在Starting kernel时发生以下报错，打不开root fs，请各大指点一下可能的原因，谢谢
VFS: Cannot open root device "mmcblk0p5" or unknown-block(0,0): error -6
Starting kernel ...
...
[ 2.133560] ALSA device list:
[ 2.136885] #0: audiocodec
[ 2.140123] alloc_fd: slot 0 not NULL!
[ 2.144456] cfg80211: failed to load regulatory.db
[ 2.150484] VFS: Cannot open root device "mmcblk0p5" or unknown-block(0,0): error -6
[ 2.159187] Please append a correct "root=" boot option; here are the available partitions:
[ 2.168639] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[ 2.177900] CPU: 0 PID: 1 Comm: swapper Not tainted 5.4.61 #13
[ 2.184426] Call Trace:
[ 2.187184] [<ffffffe00002a154>] walk_stackframe+0x0/0x98
[ 2.193230] [<ffffffe00002a30c>] show_stack+0x2a/0x34
[ 2.198888] [<ffffffe0004c95ac>] dump_stack+0x20/0x28
[ 2.204544] [<ffffffe00002e7cc>] panic+0xec/0x272
[ 2.209815] [<ffffffe000000ef2>] mount_block_root+0x214/0x27a
[ 2.216243] [<ffffffe000000fde>] mount_root+0x86/0x90
[ 2.221899] [<ffffffe000001130>] prepare_namespace+0x148/0x152
[ 2.228427] [<ffffffe000000b54>] kernel_init_freeable+0x166/0x198
[ 2.235256] [<ffffffe0004da17c>] kernel_init+0x12/0xee
[ 2.241014] [<ffffffe000028ec0>] ret_from_exception+0x0/0xc
[ 2.247255] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---启动SD卡是用phoenixCard（试过4.2.5/4.2.7/4.2.8三个版本都一样）烧的，在uboot控制台mmcinfo查卡信息正常，mmc part查看到有8个分区
=> mmcinfo
curr_device:0
Device: SUNXI SD/MMC
Manufacturer ID: 3
OEM: 5344
Name: SL16G
Bus Speed: 50000000
Mode : SD High Speed (50MHz)
Rd Block Len: 512
SD version 3.0
High Capacity: Yes
Capacity: 14.8 GiB
Bus Width: 4-bit
Erase Group Size: 512 Bytes
=> mmc part
Partition Map for MMC device 0 -- Partition Type: EFI
Part Start LBA End LBA Name
Attributes
Type GUID
Partition GUID
1 0x00012000 0x000121f7 "boot-resource"
attrs: 0x0000200000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e45
2 0x000121f8 0x000123ef "env"
attrs: 0xc000200000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e46
3 0x000123f0 0x000125e7 "env-redund"
attrs: 0xc000200000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e47
4 0x000125e8 0x000175e7 "boot"
attrs: 0xc000200000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e48
5 0x000175e8 0x000233e7 "rootfs"
attrs: 0xc000200000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e49
6 0x000233e8 0x00028b67 "recovery"
attrs: 0xc000200000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e4a
7 0x00028b68 0x0002b367 "rootfs_data"
attrs: 0xc000200000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e4b
8 0x0002b368 0x01dac3ff "UDISK"
attrs: 0xc000000000000000
type: ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
guid: a0085546-4166-744a-a353-fca9272b8e4c
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