嵌入式Linux之我行，主要讲述和总结了本人在学习嵌入式linux中的每个步骤。一为总结经验，二希望能给想入门嵌入式Linux的朋友提供方便。如有错误之处，谢请指正。

一、移植环境

主  机：VMWare--Fedora 9

开发板：Mini2440--64MB Nand

编译器：arm-linux-gcc-4.3.2

yaffs补丁：cvs-root.tar.gz 这里下载

Busybox：busybox-1.13.0.tar.tar

yaffs制作工具：mkyaffs2image.tgz(友善提供)

二、移植步骤

1. 准备工作目录和进入工作目录#mkdir my2440

#cd my2440

2. 给内核打上yaffs补丁，使内核对yaffs的支持#tar -zxvf cvs-root.tar.gz

#cd cvs/yaffs2/

#./patch-ker.sh c /root/my2440/linux-2.6.30.4/

3. 配置内核，使其对yaffs2文件系统的支持。配置完后重新编译内核，下载到开发板上

File systems --->

< > Second extended fs support

< > Ext3 journalling file system support

< > The Extended 4 (ext4) filesystem

< > Reiserfs support

< > JFS filesystem support

< > XFS filesystem support

< > OCFS2 file system support

< > Btrfs filesystem (EXPERIMENTAL) Unstable disk format

[*] Enable POSIX file locking API

[*] Dnotify support

[*] Inotify file change notification support

[*] Inotify support for userspace

[ ] Quota support

Kernel automounter support

Kernel automounter version 4 support (also supports v3)

FUSE (Filesystem in Userspace) support

Caches --->

CD-ROM/DVD Filesystems --->

ISO 9660 CDROM file system support

[ ] Microsoft Joliet CDROM extensions

[ ] Transparent decompression extension

< > UDF file system support

DOS/FAT/NT Filesystems --->

MSDOS fs support

VFAT (Windows-95) fs support

(437) Default codepage for FAT

(iso8859-1) Default iocharset for FAT

< > NTFS file system support

Pseudo filesystems --->

[*] Miscellaneous filesystems --->

--- Miscellaneous filesystems

< > ADFS file system support (EXPERIMENTAL)

< > Amiga FFS file system support (EXPERIMENTAL)

< > Apple Macintosh file system support (EXPERIMENTAL)

< > Apple Extended HFS file system support

< > BeOS file system (BeFS) support (read only) (EXPERIMENTAL)

< > BFS file system support (EXPERIMENTAL)

< > EFS file system support (read only) (EXPERIMENTAL)

YAFFS2 file system support

-*- 512 byte / page devices

[ ] Use older-style on-NAND data format with pageStatus byte

[ ] Lets Yaffs do its own ECC

-*- 2048 byte (or larger) / page devices

[*] Autoselect yaffs2 format

[ ] Disable lazy loading

[ ] Turn off wide tnodes

[ ] Force chunk erase check

[*] Cache short names in RAM

Journalling Flash File System v2 (JFFS2) support

(0) JFFS2 debugging verbosity (0 = quiet, 2 = noisy)

[*] JFFS2 write-buffering support

[ ] Verify JFFS2 write-buffer reads

[*] JFFS2 summary support (EXPERIMENTAL)

[ ] JFFS2 XATTR support (EXPERIMENTAL)

[ ] Advanced compression options for JFFS2

Compressed ROM file system support (cramfs)

SquashFS 4.0 - Squashed file system support

[ ] Additional option for memory-constrained systems

< > FreeVxFS file system support (VERITAS VxFS(TM) compatible)

< > Minix file system support

< > SonicBlue Optimized MPEG File System support

< > OS/2 HPFS file system support

< > QNX4 file system support (read only)

ROM file system support

RomFS backing stores (Block device-backed ROM file system support) --

< > System V/Xenix/V7/Coherent file system support

< > UFS file system support (read only)

< > NILFS2 file system support (EXPERIMENTAL)

[*] Network File Systems --->

Partition Types --->

-*- Native language support --->

< > Distributed Lock Manager (DLM) --->

4. 编译busybox生成文件系统所需要的应用程序

1)解压busybox源码，修改Makefile使之编译成ARM平台:#tar -jxvf busybox-1.13.0.tar.tar

#cd busybox-1.13.0

#gedit Makefile大概164行改成CROSS_COMPILE = arm-linux- ，189行改成ARCH = arm

2)配置busybox选项，下面只列出了要注意的地方，没有列出的默认即可#make menuconfig

Busybox Settings --->

General Configuration --->

Buffer allocation policy (Allocate with Malloc) --->

[*] Show verbose applet usage messages

[*] Store applet usage messages in compressed form

[*] Support --install [-s] to install applet links at runtime

[*] Enable locale support (system needs locale for this to work)

[*] Support for --long-options

[*] Use the devpts filesystem for Unix98 PTYs

[*] Support writing pidfiles

[*] Runtime SUID/SGID configuration via /etc/busybox.conf

[*] Suppress warning message if /etc/busybox.conf is not readable

(/proc/self/exe) Path to BusyBox executable

Build Options --->

[*] Build BusyBox as a static binary (no shared libs)

[*] Build with Large File Support (for accessing files > 2 GB)

Installation Options --->

[ ] Don't use /usr

Applets links (as soft-links) --->

(./_install) BusyBox installation prefix

Busybox Library Tuning --->

(6) Minimum password length

(2) MD5: Trade Bytes for Speed

[*] Faster /proc scanning code (+100 bytes)

[*] Command line editing

(1024) Maximum length of input

[*] vi-style line editing commands

(15) History size

[*] History saving

[*] Tab completion

[*] Fancy shell prompts

(4) Copy buffer size, in kilobytes

[*] Use ioctl names rather than hex values in error messages

[*] Support infiniband HW

Linux Module Utilities --->

(/lib/modules) Default directory containing modules

(modules.dep) Default name of modules.dep

[*] insmod

[*] rmmod

[*] lsmod

[*] modprobe

--- Options common to multiple modutils

[ ] Support version 2.2/2.4 Linux kernels

[*] Support tainted module checking with new kernels

[*] Support for module.aliases file

[*] Support for module.symbols fileLinux System Utilities --->

3)编译和安装busybox，安装完后会在busybox-1.13.0/_install/目录下生成：bin、linuxrc、sbin、usr

#make

#make install

5. 开始构建文件系统

1)新建一个目录root-2.6.30.4，把busybox-1.13.0/_install/目录下生成：bin、linuxrc、sbin、usr复制过来，并且在该目录下创建文件系统所需要的其他目录

#mkdir root-2.6.30.4

#cp -rf busybox-1.13.0/_install/* root-2.6.30.4/

#cd root-2.6.30.4/

#mkdir dev etc home lib mnt opt proc tmp var www

2)向各目录中添加文件系统所需要的目录或文件，没有提到的就不用添加。这里要注意各种文件的权限，建议都改为777，命令：#chmod 777 文件名

"dev"目录，创建两个设备文件：#mknod console c 5 1

#mknod null c 1 3

"etc"目录，创建各种配置文件并向里面添加内容，没有列出的就不用添加：

boa/boa.conf: boa WEB服务器配置文件，暂时为空。

group: 系统用户组配置文件，内容如下：root:*:0:

daemon:*:1:

bin:*:2:

sys:*:3:

adm:*:4:

tty:*:5:

disk:*:6:

lp:*:7:lp

mail:*:8:

news:*:9:

uucp:*:10:

proxy:*:13:

kmem:*:15:

dialout:*:20:

fax:*:21:

voice:*:22:

cdrom:*:24:

floppy:*:25:

tape:*:26:

sudo:*:27:

audio:*:29:

ppp:x:99:

500:x:500:plg

501:x:501:fa

inittab: 系统init进程配置文件，内容如下：# /etc/inittab

::sysinit:/etc/init.d/rcS

console::askfirst:-/bin/sh

::ctrlaltdel:/sbin/reboot

::shutdown:/bin/umount -a -r

mime.types: 暂时为空。

passwd: 系统密码文件，内容如下：root::0:0:root:/:/bin/sh

ftp::14:50:FTP User:/var/ftp:

bin:*:1:1:bin:/bin:

daemon:*:2:2:daemon:/sbin:

nobody:*:99:99:Nobody:/:

sky::502:502:Linux User,,,:/home/sky:/bin/sh

rc.d/init.d/httpd: 内容如下：#!/bin/sh

base=boa

# See how we were called.

case "$1" in

start)

/usr/sbin/$base

;;

stop)

pid=`/bin/pidof $base`

if [ -n "$pid" ]; then

kill -9 $pid

fi

;;

esac

exit 0

sysconfig/HOSTNAME: 主机名称文件，内容如下：MY2440

fstab: 系统挂载文件系统列表，内容如下：# device  mount-point   type     options     dump   fsck order

none      /proc         proc     defaults    0      0

none      /dev/pts      devpts   mode=0622   0      0

tmpfs     /dev/shm      tmpfs    defaults    0      0

init.d/rcS: 系统启动加载项，内容如下：#!/bin/sh

PATH=/sbin:/bin:/usr/sbin:/usr/bin

runlevel=S

prevlevel=N

umask 022

export PATH runlevel prevlevel

#

#    Trap CTRL-C &c only in this shell so we can interrupt subprocesses.

#

/bin/mount -t proc none /proc

/bin/mount -t tmpfs none /tmp

/bin/mount -t tmpfs none /var

/bin/mkdir -p /var/log

/bin/hostname -F /etc/sysconfig/HOSTNAME

mdev.conf: mdev设备配置文件，暂时为空。

net.conf: 网络配置文件，暂时为空。

profile: 用户环境配置文件，内容如下：# Ash profile

# vim: syntax=sh

# No core files by default

#ulimit -S -c 0 > /dev/null 2>&1

USER="`id -un`"

LOGNAME=$USER

PS1='[\u@\h \W]\# '

PATH=$PATH:/usr/local/bin

LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

HOSTNAME=`/bin/hostname`

export USER LOGNAME PS1 PATH LD_LIBRARY_PATH

resolv.conf: DNS配置文件，内容如下：nameserver 61.144.56.100

"home"目录：创建一个sky目录，与etc目录passwd文件中的sky相对应

"lib"目录：这个里面放的都是库文件，直接从交叉编译器的库文件目录中拷贝过来：#cp -f /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib/*so* lib/ -a

6. 使用yaffs制作工具编译构建好的文件系统。先解压mkyaffs2image.tgz(这个工具是友善提供的，可以在他们的网站上下载)，会自动解压到开发主机的/usr/sbin/目录下。编译后生成的文件系统镜像root-2.6.30.4.bin也在这个目录下

#tar -zxvf mkyaffs2image.tgz

#mkyaffs2image root-2.6.30.4/ root-2.6.30.4.bin

7. 下载文件系统镜像到开发板上测试，使用情况如下：

三、结束语

现在文件系统成功移植上去了，加上上一篇章的内核移植，至此开发板可以运行起来了。但是各种外设还不能正常使用，后续的篇章将逐步移植各种设备的驱动，使之完善。