按照 第三篇 6.6开发板使用NFS根文件系统
uboot设置：
uboot设置
=> setenv ipaddr 192.168.3.34
=> setenv serverip 192.168.3.51
=> ping 192.168.3.51
Using ethernet@020b4000 device
host 192.168.3.51 is alive
=> setenv nfsroot /home/book/nfs_rootfs
=> run netboot
kernel启动后 log显示ubuntu上的NFS server没有回应：
[ 4.860492] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 4.870033] Generic PHY 20b4000.ethernet-1:00: attached PHY driver [Generic PHY] (mii_bus:phy_addr=20b4000.ethernet-1:00, irq=-1)
[ 4.882393] IPv6: ADDRCONF(NETDEV_UP): eth1: link is not ready
[ 6.935269] fec 20b4000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 6.954464] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 6.984634] Sending DHCP requests ., OK
[ 7.054275] IP-Config: Got DHCP answer from 192.168.3.1, my address is 192.168.3.34
[ 7.061982] IP-Config: Complete:
[ 7.065334] device=eth0, hwaddr=00:01:3f:2d:3e:4d, ipaddr=192.168.3.34, mask=255.255.255.0, gw=192.168.3.1
[ 7.075511] host=192.168.3.34, domain=, nis-domain=(none)
[ 7.081381] bootserver=0.0.0.0, rootserver=192.168.3.51, rootpath= nameserver0=192.168.3.1
[ 7.095652] ltemodule-pwr: disabling
[ 7.099292] wifi-pwr: disabling
[ 7.102466] ALSA device list:
[ 7.106091] #0: wm8960-audio
[ 7.151750] VFS: Mounted root (nfs filesystem) readonly on device 0:15.
[ 7.160543] devtmpfs: mounted
[ 7.166115] Freeing unused kernel memory: 1024K
Starting syslogd: OK
Starting klogd: OK
Running sysctl: OK
Starting 100ask lvgl: OK
[ 9.099312] ds18b20_drv_init OK.
[ 9.218258] dht11_drv_init OK.
[ 9.331739] irda_drv_init OK.
Populating /dev using udev: [ 9.668576] udevd[176]: starting version 3.2.9
[ 10.357301] udevd[177]: starting eudev-3.2.9
[ 11.737146] inv-mpu6000-spi spi2.0: mounting matrix not found: using identity…
[ 12.629001] 8723bu: loading out-of-tree module taints kernel.
[ 13.264729] usbcore: registered new interface driver rtl8723bu
done
Initializing random number generator: OK
Saving random seed: OK
Starting system message bus: done
Starting network: udhcpc: started, v1.31.1
[ 47.494423] random: crng init done
[ 64.534950] Bluetooth: hci0: Failed to load rtl_bt/rtl8723b_config.bin
[ 64.541567] Bluetooth: hci0: rtl: loading rtl_bt/rtl8723b_fw.bin
[ 202.774482] nfs: server 192.168.3.51 not responding, still trying
[ 202.780904] nfs: server 192.168.3.51 not responding, still trying
[ 202.787850] nfs: server 192.168.3.51 not responding, still trying
[ 228.374429] nfs: server 192.168.3.51 not responding, still trying
[ 244.544408] nfs: server 192.168.3.51 not responding, still trying
Ubuntu上测试本地挂载可以的：
book@100ask:~$ sudo mount -t nfs -o nolock localhost:/home/book/nfs_rootfs /mnt
[sudo] password for book:
book@100ask:~$
book@100ask:~$ ls /mnt
01_old boot etc lib32 media opt root run selinux tmp var
bin dev lib linuxrc mnt proc rootfs.tar.bz2 sbin sys usr
请大佬帮忙看看问题出在哪儿？