Merge patch series "kbuild: Update Makefile.extrawarn to 5.1"

This series from Ilias Apalodimas <ilias.apalodimas@linaro.org> largely
finishes the re-sync with the Linux Kernel v5.1 kbuild system.

Link: https://lore.kernel.org/r/20250627185723.342553-1-ilias.apalodimas@linaro.org

1 files changed, 546 insertions, 312 deletions

diff --git a/Makefile b/Makefile
index fa9ce756083..da53efa09f1 100644
--- a/Makefile
+++ b/Makefile
@@ -12,6 +12,10 @@ NAME =
 # Comments in this file are targeted only to the developer, do not
 # expect to learn how to build the kernel reading this file.
 
+# That's our default target when none is given on the command line
+PHONY := _all
+_all:
+
 # Determine target architecture for the sandbox
 include include/host_arch.h
 ifeq ("", "$(CROSS_COMPILE)")
@@ -41,7 +45,7 @@ undefine MK_ARCH
 # 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
+# unavoidable when linking the built-in.a 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.
@@ -109,7 +113,6 @@ 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_
@@ -137,8 +140,8 @@ export quiet Q KBUILD_VERBOSE
 # 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)
+# KBUILD_SRC is not intended to be used by the regular user (for now),
+# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
 
 # OK, Make called in directory where kernel src resides
 # Do we want to locate output files in a separate directory?
@@ -146,19 +149,15 @@ 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
-$(CURDIR)/Makefile Makefile: ;
+ifneq ($(words $(subst :, ,$(CURDIR))), 1)
+  $(error main directory cannot contain spaces nor colons)
+endif
 
 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)
+								&& pwd)
 $(if $(KBUILD_OUTPUT),, \
      $(error failed to create output directory "$(saved-output)"))
 
@@ -169,6 +168,7 @@ $(if $(KBUILD_OUTPUT),, \
 # 'sub-make' below.
 MAKEFLAGS += --include-dir=$(CURDIR)
 
+need-sub-make := 1
 else
 
 # Do not print "Entering directory ..." at all for in-tree build.
@@ -176,19 +176,34 @@ MAKEFLAGS += --no-print-directory
 
 endif # ifneq ($(KBUILD_OUTPUT),)
 
+ifneq ($(filter 3.%,$(MAKE_VERSION)),)
+# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
+# We need to invoke sub-make to avoid implicit rules in the top Makefile.
+need-sub-make := 1
+# Cancel implicit rules for this Makefile.
+$(lastword $(MAKEFILE_LIST)): ;
+endif
+
 export sub_make_done := 1
+
+ifeq ($(need-sub-make),1)
+
 PHONY += $(MAKECMDGOALS) sub-make
 
 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
 	@:
 
-sub-make: FORCE
+# Invoke a second make in the output directory, passing relevant variables
+sub-make:
 	$(Q)$(MAKE) \
 	$(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
 	-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
 
-else # sub_make_done
+endif # need-sub-make
+endif # sub_make_done
+
 # We process the rest of the Makefile if this is the final invocation of make
+ifeq ($(need-sub-make),)
 
 # Do not print "Entering directory ...",
 # but we want to display it when entering to the output directory
@@ -202,8 +217,8 @@ MAKEFLAGS += --no-print-directory
 # 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.
+# See the file "Documentation/dev-tools/sparse.rst" for more details,
+# including where to get the "sparse" utility.
 
 ifeq ("$(origin C)", "command line")
   KBUILD_CHECKSRC = $(C)
@@ -216,6 +231,10 @@ endif
 # Old syntax make ... SUBDIRS=$PWD is still supported
 # Setting the environment variable KBUILD_EXTMOD take precedence
 ifdef SUBDIRS
+  $(warning ================= WARNING ================)
+  $(warning 'SUBDIRS' will be removed after Linux 5.3)
+  $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead)
+  $(warning ==========================================)
   KBUILD_EXTMOD ?= $(SUBDIRS)
 endif
 
@@ -223,18 +242,6 @@ 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
-PHONY += prepare
-prepare:
-	$(cmd_crmodverdir)
-endif
-
 ifeq ($(KBUILD_SRC),)
         # building in the source tree
         srctree := .
@@ -246,132 +253,177 @@ else
                 srctree := $(KBUILD_SRC)
         endif
 endif
+
+export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
+
 objtree		:= .
 src		:= $(srctree)
 obj		:= $(objtree)
 
-VPATH		:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
+VPATH		:= $(srctree)
 
 export srctree objtree VPATH
 
-# Make sure CDPATH settings don't interfere
-unexport CDPATH
+# 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
+env_h := include/generated/environment.h
 
-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/)
+clean-targets := %clean mrproper cleandocs
+no-dot-config-targets := $(clean-targets) \
+			 clobber distclean \
+			 help %docs check% coccicheck \
+			 ubootversion backup tests check pcheck qcheck tcheck \
+			 pylint pylint_err _pip pip pip_test pip_release
+no-sync-config-targets := $(no-dot-config-targets) install %install \
+			   kernelrelease
 
-HOSTOS := $(shell uname -s | tr '[:upper:]' '[:lower:]' | \
-	    sed -e 's/\(cygwin\).*/cygwin/')
+config-targets  := 0
+mixed-targets   := 0
+dot-config      := 1
+may-sync-config := 1
 
-export	HOSTARCH HOSTOS
+ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
+	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
+		dot-config := 0
+	endif
+endif
 
-#########################################################################
+ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
+	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
+		may-sync-config := 0
+	endif
+endif
 
-# set default to nothing for native builds
-ifeq ($(HOSTARCH),$(ARCH))
-CROSS_COMPILE ?=
+ifneq ($(KBUILD_EXTMOD),)
+	may-sync-config := 0
 endif
 
-KCONFIG_CONFIG	?= .config
-export KCONFIG_CONFIG
+ifeq ($(KBUILD_EXTMOD),)
+        ifneq ($(filter config %config,$(MAKECMDGOALS)),)
+                config-targets := 1
+                ifneq ($(words $(MAKECMDGOALS)),1)
+                        mixed-targets := 1
+                endif
+        endif
+endif
 
-# 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)
+# For "make -j clean all", "make -j mrproper defconfig all", etc.
+ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
+        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
+                mixed-targets := 1
+        endif
+endif
 
-HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
-HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
-HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
+# install and modules_install need also be processed one by one
+ifneq ($(filter install,$(MAKECMDGOALS)),)
+        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
+	        mixed-targets := 1
+        endif
+endif
 
-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) $(HOSTLDLIBS)
+ifeq ($(mixed-targets),1)
+# ===========================================================================
+# We're called with mixed targets (*config and build targets).
+# Handle them one by one.
 
-# 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
-KBUILD_HOSTCFLAGS += $(CSTD_FLAG)
+PHONY += $(MAKECMDGOALS) __build_one_by_one
 
-ifeq ($(HOSTOS),cygwin)
-KBUILD_HOSTCFLAGS	+= -ansi
-endif
+$(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
+	@:
 
-# 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 '.')
+__build_one_by_one:
+	$(Q)set -e; \
+	for i in $(MAKECMDGOALS); do \
+		$(MAKE) -f $(srctree)/Makefile $$i; \
+	done
 
-os_x_before	= $(shell if [ $(DARWIN_MAJOR_VERSION) -le $(1) -a \
-	$(DARWIN_MINOR_VERSION) -le $(2) ] ; then echo "$(3)"; else echo "$(4)"; fi ;)
+else
 
-os_x_after = $(shell if [ $(DARWIN_MAJOR_VERSION) -ge $(1) -a \
-	$(DARWIN_MINOR_VERSION) -ge $(2) ] ; then echo "$(3)"; else echo "$(4)"; fi ;)
+include scripts/Kbuild.include
 
-# 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")
+# 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
 
-# macOS Mojave (10.14.X)
-# Undefined symbols for architecture x86_64: "_PyArg_ParseTuple"
-KBUILD_HOSTLDFLAGS += $(call os_x_after, 10, 14, "-lpython -dynamclib", "")
-endif
+# Modified for U-Boot
+-include scripts/subarch.include
 
-# Decide whether to build built-in, modular, or both.
-# Normally, just do built-in.
+# Cross compiling and selecting different set of gcc/bin-utils
+# ---------------------------------------------------------------------------
+#
+# When performing cross compilation for other architectures ARCH shall be set
+# to the target architecture. (See arch/* for the possibilities).
+# ARCH can be set during invocation of make:
+# make ARCH=ia64
+# Another way is to have ARCH set in the environment.
+# The default ARCH is the host where make is executed.
 
-KBUILD_MODULES :=
-KBUILD_BUILTIN := 1
+# CROSS_COMPILE specify the prefix used for all executables used
+# during compilation. Only gcc and related bin-utils executables
+# are prefixed with $(CROSS_COMPILE).
+# CROSS_COMPILE can be set on the command line
+# make CROSS_COMPILE=ia64-linux-
+# Alternatively CROSS_COMPILE can be set in the environment.
+# Default value for CROSS_COMPILE is not to prefix executables
+# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
+ARCH		?= $(SUBARCH)
 
-# 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.
+# Architecture as present in compile.h
+UTS_MACHINE 	:= $(ARCH)
+SRCARCH 	:= $(ARCH)
 
-ifeq ($(MAKECMDGOALS),modules)
-  KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
+# Additional ARCH settings for x86
+ifeq ($(ARCH),i386)
+        SRCARCH := x86
+endif
+ifeq ($(ARCH),x86_64)
+        SRCARCH := x86
 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
+# Additional ARCH settings for sparc
+ifeq ($(ARCH),sparc32)
+       SRCARCH := sparc
+endif
+ifeq ($(ARCH),sparc64)
+       SRCARCH := sparc
+endif
 
-# U-Boot does not need modules
-#ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
-#  KBUILD_MODULES := 1
-#endif
+# Additional ARCH settings for sh
+ifeq ($(ARCH),sh64)
+       SRCARCH := sh
+endif
 
-#ifeq ($(MAKECMDGOALS),)
-#  KBUILD_MODULES := 1
-#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       = gcc
+HOSTCXX      = g++
+KBUILD_HOSTCFLAGS   := -Wall -Wstrict-prototypes -O2 \
+		-fomit-frame-pointer -std=gnu11 $(HOST_LFS_CFLAGS) \
+		$(HOSTCFLAGS) #-Wmissing-prototypes Enable it and fix warnings
+KBUILD_HOSTCXXFLAGS := -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
+KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
+KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 
 # Check ths size of a binary:
 # Args:
@@ -393,19 +445,9 @@ 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
@@ -418,10 +460,12 @@ READELF		= $(CROSS_COMPILE)readelf
 LEX		= flex
 YACC		= bison
 AWK		= awk
+INSTALLKERNEL  := installkernel
+DEPMOD		= /sbin/depmod
 PERL		= perl
-PYTHON		?= python
+PYTHON		= python
 PYTHON2		= python2
-PYTHON3		?= python3
+PYTHON3		= python3
 
 # The devicetree compiler and pylibfdt are automatically built unless DTC is
 # provided. If DTC is provided, it is assumed the pylibfdt is available too.
@@ -432,51 +476,79 @@ DTC_MIN_VERSION	:= 010406
 CHECK		= sparse
 
 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-		  -Wbitwise -Wno-return-void -Wno-unknown-attribute \
-		  -D__CHECK_ENDIAN__ $(CF)
+		  -Wbitwise -Wno-return-void -Wno-unknown-attribute -D__CHECK_ENDIAN__ $(CF)
+NOSTDINC_FLAGS :=
+CFLAGS_MODULE   =
+AFLAGS_MODULE   =
+LDFLAGS_MODULE  =
+CFLAGS_KERNEL	=
+AFLAGS_KERNEL	=
+LDFLAGS_vmlinux =
+
+# Use USERINCLUDE when you must reference the UAPI directories only.
+USERINCLUDE    := \
+		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
+		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
+		-I$(srctree)/include/uapi \
+		-I$(objtree)/include/generated/uapi \
+                -include $(srctree)/include/linux/kconfig.h
 
-KBUILD_CPPFLAGS := -D__KERNEL__ -D__UBOOT__
-
-KBUILD_CFLAGS   := -Wall -Werror=strict-prototypes -Wno-trigraphs \
-		   -Wno-format-security \
-		   -fno-builtin -ffreestanding $(CSTD_FLAG) \
-		   -fno-PIE \
-		   -Werror=implicit-function-declaration -Werror=implicit-int
-KBUILD_CFLAGS	+= -fshort-wchar -fno-strict-aliasing
-KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
-KBUILD_LDFLAGS  :=
-
-ifeq ($(cc-name),clang)
-ifneq ($(CROSS_COMPILE),)
-CLANG_TARGET	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
-LDPPFLAGS	+= $(CLANG_TARGET)
-GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
-CLANG_PREFIX	:= --prefix=$(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
-
-# 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)
+# 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 $(CONFIG_$(XPL_)MBEDTLS_LIB), \
+		"-DMBEDTLS_CONFIG_FILE=\"mbedtls_def_config.h\"" \
+		-I$(srctree)/lib/mbedtls \
+		-I$(srctree)/lib/mbedtls/port \
+		-I$(srctree)/lib/mbedtls/external/mbedtls \
+		-I$(srctree)/lib/mbedtls/external/mbedtls/include) \
+	$(if $(CONFIG_$(PHASE_)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 $(srctree)/include/linux/kconfig.h \
+	-I$(srctree)/dts/upstream/include \
+	$(if $(CONFIG_NET_LWIP), -I$(srctree)/lib/lwip/lwip/src/include \
+		-I$(srctree)/lib/lwip/u-boot)
 
-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
+KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
+KBUILD_CFLAGS   := -Wall -Werror=strict-prototypes -Wno-trigraphs \
+		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
+		   -Werror=implicit-function-declaration -Werror=implicit-int \
+		   -Wno-format-security -std=gnu11 #-Wundef Enable it and fix warnings
+UBOOT_CFLAGS	:= -ffreestanding -fno-builtin
+KBUILD_CFLAGS	+= $(UBOOT_CFLAGS)
 
+KBUILD_CPPFLAGS := -D__KERNEL__ -D__UBOOT__
+KBUILD_AFLAGS_KERNEL :=
+KBUILD_CFLAGS_KERNEL :=
+KBUILD_AFLAGS_MODULE  := -DMODULE
+KBUILD_CFLAGS_MODULE  := -DMODULE
+KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
+KBUILD_LDFLAGS :=
+GCC_PLUGINS_CFLAGS :=
+
+export ARCH SRCARCH CONFIG_SHELL HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
+export CPP AR NM STRIP OBJCOPY OBJDUMP KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS
+export MAKE LEX YACC AWK INSTALLKERNEL PERL PYTHON PYTHON2 PYTHON3 UTS_MACHINE
+export HOSTCXX KBUILD_HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
+
+export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
+export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
+export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
+export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
+export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
+export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
+export KBUILD_ARFLAGS
+
+export LDR
+export CPU BOARD VENDOR SOC CPUDIR BOARDDIR
+export UBOOTINCLUDE
 export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1)
 
 # When compiling out-of-tree modules, put MODVERDIR in the module
@@ -504,15 +576,12 @@ endif
 # ===========================================================================
 # Rules shared between *config targets and build targets
 
-# Basic helpers built in scripts/
+# Basic helpers built in scripts/basic/
 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
@@ -524,71 +593,51 @@ ifneq ($(KBUILD_SRC),)
 	$(Q)ln -fsn $(srctree) source
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
 	$(Q)test -e .gitignore || \
-       	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
+	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 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
-env_h := include/generated/environment.h
-
-no-dot-config-targets := clean clobber mrproper distclean \
-			 help %docs check% coccicheck \
-			 ubootversion backup tests check pcheck qcheck tcheck \
-			 pylint pylint_err _pip pip pip_test pip_release
-
-config-targets := 0
-mixed-targets  := 0
-dot-config     := 1
-
-ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
-	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
-		dot-config := 0
-	endif
+ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
+ifneq ($(CROSS_COMPILE),)
+CLANG_FLAGS	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
+GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
+CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)
+GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)
 endif
-
-ifeq ($(KBUILD_EXTMOD),)
-        ifneq ($(filter config %config,$(MAKECMDGOALS)),)
-                config-targets := 1
-                ifneq ($(words $(MAKECMDGOALS)),1)
-                        mixed-targets := 1
-                endif
-        endif
+ifneq ($(GCC_TOOLCHAIN),)
+CLANG_FLAGS	+= --gcc-toolchain=$(GCC_TOOLCHAIN)
+endif
+CLANG_FLAGS	+= -no-integrated-as
+KBUILD_CFLAGS	+= $(CLANG_FLAGS)
+KBUILD_AFLAGS	+= $(CLANG_FLAGS)
+export CLANG_FLAGS
 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
-	@:
+RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
+RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
+RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
+RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
+RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
+RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
+export RETPOLINE_CFLAGS
+export RETPOLINE_VDSO_CFLAGS
 
-__build_one_by_one:
-	$(Q)set -e; \
-	for i in $(MAKECMDGOALS); do \
-		$(MAKE) -f $(srctree)/Makefile $$i; \
-	done
+# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
+# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
+# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
+# and from include/config/auto.conf.cmd to detect the compiler upgrade.
+CC_VERSION_TEXT = $(shell $(CC) --version | head -n 1)
 
-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
+# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
+# KBUILD_DEFCONFIG may point out an alternative default configuration
+# used for 'make defconfig'
+# Modified for U-Boot
+-include arch/$(SRCARCH)/Makefile
+export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 
 config: scripts_basic outputmakefile FORCE
 	$(Q)$(MAKE) $(build)=scripts/kconfig $@
@@ -601,29 +650,104 @@ 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 scripts_dtc include/config/auto.conf
-	$(Q)$(MAKE) $(build)=$(@)
+# If building an external module we do not care about the all: rule
+# but instead _all depend on modules
+PHONY += all
+ifeq ($(KBUILD_EXTMOD),)
+_all: all
+else
+_all: modules
+endif
+
+# Decide whether to build built-in, modular, or both.
+# Normally, just do built-in.
+
+KBUILD_MODULES :=
+KBUILD_BUILTIN := 1
+
+# If we have only "make modules", don't compile built-in objects.
+# When we're building modules with modversions, we need to consider
+# the built-in objects during the descend as well, in order to
+# make sure the checksums are up to date before we record them.
+
+ifeq ($(MAKECMDGOALS),modules)
+  KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
+endif
+
+# If we have "make <whatever> modules", compile modules
+# in addition to whatever we do anyway.
+# Just "make" or "make all" shall build modules as well
+
+ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
+  KBUILD_MODULES := 1
+endif
+
+ifeq ($(MAKECMDGOALS),)
+  KBUILD_MODULES := 1
+endif
+
+export KBUILD_MODULES KBUILD_BUILTIN
+
+ifeq ($(KBUILD_EXTMOD),)
+# Objects we will link into vmlinux / subdirs we need to visit
+init-y		:= init/
+drivers-y	:= drivers/ sound/
+net-y		:= net/
+libs-y		:= lib/
+core-y		:= usr/
+virt-y		:= virt/
+endif # KBUILD_EXTMOD
 
 ifeq ($(dot-config),1)
-# Read in config
+# Modified for U-Boot
 -include include/config/auto.conf
+endif
+
+# The all: target is the default when no target is given on the
+# command line.
+# This allow a user to issue only 'make' to build a kernel including modules
+# Defaults to vmlinux, but the arch makefile usually adds further targets
+all: u-boot
 
-# Read in dependencies to all Kconfig* files, make sure to run
-# oldconfig if changes are detected.
+CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage \
+	$(call cc-option,-fno-tree-loop-im) \
+	$(call cc-disable-warning,maybe-uninitialized,)
+export CFLAGS_GCOV
+
+# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
+ifdef CONFIG_FUNCTION_TRACER
+  CC_FLAGS_FTRACE := -pg
+endif
+
+# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
+# values of the respective KBUILD_* variables
+ARCH_CPPFLAGS :=
+ARCH_AFLAGS :=
+ARCH_CFLAGS :=
+# Modified for U-Boot
+-include arch/$(SRCARCH)/Makefile
+
+ifeq ($(dot-config),1)
+ifeq ($(may-sync-config),1)
+# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
+# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
+# because some architectures define CROSS_COMPILE there.
 -include include/config/auto.conf.cmd
 
-# To avoid any implicit rule to kick in, define an empty command
-$(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
+$(KCONFIG_CONFIG):
+	@echo >&2 '***'
+	@echo >&2 '*** Configuration file "$@" not found!'
+	@echo >&2 '***'
+	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
+	@echo >&2 '*** "make menuconfig" or "make xconfig").'
+	@echo >&2 '***'
+	@/bin/false
 
 # 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
+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.
@@ -698,10 +822,30 @@ ifndef LDSCRIPT
 endif
 
 else
-# Dummy target needed, because used as prerequisite
-include/config/auto.conf: ;
+# External modules and some install targets need include/generated/autoconf.h
+# and include/config/auto.conf but do not care if they are up-to-date.
+# Use auto.conf to trigger the test
+PHONY += include/config/auto.conf
+
+include/config/auto.conf:
+	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
+	echo >&2;							\
+	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
+	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
+	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
+	echo >&2 ;							\
+	/bin/false)
+
+endif # may-sync-config
 endif # $(dot-config)
 
+KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
+KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
+KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
+KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
+KBUILD_CFLAGS	+= $(call cc-disable-warning, int-in-bool-context)
+KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
+
 ifdef CONFIG_CC_OPTIMIZE_FOR_DEBUG
 KBUILD_HOSTCFLAGS   := -Wall -Wstrict-prototypes -Og -g -fomit-frame-pointer \
 		$(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
@@ -721,19 +865,19 @@ endif
 
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 KBUILD_CFLAGS	+= -Os
+else
+KBUILD_CFLAGS   += -O2
 endif
 
-ifdef CONFIG_CC_OPTIMIZE_FOR_SPEED
-KBUILD_CFLAGS	+= -O2
+ifdef CONFIG_CC_DISABLE_WARN_MAYBE_UNINITIALIZED
+KBUILD_CFLAGS   += -Wno-maybe-uninitialized
 endif
 
-ifdef CONFIG_CC_OPTIMIZE_FOR_DEBUG
-KBUILD_CFLAGS	+= -Og
-# Avoid false positives -Wmaybe-uninitialized
-# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78394
-KBUILD_CFLAGS	+= -Wno-maybe-uninitialized
-endif
+# Tell gcc to never replace conditional load with a non-conditional one
+KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
 
+include scripts/Makefile.kcov
+include scripts/Makefile.gcc-plugins
 LTO_CFLAGS :=
 LTO_FINAL_LDFLAGS :=
 export LTO_CFLAGS LTO_FINAL_LDFLAGS
@@ -768,12 +912,6 @@ KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
 endif
 KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks)
 
-# disable pointer signed / unsigned warnings in gcc 4.0
-KBUILD_CFLAGS += -Wno-pointer-sign
-
-# disable stringop warnings in gcc 8+
-KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
-
 KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
 KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
@@ -813,6 +951,11 @@ KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
 KBUILD_CFLAGS += $(call cc-disable-warning, deprecated-non-prototype)
+else
+
+# These warnings generated too much noise in a regular build.
+# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
+KBUILD_CFLAGS += -Wno-unused-but-set-variable
 endif
 
 # These warnings generated too much noise in a regular build.
@@ -864,6 +1007,7 @@ 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)
 
@@ -912,7 +1056,15 @@ 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))
+libs-y		:= $(patsubst %/, %/built-in.a, $(libs-y))
+# Not needed in U-Boot
+#init-y		:= $(patsubst %/, %/built-in.a, $(init-y))
+#core-y		:= $(patsubst %/, %/built-in.a, $(core-y))
+drivers-y	:= $(patsubst %/, %/built-in.a, $(drivers-y))
+#net-y		:= $(patsubst %/, %/built-in.a, $(net-y))
+libs-y1	:= $(patsubst %/, %/lib.a, $(libs-y))
+libs-y2	:= $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
+#virt-y		:= $(patsubst %/, %/built-in.a, $(virt-y))
 
 u-boot-init := $(head-y)
 u-boot-main := $(libs-y)
@@ -1031,6 +1183,37 @@ INPUTS-$(CONFIG_ARCH_MEDIATEK) += u-boot-mtk.bin
 endif
 endif
 
+ifdef CONFIG_FUNCTION_TRACER
+ifdef CONFIG_FTRACE_MCOUNT_RECORD
+  # gcc 5 supports generating the mcount tables directly
+  ifeq ($(call cc-option-yn,-mrecord-mcount),y)
+    CC_FLAGS_FTRACE	+= -mrecord-mcount
+    export CC_USING_RECORD_MCOUNT := 1
+  endif
+  ifdef CONFIG_HAVE_NOP_MCOUNT
+    ifeq ($(call cc-option-yn, -mnop-mcount),y)
+      CC_FLAGS_FTRACE	+= -mnop-mcount
+      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
+    endif
+  endif
+endif
+ifdef CONFIG_HAVE_FENTRY
+  ifeq ($(call cc-option-yn, -mfentry),y)
+    CC_FLAGS_FTRACE	+= -mfentry
+    CC_FLAGS_USING	+= -DCC_USING_FENTRY
+  endif
+endif
+export CC_FLAGS_FTRACE
+KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
+KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
+ifdef CONFIG_DYNAMIC_FTRACE
+	ifdef CONFIG_HAVE_C_RECORDMCOUNT
+		BUILD_C_RECORDMCOUNT := y
+		export BUILD_C_RECORDMCOUNT
+	endif
+endif
+endif
+
 # Add optional build target if defined in board/cpu/soc headers
 ifneq ($(CONFIG_BUILD_TARGET),)
 INPUTS-y += $(CONFIG_BUILD_TARGET:"%"=%)
@@ -1076,6 +1259,15 @@ quiet_cmd_objcopy = OBJCOPY $@
 cmd_objcopy = $(OBJCOPY) --gap-fill=0xff $(OBJCOPYFLAGS) \
 	$(OBJCOPYFLAGS_$(@F)) $< $@
 
+# disable pointer signed / unsigned warnings in gcc 4.0
+KBUILD_CFLAGS += -Wno-pointer-sign
+
+# disable stringop warnings in gcc 8+
+KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
+
+# disable invalid "can't wrap" optimizations for signed / pointers
+KBUILD_CFLAGS	+= $(call cc-option,-fno-strict-overflow)
+
 # Provide a version which does not do this, for use by EFI and hex/srec
 quiet_cmd_zobjcopy = OBJCOPY $@
 cmd_zobjcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
@@ -1927,7 +2119,7 @@ $(sort $(u-boot-init) $(u-boot-main)): $(u-boot-dirs) ;
 
 PHONY += $(u-boot-dirs)
 $(u-boot-dirs): prepare
-	$(Q)$(MAKE) $(build)=$@
+	$(Q)$(MAKE) $(build)=$@ need-builtin=1
 
 tools: prepare
 # The "tools" are needed early
@@ -1946,7 +2138,12 @@ endef
 # Store (new) UBOOTRELEASE string in include/config/uboot.release
 include/config/uboot.release: include/config/auto.conf FORCE
 	$(call filechk,uboot.release)
-
+# Additional helpers built in scripts/
+# Carefully list dependencies so we do not try to build scripts twice
+# in parallel
+PHONY += scripts
+scripts: scripts_basic scripts_dtc
+	$(Q)$(MAKE) $(build)=$(@)
 
 # Things we need to do before we recursively start building the kernel
 # or the modules are listed in "prepare".
@@ -1954,7 +2151,6 @@ include/config/uboot.release: include/config/auto.conf FORCE
 # archprepare is used in arch Makefiles and when processed asm symlink,
 # version.h and scripts_basic is processed / created.
 
-# Listed in dependency order
 PHONY += prepare archprepare prepare1 prepare3
 
 # prepare3 is used to check if we are building in a separate output directory,
@@ -1982,14 +2178,35 @@ prepare1: $(defaultenv_h)
 
 envtools: $(defaultenv_h)
 endif
-
 archprepare: prepare1 scripts
 
-prepare0: archprepare FORCE
+prepare0: archprepare
 	$(Q)$(MAKE) $(build)=.
 
 # All the preparing..
-prepare: prepare0
+prepare: prepare0 prepare-objtool
+
+# Support for using generic headers in asm-generic
+asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
+
+PHONY += asm-generic uapi-asm-generic
+asm-generic: uapi-asm-generic
+	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
+	generic=include/asm-generic
+uapi-asm-generic:
+	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
+	generic=include/uapi/asm-generic
+
+PHONY += prepare-objtool
+prepare-objtool: $(objtool_target)
+ifeq ($(SKIP_STACK_VALIDATION),1)
+ifdef CONFIG_UNWINDER_ORC
+	@echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
+	@false
+else
+	@echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
+endif
+endif
 
 # Generate some files
 # ---------------------------------------------------------------------------
@@ -2072,13 +2289,20 @@ ifneq ($(dtstree),)
 %.dtb: prepare3 scripts_dtc
 	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
 
-PHONY += dtbs dtbs_install
-dtbs: prepare3 scripts_dtc
+PHONY += dtbs dtbs_install dt_binding_check
+dtbs dtbs_check: prepare3 scripts_dtc
 	$(Q)$(MAKE) $(build)=$(dtstree)
 
+dtbs_check: export CHECK_DTBS=1
+dtbs_check: dt_binding_check
+
 dtbs_install:
 	$(Q)$(MAKE) $(dtbinst)=$(dtstree)
 
+ifdef CONFIG_OF_EARLY_FLATTREE
+all: dtbs
+endif
+
 endif
 
 # Check dtc and pylibfdt, if DTC is provided, else build them
@@ -2180,8 +2404,6 @@ SYSTEM_MAP = \
 System.map:	u-boot
 		@$(call SYSTEM_MAP,$<) > $@
 
-#########################################################################
-
 # ARM relocations should all be R_ARM_RELATIVE (32-bit) or
 # R_AARCH64_RELATIVE (64-bit).
 checkarmreloc: u-boot
@@ -2255,9 +2477,7 @@ MRPROPER_FILES += .config .config.old include/autoconf.mk* include/config.h \
 #
 clean: rm-dirs  := $(CLEAN_DIRS)
 clean: rm-files := $(CLEAN_FILES)
-
 clean-dirs	:= $(foreach f,$(u-boot-alldirs),$(if $(wildcard $(srctree)/$f/Makefile),$f))
-
 clean-dirs      := $(addprefix _clean_, $(clean-dirs))
 
 PHONY += $(clean-dirs) clean archclean
@@ -2465,11 +2685,25 @@ checkstack:
 	$(OBJDUMP) -d u-boot $$(find . -name u-boot-spl) | \
 	$(PERL) $(src)/scripts/checkstack.pl $(ARCH)
 
+ubootversion:
+	@echo $(UBOOTVERSION)
+
 ubootrelease:
 	@$(filechk_uboot.release)
 
-ubootversion:
-	@echo $(UBOOTVERSION)
+# Clear a bunch of variables before executing the submake
+
+ifeq ($(quiet),silent_)
+tools_silent=s
+endif
+
+tools/: FORCE
+	$(Q)mkdir -p $(objtree)/tools
+	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
+
+tools/%: FORCE
+	$(Q)mkdir -p $(objtree)/tools
+	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
 
 # Single targets
 # ---------------------------------------------------------------------------
@@ -2481,41 +2715,32 @@ ubootversion:
 #  target-dir => where to store outputfile
 #  build-dir  => directory in kernel source tree to use
 
-ifeq ($(KBUILD_EXTMOD),)
-        build-dir  = $(patsubst %/,%,$(dir $@))
-        target-dir = $(dir $@)
-else
-        zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
-        build-dir  = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
-        target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
-endif
-
-%.s: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.i: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.o: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.lst: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.s: %.S prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.o: %.S prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.symtypes: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+build-target = $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD)/)$@
+build-dir = $(patsubst %/,%,$(dir $(build-target)))
+
+%.i: prepare FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
+%.ll: prepare FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
+%.lst: prepare FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
+%.o: prepare FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
+%.s: prepare FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
+%.symtypes: prepare FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
+%.ko: %.o
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 # Modules
-/: prepare FORCE
-	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
-	$(build)=$(build-dir)
+PHONY += /
+/: ./
+
+# Make sure the latest headers are built for Documentation
+Documentation/ samples/: headers_install
 %/: prepare FORCE
-	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
-	$(build)=$(build-dir)
-%.ko: prepare FORCE
-	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)   \
-	$(build)=$(build-dir) $(@:.ko=.o)
-	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
+	$(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
 
 quiet_cmd_genenv = GENENV  $@
 cmd_genenv = \
@@ -2544,15 +2769,24 @@ quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN   $(wildcard $(rm-dirs)))
 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
       cmd_rmfiles = rm -f $(rm-files)
 
+# Run depmod only if we have System.map and depmod is executable
+quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
+      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
+                   $(KERNELRELEASE)
+
+# Create temporary dir for module support files
+# clean it up only when building all modules
+cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
+                  $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
+
 # read saved command lines for existing targets
 existing-targets := $(wildcard $(sort $(targets)))
-cmd_files := $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
-$(cmd_files): ;        # Do not try to update included dependency files
--include $(cmd_files)
 
-endif    #ifeq ($(config-targets),1)
-endif    #ifeq ($(mixed-targets),1)
-endif	 # sub_make_done
+-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
+
+endif   # ifeq ($(config-targets),1)
+endif   # ifeq ($(mixed-targets),1)
+endif   # need-sub-make
 
 PHONY += FORCE
 FORCE: