如何深入分析arm9_uboot_Makefile的结构与组成？

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1. 解压文件：使用 `tar xjf u-boot-1.1.6.tar.bz2` 命令。

2.应用补丁：执行 `patch -p1

3.配置编译：运行 `make 100ask24x0_config`，然后在 Makefile 和 MKCONFIG 中设置：`$ (SRCTREE)/mkconfig unconfig`。

1.解压缩

tar xjf u-boot-1.1.6.tar.bz2

2.打补丁

patch -p1 < ../u-boot-1.1.6_jz2440.patch

3.配置

make 100ask24x0_config，下面为Makefile

MKCONFIG := $(SRCTREE)/mkconfig unconfig:　　　　　　#清楚配置信息 @rm-f$(obj)include/config.h$(obj)include/config.mk\ $(obj)board/*/config.tmp$(obj)board/*/*/config.tmp 100ask24x0_config:unconfig @$(MKCONFIG)$(@:_config=)armarm920t100ask24x0NULLs3c24x0

#上面这段翻译为：mkconfig 100ask24x0 armarm920t100ask24x0NULLs3c24x0

make 100ask24x0_config这个命令执行的就是mkconfig 100ask24x0 armarm920t100ask24x0NULLs3c24x0这个脚本，下面我们看下mkconfig文件

#!/bin/sh-e
#Scripttocreateheaderfilesandlinkstoconfigure #U-Bootforaspecificboard. # #Parameters:TargetArchitectureCPUBoard[VENDOR][SOC] # #(C)2002-2006DENXSoftwareEngineering,WolfgangDenk< [emailprotected]> #
APPEND=no#Default:Createnewconfigfile BOARD_NAME=""#Nametoprintinmakeoutput
#mkconfig100ask24x0armarm920t100ask24x0NULLs3c24x0
#$0$1$2$3$4$5$6
["${BOARD_NAME}"]||BOARD_NAME="$1"
[$#-lt4]&&exit1 [$#-gt6]&&exit1
echo"Configuringfor${BOARD_NAME}board..."
# #Createlinktoarchitecturespecificheaders # cd./include rm-fasm ln-sasm-$2asm#ln-sasm-armasm创建链接文件，以指定特定架构
rm-fasm-$2/arch
ln-s${LNPREFIX}arch-$6asm-$2/arch #ln -s arch-s3c24x0 asm-arm/arch

if["$2"="arm"];then rm-fasm-$2/proc ln-s${LNPREFIX}proc-armvasm-$2/proc #ln -sproc-armvasm-arm/proc fi
# #CreateincludefileforMake # echo"ARCH=$2">config.mk #新建 echo"CPU=$3">>config.mk #添加 echo"BOARD=$4">>config.mk #添加
["$5"]&&["$5"!="NULL"]&&echo"VENDOR=$5">>config.mk #NULL
["$6"]&&["$6"!="NULL"]&&echo"SOC=$6">>config.mk #添加
# #Createboardspecificheaderfile # if["$APPEND"="yes"]#Appendtoexistingconfigfile then echo>>config.h else >config.h#新建 fi echo"/*Automaticallygenerated-donotedit*/">>config.h echo"#include<configs/$1.h>">>config.h
exit0

mkconfig新建的文件打印内容如下：

4.编译

make

继续提取Makefile一些主要成分:

# load ARCH, BOARD, and CPU configuration include $(OBJTREE)/include/config.mk ifeq ($(ARCH),arm) CROSS_COMPILE = arm-linux- # U-Boot objects....order is important (i.e. start must be first) OBJS = cpu/$(CPU)/start.o LIBS = lib_generic/libgeneric.a LIBS += board/$(BOARDDIR)/lib$(BOARD).a LIBS += cpu/$(CPU)/lib$(CPU).a ALL = $(obj)u-boot.srec $(obj)u-boot.bin $(obj)System.map $(U_BOOT_NAND) all: $(ALL)

$(obj)u-boot.bin:$(obj)u-boot $(OBJCOPY)${OBJCFLAGS}-Obinary$< [emailprotected] $(obj)u-boot:dependversion$(SUBDIRS)$(OBJS)$(LIBS)$(LDSCRIPT) UNDEF_SYM=`$(OBJDUMP)-x$(LIBS)|sed-n-e‘s/.*\(__u_boot_cmd_.*\)/-u\1/p‘|sort|uniq`;\ cd$(LNDIR)&&$(LD)$(LDFLAGS)$$UNDEF_SYM$(__OBJS)\ --start-group$(__LIBS)--end-group$(PLATFORM_LIBS)\ -Mapu-boot.map-ou-boot

# LDFLAGS在根目录config.mk中： LDFLAGS+=-Bstatic-T$(LDSCRIPT)-Ttext$(TEXT_BASE)$(PLATFORM_LDFLAGS) #TEXT_BASE在board/100ask24x0/config.mk中：TEXT_BASE = 0x33F80000

再看一下u-boot.lds

/* * (C) Copyright 2002 * Gary Jennejohn, DENX Software Engineering, <[emailprotected]> * * 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 */ OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm") /*OUTPUT_FORMAT("elf32-arm", "elf32-arm", "elf32-arm")*/ OUTPUT_ARCH(arm) ENTRY(_start) SECTIONS { . = 0x00000000; //0x33F80000这个地址是0x30000000+64M-512Kb所在位置，当uboot大于512就要修改这个地址 . = ALIGN(4); .text : { cpu/arm920t/start.o (.text) board/100ask24x0/boot_init.o (.text) *(.text) } . = ALIGN(4); .rodata : { *(.rodata) } . = ALIGN(4); .data : { *(.data) } . = ALIGN(4); .got : { *(.got) } . = .; __u_boot_cmd_start = .; .u_boot_cmd : { *(.u_boot_cmd) } __u_boot_cmd_end = .; . = ALIGN(4); __bss_start = .; .bss : { *(.bss) } _end = .; }