Booting PhyTec PCM043/IMX35 from USB/SD-Card

[Peter Kuennemann@Crane-Soft]

  mit freundlichen Grüßen,
  sincerely yours
  sincères salutations

Peter Künnemann
Kappeler Strasse 207
D-40599 Düsseldorf

Mobil: +49 151 40511525
       +49 211 1663157

http://www.crane-soft.de

Am 31.05.2012 20:27, schrieb Sascha Hauer:
> Hi Peter,
> 
> On Fri, May 25, 2012 at 11:35:36AM +0200, Peter Kuennemann at Crane-Soft wrote:
>>
>>
>> To have kernel in flash and rootfs on MMC i tried bootargs as:
>>
>> ... root=/dev/mmcblk0p1 rootfstype=ext2 rootflags=noatime rw noinitrd rootwait ..
>>
>> and it boots the kernel properly from flash up to:
>> ...
>> mmcblk0: mmc0:a95c SD01G 968 MiB     <== Recognized the sd card
>>  mmcblk0: p1                         <== and partion 1
>> ...
>> 1f00             256 mtdblock0 (driver?)
>> 1f01             128 mtdblock1 (driver?)
>> 1f02            2048 mtdblock2 (driver?)
>> 1f03           30336 mtdblock3 (driver?)
>> 1f04         1048576 mtdblock4 (driver?)
>> b300          992000 mmcblk0 driver: mmcblk
>>   b301          991585 mmcblk0p1                    <=== Something missing here?
>> No filesystem could mount root, tried:  ext2        <===
>> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,1) <===
>>
>> The mmc does contain a ext2 filesystem with the proper rootfs copied from
>> the jffs2.image that I mounted under Ubuntu as loop device. The kernel has ext2 fs
>> support compiled in.
>>
>> The rootfs on the mmc is properly accessible when booting kernel and flash footfs
>> on the very same platform.
> 
> Has this been solved in the mean time? The above looks correct, I have
> no idea what's wrong.

The case has been partly solved now. I am able to boot from NAND and NOR but I cannot
access the MMC. Reason for the kernel messages ...(driver?) above was a missing device
"mxc_nand" in the kernel parms for mtdparts:

    mtdparts=physmap-flash.0:256k(barebox)ro,128k(bareboxenv),2M(kernel),-(root); \
    mxc_nand:256k(barebox)ro,128k(bareboxenv),2M(kernel),-(root)

However, I still cannot access the mmc from barebox. It would be enough to be able to
read the mmc. I want to be able to store kernel or rootfs image updates on the mmc
and flash them to either NAND or NOR after reboot to enable remote update services.

Question: "How can I access the MMC from barebox (read only may be sufficient)

Regards, Peter

-- 
Barebox device list:

barebox at MKT.i357-CPU:/ ls -l /dev
crw-------         32 imx_iim_bank0
crw-------         32 imx_iim_bank1
crw-------         32 imx_iim_bank2
crw-------         32 imx_iim_bank3
crw-------         32 imx_iim_bank4
crw-------         32 imx_iim_bank5
crw-------         32 imx_iim_bank6
crw-------         32 imx_iim_bank7
cr-------- 4294967295 zero
crw-------  134217728 ram0
crw-------       8281 defaultenv
crw------- 4294967295 mem
crw-------         64 phy0
crw------- 1073741824 nand0
cr--------   33554432 nand_oob0
crw-------   33554432 nor0
crw-------     262144 self0
crw-------     131072 env0
crw-------     262144 nor0.barebox
crw-------     131072 nor0.bareboxenv
crw-------    2097152 nor0.kernel
crw-------   31064064 nor0.root
crw-------     262144 nand0.barebox
crw-------     131072 nand0.bareboxenv
crw-------    2097152 nand0.kernel
crw------- 1071251456 nand0.root
crw------- 1070071808 nand0.root.bb
crw-------    2097152 nand0.kernel.bb
crw-------     131072 nand0.bareboxenv.bb
crw-------     262144 nand0.barebox.bb