Ramdisk creation process

1. Create the root file system structure # mkdir rootfs (which I created directly in the root directory) # cd rootfs # mkdir bin Dev etc lib proc sbin tmp usr var # chmod 1777 TMP # mkdir usr/bin usr/lib usr/sbin # mkdir var/lib var/lock var/log var/run var/tmp # chmod 1777 var/tmp 2 prepare the Link Library # cd $ {obj_lib}/lib ($ {obj_lib} is the directory of the Cross-compilation environment) # For file in libc libcrypt libdl libm \> libpthread libresolv libutil> do> CP $ file -*. so/home/Fortis/rootfs/lib (because the link is established in the root directory, this is CP $ file -*. so/rootfs/LIB)> CP-d $ file. so. [* 0-9]/home/Fortis/rootfs/lib (same as above)> done # cp-d ld *. so */home/Fortis/rootfs/lib 3 Use busybox to create System Applications Program 3.1 download busybox (http://www.busybox.net/) and unzip it. 3.2 enter the decompressed directory, configure busybox $ make menuconfig busybox Settings> general configuration> [*] Support for devfs build Options> [*] Build busybox as a static binary (no shared libs) /* compile busybox as a static connection, which reduces the trouble of finding a dynamic library during startup */[*] Do you want to build busybox with a cross compiler? (/Usr/local/ARM/3.3.2/bin/armlinux) cross Compiler prefix/* specifies the path of the Cross-compilation tool */init utilities> [*] init [*] Support reading an inittab file/* supports init to read the/etc/inittab configuration file, be sure to select */Shells> choose your default shell (Ash)>/* (x) ash to select ash, in this way, the bin/sh file will be generated *. Let's look at the first line of the linuxrc Script :*#! /Bin/sh is interpreted and executed by bin/sh */[*] Ash coreutils> [*] CP [*] cat [*] ls [*] mkdir [*] echo (Basic susv3 version taking no options) [*] env [*] MV [*] PWD [*] RM [*] Touch editors> [*] vi Linux system utilities> [*] Mount [*] umount [*] Support loopback mounts [*] Support for the old/etc/mtab file networking utilities> [*] inetd/** support for inetd super server */3.3 compilation and installation of busybox (if busybox compile a compilation tool) $ make T Arget_arch = arm cross = armlinux \ prefix =/home/ARM/dev_home/rootfs/my_rootfs/all install prefix specifies the installation path: the path of our root file system. 4. You can directly copy the required device files on the host, or create several files on the host. # Cd rootfs/dev # mknod-m 600 console C 5 15 create the linuxrc file as follows: $ Vim rootfs/linuxrc #! /Bin/shecho "Hello Linux, gggggg" exec/sbin/init and then modify the permission: chmod 775 linuxrc 6: Create the initrd image file # mkdir initrd # dd If =/dev/Zero of = initrd. img bs = 1 k count = 8192 #/sbin/mke2fs-F-v-M0 initrd. IMG # Mount-o loop initrd. IMG initrd # cp-AV rootfs/* initrd # umount # gzip-9 initrd. IMG from: http://blog.csdn.net/lyw2698/article/details/1921033