MDK3308-EK 网卡驱动

用放大镜，看到板子上的usb转以太网芯片为sr9900a。网上查到，其驱动为 Ethernet Gadget (with CDC Ethernet support)
不过在尝试了编译USB CDC Ethernet驱动后，仍然不能工作。后来发现插入鼠标、键盘到usb口也不能工作。查阅资料后发现rk3308还要打开一系列的usb选项
https://usermanual.wiki/Document/RockchipDeveloperGuidelinux44USB.1954440366/view

打开方法为，
make rk3308_linux_defconfig
make menuconfig

 Device Drivers  --->
    [*] USB support  --->
        <*>   Support for Host-side USB
        <*>     EHCI HCD (USB 2.0) support
        [*]       Improved Transaction Translator scheduling 
        <*>     Generic EHCI driver for a platform device
        <*>     OHCI HCD (USB 1.1) support
        <*>       Generic OHCI driver for a platform device

    [*] Network device support  --->
        <*>   USB Network Adapters (NEW)  --->
            <*>   Multi-purpose USB Networking Framework
                -*-     CDC Ethernet support (smart devices such as cable modems)

顺手把usb存储的的支持也打开

 Device Drivers  --->
    SCSI device support  --->
        <*> SCSI device support
        [*] legacy /proc/scsi/ support
        <*> SCSI disk support
        <*> SCSI generic support
        <*> SCSI media changer support

    [*] USB support  --->
        <*>     USB Mass Storage support

想保存下来，可以
make savedefconfig
cp defconfig arch/arm64/configs/rk3308_linux_xxx_defconfig

编译内核
make rk3308-evb-dmic-i2s-v10.img

把这个boot.img烧录到板子上，重启，运行 ifconfg，可以看到多出来一个 eth0 了。这时网口的灯也终于亮了

设置ip和网关
ifconfig eth0 192.168.2.14
ifconfig eth0 netmask 255.255.255.0
route add default gw 192.168.2.1

可以把上述语句添加到 /data/RkLunch.sh ，每次开机自动配置

配置dns
vi /etc/resolve.conf

参考
https://blog.csdn.net/kangear/article/details/37605811