the fail log:
imx mcc test is registered.
input: gpio-keys.21 as /devices/soc0/gpio-keys.21/input/input8
snvs_rtc 20cc034.snvs-rtc-lp: setting system clock to 1970-01-01 00:00:01 UTC (1)
ALSA device list:
#0: wm8962-audio
#1: imx-hdmi-soc
random: nonblocking pool is initialized
VFS: Unable to mount root fs via NFS, trying floppy.
VFS: Cannot open root device "nfs" or unknown-block(2,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
1f00 32 mtdblock0 (driver?)
b300 7757824 mmcblk3 driver: mmcblk
b301 512000 mmcblk3p1 00000000-01
b302 7143424 mmcblk3p2 00000000-02
b318 128 mmcblk3rpmb (driver?)
b310 1024 mmcblk3boot1 (driver?)
b308 1024 mmcblk3boot0 (driver?)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)
CPU2: stopping
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 3.14.28-1.0.0_ga+g91cf351 #2
[<800149f8>] (unwind_backtrace) from [<80011714>] (show_stack+0x10/0x14)
[<80011714>] (show_stack) from [<806ecc7c>] (dump_stack+0x7c/0xbc)
[<806ecc7c>] (dump_stack) from [<80013998>] (handle_IPI+0x144/0x158)
[<80013998>] (handle_IPI) from [<80008598>] (gic_handle_irq+0x58/0x5c)
[<80008598>] (gic_handle_irq) from [<80012200>] (__irq_svc+0x40/0x70)
Exception stack(0xa80a9f50 to 0xa80a9f98)
9f40: a80a9f98 3b9aca00 1148b60e 00000017
