Re: [Gumstix-users] Trouble booting from mmc card on Verdex-pro

[Chuck R. <shi...@ro...>]

On May 6, 2009, at 6:05 PM, Jim Doutt wrote:
>
> Chuck Randall wrote:
>> On May 6, 2009, at 1:04 PM, jdoutt wrote:
>>
>>> Boot from mmc card gives:  'Kernel panic - not syncing: VFS: Unable
>>> to mount root fs on unknown-block(0,0)'
>>>
>> Before you install the uImage and rootfs onto the MMC card, you need
>> to rebuild those 2 images. Specifically, you need to make certain  
>> that
>> you have built a kernel that can boot from the MMC card. Otherwise  
>> you
>> will encounter the 'unknown-block(0,0)' error upon booting the  
>> gumstix
>> from the MMC card. Modify gumstix-custom-verdex.conf to include
>> mmcroot, ext2 and fat.
>>
>> Chuck
>>
>
> Thanks so much  -  ext2 and fat were enabled, but mmcroot was not.   
> I'm
> rebuilding now!
>
> I'm using the microSD card  (NOT the MMC as stated above!!!!).  I
> understand that mmcroot is used for the microSD also  -  IS THAT  
> CORRECT?
>
> ....  BUT, get the same eror:

Don't worry, the 'mmcroot' setting covers both microSD and MMC cards.
Note the message in the bootup log:
     Booting from mmc/microSD...

The only times I have received the 'unknown-block(0,0)' error is when  
I've made the 'mmcroot' setting incorrectly, or I copied the wrong  
uImage and rootfs to the microSD card.

Make sure you edited the file located here and not some other version  
of it (the changes wouldn't get picked up):
     ~/gumstix/gumstix-oe/com.gumstix.collection/conf/machine/gumstix- 
custom-verdex.conf

with the following line (NO whitespace at the beginning of the line):
     MACHINE_FEATURES += "mmcroot"

Now, rebuild the images:
    bitbake -c rebuild task-base-gumstix
    bitbake -c rebuild gumstix-kernel
    bitbake -c rebuild gumstix-basic-image

The products of this rebuild will be in this folder:
       ~/gumstix/gumstix-oe/tmp/deploy/glibc/images/gumstix-custom- 
verdex/
     specifically:
       a. The uimage that goes into the FAT16 partition (mmcblk0p1)
             uImage-2.6.21-r1-gumstix-custom-verdex.bin
       b. The rootfs that goes into the ext2 partition (mmcblk0p2)
             gumstix-basic-image-gumstix-custom-verdex.rootfs.tar.gz

Chuck