diff --git a/arch/arm/imx-common/Makefile b/arch/arm/imx-common/Makefile
index ee5c872..9dda59d 100644
--- a/arch/arm/imx-common/Makefile
+++ b/arch/arm/imx-common/Makefile
@@ -25,7 +25,7 @@
 
 $(OBJTREE)/$(patsubst "%",%,$(CONFIG_IMX_CONFIG)).cfgtmp: $(OBJTREE)/%.cfgtmp : $(SRCTREE)/%
 	mkdir -p $(dir $@)
-	$(CC) -E -x c $< $(CPPFLAGS) -o $@
+	$(CPP) $(cpp_flags) -x c -o $@ $<
 
 $(OBJTREE)/u-boot.imx: $(OBJTREE)/u-boot.bin $(OBJTREE)/$(patsubst "%",%,$(CONFIG_IMX_CONFIG)).cfgtmp
 	$(OBJTREE)/tools/mkimage -n $(filter-out %.bin,$^) -T imximage \
diff --git a/arch/blackfin/cpu/Makefile b/arch/blackfin/cpu/Makefile
index 369dc74..dd4d2d1 100644
--- a/arch/blackfin/cpu/Makefile
+++ b/arch/blackfin/cpu/Makefile
@@ -25,7 +25,7 @@
 
 # make sure our initcode (which goes into LDR) does not
 # have relocs or external references
-$(obj)/initcode.o: CFLAGS += -fno-function-sections -fno-data-sections
+CFLAGS_REMOVE_initcode.o := -ffunction-sections -fdata-sections
 READINIT = env LC_ALL=C $(CROSS_COMPILE)readelf -s $<
 $(obj)/check_initcode: $(obj)/initcode.o
 ifneq ($(CONFIG_BFIN_BOOT_MODE),BFIN_BOOT_BYPASS)
@@ -35,7 +35,6 @@
 	fi
 endif
 
-$(obj)/init.lds: $(src)/init.lds.S
-	$(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P $^ -o $@
+CPPFLAGS_init.lds := -ansi
 $(obj)/init.elf: $(obj)/init.lds $(obj)/init.o $(obj)/initcode.o
 	$(LD) $(LDFLAGS) -T $^ -o $@
diff --git a/arch/blackfin/lib/Makefile b/arch/blackfin/lib/Makefile
index a5c552f..4ba7bf6 100644
--- a/arch/blackfin/lib/Makefile
+++ b/arch/blackfin/lib/Makefile
@@ -9,7 +9,10 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-CFLAGS += -DBFIN_BOARD_NAME='"$(BOARD)"'
+# Unnecessary.
+# Use CONFIG_SYS_BOARD instead of BFIN_BOARD_NAME
+# and delete this.
+ccflags-y += -DBFIN_BOARD_NAME='"$(BOARD)"'
 
 obj-y	+= ins.o
 obj-y	+= memcmp.o
diff --git a/arch/m68k/cpu/mcf5227x/Makefile b/arch/m68k/cpu/mcf5227x/Makefile
index a47fd56..e0c5db6 100644
--- a/arch/m68k/cpu/mcf5227x/Makefile
+++ b/arch/m68k/cpu/mcf5227x/Makefile
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# CFLAGS += -DET_DEBUG
+# ccflags-y += -DET_DEBUG
 
 extra-y	= start.o
 obj-y	= cpu.o speed.o cpu_init.o interrupts.o
diff --git a/arch/m68k/cpu/mcf523x/Makefile b/arch/m68k/cpu/mcf523x/Makefile
index a47fd56..e0c5db6 100644
--- a/arch/m68k/cpu/mcf523x/Makefile
+++ b/arch/m68k/cpu/mcf523x/Makefile
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# CFLAGS += -DET_DEBUG
+# ccflags-y += -DET_DEBUG
 
 extra-y	= start.o
 obj-y	= cpu.o speed.o cpu_init.o interrupts.o
diff --git a/arch/m68k/cpu/mcf52x2/Makefile b/arch/m68k/cpu/mcf52x2/Makefile
index d9bf900..b92fd86 100644
--- a/arch/m68k/cpu/mcf52x2/Makefile
+++ b/arch/m68k/cpu/mcf52x2/Makefile
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# CFLAGS += -DET_DEBUG
+# ccflags-y += -DET_DEBUG
 
 extra-y	= start.o
 obj-y	= interrupts.o cpu.o speed.o cpu_init.o
diff --git a/arch/m68k/cpu/mcf532x/Makefile b/arch/m68k/cpu/mcf532x/Makefile
index 97aa3f1..9c53c50 100644
--- a/arch/m68k/cpu/mcf532x/Makefile
+++ b/arch/m68k/cpu/mcf532x/Makefile
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# CFLAGS += -DET_DEBUG
+# ccflags-y += -DET_DEBUG
 
 extra-y := start.o
 obj-y	= cpu.o speed.o cpu_init.o interrupts.o
diff --git a/arch/m68k/cpu/mcf5445x/Makefile b/arch/m68k/cpu/mcf5445x/Makefile
index b506719..9be91ed 100644
--- a/arch/m68k/cpu/mcf5445x/Makefile
+++ b/arch/m68k/cpu/mcf5445x/Makefile
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# CFLAGS += -DET_DEBUG
+# ccflags-y += -DET_DEBUG
 
 extra-y	= start.o
 obj-y	= cpu.o speed.o cpu_init.o interrupts.o pci.o
diff --git a/arch/m68k/cpu/mcf547x_8x/Makefile b/arch/m68k/cpu/mcf547x_8x/Makefile
index 0fa50bf..4f82099 100644
--- a/arch/m68k/cpu/mcf547x_8x/Makefile
+++ b/arch/m68k/cpu/mcf547x_8x/Makefile
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# CFLAGS += -DET_DEBUG
+# ccflags-y += -DET_DEBUG
 
 extra-y = start.o
 obj-y	= cpu.o speed.o cpu_init.o pci.o interrupts.o slicetimer.o
diff --git a/arch/powerpc/cpu/mpc8xx/Makefile b/arch/powerpc/cpu/mpc8xx/Makefile
index d40bdab..f83fd5e 100644
--- a/arch/powerpc/cpu/mpc8xx/Makefile
+++ b/arch/powerpc/cpu/mpc8xx/Makefile
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# CFLAGS += -DET_DEBUG
+# ccflags-y += -DET_DEBUG
 
 extra-y += start.o
 extra-y += traps.o
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index ac780d4..e6d8be5 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -54,11 +54,11 @@
 # Workaround for local bus unaligned access problems
 # on MPC512x and MPC5200
 ifdef CONFIG_MPC512X
-$(obj)/ppcstring.o: AFLAGS += -Dmemcpy=__memcpy
+AFLAGS_ppcstring.o += -Dmemcpy=__memcpy
 obj-y += memcpy_mpc5200.o
 endif
 ifdef CONFIG_MPC5200
-$(obj)/ppcstring.o: AFLAGS += -Dmemcpy=__memcpy
+AFLAGS_ppcstring.o += -Dmemcpy=__memcpy
 obj-y += memcpy_mpc5200.o
 endif
 endif
diff --git a/arch/sandbox/cpu/Makefile b/arch/sandbox/cpu/Makefile
index c5f5426..63deded 100644
--- a/arch/sandbox/cpu/Makefile
+++ b/arch/sandbox/cpu/Makefile
@@ -10,7 +10,10 @@
 obj-y	:= cpu.o os.o start.o state.o
 
 # os.c is build in the system environment, so needs standard includes
-$(obj)/os.o: CFLAGS := $(filter-out -nostdinc,\
-	$(patsubst -I%,-idirafter%,$(CFLAGS)))
-$(obj)/.depend.os: CPPFLAGS := $(filter-out -nostdinc,\
-	$(patsubst -I%,-idirafter%,$(CPPFLAGS)))
+# CFLAGS_REMOVE_os.o cannot be used to drop header include path
+quiet_cmd_cc_os.o = CC $(quiet_modtag)  $@
+cmd_cc_os.o = $(CC) $(filter-out -nostdinc, \
+	$(patsubst -I%,-idirafter%,$(c_flags))) -c -o $@ $<
+
+$(obj)/os.o: $(src)/os.c FORCE
+	$(call if_changed_dep,cc_os.o)