三、【s3c2440移植linux-3.5】制作根文件并制作jffs2镜像

（一）移植Busybox

1、修改Busybox配置

book@ubuntu:~$ tar jxf busybox-1.20.0.tar.bz2
book@ubuntu:~$ cd busybox-1.20.0/
book@ubuntu:~/busybox-1.20.0$ make menuconfig

CONFIG_CROSS_COMPILER_PREFIX: 
Location:
    -> Busybox Settings 
        -> Build Options

保存退出

2、编译、安装Busybox

book@ubuntu:~/busybox-1.20.0$ make
book@ubuntu:~/busybox-1.20.0$ mkdir /work/s3c2440/nfs/fs/fs_mini_mdev -p
book@ubuntu:~/busybox-1.20.0$ make install CONFIG_PREFIX=/work/s3c2440/nfs/fs/fs_mini_mdev
book@ubuntu:~/busybox-1.20.0$ cd /work/s3c2440/nfs/fs/fs_mini_mdev
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ ls
bin  linuxrc  sbin  usr

3、安装glibc库

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ mkdir lib
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ mkdir usr/lib -p
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ cp /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib/*so*  /work/s3c2440/nfs/fs/fs_mini_mdev/lib -d
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ cp /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/usr/lib/*so*  /work/s3c2440/nfs/fs/fs_mini_mdev/usr/lib -d

（二）构建根文件系统

1、创建etc/inittab文件

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ mkdir etc
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ cd etc
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc$ vi inittab

inittab：
# /etc/inittab
::sysinit:/etc/init.d/rcS
console::askfirst:-/bin/sh
::ctrlaltdel:/sbin/reboot
::shutdown:/bin/mount -a -r

2、创建etc/init.d/rcS文件

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc$ mkdir init.d
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc$ cd init.d
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc/init.d$ vi rcS

rcS：
#!/bin/sh
#ifconfig eth0 172.16.122.84
mount -a
mkdir /dev/pts
mount -t devpts devpts /dev/pts
echo /sbin/mdev > /proc/sys/kernel/hotplug
mdev -s

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc/init.d$ chmod +x rcS

3、创建etc/fstab文件

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc/init.d$ cd ..
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc$ vi fstab

fstab：
# device   mount-point  type   options  dump  fsck   order
proc       /proc        proc   defaults  0    0
tmpfs      /tmp         tmpfs  defaults  0    0
sysfs      /sys         sysfs  defaults  0    0
tmpfs      /dev         tmpfs  defaults  0    0

4、创建dev/console和dev/null文件

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/etc$ cd ..
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ mkdir dev
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ cd dev
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/dev$ sudo mknod console c 5 1
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/dev$ sudo mknod null c 1 3
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/dev$ ls
console  null

5、创建其他目录

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev/dev$ cd ..
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ mkdir mnt proc tmp sys root
book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ ls
bin  dev  etc  lib  linuxrc  mnt  proc  root  sbin  sys  tmp  usr

（三）制作jffs2文件系统

1、创建jffs2文件系统

book@ubuntu:/work/s3c2440/nfs/fs/fs_mini_mdev$ cd ..
book@ubuntu:/work/s3c2440/nfs/fs$ sudo apt-get install mtd-utils
book@ubuntu:/work/s3c2440/nfs/fs$ mkfs.jffs2 -n -s 2048 -e 128KiB -d fs_mini_mdev -o fs_mini_mdev.jffs2
book@ubuntu:/work/s3c2440/nfs/fs$ ls
fs_mini_mdev  fs_mini_mdev.jffs2

2、烧写jffs2到Nand flash的roots分区

启动u-boot

SMDK2440 # nfs 30000000 $serverip:/work/s3c2440/nfs/fs/fs_mini_mdev.jffs2
SMDK2440 # nand erase.part rootfs
SMDK2440 # nand write.jffs2 30000000 260000  $filesize
SMDK2440 # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3 rootfstype=jffs2
SMDK2440 # set bootcmd "nfs 30000000 $serverip:/work/s3c2440/nfs/kernel/uImage_3.5;bootm 30000000"
SMDK2440 # save
SMDK2440 # reset

启动失败内核但挂载jffs2成功

（四）分析解决启动失败的原因

1、分析linux源码

Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004

在Source Insight中查找Attempted to kill init!
反向查找调用函数：
do_exit
    exit_notify
        forget_original_parent
            find_new_reaper
                panic("Attempted to kill init! exitcode=0x%08x\n",
                        father->signal->group_exit_code ?:
                            father->exit_code);

根据上面提示信息 exitcode=0x00000004
内核启动出错调用do_exit(SIGILL)
SIGILL为非法指令

产生非法指令的原因，我们来查看交叉编译工具
book@ubuntu:/work/s3c2440/nfs/fs$ arm-linux-gcc -v
Using built-in specs.
Target: arm-none-linux-gnueabi
Configured with: /scratch/julian/lite-respin/linux/src/gcc-4.3/configure --build=i686-pc-linux-gnu --host=i686-pc-linux-gnu --target=arm-none-linux-gnueabi --enable-threads --disable-libmudflap --disable-libssp --disable-libstdcxx-pch --with-gnu-as --with-gnu-ld --enable-languages=c,c++ --enable-shared --enable-symvers=gnu --enable-__cxa_atexit --with-pkgversion='Sourcery G++ Lite 2008q3-72' --with-bugurl=https://support.codesourcery.com/GNUToolchain/ --disable-nls --prefix=/opt/codesourcery --with-sysroot=/opt/codesourcery/arm-none-linux-gnueabi/libc --with-build-sysroot=/scratch/julian/lite-respin/linux/install/arm-none-linux-gnueabi/libc --with-gmp=/scratch/julian/lite-respin/linux/obj/host-libs-2008q3-72-arm-none-linux-gnueabi-i686-pc-linux-gnu/usr --with-mpfr=/scratch/julian/lite-respin/linux/obj/host-libs-2008q3-72-arm-none-linux-gnueabi-i686-pc-linux-gnu/usr --disable-libgomp --enable-poison-system-directories --with-build-time-tools=/scratch/julian/lite-respin/linux/install/arm-none-linux-gnueabi/bin --with-build-time-tools=/scratch/julian/lite-respin/linux/install/arm-none-linux-gnueabi/bin
Thread model: posix
gcc version 4.3.2 (Sourcery G++ Lite 2008q3-72)

交叉编译工具用的是eabi接口编译内核的

2、使内核支持eabi接口

book@ubuntu:/work/s3c2440/nfs/fs$ cd ~/linux-3.5
book@ubuntu:~/linux-3.5$ make menuconfig

CONFIG_AEABI:
Location:
    -> Kernel Features

保存退出，重新编译内核

book@ubuntu:~/linux-3.5$ make uImage

3、使用新内核启动

至此已经可以成功启动jffs2制作的根文件系统了