[elbe-devel] rootfs partition image?

[Manuel Traut]

Hi Norbert,
 
> I have a bootable image for my board created with buildroot. Now I
> am trying to set up an ELBE build in the same way.
> 
> The difficulty is that with buildroot I am installing the u-boot
> binary into the boot sector of the disk, not inside any partition.
> The rootfs that drops out of buildroot is an image of a single
> partition, not a whole disk. In essence the script for writing the
> buildroot binaries to an SD card is as follows:
> 
> --------------
> dd if=/dev/zero of=$CARD bs=1M count=1
> dd if=$IMAGES/u-boot-with-spl.bin of=$CARD bs=1024 seek=8
> sfdisk --in-order -L -uM $CARD <<EOT
> 1,256,L
> EOT
> dd if=$IMAGES/rootfs.ext2 of=${CARD}p1
> --------------
> 
> Now: with ELBE, I could only find examples producing disk images or
> rootfs tar archives. For the former, I am missing some way to write
> a binary chunk at the beginning of the image outside the partitions.

Yes, that's not supported at the moment :(

> For the latter: I tried to unpack the tar directly into the empty
> partition, but this took ages and the result did not work as
> expected. (My guess is that a naive 'tar xfz' was missing some
> details in unpacking)

You need to untar it with root privileges.

> Is it possible with elbe to create a partition image instead of a
> full disk image? Or to write a boot sector to the disk image? Any
> other ideas?

At the moment, we only create filesystem-images for ubifs.
There is no support for writing an own boot-sector.

I think support for sth. like
--8<--
<images>
  <msdoshd>
    <name>..</name>
    <size>..</size>
    <binaries>
      <binary bs=1024 seek=8>/tmp/u-boot-with-spl.bin</binary> 
    </binaries>
    <partition>
      <size>1G</size>
      <label>rfs</label>
      <offset>1M</offset>
    </partition>
  </msdoshd>
</images>
--8<--

would be nice.


> Does anyone have experience with boards that expect to find u-boot
> at the beginning of the disk?

IMHO this boot-method is popular for Allwinner SoCs?

I have never used elbe with this kind of boot-method.

Regards,
  Manuel

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