移植Linux3.4.2版本内核到mini2440

      
        该移植工作主要参考了韦东山的《嵌入式Linux应用开发完全手册》，第二期毕业班视频教程和友善之臂mini2440光盘提供的《Mini2440 Linux移植开发实战指南.pdf》，使用的bootloader是我根据韦东山老师制作的2012.04.01版本u-boot，具体制作方法可参考我的另一篇博客《u-boot-2012.04.01修改移植和制作补丁文件 》，交叉编译器使用的是arm-linux-gcc : v4.3.2。

一. 内核启动流程，据此配置内核(机器ID)
    1. 获取内核源码 www.kernel.org
        https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.4.2.tar.bz2
    2. 解压内核
        # tar xjvf linux-3.4.2.tar.bz2
    3. 修改顶层Makefile，指定交叉编译器
            ARCH ?= arm
            CROSS_COMPILE ?= arm-linux-
    4. 使用默认配置编译内核，可使用如下命令查看内核有哪些默认配置
        # find -name "*defconfig"
        使用缺省内核配置文件,s3c2410_defconfig 是SMDK2410 的缺省配置文件
            # make s3c2410_defconfig
        编译、测试
            # make uImage
        拷贝uImage到tftpboot目录
            # cp arch/arm/boot/uImage /work/tftpboot/uImage_3.4.2
        下载、启动内核
            # tftp 32000000 uImage_3.4.2
            # bootm 32000000
        结果， 启动后会产生乱码，原因是bootargs参数并未指定串口波特率，修改bootargs如下即可正常启动看到输出
            # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3
    5. 修改晶振频率
        # vim arch/arm/mach-s3c24xx/mach-smdk2440.c
                --s3c24xx_init_clocks(16934400);
                ++s3c24xx_init_clocks(12000000);
    编译、测试
        # make s3c2410_defconfig          //支持内核较多
        # make uImage
    
        # set machid 16a                        //SMDK2440的机器ID
        # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3
        # tftp 32000000 uImage_3.4.2
        # bootm 32000000
    可正常输出内核启动信息，说明串口工作正常

二. 修改分区, 制作新的文件系统 
    2.1 修改分区，和我修改后的u-boot-2012.04.01一致，参考友善之臂文档《Mini2440 Linux移植开发实战指南.pdf》
            0x00000000-0x00060000 : "bootloader"
            0x00060000-0x00080000 : "params"
            0x00050000-0x00580000 : "kernel"
            0x00580000-                  : "root"
        # vim arch/arm/mach-s3c24xx/common-smdk.c

点击(此处)折叠或打开

 static struct mtd_partition smdk_default_nand_part[] = {
         [0] = {
                 .name = "bootloader",
                 .size = SZ_256K + SZ_128K,
                 .offset = 0,
         },
         [1] = {
                 .name = "params",
                 .offset = SZ_256K + SZ_128K,
                 .size = SZ_128K,
         },
         [2] = {
                 .name = "kernel",
                 .offset = SZ_512K,
                 .size = 0x00500000,
         },
         [3] = {
                 .name = "root",
                 .offset = SZ_512K + 0x00500000,
                 .size = MTDPART_SIZ_FULL,
         },
 };

        编译、测试
            # make uImage
            # cp arch/arm/boot/uImage /work/tftpboot/uImage_3.4.2 
    
            # setenv bootcmd 'tftp 32000000 uImage_3.4.2;bootm 32000000'
            # boot
    可看到打印出如下分区信息

点击(此处)折叠或打开

 List of all partitions:
 1f00 384 mtdblock0 (driver?)
 1f01 128 mtdblock1 (driver?)
 1f02 5120 mtdblock2 (driver?)
 1f03 1042944 mtdblock3 (driver?)

        
        
        烧写文件系统、测试 fs_mini_mdev.yaffs2<该文件系统来自韦东山老师的教程>
            # tftp 32000000 fs_mini_mdev.yaffs2
            # nand erase.part root
            # nand write.yaffs 32000000 0x580000  $filesize
         测试
            # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3
            # setenv bootcmd 'tftp 32000000 uImage_3.4.2;bootm 32000000'
            # boot
        结果：
            No filesystem could mount root, tried:  ext3 ext2 cramfs vfat msdos iso9660 romfs

        测试jffs2 
            # tftp 32000000 fs_mini_mdev.jffs2
            # nand erase.part root
            # nand write.jffs2 32000000 580000  $filesize
            # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3 rootfstype=jffs2
            # boot
        不能使用

    2.2 制作根文件系统  
        ① 编译安装busybox
                编译 busybox-1.20.0.tar.bz2
                # tar xjvf busybox-1.20.0.tar.bz2
                # cd busybox-1.20.0
                # make menuconfig
                    Busybox Settings  ---> 
                        Build Options  ---> 
                            ()  Cross Compiler prefix 
                                    填入arm-linux-  
            保存、退出，执行make
                # make
            创建文件系统目录
                # cd /work/nfsroot
                # mkdir fs_mini_mdev_new
            安装
                # make install CONFIG_PREFIX=/work/nfsroot/fs_mini_mdev_new
        ② 安装libc库，使用arm-linux-gcc 4.3.2 中的库文件
                # cd /work/nfsroot/fs_mini_mdev_new
                # mkdir lib
                # cd lib
                # cp /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/lib/*so* ./ -d 
                # cd ../
                # mkdir usr/lib -p
                # cd usr/lib
                # cp /usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/armv4t/usr/lib/*so* ./ -d

        ③ 构建etc目录 
                # cp -rf ../fs_mini_mdev/etc ./
            修改inttab
                # vim inittab
                    将s3c2410_serial0改为console
        ④ 构建dev目录 
                # mkdir dev
                # cd dev
                # mknod console c 5 1 
                # mknod null c 1 3
        ⑤ 创建其他目录
                # mkdir proc tmp mnt sys root

        ⑥ 制作jffs2根文件系统，参考《嵌入式Linux应用开发完全手册》
                # mkfs.jffs2 -n -s 2048 -e 128KiB -d fs_mini_mdev_new -o fs_mini_mdev_new.jffs2 
        ⑦ 烧写测试
                # cp fs_mini_mdev_new.jffs2 /work/tftpboot
                # tftp 32000000 fs_mini_mdev_new.jffs2
                # nand erase.part root
                # nand write.jffs2 32000000 580000  $filesize
                # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3 rootfstype=jffs2
                # boot
        ⑧ 结果
                Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
        出错、退出

    解决方法
    配置内核
        # make menuconfig
            Kernel Features  --->  
                [*] Use the ARM EABI to compile the kernel  //选中该项
        # make uImage
        # cp arch/arm/boot/uImage /work/tftpboot/uImage_3.4.2_eabi

    测试
            # tftp 32000000 uImage_3.4.2_eabi
            # bootm 32000000
    可正常启动
            Please press Enter to activate this console. 
            / # 

三. 移植YAFFS文件系统
    获取yaffs2源码
        # git clone git://www.aleph1.co.uk/yaffs2
    给内核打yaffs2补丁，参考readme
        # cd yaffs2 
        # ./patch-ker.sh c m /work/kernel/linux-3.4.2
    配置内核使其支持yaffs2文件系统
        # make menuconfig
            File systems --->
                [*]Miscellaneous filesystems --->
                    <*> yaffs2 file system support
        # make uImage

    制作yaffs2根文件系统 
        # mkyaffs2image fs_mini_mdev_new fs_mini_mdev_new.yaffs2
        # mv fs_mini_mdev_new.yaffs2 /work/tftpboot/
        # cp arch/arm/boot/uImage /work/tftpboot/uImage_3.4.2_yaffs2
    烧写Yaffs2文件系统
        # tftp 32000000 fs_mini_mdev_new.yaffs2
        # nand erase.part root                                         //擦除root分区
        # nand write.yaffs 32000000 580000  $filesize         //亲测用nand write.jffs2会出错，找不到init进程

    启动内核
        # tftp 32000000 uImage_3.4.2_yaffs2
        # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3
        # bootm 32000000 
        
    可修改bootcmd参数便捷启动
        # setenv bootcmd 'tftp 32000000 uImage_3.4.2_yaffs2;bootm 32000000'

四. 裁剪内核
    查看现在内核大小
        # ls arch/arm/boot/uImage -l
            -rw-r--r-- 1 root root 2486104 Dec 30 22:41 arch/arm/boot/uImage
        # make menuconfig         //去掉不需要的项
    a. 去掉不需要支持的单板
        System Type  ---> 
            SAMSUNG S3C24XX SoCs Support  ---> 
             *** S3C24XX SoCs ***                                                         
                    [ ] SAMSUNG S3C2410                                                       
                    [ ] SAMSUNG S3C2412                                                  
                    [ ] SAMSUNG S3C2416/S3C2450                                          
                    [*] SAMSUNG S3C2440                                      
                    [ ] SAMSUNG S3C2442                                              
                    [ ] SAMSUNG S3C2443                                         
                        *** S3C2440 Boards ***                                      
                    [ ] Simtec Electronics ANUBIS                                  
                    [ ] Avantech AT2440EVB development board                            
                    [*] MINI2440 development board                                     
                    [ ] NexVision NEXCODER 2440 Light Board                       
                    [ ] Simtec IM2440D20 (OSIRIS) module                                
                    [ ] HP iPAQ rx3715                                            
                    [*] SMDK2440                                                       
                    [*] SMDK2440 with S3C2440 CPU module         
                                                   
    b. 裁剪对文件系统的支持
        File systems  ---> 
            < > Second extended fs support                      //去掉对ext2的支持
            < > Ext3 journalling file system support             //去掉对ext3的支持
            DOS/FAT/NT Filesystems  --->                         //不作修改，对U盘的支持需要
     c . 裁剪对驱动的支持
        Device Drivers  ---> 
            Input device support  ---> 
                [ ]     Provide legacy /dev/psaux device   //delete
                [ ]   Mice  --->                                   //delete
                [ ]   Keyboards  --->                             //delete
       d.继续裁剪
        File systems  ---> 
                CD-ROM/DVD Filesystems  --->
                    < > ISO 9660 CDROM file system support //去掉对光盘的支持
                [*] Miscellaneous filesystems  ---> 
                    < >   Compressed ROM file system support (cramfs) //delete
                    [ ]     Include support for ZLIB compressed file systems //delete
                    < >   ROM file system support //delete
        Device Drivers  --->
            Input device support  ---> 
                [*]   Touchscreens  --->
                    <*>   Samsung S3C2410/generic touchscreen input driver //配置上该项
                    < >   USB Touchscreen Driver   //delete

        Device Drivers  --->
                <*> Sound card support  ---> 
                <*>   Advanced Linux Sound Architecture  ---> 
                [ ]   USB sound devices  ---> //delete
        Device Drivers  --->
                [*] USB support  --->
                        [ ]   The shared table of common (or usual) storage devices   //delete
         保存、退出编译内核
        # make uImage
        # cp arch/arm/boot/uImage /work/tftpboot/uImage_3.4.2_sm
    烧写内核
        # tftp 30000000 uImage_3.4.2_sm
        # nand erase.part kernel; nand write 30000000 kernel
    启动内核
        # set bootcmd 'nand read 30000000 kernel;bootm 30000000'
        # set bootargs console=ttySAC0,115200 root=/dev/mtdblock3
        # set machid 16a
        # save
        # boot
    可正常启动
        

    制作内核补丁
            # cp .config config_mini2440
            # make distclean
            # cd ..
            # mv linux-3.4.2 linux-3.4.2_mini2440 
            # tar xjv linux-3.4.2.tar.bz2
            # diff -urN linux-3.4.2 linux-3.4.2_mini2440 > linux-3.4.2_mini2440.patch
    附上我移植的内核补丁，kernel_patch
    使用内核补丁：
            # patch -p1 < ../linux-3.4.2_mini2440.patch 
            # cp config_mini2440 .config
            # make uImage
    总结：移植测试过程采用的是SMDK2440的机器ID（16a），默认没有加入对网卡DM9000的支持，到这里该内核还不能够通过NFS方式挂接根文件系统，将在下一步完善该功能~~~，很多详细内容未作详细介绍，可参考我提到的资料~