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e03dabe86b
u-boot/config.mk
Sebastien Carlier 6d8962e814 Switch from archive libraries to partial linking 
Before this commit, weak symbols were not overridden by non-weak symbols
found in archive libraries when linking with recent versions of
binutils.  As stated in the System V ABI, "the link editor does not
extract archive members to resolve undefined weak symbols".

This commit changes all Makefiles to use partial linking (ld -r) instead
of creating library archives, which forces all symbols to participate in
linking, allowing non-weak symbols to override weak symbols as intended.
This approach is also used by Linux, from which the gmake function
cmd_link_o_target (defined in config.mk and used in all Makefiles) is
inspired.

The name of each former library archive is preserved except for
extensions which change from ".a" to ".o".  This commit updates
references accordingly where needed, in particular in some linker
scripts.

This commit reveals board configurations that exclude some features but
include source files that depend these disabled features in the build,
resulting in undefined symbols.  Known such cases include:
- disabling CMD_NET but not CMD_NFS;
- enabling CONFIG_OF_LIBFDT but not CONFIG_QE.

Signed-off-by: Sebastien Carlier <sebastien.carlier@gmail.com>
2010-11-17 21:02:18 +01:00

269 lines
8.2 KiB
Makefile
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#
# (C) Copyright 2000-2006
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# See file CREDITS for list of people who contributed to this
# project.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#
#########################################################################
ifneq ($(OBJTREE),$(SRCTREE))
ifeq ($(CURDIR),$(SRCTREE))
dir :=
else
dir := $(subst $(SRCTREE)/,,$(CURDIR))
endif
obj := $(if $(dir),$(OBJTREE)/$(dir)/,$(OBJTREE)/)
src := $(if $(dir),$(SRCTREE)/$(dir)/,$(SRCTREE)/)
$(shell mkdir -p $(obj))
else
obj :=
src :=
endif
# clean the slate ...
PLATFORM_RELFLAGS =
PLATFORM_CPPFLAGS =
PLATFORM_LDFLAGS =
#########################################################################
HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer \
$(HOSTCPPFLAGS)
HOSTSTRIP = strip
#
# Mac OS X / Darwin's C preprocessor is Apple specific. It
# generates numerous errors and warnings. We want to bypass it
# and use GNU C's cpp. To do this we pass the -traditional-cpp
# option to the compiler. Note that the -traditional-cpp flag
# DOES NOT have the same semantics as GNU C's flag, all it does
# is invoke the GNU preprocessor in stock ANSI/ISO C fashion.
#
# Apple's linker is similar, thanks to the new 2 stage linking
# multiple symbol definitions are treated as errors, hence the
# -multiply_defined suppress option to turn off this error.
#
ifeq ($(HOSTOS),darwin)
# get major and minor product version (e.g. '10' and '6' for Snow Leopard)
DARWIN_MAJOR_VERSION = $(shell sw_vers -productVersion | cut -f 1 -d '.')
DARWIN_MINOR_VERSION = $(shell sw_vers -productVersion | cut -f 2 -d '.')
os_x_before = $(shell if [ $(DARWIN_MAJOR_VERSION) -le $(1) -a \
$(DARWIN_MINOR_VERSION) -le $(2) ] ; then echo "$(3)"; else echo "$(4)"; fi ;)
# Snow Leopards build environment has no longer restrictions as described above
HOSTCC = $(call os_x_before, 10, 5, "cc", "gcc")
HOSTCFLAGS += $(call os_x_before, 10, 4, "-traditional-cpp")
HOSTLDFLAGS += $(call os_x_before, 10, 5, "-multiply_defined suppress")
else
HOSTCC = gcc
endif
ifeq ($(HOSTOS),cygwin)
HOSTCFLAGS += -ansi
endif
# We build some files with extra pedantic flags to try to minimize things
# that won't build on some weird host compiler -- though there are lots of
# exceptions for files that aren't complaint.
HOSTCFLAGS_NOPED = $(filter-out -pedantic,$(HOSTCFLAGS))
HOSTCFLAGS += -pedantic
#########################################################################
#
# Option checker (courtesy linux kernel) to ensure
# only supported compiler options are used
#
cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
> /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
#
# Include the make variables (CC, etc...)
#
AS = $(CROSS_COMPILE)as
LD = $(CROSS_COMPILE)ld
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
#########################################################################
# Load generated board configuration
sinclude $(OBJTREE)/include/autoconf.mk
# Some architecture config.mk files need to know what CPUDIR is set to,
# so calculate CPUDIR before including ARCH/SOC/CPU config.mk files.
# Check if arch/$ARCH/cpu/$CPU exists, otherwise assume arch/$ARCH/cpu contains
# CPU-specific code.
CPUDIR=arch/$(ARCH)/cpu/$(CPU)
ifneq ($(SRCTREE)/$(CPUDIR),$(wildcard $(SRCTREE)/$(CPUDIR)))
CPUDIR=arch/$(ARCH)/cpu
endif
sinclude $(TOPDIR)/arch/$(ARCH)/config.mk # include architecture dependend rules
sinclude $(TOPDIR)/$(CPUDIR)/config.mk # include CPU specific rules
ifdef SOC
sinclude $(TOPDIR)/$(CPUDIR)/$(SOC)/config.mk # include SoC specific rules
endif
ifdef VENDOR
BOARDDIR = $(VENDOR)/$(BOARD)
else
BOARDDIR = $(BOARD)
endif
ifdef BOARD
sinclude $(TOPDIR)/board/$(BOARDDIR)/config.mk # include board specific rules
endif
#########################################################################
ifneq (,$(findstring s,$(MAKEFLAGS)))
ARFLAGS = cr
else
ARFLAGS = crv
endif
RELFLAGS= $(PLATFORM_RELFLAGS)
DBGFLAGS= -g # -DDEBUG
OPTFLAGS= -Os #-fomit-frame-pointer
ifndef LDSCRIPT
#LDSCRIPT := $(TOPDIR)/board/$(BOARDDIR)/u-boot.lds.debug
ifeq ($(CONFIG_NAND_U_BOOT),y)
LDSCRIPT := $(TOPDIR)/board/$(BOARDDIR)/u-boot-nand.lds
else
LDSCRIPT := $(TOPDIR)/board/$(BOARDDIR)/u-boot.lds
endif
endif
OBJCFLAGS += --gap-fill=0xff
gccincdir := $(shell $(CC) -print-file-name=include)
CPPFLAGS := $(DBGFLAGS) $(OPTFLAGS) $(RELFLAGS) \
-D__KERNEL__
ifneq ($(CONFIG_SYS_TEXT_BASE),)
CPPFLAGS += -DCONFIG_SYS_TEXT_BASE=$(CONFIG_SYS_TEXT_BASE)
endif
ifneq ($(RESET_VECTOR_ADDRESS),)
CPPFLAGS += -DRESET_VECTOR_ADDRESS=$(RESET_VECTOR_ADDRESS)
endif
ifneq ($(OBJTREE),$(SRCTREE))
CPPFLAGS += -I$(OBJTREE)/include2 -I$(OBJTREE)/include
endif
CPPFLAGS += -I$(TOPDIR)/include
CPPFLAGS += -fno-builtin -ffreestanding -nostdinc \
-isystem $(gccincdir) -pipe $(PLATFORM_CPPFLAGS)
ifdef BUILD_TAG
CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes \
-DBUILD_TAG='"$(BUILD_TAG)"'
else
CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes
endif
CFLAGS += $(call cc-option,-fno-stack-protector)
# $(CPPFLAGS) sets -g, which causes gcc to pass a suitable -g<format>
# option to the assembler.
AFLAGS_DEBUG :=
# turn jbsr into jsr for m68k
ifeq ($(ARCH),m68k)
ifeq ($(findstring 3.4,$(shell $(CC) --version)),3.4)
AFLAGS_DEBUG := -Wa,-gstabs,-S
endif
endif
AFLAGS := $(AFLAGS_DEBUG) -D__ASSEMBLY__ $(CPPFLAGS)
LDFLAGS += -Bstatic -T $(obj)u-boot.lds $(PLATFORM_LDFLAGS)
ifneq ($(CONFIG_SYS_TEXT_BASE),)
LDFLAGS += -Ttext $(CONFIG_SYS_TEXT_BASE)
endif
# Location of a usable BFD library, where we define "usable" as
# "built for ${HOST}, supports ${TARGET}". Sensible values are
# - When cross-compiling: the root of the cross-environment
# - Linux/ppc (native): /usr
# - NetBSD/ppc (native): you lose ... (must extract these from the
# binutils build directory, plus the native and U-Boot include
# files don't like each other)
#
# So far, this is used only by tools/gdb/Makefile.
ifeq ($(HOSTOS),darwin)
BFD_ROOT_DIR = /usr/local/tools
else
ifeq ($(HOSTARCH),$(ARCH))
# native
BFD_ROOT_DIR = /usr
else
#BFD_ROOT_DIR = /LinuxPPC/CDK # Linux/i386
#BFD_ROOT_DIR = /usr/pkg/cross # NetBSD/i386
BFD_ROOT_DIR = /opt/powerpc
endif
endif
#########################################################################
export HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE \
AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
export CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS CPPFLAGS CFLAGS AFLAGS
#########################################################################
# Allow boards to use custom optimize flags on a per dir/file basis
BCURDIR = $(subst $(SRCTREE)/,,$(CURDIR:$(obj)%=%))
$(obj)%.s: %.S
$(CPP) $(AFLAGS) $(AFLAGS_$(BCURDIR)/$(@F)) $(AFLAGS_$(BCURDIR)) \
-o $@ $<
$(obj)%.o: %.S
$(CC) $(AFLAGS) $(AFLAGS_$(BCURDIR)/$(@F)) $(AFLAGS_$(BCURDIR)) \
-o $@ $< -c
$(obj)%.o: %.c
$(CC) $(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
-o $@ $< -c
$(obj)%.i: %.c
$(CPP) $(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
-o $@ $< -c
$(obj)%.s: %.c
$(CC) $(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
-o $@ $< -c -S
#########################################################################
# If the list of objects to link is empty, just create an empty built-in.o
cmd_link_o_target = $(if $(strip $1),\
$(LD) -r -o $@ $1 ,\
rm -f $@; $(AR) rcs $@ )
#########################################################################
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