2010.03 u-boot--Makefile完全分析

#
# (C) Copyright 2000-2009
# 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 Foundatio; either version 2 of
# the License, or (at your option) any later version.
#
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# 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.
#
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# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#

VERSION = 2010
PATCHLEVEL = 03
SUBLEVEL =
EXTRAVERSION =
****uboot版本号的变量定义
ifneq "$(SUBLEVEL)" ""
U_BOOT_VERSION = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
else
U_BOOT_VERSION = $(VERSION).$(PATCHLEVEL)$(EXTRAVERSION)
endif
****U_BOOT_VERSION赋值=2010.03
TIMESTAMP_FILE = $(obj)include/timestamp_autogenerated.h
****时间戳文件变量
VERSION_FILE = $(obj)include/version_autogenerated.h
****版本文件变量

HOSTARCH := $(shell uname -m | \
    sed -e s/i.86/i386/ \
        -e s/sun4u/sparc64/ \
        -e s/arm.*/arm/ \
        -e s/sa110/arm/ \
        -e s/powerpc/ppc/ \
        -e s/ppc64/ppc/ \
        -e s/macppc/ppc/)
********当输入命令 make all,讲寻找到此次的伪目标all，all依赖于 $(ALL),ALL由5部分组成。那么接下去就分别对这5部分进行递归的处理。（贴出来格式变了，最好自己看源码）。看到308行，

（1）目标文件u-boot.bin依赖于 $(obj)u-boot目标，可以在344行找到；

    （1.1）$(obj)u-boot依赖于：depend  $(SUBDIRS)  $(OBJS)  $(LIBBOARD)  $(LIBS)  $(LDSCRIPT)  $(obj)u-boot.lds；

          （1.1.1）depend；402行。执行的操作为：进入到$(SUBDIRS)，生成各个子目

                  录的.depend文件。通过调用各个子目录的make _depend。

          （1.1.2）$(SUBDIRS)；363行。依赖depend。执行操作为：对各个子目录执行

                   makefile文件。

          (1.1.3) $(OBJS);354行。依赖depend。执行：

             $(MAKE) -C cpu/$(CPU) $(if $(REMOTE_BUILD),$@,$(notdir $@))

                   如果cpu为arm920t，编译文件cpu/arm920t。

          (1.1.4) $(LIBS) ;357行。依赖$(SUBDIRS).执行操作为：

                  $(MAKE) -C $(dir $(subst $(obj),,$@))，

                  dir为GNU内嵌函数为取目录操作，比如$(dir a/b/c) 结果为

                  a/b/;subst 也是GNU内嵌函数$(subst from,to,text)表示在text

                  中把form 字符串替换为字符串to。subst资料上面是这样讲的。但是

                  在此处，我认为是：$(subst text， to， from)。总之，这样理解

                  吧：在LIBS包含的n个路径下面执行make

          (1.1.5) $(LIBBOARD);360行。依赖depend，$（LIBS）。执行：

                  $(MAKE) -C $(dir $(subst $(obj),,$@))。

                  再在之前，$(LIBS)已经执行完毕，现在obj只剩下了：LIBBOAED路径

                  集合了。在这些路径集合下面执行make。

          (1.1.6) $(LDSCRIPT);336行。依赖depend。执行：

                  $(MAKE) -C $(dir $@) $(notdir $@)，notdir为取文件名函数，

                  比如，$(notdir a/my.o)结果为my.o。

                 

          (1.1.7) $(obj)u-boot.lds。369行。依赖$(LDSCRIPT).执行：

      $(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - <$^ >$@

                  生成链接文件。

*****上面这段文字引自：http://blog.chinaunix.net/u3/108840/showart_2135045.html
$(obj)u-boot.hex:    $(obj)u-boot
        $(OBJCOPY) ${OBJCFLAGS} -O ihex $< $@

$(obj)u-boot.srec:    $(obj)u-boot
        $(OBJCOPY) -O srec $< $@

$(obj)u-boot.bin:    $(obj)u-boot
        $(OBJCOPY) ${OBJCFLAGS} -O binary $< $@

$(obj)u-boot.ldr:    $(obj)u-boot
        $(CREATE_LDR_ENV)
        $(LDR) -T $(CONFIG_BFIN_CPU) -c $@ $< $(LDR_FLAGS)

$(obj)u-boot.ldr.hex:    $(obj)u-boot.ldr
        $(OBJCOPY) ${OBJCFLAGS} -O ihex $< $@ -I binary

$(obj)u-boot.ldr.srec:    $(obj)u-boot.ldr
        $(OBJCOPY) ${OBJCFLAGS} -O srec $< $@ -I binary

$(obj)u-boot.img:    $(obj)u-boot.bin
        ./tools/mkimage -A $(ARCH) -T firmware -C none \
        -a $(TEXT_BASE) -e 0 \
        -n $(shell sed -n -e 's/.*U_BOOT_VERSION//p' $(VERSION_FILE) | \
            sed -e 's/"[     ]*$$/ for $(BOARD) board"/') \
        -d $< $@

$(obj)u-boot.imx:       $(obj)u-boot.bin
        $(obj)tools/mkimage -n $(IMX_CONFIG) -T imximage \
        -e $(TEXT_BASE) -d $< $@

$(obj)u-boot.kwb:       $(obj)u-boot.bin
        $(obj)tools/mkimage -n $(KWD_CONFIG) -T kwbimage \
        -a $(TEXT_BASE) -e $(TEXT_BASE) -d $< $@

$(obj)u-boot.sha1:    $(obj)u-boot.bin
        $(obj)tools/ubsha1 $(obj)u-boot.bin

$(obj)u-boot.dis:    $(obj)u-boot
        $(OBJDUMP) -d $< > $@

GEN_UBOOT = \
        UNDEF_SYM=`$(OBJDUMP) -x $(LIBBOARD) $(LIBS) | \
        sed  -n -e 's/.*\($(SYM_PREFIX)__u_boot_cmd_.*\)/-u\1/p'|sort|uniq`;\
        cd $(LNDIR) && $(LD) $(LDFLAGS) $$UNDEF_SYM $(__OBJS) \
            --start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \
            -Map u-boot.map -o u-boot
$(obj)u-boot:    depend $(SUBDIRS) $(OBJS) $(LIBBOARD) $(LIBS) $(LDSCRIPT) $(obj)u-boot.lds
****LDSCRIPT是一个和nand相关的的u-boot.lds的脚本？
        $(GEN_UBOOT)
ifeq ($(CONFIG_KALLSYMS),y)
        smap=`$(call SYSTEM_MAP,u-boot) | \
            awk '$$2 ~ /[tTwW]/ {printf $$1 $$3 "\\\\000"}'` ; \
        $(CC) $(CFLAGS) -DSYSTEM_MAP="\"$${smap}\"" \
            -c common/system_map.c -o $(obj)common/system_map.o
        $(GEN_UBOOT) $(obj)common/system_map.o
endif
****产生Elf格式的U-boot，用于其它目标的转换
$(OBJS):    depend
        $(MAKE) -C cpu/$(CPU) $(if $(REMOTE_BUILD),$@,$(notdir $@))

$(LIBS):    depend $(SUBDIRS)
        $(MAKE) -C $(dir $(subst $(obj),,$@))

$(LIBBOARD):    depend $(LIBS)
        $(MAKE) -C $(dir $(subst $(obj),,$@))

$(SUBDIRS):    depend
        $(MAKE) -C $@ all

$(LDSCRIPT):    depend
        $(MAKE) -C $(dir $@) $(notdir $@)

$(obj)u-boot.lds: $(LDSCRIPT)
        $(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - <$^ >$@

$(NAND_SPL):    $(TIMESTAMP_FILE) $(VERSION_FILE) $(obj)include/autoconf.mk
        $(MAKE) -C nand_spl/board/$(BOARDDIR) all

$(U_BOOT_NAND):    $(NAND_SPL) $(obj)u-boot.bin
        cat $(obj)nand_spl/u-boot-spl-16k.bin $(obj)u-boot.bin > $(obj)u-boot-nand.bin

$(ONENAND_IPL):    $(TIMESTAMP_FILE) $(VERSION_FILE) $(obj)include/autoconf.mk
        $(MAKE) -C onenand_ipl/board/$(BOARDDIR) all

$(U_BOOT_ONENAND):    $(ONENAND_IPL) $(obj)u-boot.bin
        cat $(ONENAND_BIN) $(obj)u-boot.bin > $(obj)u-boot-onenand.bin

$(VERSION_FILE):
        @( printf '#define U_BOOT_VERSION "U-Boot %s%s"\n' "$(U_BOOT_VERSION)" \
         '$(shell $(TOPDIR)/tools/setlocalversion $(TOPDIR))' ) > $@.tmp
        @cmp -s $@ $@.tmp && rm -f $@.tmp || mv -f $@.tmp $@

$(TIMESTAMP_FILE):
        @date +'#define U_BOOT_DATE "%b %d %C%y"' > $@
        @date +'#define U_BOOT_TIME "%T"' >> $@

gdbtools:
        $(MAKE) -C tools/gdb all || exit 1

updater:
        $(MAKE) -C tools/updater all || exit 1

env:
        $(MAKE) -C tools/env all MTD_VERSION=${MTD_VERSION} || exit 1

# Explicitly make _depend in subdirs containing multiple targets to prevent
# parallel sub-makes creating .depend files simultaneously.
depend dep:    $(TIMESTAMP_FILE) $(VERSION_FILE) $(obj)include/autoconf.mk
        for dir in $(SUBDIRS) cpu/$(CPU) $(dir $(LDSCRIPT)) ; do \
            $(MAKE) -C $$dir _depend ; done

TAG_SUBDIRS = $(SUBDIRS)
TAG_SUBDIRS += $(dir $(__LIBS))
TAG_SUBDIRS += include

tags ctags:
        ctags -w -o $(obj)ctags `find $(TAG_SUBDIRS) \
                        -name '*.[chS]' -print`

etags:
        etags -a -o $(obj)etags `find $(TAG_SUBDIRS) \
                        -name '*.[chS]' -print`
cscope:
        find $(TAG_SUBDIRS) -name '*.[chS]' -print > cscope.files
        cscope -b -q -k

SYSTEM_MAP = \
        $(NM) $1 | \
        grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] \)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' | \
        LC_ALL=C sort
$(obj)System.map:    $(obj)u-boot
        @$(call SYSTEM_MAP,$<) > $(obj)System.map

#
# Auto-generate the autoconf.mk file (which is included by all makefiles)
#
# This target actually generates 2 files; autoconf.mk and autoconf.mk.dep.
# the dep file is only include in this top level makefile to determine when
# to regenerate the autoconf.mk file.
$(obj)include/autoconf.mk.dep: $(obj)include/config.h include/common.h
    @$(XECHO) Generating $@ ; \
    set -e ; \
    : Generate the dependancies ; \
    $(CC) -x c -DDO_DEPS_ONLY -M $(HOSTCFLAGS) $(CPPFLAGS) \
        -MQ $(obj)include/autoconf.mk include/common.h > $@

$(obj)include/autoconf.mk: $(obj)include/config.h
    @$(XECHO) Generating $@ ; \
    set -e ; \
    : Extract the config macros ; \
    $(CPP) $(CFLAGS) -DDO_DEPS_ONLY -dM include/common.h | \
        sed -n -f tools/scripts/define2mk.sed > $@.tmp && \
    mv $@.tmp $@

#########################################################################
else    # !config.mk
all $(obj)u-boot.hex $(obj)u-boot.srec $(obj)u-boot.bin \
$(obj)u-boot.img $(obj)u-boot.dis $(obj)u-boot \
$(filter-out tools,$(SUBDIRS)) $(TIMESTAMP_FILE) $(VERSION_FILE) gdbtools \
updater env depend dep tags ctags etags cscope $(obj)System.map:
    @echo "System not configured - see README" >&2
    @ exit 1

tools:
    $(MAKE) -C tools
tools-all:
    $(MAKE) -C tools HOST_TOOLS_ALL=y
endif    # config.mk

.PHONY : CHANGELOG
CHANGELOG:
    git log --no-merges U-Boot-1_1_5.. | \
    unexpand -a | sed -e 's/\s\s*$$//' > $@

include/license.h: tools/bin2header COPYING
     cat COPYING | gzip -9 -c | ./tools/bin2header license_gzip > include/license.h
#########################################################################

unconfig:
    @rm -f $(obj)include/config.h $(obj)include/config.mk \
        $(obj)board/*/config.tmp $(obj)board/*/*/config.tmp \
        $(obj)include/autoconf.mk $(obj)include/autoconf.mk.dep

%: %_config
    $(MAKE)


Makefile就分析到这，对all目标建立过程这段还是分析的很粗糙，这段主要是参考网友的观点，我现在SHELL这块还很薄弱，先分析到这，以后再补充。下面分析mkconfig文件。