[U-Boot] Device tree on ppc board

[U-Boot] Device tree on ppc board

[Olivier DAVID]

Hi,

 

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
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 ?

 

Thank you !

 

 

[U-Boot] Device tree on ppc board

[Scott Wood]

Olivier DAVID 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,

It was merged quite a bit earlier, that's just when the old fork was 
finally discarded.

> and device tree the unique way to pass
> 'bdinfo'. The uboot version can't be more than 1.1.6,

Why not?

> the linux must be 2.6.27, 

Why 2.6.27 and not, say, 2.6.30?  You may have problems with PCI DMA in 
2.6.27, for example.  In general, it's best to go with the latest unless 
you have a specific reason otherwise.

> and I can't find the information if it's compatible.

You can boot using cuImage if you must stay with an old u-boot.  Add 
cuImage entries for your board in arch/powerpc/boot/Makefile and 
arch/powerpc/boot/wrapper, then make zImage.

> 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 ?

mpc8272ads is probably the closest board to yours; you could use its 
device tree as an example.

-Scott

[U-Boot] Device tree on ppc board

[Kim Phillips]

On Tue, 23 Jun 2009 22:57:50 +0200
"Olivier DAVID" <olivier.david@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