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Makefile: move some variable definitions to the top Makefile
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This commit moves some variable definitions from config.mk
to the top Makefile:

  - HOSTCC, HOSTCFLAGS, HOSTLDFLAGS
  - AS, LD, CC, CPP, etc.
  - SHELL (renamed to CONFIG_SHELL)

I'd like to slim down config.mk file
because it is included from all recursive make.
It is redundant to re-define the variables
every time descending into sub directories.
We should rather define them at the top Makefile
and export them.

U-Boot makefiles has been used "SHELL" variable to store shell
chosen for the user, whereas Linux Kernel uses "CONFIG_SHELL".

We should never use "SHELL" variable because it is
a special variable for GNU Make.
Changing SHELL may cause unpredictable side effects
whose root cause is usually difficult to find.
We should use a generic variable name "CONFIG_SHELL".

We should not use the syntax as follows either:

    rm -f $(obj)tools/env/{fw_printenv,fw_setenv}

This depends on "bash" although GNU Make generally
invokes "sh" to run the each rule.

Signed-off-by: Masahiro Yamada <[email protected]>
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masahir0y authored and trini committed Feb 19, 2014
1 parent 5651ccf commit f6322eb
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Showing 2 changed files with 84 additions and 88 deletions.
94 changes: 81 additions & 13 deletions Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,73 @@ ifeq ($(HOSTARCH),$(ARCH))
CROSS_COMPILE ?=
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)

HOSTCC = gcc
HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer

ifeq ($(HOSTOS),cygwin)
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 ;)

# 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")
endif

# 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
AWK = awk
RANLIB = $(CROSS_COMPILE)RANLIB
DTC = dtc
CHECK = sparse

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

export CONFIG_SHELL HOSTCC HOSTCFLAGS HOSTLDFLAGS CROSS_COMPILE AS LD CC
export CPP AR NM LDR STRIP OBJCOPY OBJDUMP
export MAKE AWK
export DTC CHECK CHECKFLAGS

# load other configuration
include $(TOPDIR)/config.mk

Expand Down Expand Up @@ -788,27 +855,28 @@ clean:
$(obj)examples/standalone/interrupt \
$(obj)examples/standalone/mem_to_mem_idma2intr \
$(obj)examples/standalone/sched \
$(obj)examples/standalone/smc911{11,x}_eeprom \
$(addprefix $(obj)examples/standalone/, smc91111_eeprom smc911x_eeprom) \
$(obj)examples/standalone/test_burst \
$(obj)examples/standalone/timer
@rm -f $(obj)examples/api/demo{,.bin}
@rm -f $(addprefix $(obj)examples/api/, demo demo.bin)
@rm -f $(obj)tools/bmp_logo $(obj)tools/easylogo/easylogo \
$(obj)tools/env/fw_printenv \
$(obj)tools/envcrc \
$(obj)tools/gdb/{gdbcont,gdbsend} \
$(addprefix $(obj)tools/gdb/, gdbcont gdbsend) \
$(obj)tools/gen_eth_addr $(obj)tools/img2srec \
$(obj)tools/dump{env,}image \
$(obj)tools/mk{env,}image $(obj)tools/mpc86x_clk \
$(obj)tools/mk{$(BOARD),exynos}spl \
$(obj)tools/dumpimage \
$(addprefix $(obj)tools/, mkenvimage mkimage) \
$(obj)tools/mpc86x_clk \
$(addprefix $(obj)tools/, mk$(BOARD)spl mkexynosspl) \
$(obj)tools/mxsboot \
$(obj)tools/ncb $(obj)tools/ubsha1 \
$(obj)tools/kernel-doc/docproc \
$(obj)tools/proftool
@rm -f $(obj)board/cray/L1/{bootscript.c,bootscript.image} \
@rm -f $(addprefix $(obj)board/cray/L1/, bootscript.c bootscript.image) \
$(obj)board/matrix_vision/*/bootscript.img \
$(obj)spl/board/samsung/$(BOARD)/tools/mk$(BOARD)spl \
$(obj)u-boot.lds \
$(obj)arch/blackfin/cpu/init.{lds,elf}
$(addprefix $(obj)arch/blackfin/cpu/, init.lds init.elf)
@rm -f $(obj)include/bmp_logo.h
@rm -f $(obj)include/bmp_logo_data.h
@rm -f $(obj)lib/asm-offsets.s
Expand Down Expand Up @@ -843,11 +911,11 @@ clobber: tidy
@rm -f $(obj)u-boot.dtb
@rm -f $(obj)u-boot.sb
@rm -f $(obj)u-boot.spr
@rm -f $(obj)nand_spl/{u-boot.{lds,lst},System.map}
@rm -f $(obj)nand_spl/{u-boot-nand_spl.lds,u-boot-spl,u-boot-spl.map}
@rm -f $(obj)spl/{u-boot-spl,u-boot-spl.bin,u-boot-spl.map}
@rm -f $(addprefix $(obj)nand_spl/, u-boot.lds u-boot.lst System.map)
@rm -f $(addprefix $(obj)nand_spl/, u-boot-nand_spl.lds u-boot-spl u-boot-spl.map)
@rm -f $(addprefix $(obj)spl/, u-boot-spl u-boot-spl.bin u-boot-spl.map)
@rm -f $(obj)spl/u-boot-spl.lds
@rm -f $(obj)tpl/{u-boot-tpl,u-boot-tpl.bin,u-boot-tpl.map}
@rm -f $(addprefix $(obj)tpl/, u-boot-tpl u-boot-tpl.bin u-boot-tpl.map)
@rm -f $(obj)tpl/u-boot-spl.lds
@rm -f $(obj)MLO MLO.byteswap
@rm -f $(obj)SPL
Expand All @@ -856,7 +924,7 @@ clobber: tidy
@rm -fr $(obj)include/generated
@[ ! -d $(obj)nand_spl ] || find $(obj)nand_spl -name "*" -type l -print | xargs rm -f
@rm -f $(obj)dts/*.tmp
@rm -f $(obj)spl/u-boot-spl{,-pad}.ais
@rm -f $(addprefix $(obj)spl/, u-boot-spl.ais, u-boot-spl-pad.ais)

mrproper \
distclean: clobber unconfig
Expand Down
78 changes: 3 additions & 75 deletions config.mk
Original file line number Diff line number Diff line change
Expand Up @@ -6,13 +6,6 @@
#
#########################################################################

# 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
Expand Down Expand Up @@ -54,44 +47,6 @@ PLATFORM_RELFLAGS =
PLATFORM_CPPFLAGS =
PLATFORM_LDFLAGS =

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

HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer \
$(HOSTCPPFLAGS)

#
# 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

#########################################################################
#
# Option checker, gcc version (courtesy linux kernel) to ensure
Expand All @@ -117,30 +72,9 @@ 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
cc-version = $(shell $(CONFIG_SHELL) $(SRCTREE)/scripts/gcc-version.sh $(CC))
binutils-version = $(shell $(CONFIG_SHELL) $(SRCTREE)/scripts/binutils-version.sh $(AS))
dtc-version = $(shell $(CONFIG_SHELL) $(SRCTREE)/scripts/dtc-version.sh $(DTC))

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

Expand Down Expand Up @@ -286,10 +220,6 @@ 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
Expand All @@ -315,6 +245,4 @@ endif

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

export HOSTCC HOSTCFLAGS HOSTLDFLAGS CROSS_COMPILE \
AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
export CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS CPPFLAGS CFLAGS AFLAGS

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