arm-linux 求助 Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)

baudrate=115200
bootargs=root=/dev/mmcblk0p2 rw rootfstype=ext4 rootwait init=/linuxrc console=ttySAC0 maxcpus=1 lcd=wy070ml tp=gslx680 ip=192.168.3.165:192.168.3.113:192.168.3.1:255.255.255.0
bootcmd=mmc read 48000000 1800 3000; bootm 48000000
bootdelay=3
bootfile=uImage
ethact=dwmac.c0060000
ethaddr=00:e2:1c:ba:e8:60
ethprime=RTL8211
fileaddr=48000000
filesize=800000
gateway=192.168.3.1
gatewayip=192.168.3.1
ipaddr=192.168.3.165
netmask=255.255.255.0
serverip=192.168.3.113
stderr=serial
stdin=serial
stdout=serial
           

[    2.375000] eth0: device MAC address 3a:ce:be:70:01:36
[    2.390000] stmmac_open: failed PTP initialisation
[    2.401000] IP-Config: Complete:
[    2.401000]      device=eth0, addr=192.168.3.165, mask=255.255.255.0, gw=192.168.3.1
[    2.402000]      host=192.168.3.165, domain=, nis-domain=(none)
[    2.403000]      bootserver=192.168.3.113, rootserver=192.168.3.113, rootpath=
[    2.404000] ALSA device list:
[    2.405000]   #0: I2S-alc5623
[    2.406000]   #1: SPDIF-Transciever
[    2.410000] EXT4-fs (mmcblk0p2): couldn't mount RDWR because of unsupported optional features (400)
[    2.414000] List of all partitions:
[    2.414000] b300         7634944 mmcblk0  driver: mmcblk
[    2.416000]   b301           65536 mmcblk0p1 00000000-0000-0000-0000-000000000000
[    2.417000]   b302          819200 mmcblk0p2 00000000-0000-0000-0000-000000000000
[    2.418000]   b303         6747136 mmcblk0p3 00000000-0000-0000-0000-000000000000
[    2.420000] b310            4096 mmcblk0boot1  (driver?)
[    2.422000] b308            4096 mmcblk0boot0  (driver?)
[    2.424000] No filesystem could mount root, tried:  ext4
[    2.426000] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)
[    2.427000] [<c0014e80>] (unwind_backtrace+0x0/0x138) from [<c06c7214>] (panic+0x8c/0x1e4)
[    2.428000] [<c06c7214>] (panic+0x8c/0x1e4) from [<c09e6d70>] (mount_block_root+0x1e4/0x220)
[    2.429000] [<c09e6d70>] (mount_block_root+0x1e4/0x220) from [<c09e6ea0>] (mount_root+0xf4/0x114)
[    2.430000] [<c09e6ea0>] (mount_root+0xf4/0x114) from [<c09e6fec>] (prepare_namespace+0x12c/0x18c)
[    2.431000] [<c09e6fec>] (prepare_namespace+0x12c/0x18c) from [<c09e69bc>] (kernel_init+0x180/0x1c0)
[    2.432000] [<c09e69bc>] (kernel_init+0x180/0x1c0) from [<c000f7a4>] (kernel_thread_exit+0x0/0x8)
[    2.433000] Rebooting in 5 seconds..
[    5.277000] Restarting Linux version 3.4.39-tarena ([email protected]) (gcc version 4.7.4 20131111 (prerelease) (crosstool-NG linaro-1.13.1-4.8-2013.11 - nexell) ) #1 SMP PREEMPT Mon Apr 26 22:35:54 +08 20I2C_WriteByte nack returned
           

問題如上, 不知道怎麼解決好了, 求大神幫忙