOS),linux)
KBUILD_HOSTCFLAGS += $(CSTD_FLAG)
endif

ifeq ($(HOSTOS),cygwin)
KBUILD_HOSTCFLAGS	+= -ansi
endif

# 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 ;)

os_x_after = $(shell if [ $(DARWIN_MAJOR_VERSION) -ge $(1) -a \
	$(DARWIN_MINOR_VERSION) -ge $(2) ] ; then echo "$(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")
KBUILD_HOSTCFLAGS  += $(call os_x_before, 10, 4, "-traditional-cpp")
KBUILD_HOSTLDFLAGS += $(call os_x_before, 10, 5, "-multiply_defined suppress")

# since Lion (10.7) ASLR is on by default, but we use linker generated lists
# in some host tools which is a problem then ... so disable ASLR for these
# tools
KBUILD_HOSTLDFLAGS += $(call os_x_before, 10, 7, "", "-Xlinker -no_pie")

# macOS Mojave (10.14.X) 
# Undefined symbols for architecture x86_64: "_PyArg_ParseTuple"
KBUILD_HOSTLDFLAGS += $(call os_x_after, 10, 14, "-lpython -dynamclib", "")
endif

# Decide whether to build built-in, modular, or both.
# Normally, just do built-in.

KBUILD_MODULES :=
KBUILD_BUILTIN := 1

# If we have only "make modules", don't compile built-in objects.
# When we're building modules with modversions, we need to consider
# the built-in objects during the descend as well, in order to
# make sure the checksums are up to date before we record them.

ifeq ($(MAKECMDGOALS),modules)
  KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
endif

# If we have "make <whatever> modules", compile modules
# in addition to whatever we do anyway.
# Just "make" or "make all" shall build modules as well

# U-Boot does not need modules
#ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
#  KBUILD_MODULES := 1
#endif

#ifeq ($(MAKECMDGOALS),)
#  KBUILD_MODULES := 1
#endif

# Check ths size of a binary:
# Args:
#   $1: File to check
#   #2: Size limit in bytes (decimal or 0xhex)
define size_check
	actual=$$( wc -c $1 | awk '{print $$1}'); \
	limit=$$( printf "%d" $2 ); \
	if test $$actual -gt $$limit; then \
		echo "$1 exceeds file size limit:" >&2; \
		echo "  limit:  $$(printf %#x $$limit) bytes" >&2; \
		echo "  actual: $$(printf %#x $$actual) bytes" >&2; \
		echo "  excess: $$(printf %#x $$((actual - limit))) bytes" >&2;\
		exit 1; \
	fi
endef
export size_check

export KBUILD_MODULES KBUILD_BUILTIN
export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD

# We need some generic definitions (do not try to remake the file).
scripts/Kbuild.include: ;
include scripts/Kbuild.include

# Make variables (CC, etc...)

AS		= $(CROSS_COMPILE)as
# Always use GNU ld
ifneq ($(shell $(CROSS_COMPILE)ld.bfd -v 2> /dev/null),)
LD		= $(CROSS_COMPILE)ld.bfd
else
LD		= $(CROSS_COMPILE)ld
endif
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
LEX		= flex
YACC		= bison
AWK		= awk
PERL		= perl
PYTHON		?= python
PYTHON2		= python2
PYTHON3		= python3
DTC		?= $(objtree)/scripts/dtc/dtc
CHECK		= sparse

CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
		  -Wbitwise -Wno-return-void -D__CHECK_ENDIAN__ $(CF)

KBUILD_CPPFLAGS := -D__KERNEL__ -D__UBOOT__

KBUILD_CFLAGS   := -Wall -Wstrict-prototypes \
		   -Wno-format-security \
		   -fno-builtin -ffreestanding $(CSTD_FLAG)
KBUILD_CFLAGS	+= -fshort-wchar -fno-strict-aliasing
KBUILD_AFLAGS   := -D__ASSEMBLY__
KBUILD_LDFLAGS  :=

ifeq ($(cc-name),clang)
ifneq ($(CROSS_COMPILE),)
CLANG_TARGET	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
CLANG_PREFIX	:= --prefix=$(GCC_TOOLCHAIN_DIR)
GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)
endif
ifneq ($(GCC_TOOLCHAIN),)
CLANG_GCC_TC	:= --gcc-toolchain=$(GCC_TOOLCHAIN)
endif
KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
endif

# Don't generate position independent code
KBUILD_CFLAGS	+= $(call cc-option,-fno-PIE)
KBUILD_AFLAGS	+= $(call cc-option,-fno-PIE)

# Read UBOOTRELEASE from include/config/uboot.release (if it exists)
UBOOTRELEASE = $(shell cat include/config/uboot.release 2> /dev/null)
UBOOTVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)

export VERSION PATCHLEVEL SUBLEVEL UBOOTRELEASE UBOOTVERSION
export ARCH CPU BOARD VENDOR SOC CPUDIR BOARDDIR
export CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
export CPP AR NM LDR STRIP OBJCOPY OBJDUMP KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
export MAKE LEX YACC AWK PERL PYTHON PYTHON2 PYTHON3
export HOSTCXX KBUILD_HOSTCXXFLAGS CHECK CHECKFLAGS DTC DTC_FLAGS

export KBUILD_CPPFLAGS NOSTDINC_FLAGS UBOOTINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
export KBUILD_CFLAGS KBUILD_AFLAGS

export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1)

# When compiling out-of-tree modules, put MODVERDIR in the module
# tree rather than in the kernel tree. The kernel tree might
# even be read-only.
export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions

# Files to ignore in find ... statements

export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
			  -prune -o
export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
			 --exclude CVS --exclude .pc --exclude .hg --exclude .git

# ===========================================================================
# Rules shared between *config targets and build targets

# Basic helpers built in scripts/
PHONY += scripts_basic
scripts_basic:
	$(Q)$(MAKE) $(build)=scripts/basic
	$(Q)rm -f .tmp_quiet_recordmcount

# To avoid any implicit rule to kick in, define an empty command.
scripts/basic/%: scripts_basic ;

PHONY += outputmakefile
# outputmakefile generates a Makefile in the output directory, if using a
# separate output directory. This allows convenient use of make in the
# output directory.
outputmakefile:
ifneq ($(KBUILD_SRC),)
	$(Q)ln -fsn $(srctree) source
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
	    $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
endif

# To make sure we do not include .config for any of the *config targets
# catch them early, and hand them over to scripts/kconfig/Makefile
# It is allowed to specify more targets when calling make, including
# mixing *config targets and build targets.
# For example 'make oldconfig all'.
# Detect when mixed targets is specified, and make a second invocation
# of make so .config is not included in this case either (for *config).

version_h := include/generated/version_autogenerated.h
timestamp_h := include/generated/timestamp_autogenerated.h
defaultenv_h := include/generated/defaultenv_autogenerated.h
dt_h := include/generated/dt.h

no-dot-config-targets := clean clobber mrproper distclean \
			 help %docs check% coccicheck \
			 ubootversion backup tests check qcheck tcheck

config-targets := 0
mixed-targets  := 0
dot-config     := 1

ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
		dot-config := 0
	endif
endif

ifeq ($(KBUILD_EXTMOD),)
        ifneq ($(filter config %config,$(MAKECMDGOALS)),)
                config-targets := 1
                ifneq ($(words $(MAKECMDGOALS)),1)
                        mixed-targets := 1
                endif
        endif
endif

ifeq ($(mixed-targets),1)
# ===========================================================================
# We're called with mixed targets (*config and build targets).
# Handle them one by one.

PHONY += $(MAKECMDGOALS) __build_one_by_one

$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
	@:

__build_one_by_one:
	$(Q)set -e; \
	for i in $(MAKECMDGOALS); do \
		$(MAKE) -f $(srctree)/Makefile $$i; \
	done

else
ifeq ($(config-targets),1)
# ===========================================================================
# *config targets only - make sure prerequisites are updated, and descend
# in scripts/kconfig to make the *config target

KBUILD_DEFCONFIG := sandbox_defconfig
export KBUILD_DEFCONFIG KBUILD_KCONFIG

config: scripts_basic outputmakefile FORCE
	$(Q)$(MAKE) $(build)=scripts/kconfig $@

%config: scripts_basic outputmakefile FORCE
	$(Q)$(MAKE) $(build)=scripts/kconfig $@

else
# ===========================================================================
# Build targets only - this includes vmlinux, arch specific targets, clean
# targets and others. In general all targets except *config targets.

# Additional helpers built in scripts/
# Carefully list dependencies so we do not try to build scripts twice
# in parallel
PHONY += scripts
scripts: scripts_basic include/config/auto.conf
	$(Q)$(MAKE) $(build)=$(@)

ifeq ($(dot-config),1)
# Read in config
-include include/config/auto.conf

# Read in dependencies to all Kconfig* files, make sure to run
# oldconfig if changes are detected.
-include include/config/auto.conf.cmd

# To avoid any implicit rule to kick in, define an empty command
$(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;

# If .config is newer than include/config/auto.conf, someone tinkered
# with it and forgot to run make oldconfig.
# if auto.conf.cmd is missing then we are probably in a cleaned tree so
# we execute the config step to be sure to catch updated Kconfig files
include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
	@# If the following part fails, include/config/auto.conf should be
	@# deleted so "make silentoldconfig" will be re-run on the next build.
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.autoconf || \
		{ rm -f include/config/auto.conf; false; }
	@# include/config.h has been updated after "make silentoldconfig".
	@# We need to touch include/config/auto.conf so it gets newer
	@# than include/config.h.
	@# Otherwise, 'make silentoldconfig' would be invoked twice.
	$(Q)touch include/config/auto.conf

u-boot.cfg spl/u-boot.cfg tpl/u-boot.cfg:
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.autoconf $(@)

-include include/autoconf.mk
-include include/autoconf.mk.dep

# We want to include arch/$(ARCH)/config.mk only when include/config/auto.conf
# is up-to-date. When we switch to a different board configuration, old CONFIG
# macros are still remaining in include/config/auto.conf. Without the following
# gimmick, wrong config.mk would be included leading nasty warnings/errors.
ifneq ($(wildcard $(KCONFIG_CONFIG)),)
ifneq ($(wildcard include/config/auto.conf),)
autoconf_is_old := $(shell find . -path ./$(KCONFIG_CONFIG) -newer \
						include/config/auto.conf)
ifeq ($(autoconf_is_old),)
include config.mk
include arch/$(ARCH)/Makefile
endif
endif
endif

# These are set by the arch-specific config.mk. Make sure they are exported
# so they can be used when building an EFI application.
export EFI_LDS		# Filename of EFI link script in arch/$(ARCH)/lib
export EFI_CRT0		# Filename of EFI CRT0 in arch/$(ARCH)/lib
export EFI_RELOC	# Filename of EFU relocation code in arch/$(ARCH)/lib
export CFLAGS_EFI	# Compiler flags to add when building EFI app
export CFLAGS_NON_EFI	# Compiler flags to remove when building EFI app
export EFI_TARGET	# binutils target if EFI is natively supported

# If board code explicitly specified LDSCRIPT or CONFIG_SYS_LDSCRIPT, use
# that (or fail if absent).  Otherwise, search for a linker script in a
# standard location.

ifndef LDSCRIPT
	#LDSCRIPT := $(srctree)/board/$(BOARDDIR)/u-boot.lds.debug
	ifdef CONFIG_SYS_LDSCRIPT
		# need to strip off double quotes
		LDSCRIPT := $(srctree)/$(CONFIG_SYS_LDSCRIPT:"%"=%)
	endif
endif

# If there is no specified link script, we look in a number of places for it
ifndef LDSCRIPT
	ifeq ($(wildcard $(LDSCRIPT)),)
		LDSCRIPT := $(srctree)/board/$(BOARDDIR)/u-boot.lds
	endif
	ifeq ($(wildcard $(LDSCRIPT)),)
		LDSCRIPT := $(srctree)/$(CPUDIR)/u-boot.lds
	endif
	ifeq ($(wildcard $(LDSCRIPT)),)
		LDSCRIPT := $(srctree)/arch/$(ARCH)/cpu/u-boot.lds
	endif
endif

else
# Dummy target needed, because used as prerequisite
include/config/auto.conf: ;
endif # $(dot-config)

#
# Xtensa linker script cannot be preprocessed with -ansi because of
# preprocessor operations on strings that don't make C identifiers.
#
ifeq ($(CONFIG_XTENSA),)
LDPPFLAGS	+= -ansi
endif

ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
KBUILD_CFLAGS	+= -Os
else
KBUILD_CFLAGS	+= -O2
endif

KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks)

# disable stringop warnings in gcc 8+
KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)

# Enabled with W=2, disabled by default as noisy
KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)

# change __FILE__ to the relative path from the srctree
KBUILD_CFLAGS	+= $(call cc-option,-fmacro-prefix-map=$(srctree)/=)

KBUILD_CFLAGS	+= -g
# $(KBUILD_AFLAGS) sets -g, which causes gcc to pass a suitable -g<format>
# option to the assembler.
KBUILD_AFLAGS	+= -g

# Report stack usage if supported
# ARC tools based on GCC 7.1 has an issue with stack usage
# with naked functions, see commit message for more details
ifndef CONFIG_ARC
ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-stack-usage.sh $(CC)),y)
	KBUILD_CFLAGS += -fstack-usage
endif
endif

KBUILD_CFLAGS += $(call cc-option,-Wno-format-nonliteral)
KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)

ifeq ($(cc-name),clang)
KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
# Quiet clang warning: comparison of unsigned expression < 0 is always false
KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
# source of a reference will be _MergedGlobals and not on of the whitelisted names.
# See modpost pattern 2
KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
else

# These warnings generated too much noise in a regular build.
# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
endif

# Prohibit date/time macros, which would make the build non-deterministic
KBUILD_CFLAGS   += $(call cc-option,-Werror=date-time)

include scripts/Makefile.extrawarn

# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
KBUILD_CPPFLAGS += $(KCPPFLAGS)
KBUILD_AFLAGS += $(KAFLAGS)
KBUILD_CFLAGS += $(KCFLAGS)

KBUILD_HOSTCFLAGS += $(if $(CONFIG_TOOLS_DEBUG),-g)

# Use UBOOTINCLUDE when you must reference the include/ directory.
# Needed to be compatible with the O= option
UBOOTINCLUDE    := \
	-Iinclude \
	$(if $(KBUILD_SRC), -I$(srctree)/include) \
	$(if $(CONFIG_$(SPL_)SYS_THUMB_BUILD), \
		$(if $(CONFIG_HAS_THUMB2), \
			$(if $(CONFIG_CPU_V7M), \
				-I$(srctree)/arch/arm/thumb1/include), \
			-I$(srctree)/arch/arm/thumb1/include)) \
	-I$(srctree)/arch/$(ARCH)/include \
	-include $(srctree)/include/linux/kconfig.h

NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)

# FIX ME
cpp_flags := $(KBUILD_CPPFLAGS) $(PLATFORM_CPPFLAGS) $(UBOOTINCLUDE) \
							$(NOSTDINC_FLAGS)
c_flags := $(KBUILD_CFLAGS) $(cpp_flags)

#########################################################################
# U-Boot objects....order is important (i.e. start must be first)

HAVE_VENDOR_COMMON_LIB = $(if $(wildcard $(srctree)/board/$(VENDOR)/common/Makefile),y,n)

libs-y += lib/
libs-$(HAVE_VENDOR_COMMON_LIB) += board/$(VENDOR)/common/
libs-$(CONFIG_OF_EMBED) += dts/
libs-y += fs/
libs-y += net/
libs-y += disk/
libs-y += drivers/
libs-y += drivers/dma/
libs-y += drivers/gpio/
libs-y += drivers/i2c/
libs-y += drivers/net/
libs-y += drivers/net/phy/
libs-y += drivers/power/ \
	drivers/power/domain/ \
	drivers/power/fuel_gauge/ \
	drivers/power/mfd/ \
	drivers/power/pmic/ \
	drivers/power/battery/ \
	drivers/power/regulator/
libs-y += drivers/spi/
libs-$(CONFIG_FMAN_ENET) += drivers/net/fm/
libs-$(CONFIG_SYS_FSL_DDR) += drivers/ddr/fsl/
libs-$(CONFIG_SYS_FSL_MMDC) += drivers/ddr/fsl/
libs-$(CONFIG_$(SPL_)ALTERA_SDRAM) += drivers/ddr/altera/
libs-y += drivers/serial/
libs-y += drivers/usb/cdns3/
libs-y += drivers/usb/dwc3/
libs-y += drivers/usb/common/
libs-y += drivers/usb/emul/
libs-y += drivers/usb/eth/
libs-$(CONFIG_USB_GADGET) += drivers/usb/gadget/
libs-$(CONFIG_USB_GADGET) += drivers/usb/gadget/udc/
libs-y += drivers/usb/host/
libs-y += drivers/usb/musb/
libs-y += drivers/usb/musb-new/
libs-y += drivers/usb/phy/
libs-y += drivers/usb/ulpi/
libs-y += cmd/
libs-y += common/
libs-y += env/
libs-$(CONFIG_API) += api/
ifdef CONFIG_POST
libs-y += post/
endif
libs-$(CONFIG_UNIT_TEST) += test/ test/dm/
libs-$(CONFIG_UT_ENV) += test/env/
libs-$(CONFIG_UT_OPTEE) += test/optee/
libs-$(CONFIG_UT_OVERLAY) += test/overlay/

libs-y += $(if $(BOARDDIR),board/$(BOARDDIR)/)

libs-y := $(sort $(libs-y))

u-boot-dirs	:= $(patsubst %/,%,$(filter %/, $(libs-y))) tools examples

u-boot-alldirs	:= $(sort $(u-boot-dirs) $(patsubst %/,%,$(filter %/, $(libs-))))

libs-y		:= $(patsubst %/, %/built-in.o, $(libs-y))

u-boot-init := $(head-y)
u-boot-main := $(libs-y)


# Add GCC lib
ifeq ($(CONFIG_USE_PRIVATE_LIBGCC),y)
PLATFORM_LIBGCC = arch/$(ARCH)/lib/lib.a
else
PLATFORM_LIBGCC := -L $(shell dirname `$(CC) $(c_flags) -print-libgcc-file-name`) -lgcc
endif
PLATFORM_LIBS += $(PLATFORM_LIBGCC)

ifdef CONFIG_CC_COVERAGE
KBUILD_CFLAGS += --coverage
PLATFORM_LIBGCC += -lgcov
endif

export PLATFORM_LIBS
export PLATFORM_LIBGCC

# Special flags for CPP when processing the linker script.
# Pass the version down so we can handle backwards compatibility
# on the fly.
LDPPFLAGS += \
	-include $(srctree)/include/u-boot/u-boot.lds.h \
	-DCPUDIR=$(CPUDIR) \
	$(shell $(LD) --version | \
	  sed -ne 's/GNU ld version \([0-9][0-9]*\)\.\([0-9][0-9]*\).*/-DLD_MAJOR=\1 -DLD_MINOR=\2/p')

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

ifneq ($(CONFIG_BOARD_SIZE_LIMIT),)
BOARD_SIZE_CHECK= @ $(call size_check,$@,$(CONFIG_BOARD_SIZE_LIMIT))
else
BOARD_SIZE_CHECK =
endif

ifneq ($(CONFIG_SPL_SIZE_LIMIT),0)
SPL_SIZE_CHECK = @$(call size_check,$@,$$(tools/spl_size_limit))
else
SPL_SIZE_CHECK =
endif

ifneq ($(CONFIG_TPL_SIZE_LIMIT),0)
TPL_SIZE_CHECK = @$(call size_check,$@,$(CONFIG_TPL_SIZE_LIMIT))
else
TPL_SIZE_CHECK =
endif

# Statically apply RELA-style relocations (currently arm64 only)
# This is useful for arm64 where static relocation needs to be performed on
# the raw binary, but certain simulators only accept an ELF file (but don't
# do the relocation).
ifneq ($(CONFIG_STATIC_RELA),)
# $(1) is u-boot ELF, $(2) is u-boot bin, $(3) is text base
quiet_cmd_static_rela = RELOC   $@
cmd_static_rela = \
	start=$$($(NM) $(2) | grep __rel_dyn_start | cut -f 1 -d ' '); \
	end=$$($(NM) $(2) | grep __rel_dyn_end | cut -f 1 -d ' '); \
	tools/relocate-rela $(3) $(4) $$start $$end
else
quiet_cmd_static_rela =
cmd_static_rela =
endif

# Always append INPUTS so that arch config.mk's can add custom ones
INPUTS-y += u-boot.srec u-boot.bin u-boot.sym System.map binary_size_check

INPUTS-$(CONFIG_ONENAND_U_BOOT) += u-boot-onenand.bin
ifeq ($(CONFIG_SPL_FSL_PBL),y)
INPUTS-$(CONFIG_RAMBOOT_PBL) += u-boot-with-spl-pbl.bin
else
ifneq ($(CONFIG_NXP_ESBC), y)
# For Secure Boot The Image needs to be signed and Header must also
# be included. So The image has to be built explicitly
INPUTS-$(CONFIG_RAMBOOT_PBL) += u-boot.pbl
endif
endif
INPUTS-$(CONFIG_SPL) += spl/u-boot-spl.bin
ifeq ($(CONFIG_MX6)$(CONFIG_IMX_HAB), yy)
INPUTS-$(CONFIG_SPL_FRAMEWORK) += u-boot-ivt.img
else
ifeq ($(CONFIG_MX7)$(CONFIG_IMX_HAB), yy)
INPUTS-$(CONFIG_SPL_FRAMEWORK) += u-boot-ivt.img
else
INPUTS-$(CONFIG_SPL_FRAMEWORK) += u-boot.img
endif
endif
INPUTS-$(CONFIG_TPL) += tpl/u-boot-tpl.bin
INPUTS-$(CONFIG_OF_SEPARATE) += u-boot.dtb
ifeq ($(CONFIG_SPL_FRAMEWORK),y)
INPUTS-$(CONFIG_OF_SEPARATE) += u-boot-dtb.img
endif
INPUTS-$(CONFIG_OF_HOSTFILE) += u-boot.dtb
ifneq ($(CONFIG_SPL_TARGET),)
INPUTS-$(CONFIG_SPL) += $(CONFIG_SPL_TARGET:"%"=%)
endif
INPUTS-$(CONFIG_REMAKE_ELF) += u-boot.elf
INPUTS-$(CONFIG_EFI_APP) += u-boot-app.efi
INPUTS-$(CONFIG_EFI_STUB) += u-boot-payload.efi

# Build a combined spl + u-boot image for sunxi
ifeq ($(CONFIG_ARCH_SUNXI)$(CONFIG_ARM64)$(CONFIG_SPL),yyy)
INPUTS-y += u-boot-sunxi-with-spl.bin
endif

# Generate this input file for binman
ifeq ($(CONFIG_SPL),)
INPUTS-$(CONFIG_ARCH_MEDIATEK) += u-boot-mtk.bin
endif

# Add optional build target if defined in board/cpu/soc headers
ifneq ($(CONFIG_BUILD_TARGET),)
INPUTS-y += $(CONFIG_BUILD_TARGET:"%"=%)
endif

ifeq ($(CONFIG_INIT_SP_RELATIVE)$(CONFIG_OF_SEPARATE),yy)
INPUTS-y += init_sp_bss_offset_check
endif

ifeq ($(CONFIG_MPC85xx)$(CONFIG_OF_SEPARATE),yy)
INPUTS-y += u-boot-with-dtb.bin
endif

ifeq ($(CONFIG_ARCH_ROCKCHIP),y)
# On ARM64 this target is produced by binman so we don't need this dep
ifeq ($(CONFIG_ARM64),y)
ifeq ($(CONFIG_SPL),y)
# TODO: Get binman to generate this too
INPUTS-y += u-boot-rockchip.bin
endif
else
ifeq ($(CONFIG_SPL),y)
# Generate these inputs for binman which will create the output files
INPUTS-y += idbloader.img u-boot.img
endif
endif
endif

INPUTS-$(CONFIG_X86) += u-boot-x86-start16.bin u-boot-x86-reset16.bin \
	$(if $(CONFIG_SPL_X86_16BIT_INIT),spl/u-boot-spl.bin) \
	$(if $(CONFIG_TPL_X86_16BIT_INIT),tpl/u-boot-tpl.bin)

LDFLAGS_u-boot += $(LDFLAGS_FINAL)

# Avoid 'Not enough room for program headers' error on binutils 2.28 onwards.
LDFLAGS_u-boot += $(call ld-option, --no-dynamic-linker)

ifeq ($(CONFIG_ARC)$(CONFIG_NIOS2)$(CONFIG_X86)$(CONFIG_XTENSA),)
LDFLAGS_u-boot += -Ttext $(CONFIG_SYS_TEXT_BASE)
endif

# insure the checker run with the right endianness
CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)

# the checker needs the correct machine size
CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)

# Normally we fill empty space with 0xff
quiet_cmd_objcopy = OBJCOPY $@
cmd_objcopy = $(OBJCOPY) --gap-fill=0xff $(OBJCOPYFLAGS) \
	$(OBJCOPYFLAGS_$(@F)) $< $@

# Provide a version which does not do this, for use by EFI
quiet_cmd_zobjcopy = OBJCOPY $@
cmd_zobjcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@

quiet_cmd_efipayload = OBJCOPY $@
cmd_efipayload = $(OBJCOPY) -I binary -O $(EFIPAYLOAD_BFDTARGET) -B $(EFIPAYLOAD_BFDARCH) $< $@

MKIMAGEOUTPUT ?= /dev/null

quiet_cmd_mkimage = MKIMAGE $@
cmd_mkimage = $(objtree)/tools/mkimage $(MKIMAGEFLAGS_$(@F)) -d $< $@ \
	>$(MKIMAGEOUTPUT) $(if $(KBUILD_VERBOSE:0=), && cat $(MKIMAGEOUTPUT))