[ELDK] Kernel hangs after fdt unpacking

Wolfgang Grandegger wg at grandegger.com
Thu May 20 11:22:00 CEST 2010

On 05/20/2010 11:01 AM, Axel Beierlein wrote:
> Hello,
> i try to port our TQM5200S Module OS from Kernel Version 2.4 to 2.6.
> I choose the Kernel Version from the Denx Repository cause this
> was the last version wich i can patch with the lates Xenomai Stable
> release (2.5.3).
> Ok, patching and building Kernel was no Problem.
> I use the latest U-Boot commit to build an actual Bootloader with
> the configuration for an TQM5200B Board.
> I use tqm5200.dts from /arch/powerpc/boot/dts to build an fdt blob with
> the dtc compiler on my Ubuntu 9.10.
> dtc -I dts -O dtb -o tqm5200.dtb tqm5200.dts

You need to reserve some spare space, e.g. by adding "-p 0x1000" or even
better, use make to build tqm5200.dtb:

  $ cd linux-2.6-denx
  $ make tqm5200.dtb

That's documented in

> was the command to getting the fdt blob for the Board.
> But when i try to boot the Kernel the System hangs after uncompressing
> the fdt blob.
> Where is the Problem? Where can i see why the Kernel doesn't boot?

Also, make sure that the right console bootargs are used:


Most likely that's the primary problem.

> Also when i try to get some information about the device tree blob with
> fdt header. The System hangs after the output.

What exactly did you do?


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