Cannot mount rootfs of i.mx6q sabresd board

[shijunzhao]

I'm using the i.mx6q sabresd board, but I cannot mount rootfs. The rootfs is stored on the second partition of a SD card (/dev/sdb2).

The uboot  environment:

bootargs console=${console},${baudrate} ${smp} root=${mmcroot}

mmcroot=/dev/mmcblk2p2 rootwait rw

The print log:

Waiting for root device /dev/mmcblk2p2...
mmc2: new high speed SDHC card at address 0003
mmcblk2: mmc2:0003 SD 3.69 GiB (ro)
mmcblk2: p1 p2
VFS: Cannot open root device "mmcblk2p2" or unknown-block(179,2): error -30
Please append a correct "root=" boot option; here are the available partitions:
0100 65536 ram0 (driver?)
0101 65536 ram1 (driver?)
0102 65536 ram2 (driver?)
0103 65536 ram3 (driver?)
0104 65536 ram4 (driver?)
0105 65536 ram5 (driver?)
0106 65536 ram6 (driver?)
0107 65536 ram7 (driver?)
0108 65536 ram8 (driver?)
0109 65536 ram9 (driver?)
010a 65536 ram10 (driver?)
010b 65536 ram11 (driver?)
010c 65536 ram12 (driver?)
010d 65536 ram13 (driver?)
010e 65536 ram14 (driver?)
010f 65536 ram15 (driver?)
b300 3870720 mmcblk2 driver: mmcblk
b301 501760 mmcblk2p1 f65c1f66-01
b302 3256320 mmcblk2p2 f65c1f66-02
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)
CPU1: stopping
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.1.15 #1
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[<80015dc4>] (unwind_backtrace) from [<80012748>] (show_stack+0x10/0x14)
[<80012748>] (show_stack) from [<808005f4>] (dump_stack+0x84/0xc4)
[<808005f4>] (dump_stack) from [<80014cc0>] (handle_IPI+0x178/0x18c)
[<80014cc0>] (handle_IPI) from [<80009488>] (gic_handle_irq+0x58/0x5c)
[<80009488>] (gic_handle_irq) from [<80013240>] (__irq_svc+0x40/0x74)
Exception stack(0xa60a1f48 to 0xa60a1f90)
1f40: 00000000 a9756380 00000001 a60a0000 a9752e90 00000001
1f60: 36104fef 00000001 367ef18d 00000001 00000001 00000000 00000001 a60a1f90
1f80: 808088f0 80574690 20000013 ffffffff
[<80013240>] (__irq_svc) from [<80574690>] (cpuidle_enter_state+0xd8/0x214)
[<80574690>] (cpuidle_enter_state) from [<80066210>] (cpu_startup_entry+0x1fc/0x320)
[<80066210>] (cpu_startup_entry) from [<1000952c>] (0x1000952c)
---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)

[pandapravaskuma]

how to check if the sdcard is write protected or not and by the way how you are dumping the linux by yocto build or some other way? Even I have a IMX6q sabre board how should i dump linux on that . can u help me step by step what is the prodce

Thanks in advance.

[joanxie]

it seems you don't set the root correct, try to make sure you set the correct partitions, and try to ensure you use the correct bootloader for your board, different board has different image, and then you can refer to the enclosed imx

[shijunzhao]

I think I set the root correctly, it is indeed /dev/mmcblk2p2. I'm using i.mx6q sabresd card, and Slot 3 sd card.

[joanxie · Accepted solution]

1)Make sure the SD card you are using is NOT write protected.  The default mount command

for SD cards (in uboot) use the "rw" option.  If the card is write protected, the mount will

fail and give you this same error message.

2) did you set rootfstype for your sd card? maybe you can set the sd card step by step refer to the user guide.

[shijunzhao]

Thanks a lot. Yes, the SD card is write protected.