嵌入式Linux之我行——Linux-2.6.30.4在2440上的移植之文件系统

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。

• 共享资源，欢迎转载：http://hbhuanggang.cublog.cn

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http://www.aleph1.co.uk/cgi-bin/viewcvs.cgi/
• 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。