arm linux下rootfs制作

1.下载最新版本busybox(busybox-1.14.3.tar.bz2)
2.交叉编译busybox
解压进入其目录，执行：
#make ARCH=arm-linux CROSS_COMPLIE=arm-linux-  menuconfig
选择编译成动态库加载模式(Build shared libbusybox)
CROSS_COMPLIER prefix(arm-linux)
ADDitional CFLAGS再填入-march=armv6
指定安装目录(./install)BusyBox installation  prefix
后面用到
PS1='[\u@\h\W]\$'
分别表示的是当前用户、主机名和当前目录
busybox settings->busybox library tuning->username completion、fancy shell prompts选上

#make
#make install

3.创建文件系统目录
#mkdir rootfs
#cd rootfs
#mkdir  dev etc lib proc sys usr mnt tmp var
#cp (**/busybox/)install ./
#cp -rf (**/busybox/)examples/bootfloppy/etc/ ./
#sudo mknod -m 666 dev/console c 5 1
#sudo mknod -m 666 dev/ttyS0 c 4 64
#sudo mknod -m 666 dev/ttyS1 c 4 65
#sudo mknod -m 666 dev/null c 1 3
#cp /usr/local/arm/4.2.2-eabi/lib/ld* lib/
#cp /usr/local/arm/4.2.2-eabi/lib/libc-2.6.1.* lib/
#cp /usr/local/arm/4.2.2-eabi/lib/libc.so* lib/
#cp /usr/local/arm/4.2.2-eabi/lib/libm.so.6 lib/
#cp /usr/local/arm/4.2.2-eabi/lib/libm-2.6.1.so lib/
#cp /usr/local/arm/4.2.2-eabi/lib/libcrypt* lib/
#cp /usr/local/arm/4.2.2-eabi/usr/lib/libdl.so  lib/
#cp /usr/local/arm/4.2.2-eabi/usr/lib/libpthread.so  lib/
#cp /usr/local/arm/4.2.2-eabi/usr/lib/libz.so* lib/
#cp /usr/local/arm/4.2.2-eabi/usr/lib/libbz2.so  lib/
#cp /usr/local/arm/4.2.2-eabi/usr/arm-unknown-linux-gnueabi/lib/libstdc++.so* lib/
#cd lib
#然后把同样大小的文件删除一个，另一个用ln -s链接出来
类似这样
rm libstdc++.so libstdc++.so.6
ln -s libstdc++.so.6.0.9 libstdc++.so
ln -s libstdc++.so.6.0.9 libstdc++.so.6

strip一下文件系统：
#arm-linux-strip  bin/busybox
#arm-linux-strip  lib/*

udev配置
1、wget http://www.us.kernel.org/pub/linux/utils/kernel/hotplug/udev-100.tar.bz2
2、tar xjf udev-100.tar.bz2
3、cd udev-100 编辑Makefile，查找CROSS_COMPILE，修改CROSS_COMPILE ?= arm-linux-
4、make
在嵌入式系统里，我们只需要udevd和udevadm就能使udev工作得很好
把生成的udevadm,udevd复制到sbin目录下，然后做下链接
ln -s udevadm udevcontrol
ln -s udevadm udevsettle
ln -s udevadm udevtrigger

修改etc下配置文件
etc/udev/udev.conf
内容可以为空
etc/udev/rules.d目录添加具体规则
-------------------------------------
更改为使用busybox自带的mdev,上面的蓝色部分udev可以不用了
etc/mdev.conf
填入自己的mdev rules
etc/fstab
proc    /proc   proc defaults 0 0
none    /tmp    ramfs   defaults 0 0
none    /var    ramfs   defaults 0 0
mdev    /dev    ramfs   defaults 0 0
sysfs   /sys    sysfs   defaults 0 0
--------------------------------------------
etc/inittab
::sysinit:/etc/init.d/rcS
::respawn:-/bin/sh
::ctrlaltdel:/bin/umount -a -r
::shutdown:/bin umount -a -r
::shutdown:/sbin/swapoff -a
--------------------------------------------
etc/profile
# /etc/profile: system-wide .profile file for the Bourne shells

echo
echo -n "Processing /etc/profile... "
# Set search library path
export LD_LIBRARY_PATH=/lib:/usr/lib

# set user path
export PATH=/bin:/sbin:/usr/bin:/usr/sbin

#Set PS1
PS1='[\u@\h\W]\$'
#export PS1="\\e[05;32m[$USER@\\w\\a]\\$\\e[00;34m"
PATH=$PATH
echo "Set local script:/usr/etc/rc.local...."
source /usr/etc/rc.local
echo "Done"
echo
--------------------------------------------
etc/hostname
arm-linux
--------------------------------------------
etc/init.d/rcS
#! /bin/sh

/bin/mount -a

# devpts doesn't mount since mounting /dev wipes /dev/pts
mkdir /dev/pts
date
echo "S: devpts"
mount -t devpts none /dev/pts

# Udev seems to throw a warning if /dev/null is not found
mknod /dev/null c 1 3

# Set hostname if the corresponding file is found
if test -e /etc/hostname; then
    hostname -F /etc/hostname
fi

date

echo "S: udev"
if test -x /sbin/udevd ;
then
  echo "Starting udev..." >> /boot.log
  /sbin/udevd --daemon
  echo "Trigger initial udev events..." >> /boot.log
  /sbin/udevtrigger

  echo "Waiting for the udevd to settle..." >> /boot.log
  /sbin/udevsettle
fi
--------------------------------------
更改为使用mdev,上面蓝色部分可以不要了

/bin/echo /sbin/mdev > /proc/sys/kernel/hotplug
mdev -s