openwrt拆离dl目录和toolchain的方法
公司为了把openwrt的代码用svn集中管理，又避免每个人重复的下载dl，以及编译toolchain，因此需要所有人共用dl和toolchain。
先总结一下方法：
1. 修改rules.mk
PREBUILT_DIR:=$(TOPDIR)/prebuilt/$(BOARD)
ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
GCCV:=$(call qstrip,$(CONFIG_GCC_VERSION))
LIBC:=$(call qstrip,$(CONFIG_LIBC))
LIBCV:=$(call qstrip,$(CONFIG_LIBC_VERSION))
REAL_GNU_TARGET_NAME=$(OPTIMIZE_FOR_CPU)-openwrt-linux$(if $(TARGET_SUFFIX),-$(TARGET_SUFFIX))
GNU_TARGET_NAME=$(OPTIMIZE_FOR_CPU)-openwrt-linux
DIR_SUFFIX:=_$(LIBC)-$(LIBCV)$(if $(CONFIG_arm),_eabi)
BUILD_DIR:=$(BUILD_DIR_BASE)/target-$(ARCH)$(ARCH_SUFFIX)$(DIR_SUFFIX)$(if $(BUILD_SUFFIX),_$(BUILD_SUFFIX))
STAGING_DIR:=$(TOPDIR)/staging_dir/target-$(ARCH)$(ARCH_SUFFIX)$(DIR_SUFFIX)$(if $(BUILD_SUFFIX),_$(BUILD_SUFFIX))
BUILD_DIR_TOOLCHAIN:=$(BUILD_DIR_BASE)/toolchain-$(ARCH)$(ARCH_SUFFIX)_gcc-$(GCCV)$(DIR_SUFFIX)
#TOOLCHAIN_DIR:=$(TOPDIR)/staging_dir/toolchain-$(ARCH)$(ARCH_SUFFIX)_gcc-$(GCCV)$(DIR_SUFFIX)
TOOLCHAIN_DIR:=/opt/staging_dir/toolchain-$(ARCH)$(ARCH_SUFFIX)_gcc-$(GCCV)$(DIR_SUFFIX)#修改为你要存放公共toolchain的地方
PACKAGE_DIR:=$(BIN_DIR)/packages
else
ifeq ($(CONFIG_NATIVE_TOOLCHAIN),)
GNU_TARGET_NAME=$(call qstrip,$(CONFIG_TARGET_NAME))
else
GNU_TARGET_NAME=$(shell gcc -dumpmachine)
endif
REAL_GNU_TARGET_NAME=$(GNU_TARGET_NAME)
BUILD_DIR:=$(BUILD_DIR_BASE)/target-$(GNU_TARGET_NAME)$(if $(BUILD_SUFFIX),_$(BUILD_SUFFIX))
STAGING_DIR:=$(TOPDIR)/staging_dir/target-$(GNU_TARGET_NAME)$(if $(BUILD_SUFFIX),_$(BUILD_SUFFIX))
BUILD_DIR_TOOLCHAIN:=$(BUILD_DIR_BASE)/toolchain-$(GNU_TARGET_NAME)
#TOOLCHAIN_DIR:=$(TOPDIR)/staging_dir/toolchain-$(GNU_TARGET_NAME)
TOOLCHAIN_DIR:=/opt/staging_dir/toolchain-$(GNU_TARGET_NAME) #修改为你要存放公共toolchain的地方
PACKAGE_DIR:=$(BIN_DIR)/packages
endif
STAMP_DIR:=$(BUILD_DIR)/stamp
STAMP_DIR_HOST=$(BUILD_DIR_HOST)/stamp
2. 编译openwrt：
#make V=s -j4
这样就可以生成你的toolchain在opt/staging_dir下面
3. 修改根目录下的Makefile
#---------------------------------------------------------------------------------
ifneq ($(OPENWRT_BUILD),1)
# XXX: these three lines are normally defined by rules.mk
# but we can't include that file in this context
empty:=
space:= $(empty) $(empty)
_SINGLE=export MAKEFLAGS=$(space);
override OPENWRT_BUILD=1
export OPENWRT_BUILD
GREP_OPTIONS=
export GREP_OPTIONS
include $(TOPDIR)/include/debug.mk
include $(TOPDIR)/include/depends.mk
include $(TOPDIR)/include/toplevel.mk
else
include rules.mk
include $(INCLUDE_DIR)/depends.mk
include $(INCLUDE_DIR)/subdir.mk
include target/Makefile
include package/Makefile
include tools/Makefile
# include toolchain/Makefile #这里为注释掉的地方
$(toolchain/stamp-install): $(tools/stamp-install)
$(target/stamp-compile): $(toolchain/stamp-install) $(tools/stamp-install) $(BUILD_DIR)/.prepared
$(package/stamp-cleanup): $(target/stamp-compile)
#----------------------------------------------------------------------------------------------
prepare: .config $(tools/stamp-install) $(toolchain/stamp-install)
#world: prepare $(target/stamp-compile) $(package/stamp-cleanup) $(package/stamp-compile) $(package/stamp-install) $(package/stamp-rootfs-prepare) $(target/stamp-instal
l) FORCE
world: $(target/stamp-compile) $(package/stamp-cleanup) $(package/stamp-compile) $(package/stamp-install) $(package/stamp-rootfs-prepare) $(target/stamp-instal
l) FORCE #删除prepare
#----------------------------------------------------------------------------------------------
4.修改package/uclibc++/Makefile
define Build/InstallDev
$(INSTALL_DIR) $(2)/bin $(1)/usr/include/uClibc++ $(1)/usr/lib
# $(INSTALL_BIN) $(PKG_INSTALL_DIR)/bin/g++-uc $(TOOLCHAIN_DIR)/bin/
$(CP) $(PKG_INSTALL_DIR)/include/* $(1)/usr/include/uClibc++/
$(CP) $(PKG_INSTALL_DIR)/lib/libuClibc++*.{a,so}* $(1)/usr/lib/
# $(SED) 's|-I/include/|-I$(STAGING_DIR)/usr/include/uClibc++/|g' $(TOOLCHAIN_DIR)/bin/g++-uc
# $(SED) 's|-L/lib/|-L$(STAGING_DIR)/usr/lib/|g' $(TOOLCHAIN_DIR)/bin/g++-uc
# add another wrapper which links against both uClibc++ and libstdc++
# $(INSTALL_BIN) $(TOOLCHAIN_DIR)/bin/g++-uc $(TOOLCHAIN_DIR)/bin/g++-uc+std
# $(SED) 's|^WRAPPER_INCLUDEDIR=.*||g' $(TOOLCHAIN_DIR)/bin/g++-uc+std
# $(SED) 's|-luClibc++|-Wl,-Bdynamic,-luClibc++,-Bstatic,-lstdc++,-Bdynamic|g' $(TOOLCHAIN_DIR)/bin/g++-uc+std
# $(SED) 's|-nostdinc++||g' $(TOOLCHAIN_DIR)/bin/g++-uc+std
endef
注释掉上面几行
5.提交整个工程的代码，大功告成。
6.现在切换账号，checkout代码，再编译，OK
