[U-Boot] Device tree on ppc board

[Kim Phillips]

On Tue, 23 Jun 2009 22:57:50 +0200
"Olivier DAVID" <olivier.david at innes.fr> wrote:

> I work on a custom board, MPC8248 based (my reference BSP was MPC8260ADS),
> with uboot 1.1.4 and linux 2.6.11, and works perfectly.
> 
> We have to pass to linux 2.6.27, and it is just the version from which ppc
> and powerpc has been merged, and device tree the unique way to pass
> 'bdinfo'. The uboot version can't be more than 1.1.6, the linux must be

if you're going to go from a Jan. 2005 u-boot to a Nov. 2006 u-boot,
looking to boot an Oct. 2008 kernel, why not just go all the way to the
present versions on both?

> 2.6.27, and I can't find the information if it's compatible.
> 
> Can anybody affirm me if it's possible, and how to do it in linux 1.1.4 ?
> 
> How do we change the bdinfo structure header to device tree, is there any
> board which uses this feature ?

if you really cannot update u-boot, try making a linux cuImage for your
board; it contains a wrapper that combines the device tree and bdinfo,
then boots the linux kernel proper.

as a guide, see e.g., the ep8248e dts in
linux-2.6/arch/powerpc/boot/dts, and corresponding platform code in
linux-2.6/arch/powerpc/platforms/82xx.

please also consider submitting patches for your board to both upstream
projects, so this problem doesn't occur again in the future.

Kim