根文件挂载问题

msm007

[    2.344000] mmc_host mmc0: device is being hw reset
[    2.345000] tmu[0] = trim 52:0, ret 1
[    2.347000] TMU: register tmu.0 to hwmon (max 1400000khz)
[    2.348000] ALSA device list:
[    2.349000]   #0: I2S-alc5623
[    2.350000]   #1: SPDIF-Transciever
[    2.352000] VFS: Cannot open root device "mmcblk0p2" or unknown-block(0,0): error -6
[    2.353000] Please append a correct "root=" boot option; here are the available partitions:
[    2.354000] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[    2.355000] [<c0014e80>] (unwind_backtrace+0x0/0x138) from [<c06c80c0>] (panic+0x8c/0x1e4)
[    2.356000] [<c06c80c0>] (panic+0x8c/0x1e4) from [<c09e8d00>] (mount_block_root+0x174/0x220)
[    2.357000] [<c09e8d00>] (mount_block_root+0x174/0x220) from [<c09e8f8c>] (mount_root+0xf4/0x114)
[    2.358000] [<c09e8f8c>] (mount_root+0xf4/0x114) from [<c09e9110>] (prepare_namespace+0x164/0x1c4)
[    2.359000] [<c09e9110>] (prepare_namespace+0x164/0x1c4) from [<c09e89bc>] (kernel_init+0x180/0x1c0)
[    2.360000] [<c09e89bc>] (kernel_init+0x180/0x1c0) from [<c000f7a4>] (kernel_thread_exit+0x0/0x8)
[    2.361000] Rebooting in 5 seconds..
内核启动以后，找不到根文件，下面是我设置的bootargs，不知道为什么这样，有没有遇到过这样的问题，指点一下，谢谢！
setenv bootargs root=/dev/mmcblk0p2 rootfstype=ext4 console=ttySAC0,115200 maxcpus=1 lcd=vs070cxn tp=gslx680-linux