建立精简的linux文件系统

• 建立16M的ramdisk,在grub启动参数中加入下面这行,如何加入参数，查看启动时grub下面的提示。

   
  ramdisk_size=16384
  

• 建立ext2文件系统，mount到系统中,假设为dom目录

  mke2fs /dev/ram0 -m0
  mount /dev/ram0 /mnt/dom -o loop
  

• 下载Busybox，在google中可以随便搜到，解压，选择系统需要的程序或服务，编译，并拷到ramdisk中

  tar xjf busybox?????.tar.gz2
  make menuconfig
  make
  make install (如果缺省安装在当前目录下的_install目录下）
  cd _install
  cp * /mnt/dom -r
  

－ 建立系统设备的结点文件，原则上每个结点都建立，但是比较麻烦,可以用以下脚本完成。(由刘火明提供)

#!/bin/sh
#
# makedev.sh - creates device files for a busybox boot floppy image


# we do our work in the dev/ directory
if [ -z "$1" ]; then
	echo "usage: `basename $0` path/to/dev/dir"
	exit 1
fi

cd $1


# miscellaneous one-of-a-kind stuff
mknod console c 5 1
ln -s /proc/kcore core
mknod fb0 c 29 0
mknod full c 1 7
mknod kmem c 1 2
mknod mem c 1 1
mknod null c 1 3
mknod port c 1 4
mknod random c 1 8
mknod urandom c 1 9
mknod zero c 1 5
mknod sda1 b 8 1

# IDE HD devs
# note: not going to bother creating all concievable partitions;
＃ you can do that yourself as you need 'em.
#mknod hda b 3 0
# loop devs
for i in `seq 0 10`; do
        mknod hda$i b 3 $i
done

#mknod hdb b 3 64
# loop devs
for i in `seq 64 74`; do
        mknod hdb$i b 3 $i
done

#mknod hdc b 22 0
# loop devs
for i in `seq 0 10`; do
        mknod hdc$i b 22 $i
done

#mknod hdd b 22 64
# loop devs
for i in `seq 64 74`; do
        mknod hdd$i b 22 $i
done


# loop devs
for i in `seq 0 7`; do
	mknod loop$i b 7 $i
done

# ram devs
for i in `seq 0 9`; do
	mknod ram$i b 1 $i
done
ln -s ram1 ram

# ttys
mknod tty c 5 0
for i in `seq 0 9`; do
	mknod tty$i c 4 $i
done

# virtual console screen devs
for i in `seq 0 9`; do
	mknod vcs$i b 7 $i
done
ln -s vcs0 vcs

# virtual console screen w/ attributes devs
for i in `seq 0 9`; do
	mknod vcsa$i b 7 $i
done
ln -s vcsa0 vcsa

• 建立各种linux的目录，如root，home，etc，tmp，var等,可以参照一个普通的linux的目录结构。

  mkdir root tmp etc ....
  

• 把busybox下面的example下的etc目录下载设置文件拷到dom里面。主要是启动时的某些配置文件。

  cp busybox-1.00-pre9/examples/bootfloppy/etc/* /mnt/dom/etc -r
  

• 如果需要可以把自己的程序放到dom目录下
• 建立镜像dom,并压缩成dom.gz

  umount /mnt/dom
  dd if=/dev/ram0 of=dom bz=16384k count=1
  gzip dom
  

• 建立windows98的启动环境，把内核bzImage，loadlin.exe，dom.gz拷到windows目录下，利用 以下提供的文件启动 ，config 和 linux.bat

config

c:\bzImage             # first value must be the filename of the Linux-kernel
root=/dev/ram0       # the device which gets mounted as root FS
rw                   # mount it read-write

initrd=\dom2.gz    # this file gets loaded as 'initial ramdisk'
init=linuxrc         # start /linuxrc script from initrd.gz image
load_ramdisk=1       # 
prompt_ramdisk=1     # we do not need to be prompted
ramdisk_size=16384    # our initrd.gz is 7777 KB of size when unpacked

linux.bat

REM #########################################################################
REM DOS batch file to boot Linux.


REM First, ensure any unwritten disk buffers are flushed:
@smartdrv /C

REM Start the LOADLIN process:
cls
loadlin @config %1 %2 %3 %4 %5 %6 %7 %8 %9

REM #########################################################################