EEPW论坛

想通过tftp+nfs来调试程序，网线已经插到板子上，使用emmc boot启动ubuntu没有问题。启动log如下：
U-Boot 2017.09-03676-g0cbcc01 (Mar 26 2020 - 14:06:50 +0800)

Model: Firefly-RK3288
DRAM:  2 GiB
Sysmem: init
Relocation Offset is: 00000000
Using default environment

dwmmc@ff0c0000: 1, dwmmc@ff0f0000: 0
MMC: no card present
mmc_init: -123, time 0
switch to partitions #0, OK
mmc0(part 0) is current device
Bootdev: mmc 0
MMC0: High Speed, 52Mhz
PartType: EFI
rockchip_get_boot_mode: Could not found misc partition
boot mode: None
Load FDT from boot part
DTB: rk-kernel.dtb
I2c0 speed: 400000Hz
vdd_log 1100000 uV
In:    serial@ff690000
Out:   serial@ff690000
Err:   serial@ff690000
Model: Firefly-RK3288 Board (Linux Opensource)
Rockchip UBOOT DRM driver version: v1.0.1
xfer: num: 2, addr: 0x50
xfer: num: 2, addr: 0x50
Monitor has basic audio support
Could not find baseparameter partition
mode:1920x1080
CEA mode used vic=16
final pixclk = 148500000 tmdsclk = 148500000
PHY powered down in 0 iterations
PHY PLL locked 1 iterations
PHY powered down in 1 iterations
PHY PLL locked 1 iterations
sink has audio support
hdmi_set_clk_regenerator: fs=48000Hz ftdms=148.500MHz N=6144 cts=148500
CLK: (uboot. arm: enter 1000000 KHz, init 1000000 KHz, kernel 0N/A)
apll 1000000 KHz
dpll 396000 KHz
cpll 742000 KHz
gpll 594000 KHz
npll 24000 KHz
aclk_bus 297000 KHz
Net:   No ethernet found.

测试如下：

=> print ipaddr
ipaddr=192.168.1.20
=> print serverip
serverip=192.168.1.8
=> ping 192.168.1.8
No ethernet found.
ping failed; host 192.168.1.8 is not alive

请问如何解决