流程

　　片内os起来后，从SDCARD加载uboot，然后使用 tftp 从 PC 下载 kernel，然后使用 nfs 挂载 PC 上的文件系统。

搭建 TFTP 和 NFS server

TFTP

　　sudo apt-get install tftp-hpa  tftpd-hpa xinetd

　　sudo vim /etc/xinetd.d/tftp

　　service tftp
　　{
        socket_type    = dgram
        protocol       = udp
        wait           = yes
        user           = root
        server         = /usr/sbin/in.tftpd
        server_args    = -s /data/tftpdir/ -c
        disable        = no
        per_source     = 11
        cps            = 100 2
        flags          = IPv4
　　}

　　sudo vim /etc/default/tftpd-hpa

　　# /etc/default/tftpd-hpa

　　TFTP_USERNAME="tftp"
　　TFTP_DIRECTORY="/data/tftpdir"
　　TFTP_ADDRESS="[::]:69"
　　TFTP_OPTIONS="--secure"　

　　sudo vim /etc/xinetd.conf

defaults{# Please note that you need a log_type line to be able to use log_on_success ont-size: 12pt; "> # log_type = SYSLOG daemon info}includedir /etc/xinetd.d

　　restart tftp server：　

　　sudo service tftpd-hpa restart 

　　sudo /etc/init.d/xinetd reload

　　sudo /etc/init.d/xinetd restart

　　若遇到错误可查看：tail /var/log/syslog

　　某些情况下要kill进程：

　　　　ps -aux | grep tftp

　　　　ps -aux | grep xine

　　　　sudo kill xxx

NFS

sudo apt-get install nfs-kernel-serverportmap

sudo vim /etc/exports

/data/nfsdir/ *(rw,no_root_squash,sync)

sudo /etc/init.d/nfs-kernel-server restart

测试：sudo mount -t nfs <ip>:/data/nfsdir /mnt

配置bootargs

#define CONFIG_ETHADDR        d0:67:e5:18:02:a4
#define CONFIG_NETMASK      255.255.255.0
#define CONFIG_IPADDR        10.0.161.50
#define CONFIG_SERVERIP        10.0.161.83
#define CONFIG_GATEWAYIP    10.0.161.254

#define CONFIG_BOOTARGS        "console=ttySAC0,115200 rw root=/dev/nfs nfsroot=10.0.161.83:/data/nfsdir ip=10.0.161.50:10.0.161.83:10.0.161.254:255.255.255.0:chuck:eth0:off"
#define CONFIG_BOOTCOMMAND        "tftp 0x20008000 uImage.bin;bootm 0x20008000"

配置DM9000寄存器地址

#ifdef CONFIG_DM9000
#define S5PV210_PA_DM9000_A     (0x88001000)
#define S5PV210_PA_DM9000_F     (S5PV210_PA_DM9000_A + 0x300C)
static struct resource tq210_dm9000_resources[] = {
    [0] = {
        .start = S5PV210_PA_DM9000_A,
        .end = S5PV210_PA_DM9000_A + SZ_1K*4 - 1,
        .flags = IORESOURCE_MEM,
    },
    [1] = {
        .start = S5PV210_PA_DM9000_F,
        .end = S5PV210_PA_DM9000_F + SZ_1K*4 - 1,
        .flags = IORESOURCE_MEM,
    },
    [2] = {
        .start = IRQ_EINT(10),
        .end = IRQ_EINT(10),
        .flags = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHLEVEL,
    },
};