Booting PhyTec PCM043/IMX35 from USB/SD-Card

[Peter]

Am 24.08.2012 10:46, schrieb Jan Lübbe:

Jan, thanks very much for pointing me into the right direction

> Hi!
> 
> On Thu, 2012-08-23 at 19:59 +0200, Peter wrote:
>> I am able to boot the kernel from NOR flash and use the mmc as rootfs. However
>> I did not yet find a way to boot the kernel from the MMC. I set up the MMC
>> with 255 heads, 63 sectors/track, 245 cylinders and formated partition 1 as
>> VFAT and made it bootable. I then copied uImage to it. Partition 2 contains
>> the rootfs which can be used when booting the kernel from flash.
>>
>> Barebox /env/config contains: (besides others)
>> ...
>>  kernel_loc=disk
>>  rootfs_loc=disk
>>  rootfs_type=ext2
>>  rootfs_part_linux_dev=mmcblk0p2
>>  kernel_part=disk0.0
>> ...
>>
>> Trying to boot results in:
>> booting kernel from /dev/disk0.0
>>
>> and then followed by the barebox prompt.
> 
> You're using the old default-env which does not support uImage on FAT
> (only a kernel directly in a partition). Either switch to default-env-2
> and mount the FAT ('mount /dev/disk0.0 fat /mnt') before loading the
> kernel from /mnt/uImage.
> Otherwise for the old default-env take a look at
> <1345472428-17417-13-git-send-email-jlu at pengutronix.de>. Note that for
> that to work, the FAT must be mounted by the board code or you need to
> setup an automount.


After implementing all required driver and support into barebox, it turns
out that I also need to increase it's partition size to 512K. I then was
able to use the existing environment and changed the boot script as follows

elif [ x$kernel_loc = xdisk ]; then
     kdev="/dev/$kernel_part"
+    mkdir /boot
+    mount $kdev fat /boot
+    kdev=/boot/UIMAGE

Many thanks, Peter