参考博客：RK3568开发笔记-buildroot移远EC20模块调试记录

一、内核配置

cd 到kernel目录，执行make ARCH=arm64 menuconfig，

 Device Drivers 

                >USB support

                        > USB Serial Converter support

选中 USB driver for GSM and CDMA modems选项，usb串口驱动内核配置如下截图所示：

 sdk默认已选中。

 Device Drivers

        >Network device support 

                >USB Network Adapters

选中 QMI WWAN driver for Qualcomm MSM based 3G and LTE modems

 sdk默认没选中，需要选择。然后点击save，最新的配置已保存到.config文件中了，需要将.config的内容覆盖编译所用的config文件，我编译所用的config文件为rockchip_linux_defconfig，那么执行cp .config arch/arm64/configs/rockchip_linux_defconfig

然后重新编译kernel。

二、测试

重新烧写boot.img，然后重启设备。

执行lsusb执行查看是否有id为2c7c:0125的设备：

[root@RK356X:/]# lsusb
Bus 005 Device 001: ID 1d6b:0002
Bus 003 Device 001: ID 1d6b:0001
Bus 001 Device 001: ID 1d6b:0002
Bus 005 Device 002: ID 2c7c:0125
Bus 006 Device 001: ID 1d6b:0003
Bus 004 Device 001: ID 1d6b:0001
Bus 002 Device 001: ID 1d6b:0002

执行ifconfig查看是否有wwan0网卡：

[root@RK356X:/]# ifconfig
eth0      Link encap:Ethernet  HWaddr 8C:AE:49:61:00:6B
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:35

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:58 errors:0 dropped:0 overruns:0 frame:0
          TX packets:58 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3928 (3.8 KiB)  TX bytes:3928 (3.8 KiB)

p2p0      Link encap:Ethernet  HWaddr 16:F5:F9:87:0F:BE
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

wlan0     Link encap:Ethernet  HWaddr 14:F5:F9:87:0F:BE
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

wwan0     Link encap:Ethernet  HWaddr BE:F6:0A:C3:6E:E3
          inet addr:169.254.14.152  Bcast:169.254.255.255  Mask:255.255.0.0
          inet6 addr: fe80::f786:a01:d513:29c6/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:19 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:2656 (2.5 KiB)