WhyCan Forum(哇酷开发者社区)

有没有人遇到过这样的问题：
V3S，SD卡正常启动，登陆名为root，没有设置密码，可以正常登录；同样的内核和根文件系统，使用TFTP下载，文件系统用NFS挂载，启动成功之后，同样使用登录名root，却一直提示输入密码，输入密码root或直接按回车，提示密码错误，不知道这是什么情况

[    1.365236] dwmac-sun8i 1c30000.ethernet eth0: No MAC Management Counters available
[    1.372990] dwmac-sun8i 1c30000.ethernet eth0: PTP not supported by HW
[    1.386150] mmc1: queuing unknown CIS tuple 0x1a (5 bytes)
[    1.394729] mmc1: queuing unknown CIS tuple 0x1b (8 bytes)
[    1.402170] mmc1: queuing unknown CIS tuple 0x80 (1 bytes)
[    1.407768] mmc1: queuing unknown CIS tuple 0x81 (1 bytes)
[    1.413308] mmc1: queuing unknown CIS tuple 0x82 (1 bytes)
[    1.418851] mmc1: new high speed SDIO card at address 0001
[    1.479880] musb-hdrc musb-hdrc.1.auto: VBUS_ERROR in b_idle (80, <SessEnd), retry #0, port1 00000100
[    3.446216] dwmac-sun8i 1c30000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[    3.505645] IP-Config: Complete:
[    3.508886]      device=eth0, hwaddr=02:00:bd:ce:ea:e2, ipaddr=10.36.5.122, mask=255.255.0.0, gw=10.36.5.1
[    3.518553]      host=10.36.5.122, domain=, nis-domain=(none)
[    3.524295]      bootserver=10.36.5.120, rootserver=10.36.5.120, rootpath=
[    3.531599] vcc5v0: disabling
[    3.534577] ALSA device list:
[    3.537602]   #0: V3s Audio Codec
[    3.557495] VFS: Mounted root (nfs filesystem) on device 0:13.
[    3.565563] devtmpfs: mounted
[    3.569857] Freeing unused kernel memory: 1024K
Starting logging: OK
Starting mdev...
modprobe: can't change directory to '/lib/modules': No such file or directory
read-only file system detected...done
Starting network: ip: RTNETLINK answers: File exists
FAIL

Welcome to Buildroot
buildroot-HS login: root
Password:
Login incorrect
buildroot-HS login: root
Password: