今天我们来一步步手动构建一个小于10M的类嵌入式Linux系统，所谓"工欲善其事，必先利其器"，所以我们得先准备一下工具才能完成Mini Linux的构建。
环境准备
1、宿主机系统：CentOS5.8 x86_64
2、硬盘：
①/dev/hda1(50M) ext3 boot分区
②/dev/hda2(512M) ext3 /分区
3、Kernel：linux-2.6.39.tar.xz
[root@soysauce tmp]# wget https://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.39.tar.xz
4、busybox：busybox-1.23.2.tar.bz2
[root@soysauce tmp]# wget http://www.busybox.net/downloads/busybox-1.23.2.tar.bz2
5、开发库安装
[root@soysauce tmp]# yum groupinstall -y "Development Tools" "Development Libraries"
一、完成boot(50M)分区和/(512M)分区的创建、格式化及挂载
[root@CentOS5 test]# fdisk -l # 查看所有磁盘及分区Disk /dev/hda: 21.4 GB, 21474836480 bytes15 heads, 63 sectors/track, 44384 cylindersUnits = cylinders of 945 * 512 = 483840 bytesDisk /dev/hda doesn't contain a valid partition tableDisk /dev/sda: 21.4 GB, 21474836480 bytes255 heads, 63 sectors/track, 2610 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System/dev/sda1 * 1 13 104391 83 Linux/dev/sda2 14 2610 20860402+ 8e Linux LVM[root@CentOS5 test]# fdisk /dev/hda # 对/dev/hda进行分区操作The number of cylinders for this disk is set to 44384.There is nothing wrong with that, but this is larger than 1024,and could in certain setups cause problems with:1) software that runs at boot time (e.g., old versions of LILO)2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK)Command (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 1First cylinder (1-44384, default 1): Using default value 1Last cylinder or +size or +sizeM or +sizeK (1-44384, default 44384): +50MCommand (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 2First cylinder (105-44384, default 105): Using default value 105Last cylinder or +size or +sizeM or +sizeK (105-44384, default 44384): +512MCommand (m for help): pDisk /dev/hda: 21.4 GB, 21474836480 bytes15 heads, 63 sectors/track, 44384 cylindersUnits = cylinders of 945 * 512 = 483840 bytes Device Boot Start End Blocks Id System/dev/hda1 1 104 49108+ 83 Linux/dev/hda2 105 1163 500377+ 83 LinuxCommand (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.Syncing disks.[root@CentOS5 test]# partprobe /dev/hda # 通知内核重读分区信息[root@CentOS5 test]# cat /proc/partitions # 查看内核当前已识别的分区信息major minor #blocks name 3 0 20971520 hda 3 1 49108 hda1 3 2 500377 hda2 8 0 20971520 sda 8 1 104391 sda1 8 2 20860402 sda2 253 0 18776064 dm-0 253 1 2064384 dm-1[root@CentOS5 test]# mke2fs -j /dev/hda1 # 格式化/dev/hda1为ext3文件系统mke2fs 1.39 (29-May-2006)Filesystem label=OS type: LinuxBlock size=1024 (log=0)Fragment size=1024 (log=0)12288 inodes, 49108 blocks2455 blocks (5.00%) reserved for the super userFirst data block=1Maximum filesystem blocks=503316486 block groups8192 blocks per group, 8192 fragments per group2048 inodes per groupSuperblock backups stored on blocks: 8193, 24577, 40961Writing inode tables: done Creating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: doneThis filesystem will be automatically checked every 28 mounts or180 days, whichever comes first. Use tune2fs -c or -i to override.[root@CentOS5 test]# mke2fs -j /dev/hda2 # 格式化/dev/hda2为ext3文件系统mke2fs 1.39 (29-May-2006)Filesystem label=OS type: LinuxBlock size=1024 (log=0)Fragment size=1024 (log=0)125488 inodes, 500376 blocks25018 blocks (5.00%) reserved for the super userFirst data block=1Maximum filesystem blocks=6763315262 block groups8192 blocks per group, 8192 fragments per group2024 inodes per groupSuperblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409Writing inode tables: done Creating journal (8192 blocks): doneWriting superblocks and filesystem accounting information: doneThis filesystem will be automatically checked every 29 mounts or180 days, whichever comes first. Use tune2fs -c or -i to override.[root@CentOS5 test]# mount /dev/hda1 /mnt/boot/ # 挂载/dev/hda1至/mnt/boot[root@CentOS5 test]# mount /dev/hda2 /mnt/sysroot/ # 挂载/dev/hda2至/mnt/sysroot[root@CentOS5 test]# tree /mnt/ # 可以看到此时已成功挂载/mnt/|-- boot| `-- lost+found`-- sysroot `-- lost+found4 directories, 0 files
二、提供内核
1、完全编译
[root@soysauce tmp]# lsbusybox-1.23.2 busybox-1.23.2.tar.bz2 linux-2.6.39 linux-2.6.39.tar[root@soysauce tmp]# mv linux-2.6.39 /usr/src/[root@soysauce tmp]# cd /usr/src/[root@soysauce src]# ln -sv linux-linux-2.6.39/ linux-4.2.6/ [root@soysauce src]# ln -sv linux-2.6.39/ linuxcreate symbolic link `linux/linux-2.6.39' to `linux-2.6.39/'[root@soysauce linux]# make [root@soysauce linux]# make modules_install[root@soysauce linux]# make install[root@soysauce linux]# cp arch/x86/boot/bzImage /mnt/boot/vmlinuz
2、部分编译
(1)、只编译某子目录下的相关代码
make dir/make arch/make drivers/net/
(2)、只编译部分模块
make M=drivers/net/
(3)、只编译某一模块
make drivers/net/pcnet32.ko
(4)、将编译完成的结果放置于别的目录中
make O=/tmp/kernel
(5)、交叉编译
make ARCH=
3、二次编译时清理，清理前，如果有需要，请备份配置文件.config
make cleanmake mrproper
三、编译安装busybox
1、解压源码包并执行make menuconfig
[root@soysauce tmp]# lsbusybox-1.23.2.tar.bz2 linux-2.6.39 linux-2.6.39.tar.xz[root@soysauce tmp]# tar xf busybox-1.23.2.tar.bz2 # 解压busybox源码包[root@soysauce tmp]# cd busybox-1.23.2 # 进入busybox源码目录[root@soysauce busybox-1.23.2]# make menuconfig # 定义编译特性，打开图形化窗口 HOSTCC scripts/basic/fixdep HOSTCC scripts/basic/split-include HOSTCC scripts/basic/docproc GEN include/applets.h GEN include/usage.h GEN networking/Kbuild GEN networking/Config.in GEN networking/libiproute/Kbuild GEN networking/udhcp/Kbuild GEN networking/udhcp/Config.in GEN applets/Kbuild GEN shell/Kbuild GEN shell/Config.in GEN archival/Kbuild GEN archival/Config.in GEN archival/libarchive/Kbuild GEN runit/Kbuild GEN runit/Config.in GEN console-tools/Kbuild GEN console-tools/Config.in GEN selinux/Kbuild GEN selinux/Config.in GEN editors/Kbuild GEN editors/Config.in GEN coreutils/Kbuild GEN coreutils/Config.in GEN coreutils/libcoreutils/Kbuild GEN e2fsprogs/Kbuild GEN e2fsprogs/Config.in GEN e2fsprogs/old_e2fsprogs/Kbuild GEN e2fsprogs/old_e2fsprogs/Config.in GEN e2fsprogs/old_e2fsprogs/e2p/Kbuild GEN e2fsprogs/old_e2fsprogs/ext2fs/Kbuild GEN e2fsprogs/old_e2fsprogs/blkid/Kbuild GEN e2fsprogs/old_e2fsprogs/uuid/Kbuild GEN findutils/Kbuild GEN findutils/Config.in GEN util-linux/Kbuild GEN util-linux/Config.in GEN util-linux/volume_id/Kbuild GEN util-linux/volume_id/Config.in GEN procps/Kbuild GEN procps/Config.in GEN modutils/Kbuild GEN modutils/Config.in GEN sysklogd/Kbuild GEN sysklogd/Config.in GEN loginutils/Kbuild GEN loginutils/Config.in GEN debianutils/Kbuild GEN debianutils/Config.in GEN libbb/Kbuild GEN libbb/Config.in GEN scripts/Kbuild GEN miscutils/Kbuild GEN miscutils/Config.in GEN mailutils/Kbuild GEN mailutils/Config.in GEN printutils/Kbuild GEN printutils/Config.in GEN libpwdgrp/Kbuild GEN init/Kbuild GEN init/Config.in HOSTCC scripts/kconfig/conf.o HOSTCC scripts/kconfig/kxgettext.o HOSTCC scripts/kconfig/mconf.o SHIPPED scripts/kconfig/zconf.tab.c SHIPPED scripts/kconfig/lex.zconf.c SHIPPED scripts/kconfig/zconf.hash.c HOSTCC scripts/kconfig/zconf.tab.o HOSTLD scripts/kconfig/mconf HOSTCC scripts/kconfig/lxdialog/checklist.o HOSTCC scripts/kconfig/lxdialog/inputbox.o HOSTCC scripts/kconfig/lxdialog/lxdialog.o HOSTCC scripts/kconfig/lxdialog/menubox.o HOSTCC scripts/kconfig/lxdialog/msgbox.o HOSTCC scripts/kconfig/lxdialog/textbox.o HOSTCC scripts/kconfig/lxdialog/util.o HOSTCC scripts/kconfig/lxdialog/yesno.o HOSTLD scripts/kconfig/lxdialog/lxdialogscripts/kconfig/mconf Config.in## using defaults found in /dev/null#
2、busybox编译方式修改
(1)、先选择Busybox Settings，回车即可
(2)、选择Build Options，回车即可
(3)、选择以静态库方式编译，敲一下空格让前面中括号里面为*即可
(4)、一直按ESC键即可退出，然后保存设置，其他选项修改可自定义
3、安装busybox
[root@soysauce busybox-1.23.2]# make install # 篇幅原因，故只取报错部分，因为依赖新内核的头文件 CC miscutils/ubi_tools.omiscutils/ubi_tools.c:67:26: error: mtd/ubi-user.h: No such file or directorymiscutils/ubi_tools.c: In function ‘ubi_tools_main’:miscutils/ubi_tools.c:106: error: ‘UBI_DEV_NUM_AUTO’ undeclared (first use in this function)miscutils/ubi_tools.c:106: error: (Each undeclared identifier is reported only oncemiscutils/ubi_tools.c:106: error: for each function it appears in.)miscutils/ubi_tools.c:107: error: ‘UBI_VOL_NUM_AUTO’ undeclared (first use in this function)miscutils/ubi_tools.c:114: error: field ‘attach_req’ has incomplete typemiscutils/ubi_tools.c:115: error: field ‘mkvol_req’ has incomplete typemiscutils/ubi_tools.c:116: error: field ‘rsvol_req’ has incomplete typemiscutils/ubi_tools.c:177: error: ‘UBI_IOCATT’ undeclared (first use in this function)miscutils/ubi_tools.c:190: error: ‘UBI_IOCDET’ undeclared (first use in this function)miscutils/ubi_tools.c:233: error: ‘UBI_DYNAMIC_VOLUME’ undeclared (first use in this function)miscutils/ubi_tools.c:235: error: ‘UBI_STATIC_VOLUME’ undeclared (first use in this function)miscutils/ubi_tools.c:238: error: ‘UBI_MAX_VOLUME_NAME’ undeclared (first use in this function)miscutils/ubi_tools.c:243: error: ‘UBI_IOCMKVOL’ undeclared (first use in this function)miscutils/ubi_tools.c:256: error: ‘UBI_IOCRMVOL’ undeclared (first use in this function)miscutils/ubi_tools.c:274: error: ‘UBI_IOCRSVOL’ undeclared (first use in this function)miscutils/ubi_tools.c:290: error: ‘UBI_IOCVOLUP’ undeclared (first use in this function)make[1]: *** [miscutils/ubi_tools.o] Error 1make: *** [miscutils] Error 2 [root@soysauce busybox-1.23.2]# mkdir include/mtd # 拷贝新内核版本的一个头文件至此目录即可[root@soysauce busybox-1.23.2]# cp ../linux-2.6.39/include/mtd/ubi-user.h include/mtd/[root@soysauce busybox-1.23.2]# make install # 篇幅原因，故只取后面安装过程./_install//usr/sbin/ubirsvol -> ../../bin/busybox ./_install//usr/sbin/ubiupdatevol -> ../../bin/busybox ./_install//usr/sbin/udhcpd -> ../../bin/busybox--------------------------------------------------You will probably need to make your busybox binarysetuid root to ensure all configured applets willwork properly.--------------------------------------------------
四、制作initrd
1、拷贝busybox安装之后生成的_install目录至/tmp/test
[root@soysauce busybox-1.23.2]# mkdir /tmp/busyinit # 创建此目录用于创建initrd[root@soysauce busybox-1.23.2]# cp -a _install/ /tmp/busyinit # 保留所有[root@soysauce busybox-1.23.2]# cd /tmp/busyinit[root@soysauce busyinit]# lsbin linuxrc sbin usr[root@soysauce busyinit]# rm -f linuxrc # 没有的链接可以删除
2、建立rootfs
[root@soysauce busyinit]# mkdir -pv proc sys dev etc/rc.d/init.d tmp lib mnt/sysroot mkdir: created directory `proc'mkdir: created directory `sys'mkdir: created directory `dev'mkdir: created directory `etc'mkdir: created directory `etc/rc.d'mkdir: created directory `etc/rc.d/init.d'mkdir: created directory `tmp'mkdir: created directory `lib'mkdir: created directory `mnt'mkdir: created directory `mnt/sysroot'[root@soysauce busyinit]# lsbin dev etc lib mnt proc sbin sys tmp usr
3、创建两个必要的设备文件
[root@soysauce busyinit]# pwd[root@soysauce busyinit]# mknod dev/console c 5 1[root@soysauce busyinit]# mknod dev/null c 1 3[root@soysauce busyinit]# tree dev/dev/|-- console`-- null0 directories, 2 files
4、为initrd制作init程序，此程序的主要任务是实现rootfs的切换，脚本实现
[root@soysauce busyinit]# vim init # 创建init文件并添加如下内容[root@soysauce busyinit]# cat init #!/bin/sh#echo "Mounting proc and sys..."mount -t proc proc /procmount -t sysfs sysfs /sysecho "Loading jbd,ko and ext3.ko..."insmod /lib/modules/jbd.koinsmod /lib/modules/ext3.koecho "Scaning the hardware information..."mdev -secho "Mounting the real rootfs..."mount -t ext3 /dev/hda2 /mnt/sysrootexec switch_root /mnt/sysroot /sbin/init[root@soysauce busyinit]# chmod +x init # 给脚本添加可执行权限
5、拷贝jbd模块和ext3模块(如果ext3模块已经编译进内核，则此步可省)
[root@soysauce busyinit]# mkdir lib/modules/[root@soysauce busyinit]# modinfo jbd # 查看jdb模块的相关信息filename: /lib/modules/2.6.18-308.el5/kernel/fs/jbd/jbd.kolicense: GPLsrcversion: 11842879E04FE2392B988CCdepends: vermagic: 2.6.18-308.el5 SMP mod_unload gcc-4.1module_sig: 883f3504f44471a48d0a1fbae482c4c11291709e30dee9dc797f252349a5d6942c86133b252488f09d1f81bede58e78df45a8fcb29bac6f42c84f6d0[root@soysauce busyinit]# modinfo ext3 # 查看ext3模块的相关信息filename: /lib/modules/2.6.18-308.el5/kernel/fs/ext3/ext3.kolicense: GPLdescription: Second Extended Filesystem with journaling extensionsauthor: Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and otherssrcversion: 26DC008FC415305C5F65313depends: jbdvermagic: 2.6.18-308.el5 SMP mod_unload gcc-4.1module_sig: 883f3504f44471a48d0a1fbae482c4c112ea5b09f41851dad45dd445dcfb23e95fff97f19ab59e5909cd6e1f686761927393b8c58fec7726e7fc21a3[root@soysauce busyinit]# pwd/tmp/busyinit[root@soysauce busyinit]# cp /lib/modules/2.6.18-308.el5/kernel/fs/jbd/jbd.ko lib/modules[root@soysauce busyinit]# cp /lib/modules/2.6.18-308.el5/kernel/fs/ext3/ext3.ko lib/modules
6、制作initrd
[root@soysauce busyinit]# find . | cpio -H newc --quiet -o | gzip -9 > /mnt/boot/initrd.gz # cpio打包
五、建立真正的根文件系统
1、拷贝busybox安装之后生成的_install目录至/mnt/sysroot
[root@soysauce busyinit]# cd /mnt/sysroot/ [root@soysauce sysroot]# lslost+found[root@soysauce sysroot]# cp -a /tmp/busybox-1.23.2/_install/* ./[root@soysauce sysroot]# rm -f linuxrc # 没有的链接可以删除[root@soysauce sysroot]# lsbin lost+found sbin usr
2、建立rootfs
[root@soysauce sysroot]# mkdir -pv dev sys proc etc/rc.d/init.d root boot var/{log,lock,run} tmp mnt/sysroot media home lib mkdir: created directory `dev'mkdir: created directory `sys'mkdir: created directory `proc'mkdir: created directory `etc'mkdir: created directory `etc/rc.d'mkdir: created directory `etc/rc.d/init.d'mkdir: created directory `root'mkdir: created directory `boot'mkdir: created directory `var'mkdir: created directory `var/log'mkdir: created directory `var/lock'mkdir: created directory `var/run'mkdir: created directory `tmp'mkdir: created directory `mnt'mkdir: created directory `mnt/sysroot'mkdir: created directory `media'mkdir: created directory `home'mkdir: created directory `lib'[root@soysauce sysroot]# lsbin boot dev etc home lib lost+found media mnt proc root sbin sys tmp usr var 3、创建两个必要的设备文件
[root@soysauce sysroot]# mknod dev/console c 5 1[root@soysauce sysroot]# mknod dev/null c 1 3 # 与前面制作initrd时指定的主次设备号要一致[root@soysauce sysroot]# tree dev/dev/|-- console`-- null0 directories, 2 files
4、配置init及其所需要inittab文件
[root@soysauce sysroot]# vim etc/inittab[root@soysauce sysroot]# cat etc/inittab::sysinit:/etc/rc.d/rc.sysinit::respawn:/sbin/getty 9600 tty1::respawn:/sbin/getty 9600 tty2::ctrlaltdel:/sbin/reboot::shutdown:/bin/umount -a -r
5、建立系统初始化脚本文件/etc/rc.d/rc.sysinit
[root@soysauce sysroot]# vim etc/rc.d/init.d/rc.sysinit[root@soysauce sysroot]# cat etc/rc.d/init.d/rc.sysinit#!/bin/sh#echo -e "\tWelcome to \033[31mMy Little\033[0m Linux"echo -e "Remounting the root filesystem ..."mount -t proc proc /procmount -t sysfs sysfs /sysmount -o remount,rw / echo -e "Creating the files of device ..."mdev -s echo -e "Mounting the filesystem ..."mount -a[root@soysauce sysroot]# chmod +x etc/rc.d/init.d/rc.sysinit # 添加可执行权限
6、为系统准备一个“文件系统表”配置文件/etc/fstab
[root@soysauce sysroot]# vim etc/fstab [root@soysauce sysroot]# cat etc/fstab /dev/hda1 /boot ext3 defaults 0 0/dev/hda2 / ext3 defaults 0 0sysfs /sys sysfs defaults 0 0proc /proc proc defaults 0 0
六、安装Grub
1、安装grub引导程序
[root@soysauce sysroot]# grub-install --root-directory=/mnt/ /dev/hda # 指定的目录为boot的父目录Installation finished. No error reported.This is the contents of the device map /mnt//boot/grub/device.map.Check if this is correct or not. If any of the lines is incorrect,fix it and re-run the script `grub-install'.(fd0) /dev/fd0(hd0) /dev/hda(hd1) /dev/sda
2、添加grub.conf配置文件
[root@soysauce sysroot]# cd /mnt/boot/[root@soysauce boot]# lsgrub initrd.gz lost+found vmlinuz[root@soysauce boot]# cd grub/ # 进入grub目录[root@soysauce grub]# pwd/mnt/boot/grub[root@soysauce grub]# vim grub.conf[root@soysauce grub]# cat grub.conf default=0timeout=2title My Test Linux root (hd0,0) kernel /vmlinuz initrd /initrd.gz[root@soysauce grub]# sync # 同步一下，然后将/dev/hda这块磁盘装到另一个主机上即可启动
七、添加用户登录功能和日志功能
[root@soysauce ~]# cd /mnt/sysroot/etc/[root@soysauce etc]# grep "^root" /etc/passwd > ./passwd # 为用户认证提供配置文件[root@soysauce etc]# grep "^root" /etc/shadow > ./shadow[root@soysauce etc]# grep "^root" /etc/group > ./group[root@soysauce sysroot]# pwd/mnt/sysroot[root@soysauce sysroot]# vim etc/syslog.conf # 为syslog服务提供配置文件[root@soysauce sysroot]# cat etc/syslog.conf *.info;auth.none /var/log/messagesauth.* /var/log/secure[root@soysauce sysroot]# touch var/log/secure[root@soysauce sysroot]# chmod 600 var/log/secure[root@soysauce sysroot]# ll var/log/secure-rw------- 1 root root 0 Dec 6 23:40 var/log/secure[root@soysauce sysroot]# vim etc/rc.d/rc.sysinit [root@soysauce sysroot]# cat etc/rc.d/rc.sysinit#!/bin/sh#echo -e "\tWelcome to \033[31mMy Little\033[0m Linux" echo -e "Remounting the root filesystem ..."mount -t proc proc /procmount -t sysfs sysfs /sysmount -o remount,rw / echo -e "Creating the files of device ..."mdev -s echo -e "Mounting the filesystem ..."mount -asyslogd # 启动syslogd和klogd服务来记录日志klogdecho "Set the hostname for the system..."[ -f /etc/hostname ] && . /etc/hostname[ -z $HOSTNAME -o $HOSTNAME == '(none)' ] && HOSTNAME=soysaucehostname $HOSTNAME
八、添加banner信息和主机名
[root@soysauce sysroot]# pwd/mnt/sysroot[root@soysauce sysroot]# lsbin boot dev etc home lib lib64 lost+found media mnt proc root sbin sys tmp usr var[root@soysauce sysroot]# cp /etc/issue etc/[root@soysauce sysroot]# vim etc/issue [root@soysauce sysroot]# cat etc/issue # 提供banner信息My Little LinuxKernel \r on an \m[root@soysauce sysroot]# sync[root@soysauce sysroot]# pwd/mnt/sysroot[root@soysauce sysroot]# lsbin boot dev etc home lib lib64 lost+found media mnt proc root sbin sys tmp usr var[root@soysauce sysroot]# vim etc/hostname[root@soysauce sysroot]# cat etc/hostname # 提供主机名HOSTNAME=soysauce[root@soysauce sysroot]# vim etc/rc.d/rc.sysinit [root@soysauce sysroot]# tail -4 etc/rc.d/rc.sysinit echo "Set the hostname for the system..."[ -f /etc/hostname ] && . /etc/hostname[ -z $HOSTNAME -o $HOSTNAME == '(none)' ] && HOSTNAME=soysaucehostname $HOSTNAME[root@soysauce sysroot]# sync
至此，一个不到10M的Mini Linux便出来了。启动成功之后如下
注：我是移植了bash替换了busybox自身提供的sh，所以如果你也是习惯bash，那么可以使用我下面那个复制命令及依赖库的脚本进行移植即可
补充相关命令
1、ldd
ldd - print shared library dependencies # 显示共享库依赖关系SYNOPSIS ldd [OPTION]... FILE... [root@soysauce scripts]# ldd /sbin/init # 显示/sbin/init所依赖的库文件路径 linux-vdso.so.1 => (0x00007fff6f1ea000) libsepol.so.1 => /lib64/libsepol.so.1 (0x0000003484e00000) libselinux.so.1 => /lib64/libselinux.so.1 (0x0000003482800000) libc.so.6 => /lib64/libc.so.6 (0x000000347e800000) libdl.so.2 => /lib64/libdl.so.2 (0x000000347ec00000) /lib64/ld-linux-x86-64.so.2 (0x000000347e400000)[root@soysauce scripts]# ldd /bin/bash # 显示/bin/bash所依赖的库文件路径 linux-vdso.so.1 => (0x00007fff24695000) libtermcap.so.2 => /lib64/libtermcap.so.2 (0x000000347f000000) libdl.so.2 => /lib64/libdl.so.2 (0x000000347ec00000) libc.so.6 => /lib64/libc.so.6 (0x000000347e800000) /lib64/ld-linux-x86-64.so.2 (0x000000347e400000)
2、mktemp
mktemp - make temporary filename (unique) # 生成唯一的临时文件或目录SYNOPSIS mktemp [-V] | [-dqtu] [-p directory] [template] -d：生成临时目录[root@soysauce testbin]# ls[root@soysauce testbin]# mktemp ./file.XX # 后缀为2位随机数的文件，注意X必须为大写./file.00[root@soysauce testbin]# mktemp ./file.XXXXX # 后缀为5位随机数的文件./file.s9601 [root@soysauce testbin]# mktemp ./file.XXXXXXXXXX # 后缀为10位随机数的文件./file.bJfocr9602[root@soysauce testbin]# mktemp ./file.XXXXXXXXXXXXXX # 后缀为14位随机数的文件./file.HqGoTLDPpL9603[root@soysauce testbin]# mktemp -d ./file.XXXXXXXXXXXXXX # 后缀为14位随机数的目录./file.MbAeMTEbMG9607[root@soysauce testbin]# ll total 24-rw------- 1 root root 0 Dec 6 11:02 file.00-rw------- 1 root root 0 Dec 6 11:02 file.bJfocr9602-rw------- 1 root root 0 Dec 6 11:02 file.HqGoTLDPpL9603drwx------ 2 root root 4096 Dec 6 11:03 file.MbAeMTEbMG9607-rw------- 1 root root 0 Dec 6 11:02 file.s9601
3、mknod
mknod - make block or character special files # 创建字符设备或是块设备SYNOPSIS mknod [OPTION]... NAME TYPE [MAJOR MINOR] [root@CentOS5 ~]# mknod /dev/console c 5 1 # 主设备号为5，次设备号为1[root@CentOS5 ~]# mknod /dev/null c 1 3 # 主设备号为1，次设备号为3
4、uname
uname - print system information # 显示系统信息SYNOPSIS uname [OPTION]...[root@soysauce testbin]# uname -a Linux soysauce 2.6.18-308.el5 #1 SMP Tue Feb 21 20:06:06 EST 2012 x86_64 x86_64 x86_64 GNU/Linux[root@soysauce testbin]# uname # 同uanme -s，显示内核名称Linux[root@soysauce testbin]# uname -n # 显示主机名soysauce[root@soysauce testbin]# uname -r # 显示内核release2.6.18-308.el5[root@soysauce testbin]# uname -v # 显示内核版本#1 SMP Tue Feb 21 20:06:06 EST 2012[root@soysauce testbin]# uname -m # 显示机器硬件架构x86_64[root@soysauce testbin]# uname -o # 显示操作系统类型GNU/Linux
5、mkinitrd
mkinitrd - creates initial ramdisk p_w_picpaths for preloading modules # 创建ramdisk磁盘映像文件SYNOPSIS mkinitrd [--version] [-v] [-f] [--preload=module] [--omit-scsi-modules] [--omit-raid-modules] [--omit-lvm-modules] [--with=module] [--p_w_picpath-version] [--fstab=fstab] [--nocompress] [--builtin=module] [--nopivot] [--with-fips] p_w_picpath kernel-versionmkinitrd /boot/initrd-`uname -r`.img `uname -r`[root@soysauce testbin]# mkinitrd ./initrd-`uname -r`.img `uname -r`[root@soysauce testbin]# lsinitrd-2.6.18-308.el5.img
6、复制二进制文件及其依赖库文件的脚本
[root@soysauce ~]# cat bincp.sh#!/bin/bash# Date:2015-12-3 21:37:15# Author: soysauce# Description: copy the libraries needed by binary file# Version: 1.0VirRoot=/mnt/sysrootfunction bincp { ComPath=`which $COM | grep -v "^alias" | awk -F' ' '{print $1}'` [ -e $VirRoot${ComPath%/*} ] || mkdir -p $VirRoot${ComPath%/*} if [ ! -e $VirRoot$ComPath ]; then cp $ComPath $VirRoot$ComPath fi}function libcp {LibPath=`ldd $ComPath | egrep -o "/.*lib(64){0,1}/[^[:space:]]+"` for Lib in $LibPath; do [ -e $VirRoot${Lib%/*} ] || mkdir -p $VirRoot${Lib%/*} if [ ! -e $VirRoot$Lib ]; then cp $Lib $VirRoot$Lib fi done}echo -en "\e[31mPlease input the command:\e[0m "read COMuntil [[ $COM == 'quit' ]]; do if which $COM &> /dev/null; then bincp && [ $? -eq 0 ] && echo "Copy $ComPath finished." || echo "$ComPath exists." libcp && [ $? -eq 0 ] && echo "Copy The Lib of $ComPath finished." || echo "The Lib of $ComPath exists."else echo "No Such Command."fiecho -en "\e[31mPlease input the command again:\e[0m "read COMdone[root@soysauce ~]# ./bincp.sh Please input the command: lsCopy /bin/ls finished.Copy The Lib of /bin/ls finished.Please input the command again: manCopy /usr/bin/man finished.Copy The Lib of /usr/bin/man finished.Please input the command again: No Such Command.Please input the command again: whichCopy /usr/bin/which finished.Copy The Lib of /usr/bin/which finished.Please input the command again: grepCopy /bin/grep finished.Copy The Lib of /bin/grep finished.Please input the command again: sssfdaNo Such Command.Please input the command again: quit 总结：要拼凑一个Linux，至少要提供以下四个
①提供grub
②提供内核
③提供initrd
④提供根文件系统