Kernel panic with Kernel (uImage) 2.6.22.18

[Marco Trapanese]

Hello,

I want to try a Linux kernel so I managed an SD card to have two
partitions. The first is formatted as FAT32 where I copied:

http://beagleboard.googlecode.com/files/MLO_revb
http://beagleboard.googlecode.com/files/flash-uboot.bin
http://beagleboard.googlecode.com/files/uImage_OTG

in that order. The second one is formatted as ext3 and contains the
root file system:

http://beagleboard.googlecode.com/files/ALSA-FS.tar.gz

which I have untar-ed directly on the SD.
I set the boot arguments and commands like these:

# setenv bootargs 'console=ttyS2,115200n8 root=/dev/mmcblk0p2 rw
rootwait'
# setenv bootcmd 'mmcinit;fatload mmc 0 80300000 uImage;bootm
80300000'

After power-up it reads the uImage and start to load the kernel. After
a while on the serial terminal I get:

VFS: Unable to mount root fs via NFS, trying floppy.
VFS: Cannot open root device "mmcblk0p2" or unknown-block(2,0)
VFS: Cannot open root device "mmcblk0p2" or unknown-block(2,0)
Please append a correct "root=" boot option; here are the available
partitions:
Please append a correct "root=" boot option; here are the available
partitions:
1f00 512 mtdblock01f00 512 mtdblock0 (driver?)
(driver?)
1f01 1920 mtdblock11f01 1920 mtdblock1 (driver?)
(driver?)
1f02 128 mtdblock21f02 128 mtdblock2 (driver?)
(driver?)
1f03 5120 mtdblock31f03 5120 mtdblock3 (driver?)
(driver?)
1f04 254464 mtdblock41f04 254464 mtdblock4 (driver?)
(driver?)
<0>Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-
block(2,0)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-
block(2,0)


I understand there is a mistake in the root arguments, but I can't
understand how to read the "available partitions" table and how to
change the bootarg value.

May you help me, please?

Thanks
Marco

[Ragha]

On Sat, Dec 27, 2008 at 3:17 PM, Marco Trapanese
<marcotr...@gmail.com> wrote:
> # setenv bootargs 'console=ttyS2,115200n8 root=/dev/mmcblk0p2 rw
> rootwait'

This works for me.
setenv bootargs 'console=ttyS2,115200n8 console=tty0
root=/dev/mmcblk0p2 rootdelay=2 rootfstype=ext3
video=omapfb:vram:2M,vram:4M'

Regards,
-Ragha

[Marco Trapanese]

> This works for me.
> setenv bootargs 'console=ttyS2,115200n8 console=tty0
> root=/dev/mmcblk0p2 rootdelay=2 rootfstype=ext3
> video=omapfb:vram:2M,vram:4M'

This works for me too :-)
But how can one deduce that parameters from the error message I wrote
before?

Thanks a lot!
Marco

[Jason Kridner]

I'm afraid it may be simply experience that tells us that the /dev/
mmcblk0p2 file system isn't ready until the kernel has been running
long enough to scan the file system. Your first clue should be that
the issue is that the roof file system isn't available. You might
focus on if the file system was prepared properly or not, but some web
searches would unveil this problem.

[Robert Nelson]

rootwait wasn't added till at-least 2.6.24 (or so), so you have to use
rootdelay=2 with TI's earlier kernel. (Common error & solution for a
lot of embedded targets, arm/avr32/etc...)

--
Robert Nelson
http://www.rcn-ee.com/

[Favor Tang]

hi.

    I meet with the same problem. but this is an error due to  the wrong  format of disk partition.

   your disk format sectors , headers and cylinders should be the same as below:

Disk /dev/sdc: 2021 MB, 2021654528 bytes

255 heads, 63 sectors/track, 245 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes


   Device Boot      Start         End      Blocks   Id  System



    please make sure that you followed the instuctions of the  LinuxBootDiskFormat to format your MMC card.

mybe you should do this again, and you will solve this problem.

http://code.google.com/p/beagleboard/wiki/LinuxBootDiskFormat

thanks!

           /favor

--
         /favor