Linux系统裁剪笔记之二insmod

Posted 2020-08-21

Linux系统裁剪笔记之二

1.什么裁剪?

本篇文章的主要目的是让笔者和读者更深的认识Linux系统的运作方式,大致内容就是把Linux拆开自己一个个组件来组装,然后完成一个微型的Linux系统.下面,让我们来实现吧..写的不好的地方请指教.

2.原理

大家都知道,操作系统的启动流程是(主要是Linux):POST—>Bios—>MBR—kernel-->initrd-->sbin/init,

POST,BIOS都不是我们管的,所以这里我们从MBR开始,Linux的系统引导先主要是用的grub这个软件,grub引导系统了,然后启动内核,内核调用initrd来实现最基本的操作系统,

3.实验 (所有操作均在虚拟机上实现，且定义硬盘时选IDE)

  环境：1).在宿主机上安装一台红帽子Linux5.4，/dev/sda上安装操作系统；

    2).在宿主机上新建一个新硬盘：/dev/hda，且分区为20M的sdb1，512M的sdb2；

    3).另建立一台测试虚拟机，将原有的硬盘删除，再将硬盘/dev/hda的新增到该测试虚拟机；

    4).系统服务启动时显示开启状态；

    5).新增启动网络模块；

   6).新增内核控制模块；

1.单用户模式无根文件系统无写入权限时使用该命令改为可读写

mount -n -o remount,rw /

2.单用户模式启用关机命令，(复制halp boot相关命令用户库文件 )

[[email protected] ~]# cat /mnt/sysroot/etc/rc.d/rc.sysdone #加可执行权限
#!/bin/bash
sync
sleep 2
sync
exec /sbin/halt -p
[[email protected] ~]# cat /mnt/sysroot/etc/inittab#加可执行权限
id:3:initdefault:
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc.sysdone

3.单用户模式启用重启命令

[[email protected] ~]# cat /mnt/sysroot/etc/rc.d/rc.sysreboot #加可执行权限
#!/bin/bash
sync
sleep 2
sync
exec /sbin/reboot

[[email protected] ~]# cat /mnt/sysroot/etc/inittab#加可执行权限
id:3:initdefault:
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc.sysdone

l6:6:wait:/etc/rc.d/rc.sysreboot

3.单用户模式启用关机和重启命令 (sysroot1.gz)

[[email protected] sysroot]# vim /mnt/sysroot/etc/rc.d/init.d/halt

#!/bin/bash
case $0 in

 *reboot)

   COMMAND=‘/sbin/halt -p‘ ;;

 *halt)

   COMMAND=‘/sbin/reboot‘ ;;

 *)

   echo "Only call this script by *reboot OR *halt;"

esac

case $1 in

start)

;;

stop)

;;

*)

echo "Usage : `basename $0` {start|stop}";;

esac

exec $COMMAND
[[email protected] sysroot]# chmod +x etc/rc.d/init.d/halt
[[email protected] sysroot]# ll etc/rc.d/init.d/halt
-rwxr-xr-x 1 root root 259 Nov 24 14:23 etc/rc.d/init.d/halt
[[email protected] rc.d]# ls /mnt/sysroot/etc/rc.d
init.d  rc.reboot  rc.sysdone  rc.sysinit  rc.sysreboot
 [[email protected] rc.d]# ls init.d/
halt
 [[email protected] rc0.d]# ln -sv ../init.d/halt S99halt

create symbolic link `S99halt‘ to `../init.d/halt‘ 
 [[email protected] rc6.d]# ln -sv ../init.d/halt S99reboot
create symbolic link `S99reboot‘ to `../init.d/halt‘
 [[email protected] rc.d]# vim rc
#!/bin/bash
#
for I in /etc/rc.d/rc$RUNLEVEL.d/K*; do
  $I stop
done
for I in /etc/rc.d/rc$RUNLEVEL.d/S*; do
  $I start
done
[[email protected] etc]#vim /mnt/sysroot/etc/inittab

id:3:initdefault:
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc 0
l6:6:wait:/etc/rc.d/rc 6

[[email protected] etc]#vim /mnt/sysroot/etc/rc.d/init.d/tserver

#!/bin/bash
#chkconfig: 35 77 22
#description: test service script

. /etc/rc.d/init.d/functions
prog=tserver
lockfile=/var/lock/subsys/$prog

start(){
  touch $lockfile
  [ $? -eq 0 ] &&success "starting $prog" || failure "Starting $prog"
}

stop(){
  rm -f $lockfile
  [ $? -eq 0 ] &&success "stopping $prog" || failure "Stopping $prog"

}
 
status(){
  if [ -f $lockfile ];then
     echo "Running..."
  else
    echo "Stopped..."
  fi
}
 
usage() {
  echo "Usage:$prog {start|stop|status|restart}"
}
 
case $1 in
start)
  start ;;
stop)

  stop ;;
restart)
  stop
  start ;;
status)
  status ;;
*)
  usage
  exit 1 ;;
esac

[[email protected] sysroot]# vim /mnt/sysroot/etc/fstab
/dev/hda2       /       ext3    defaults        0 0
/dev/hda1       /boot   ext3    defaults        0 0
proc            /proc   proc    defaults        0 0
sysfs           /sys    sysfs   defaults        0 0

4）.新增新增内核控制模块；新增内核控制模块；

[[email protected] sysroot]# vi /mnt/sysroot/etc/rc.d/rc.sysinit
#!/bin/bash
#
echo -e "Welcome to \033[34mJack\033[0m Linux  xxxxx"
echo "Remount rootfs..."

mount -n -o remount,rw /

echo "Set the hostname..."
[ -f /etc/sysconfig/network ] && . /etc/sysconfig/network
[ -z $HOSTNAME -o "HOSTNAME" == ‘(none)‘ ] && HOSTNAME=localhost
/bin/hostname $HOSTNAME

[[email protected] sysroot]# cat etc/sysconfig/network
HOSTNAME=miniLinux.jack.com

[[email protected] sysroot]# chroot /mnt/sysroot/   #小系统中验证是否有问题
bash-3.2# /etc/rc.d/rc.sysinit
Welcome to Jack Linux  xxxxx
Remount rootfs...
Set the hostname...
bash-3.2# exit

以下图中报错是缺少sh的链接

[[email protected] bin]# pwd
/mnt/sysroot/bin
[[email protected] bin]# ln -sv ./bash sh 

[[email protected] ~]# vim /mnt/sysroot/etc/inittab

id:3:initdefault:
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc 0
l3:3:wait:/etc/rc.d/rc 3
l6:6:wait:/etc/rc.d/rc 6
1:2345:respawn:/sbin/agetty -n -l /bin/bash 38400 tty1
2:2345:respawn:/sbin/agetty -n -l /bin/bash 38400 tty2
3:2345:respawn:/sbin/agetty -n -l /bin/bash 38400 tty3

以下图片中系统文件错乱时修复方法：打包所有文件后格式化该盘再恢复文件

[[email protected] sysroot]# cd /mnt/sysroot/

[[email protected] sysroot]# ls

[[email protected] sysroot]# find . | cpio -H newc --quiet -o |gzip -9 > /root/sysroot.gz  #打包

[[email protected] ~]# umount  /dev/hda2

[[email protected] ~]# fuser -km /dev/hda2

[[email protected] ~]# umount  /dev/hda2

[[email protected] ~]# mke2fs -j /dev/hda2

[[email protected] ~]#mount /dev/hda2 /mnt/sysroot/

[[email protected] sysroot]# zcat /root/sysroot.gz |cpio -id  #恢复

[[email protected] sysroot]# ls
bin boot dev etc halt home lib  lost+found  media  mnt  opt  proc  root  sbin  sys  tmp  usr  var

[[email protected] sysroot]#vim etc/rc.d/init.d/functions  #被调用的函数   (sysroot2.gz)  

#
SCREEN=`stty -F /dev/console size`
COLUMNS=${SCREEN#* }
 
SPA_COL=$[$COLUMNS-12]
RED=‘\033[1;31m‘
GREEN=‘\033[32m‘
YELLOW=‘\033[33m‘
BLUE=‘\033[34m‘
NORMAL=‘\033[0m‘
 
success(){
  string=$1
  RT_SPA=$[$SPA_COL-${#string}]
  echo -n "$string"
  for I in `seq 1 $RT_SPA` ;do
    echo -n " "
  done
  echo  -e "[    ${GREEN}OK${NORMAL}    ]"
}
 
failure(){
  string=$1
  RT_SPA=$[$SPA_COL-${#string}]
  echo -n "$string"
  for I in `seq 1 $RT_SPA` ;do
    echo -n " "
  done
  echo  -e "[  ${RED}Failure${NORMAL} ]"
}

[[email protected] sysroot]# vim etc/rc.d/rc.sysinit 

#!/bin/bash
#
echo -e "Welcome to \033[1;31mJack\033[0m Linux  xxxxx"
echo "Remount rootfs..."
mount -n -o remount,rw /
 
echo "Set the hostname..."
[ -f /etc/sysconfig/network ] && . /etc/sysconfig/network
[ -z $HOSTNAME -o "HOSTNAME" == ‘(none)‘ ] && HOSTNAME=localhost
/bin/hostname $HOSTNAME
 
echo "Initalizing network device ..."
/sbin/insmod /lib/modules/mii.ko
/sbin/insmod /lib/modules/pcnet32.ko

/sbin/insmod /lib/modules/e1000.ko

5）.新增启动网络模块，请确认网卡型号  (sysroot.netmod.3.gz)

[[email protected] sysroot]#  modinfo mii    #加载网卡模块PCNET32

[[email protected] sysroot]# cp /lib/modules/2.6.18-164.el5PAE/kernel/drivers/net/mii.ko lib/modules

[[email protected] sysroot]#  modinfo pcnet32

[[email protected] sysroot]# cp /lib/modules/2.6.18-164.el5PAE/kernel/drivers/net/pcnet32.ko lib/modules

[[email protected] ~]# modinfo e1000      #加载网卡模块e1000

[[email protected] sysroot]# cp /lib/modules/2.6.18-164.el5PAE/kernel/drivers/net/e1000/e1000.ko lib/modules

[[email protected] init.d]# vim /mnt/sysroot/etc/rc.d/init.d/network

 #!/bin/bash
#
# chkconfig:35 09 90
# description: network service
prog=network
. /etc/rc.d/init.d/functions
CONF=/etc/sysconfig/network-scripts/ifcfg-eth0
. $CONF
NETMASK=22
 
start() {
  ifconfig eth0 $IPADDR/$NETMASK up
  [ -z $GATEWAY ] && route add default gw $GATEWAY
  return 0
}
stop() {
  ifconfig eth0 down
}
status() {
  ifconfig eth0
}
usage() {
  echo "$prog: {start|stop|restart|status|"
}
case $1 in
start)

  start
  success "Config network eth0." ;;
stop)
  stop
  success "Stop network card eth0." ;;
restart)
  stop
  start
  success "Restart network card eth0" ;;
status)
  status ;;
*)
  usage
  exit 1 ;;
esac

[[email protected] sysroot]# vi /mnt/sysroot/etc/rc.d/rc.sysinit

#!/bin/bash
#
. /etc/rc.d/init.d/functions
 
echo -e "Welcome to \033[1;31mJack\033[0m Linux  xxxxx"
 
echo "Remount rootfs..."
mount -n -o remount,rw /
[ $? -eq 0 ] && success "Remount rootfs" || failure "Remount rootfs"
 
mount -a
[ $? -eq 0 ] && success "Mount others filesystem" || failure "Mount others filesystem"
 

 #grep -v "\<swap|proc|sysfs\>" /etc/fstab |awk ‘{print $1}‘ |while read LINE; do awk ‘{print $1}‘ /proc/mounts |grep "^$LINE$"; done

echo "Set the hostname..."
[ -f /etc/sysconfig/network ] && . /etc/sysconfig/network
[ -z $HOSTNAME -o "HOSTNAME" == ‘(none)‘ ] && HOSTNAME=localhost
/bin/hostname $HOSTNAME
[ $? -eq 0 ] && success "Set the hostname" || failure "Set the hostname"
 
echo "Initalizing network device ..."
/sbin/insmod /lib/modules/e1000.ko
[ $? -eq 0 ] && success "Initializing network device" || failure "Initializing network device"
 
ifconfig lo 127.0.0.1/8
[ $? -eq 0 ] && success "Activating loopback network device" || failure "Activating loopback network device"
 

以下图片中启动报错，查找N小时才找到的问题是：将目录el5写错成e15

6）.新增内核控制模块  (sysroot.kernel.4.gz)

[[email protected] ~]# vi /mnt/boot/grub/grub.conf   #加上quiet开机时将不加输出详细信息

default=0
timeout=5
title Jack Linux (2.6.18)
        root(hd0,0)
        kernel /vmlinuz ro root=/dev/hda2 quiet
        initrd /initrd.gz

[[email protected] ~]# cat /mnt/sysroot/etc/sysctl.conf
# Controls IP packet forwarding
net.ipv4.ip_forward = 1

[[email protected] ~]#cat /proc/sys/net/ipv4/ip_forward

1

[[email protected] sysroot]# cat etc/rc.d/rc.sysinit   #加上以下两行，以开机时启动内核设置文件

...

sysctl -p &> /dev/null
[ $? -eq 0 ] && success "Set Kernel Parameter" || failure "Set Kernel Parameter"

附：vi中set命令

:syntax on        #开启语法高亮显示

:set ai           #让vi自动对齐

:set noai         #取消自动对齐
:set showmatch    #高亮显示
:set noshowmatch  #不高亮显示
:set tabstop=4    #设置制表停止位(tabstop)的长度
:set shiftwidth=4 #当使用移动(shift)命令时移动的字符数
:set cindent      #在C编码时,自动完成indent缩进内嵌代码块
:set smartindent  #为C程序提供自动缩进
:set ff=unix      #将文件格式转为unix格式

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