Creating am335x sdcard images with wic

[Alexandre Belloni <alexandre.belloni@free-electrons.com>]

Hi,

I tried multiple ways of create sd card images for my am335x based
platform.

I tried to revive the sdimg image type, using the last patch from
Otavio [1]

This didn't generate bootable images.

Now, I'm trying to use wic, based on this patch from Maciej [2].
I have multiple issue, the first one is making wic load the plugin. I
have to apply the patch on poky rather than on my own layer to get wic
to load that plugin, is that intended ?

Next, I'm still not able to generate a bootable image. I tracked it down
to an issue with the fat filesystem rather than the partitionning
itself.

1/ With wic, this is the command line to generate the FAT
filesystem:

mkdosfs -F 16 -n boot -d /var/tmp/wic/build/boot -C /var/tmp/wic/build/boot 10240

This results in an image that doesn't boot.


2/ On the same SD card, if I use:

mkdosfs -F 16 -n boot -d /var/tmp/wic/build/boot /dev/mmcblk0p1

This results in an SD card that can boot, the MLO starts, loads and
starts u-boot.img but then it fails to load my dtb from the FAT
filesystem because somehow, it only has short names.


3/ On the same SD card, if I manually format and copy files
mkfs.vfat -F 16 /dev/mmcblk0p1 -n boot
mount /dev/mmcblk0p1 /mnt
cp $BUILDDIR/tmp/deploy/images/beaglebone/{MLO,u-boot.img,zImage} /mnt
cp $BUILDDIR/tmp/deploy/images/beaglebone/*.dtb /mnt
umount /dev/mmcblk0p1

This one just boots fine, with long names.

Any insight?

[1] https://lists.yoctoproject.org/pipermail/meta-ti/2011-December/000234.html
[2] https://lists.yoctoproject.org/pipermail/meta-ti/2014-July/004901.html
-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com