[ARMedslack] Anyone weigh in on Dreamplug install for 14.0?

Innes Read armedslack at innes.veryspeedy.net
Tue Oct 2 20:02:14 UTC 2012

Thanks Michael, you've confirmed a lot of what I've been discovering!

I have now built my own 3.4.11 with MTD disabled as a workaround (I also
had to disable PHYS_VIRT in my case as I have not upgraded U-Boot yet)
and that does indeed boot into the 14.0 installer successfully.

When I switch to using the Dreamplug board number / FDT config I also
see the same lockup right after the "Uncompressing...done" message -
it's interesting that upgrading U-Boot did not fix that for you (but
have you checked CONFIG_SERIAL_OF_PLATFORM as per [1], I believe the
Slackware install kernel has that set to N).  Let me know if you find
anything interesting in the U-Boot sources - I have now procured what
appears to be the original U-Boot image from another source (thanks
Jim!) so I feel a little more secure about blowing my current U-Boot
image away with a new one!

Cheers,  Innes.


On Tue, Oct 2, 2012, at 19:47, Michael Langfinger wrote:
>  Hi Innes,
>  i had some spare time today to play around with my Dreamplug and the 
>  new Slackware 14.0. I couldn't boot up the Dreamplug yet with the kernel 
>  image that is provided by the slackware installer, but on my way trying 
>  i found out some things you also might be interested in. :-)
>  1.) U-Boot Upgrade:
>  The original Dreamplug U-Boot is in fact very annoying, mainly because 
>  of the missing ext2load support. I think we spoke about that and about 
>  the workaround a while ago here on the mailing list. Anyway, you can 
>  easily upgrade your U-Boot to a newer one. Just put u-boot.kwb and 
>  uboot.elf from [1] on a vfat formatted usb flash drive (or any other 
>  media you can access) and update u-boot with the following commands 
>  (taken from [2]):
>  WARNING: All u-boot variables will be erased in the process, including 
>  the ethernet mac adresses! Don't forget to backup/restore them!
> > usb start
> > fatload usb 2 0x6400000 dreamplug/u-boot.kwb
> > sf probe 0
> > sf erase 0x0 0x80000
> > sf write 0x6400000 0x0 0x${filesize}
>  ${filesize} is the size that is displayed after executing the fatload 
>  command. You have to convert the value into the corresponding hex value.
>  You can now replace your vfat partition containing the kernel image 
>  with an ext2 formatted partition. I tried this with my old Slackware 
>  13.37 installation, worked fine.
>  2.) Booting Slackware 14.0 Installer
>  Unfortunately you can't boot the slackware installer even with the new 
>  U-Boot version (i tried 2011.12-3 and 2012.04.01-2). There are two 
>  different effects, depending on which machine id you set.
>  a) Machine ID 3550/0xDDE (Dreamplug): The kernel won't boot and hangs 
>  at "Uncompressing Linux... done, booting the kernel.". I first suspected 
>  CONFIG_ARM_PATCH_PHYS_VIRT as source of the problem, but a patch for 
>  this problem exists since february 2012 [1] and should be included in 
>  the u-boot versions i tried. Also, the kernel boots if i set another 
>  machid (see b)). Nevertheless, i haven't ruled this out yet. I will
>  b) Machine ID 2659/0xA63 (Guruplug): The kernel starts booting and then 
>  freezes, last line is "[    2.396407] brd: module loaded". I suppose 
>  this is related to the known problem with probing the NAND flash 
>  3.) Next steps?
>  I see two possibilities on how to proceed:
>  a) Build a custom kernel with NAND probing disabled and set the machine 
>  id to the one that is also used by the Guruplug. I don't like this , but 
>  it might be a quick workaround. You would also have to make sure that 
>  you don't accidentally overwrite your custom kernel with the default one 
>  from Slackware, because this would result in a non-bootable system.
>  b) Find out what causes the kernel hang from 2a). This would mean that 
>  you can set the machine id to the correct value and that you don't have 
>  to use any workarounds.
>  So, long story short: You still have to take a custom kernel to be able 
>  to use Slackware on the Dreamplug, but you can now store your kernel 
>  images on an ext2 partition if you update u-boot. I will have a look at 
>  the u-boot sources that where used to build the u-boot images under [1] 
>  later, maybe the patch for CONFIG_ARM_PATCH_PHYS_VIRT isn't included. If 
>  this is the case, i will try to patch and build u-boot myself, maybe it 
>  helps.
>  Michael
>  [1] http://people.debian.org/~tbm/u-boot/
>  [2] http://wiki.debian.org/FreedomBox/Firmware
>  [3] http://lists.denx.de/pipermail/u-boot/2012-February/117020.html
> > Hi,
> >
> > I'm about to start upgrading my Dreamplug to Slackware 14.0.  Last 
> > time
> > I had problems with the 13.37 Slackware kernel because of MTD being
> > enabled (kernel boot locks when it probes for NAND flash which isn't
> > present on the Dreamplug), and also the lack of ext2load command in 
> > the
> > U-Boot.  I got over it by using the Guruplug arcnumber (2659), 
> > putting
> > the kernel + initrd on a local memory card which U-Boot could access,
> > and using a generic kernel from another source which had no MTD 
> > turned
> > on.  That was about a year ago and it seems that while some things 
> > have
> > improved, others remain the same.
> >
> > The Dreamplug now has its own arcnumber (3550) although it seems like
> > flattened device trees may have made that stuff irrelevant.  There is 
> > a
> > problem with CONFIG_ARM_PATCH_PHYS_VIRT which causes the apparent 
> > hang
> > at the Kernel Uncompressing... message which looks to be fixed in 
> > later
> > U-Boots.  However, I don't really see a clean U-Boot replacement for 
> > the
> > Dreamplug anywhere (Debian may have one but as I don't have access to 
> > a
> > copy of my current/original U-Boot image I'm not sure I want to go
> > there).  The other issue with U-Boot is of course the booting direct
> > from disk - which I'd love to do (and the SlackwareARM install 
> > assumes
> > you can do) but cannot with my current system.
> >
> > Before I dive in and experiment, has anyone got any insights into
> > Dreamplug installs for Slackware 14.0 or am I too early?  I'd be 
> > happy
> > to continue with the current U-Boot and putting the kernel/initrd
> > elsewhere for now, but does anyone know if the Slackware kernels can 
> > be
> > used on the Dreamplug directly, or whether I need to be looking for
> > another one (or build my own)?
> >
> > Thanks,  Innes.
> > --
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