从u-boot-2012.10那里拷贝个mkimage工具放在/usr/bin目录下，在make uImage时发现load address 和entry
point都是0x50008000.结果u-boot在bootm命令后一直停在starting kernel......
手工改entry point=0x50008040就可以启动了。那么，怎样让make uImage自动把entry point设置为50008040呢？
网上有资料说arch/arm/boot/里面的Makefile文件中：
把
$(obj)/uImage: STARTADDR=$(LOADADDR)
改为
$(obj)/uImage: STARTADDR=$(shell echo $(LOADADDR) | sed -e "s/..$$/40/")
其中，sed -e "s/..$$/40/"的意思是，把输出的字符串的最后两个字符删掉，并且用40来补充，也可以理解为，
把字符串最后两个字符用40来替换。
通过对比3.0.1版本和3.6.7版本发现前者有这样的内容，但后者的make file却找不到
STARTADDR这变量。找了半天才发现，linux3.6.7版本中设置mkimage传递的参数不是放在arch/arm/boot目录的
makefile中，而是放在scripts目录下的makefile.lib文件中，内容如下：
# U-Boot mkimage
# ---------------------------------------------------------------------------
MKIMAGE := $(srctree)/scripts/mkuboot.sh
# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
# the number of overrides in arch makefiles
UIMAGE_ARCH ?= $(SRCARCH)
UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
UIMAGE_OPTS-y ?=
UIMAGE_TYPE ?= kernel
UIMAGE_LOADADDR ?= arch_must_set_this
#UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)##这是原来的配置
UIMAGE_ENTRYADDR =$(shell echo $(UIMAGE_LOADADDR) | sed -e "s/..$$/40/")##这是我修改后的配置
UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
UIMAGE_IN ?= $< UIMAGE_OUT ?= $@
quiet_cmd_uimage = UIMAGE $(UIMAGE_OUT)
cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux
-C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y)
-T $(UIMAGE_TYPE)
-a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR)
-n $(UIMAGE_NAME) -d $(UIMAGE_IN) $(UIMAGE_OUT)
通过上面修改后，make uImage如下：
root@ubuntu:/home/my/linux-3.6.7# make uImage
CHK include/linux/version.h
CHK include/generated/utsrelease.h
make[1]: “include/generated/mach-types.h”是最新的。
CALL scripts/checksyscalls.sh
CHK include/generated/compile.h
Kernel: arch/arm/boot/Image is ready
Kernel: arch/arm/boot/zImage is ready
UIMAGE arch/arm/boot/uImage
Image Name: Linux-3.6.7
Created: Mon Nov 26 12:37:17 2012
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 1476744 Bytes = 1442.13 kB = 1.41 MB
Load Address: 50008000
Entry Point: 50008040
Image arch/arm/boot/uImage is ready