gen_binary_image.md

数据镜像文件制作

Linux中dd命令详解

应用实例1

先生成一个数据为0的镜像文件(data.bin)

dd if=/dev/zero of=data.bin bs=512 count=1

查看镜像文件数据内容

hexdump –C data.bin

修改镜像里的数据(往镜像里写数据LoaderMode)

echo LoaderMode | dd of=data.bin

应用实例2

使用脚本(gen_image.sh)制作一个misc.img内容如下

00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00004000  62 6f 6f 74 2d 72 65 63  6f 76 65 72 79 00 00 00  |boot-recovery...|
00004010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00006000  67 65 6e 74 6f 6f 2d 6c  69 6e 75 78 00 00 00 00  |gentoo-linux....|
00006010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
0000c000

脚本内容如下

#!/usr/bin/env bash

out=./misc.img

pad()
{
   busybox dd if=/dev/zero bs=$1 count=1
}

echo_pad()
{
   echo -n "$1" | busybox dd bs=$2 conv=sync;
}

{
	pad 16k
	echo_pad boot-recovery 8k
	echo_pad gentoo-linux 8k
	pad 16k
} > $out