[RFC] Porting AmigaOne platform code from ppc to powerpc

[Benjamin Herrenschmidt]

On Thu, 2006-10-19 at 15:24 +0200, Gerhard Pircher wrote:
> Hi!
> 
> I'm working on the AmigaOne Linux kernel port. The AmigaOne is a G3/G4 desktop system and makes use of U-boot v1.1.0 as firmware. I intend to port the current code base of this platform to the powerpc architecture, but I'm not sure how to address this.
> 
> The "problem" is the device tree required by the powerpc architecture. The AmigaOne's U-boot version doesn't support the flattened device tree yet and also requires a special flash rom programmer tool (I guess it adds some sort of dongle code to the flash rom content). Otherwise users won't be able to boot AmigaOS4. Thus using a newer U-boot version is not really an option and AFAIK the OS4 developers are not going to update their U-boot version.
> 
> Well, some time ago I read about a CUIMAGE target that can be used to get powerpc-arch kernels working on old U-boot versions by using a precompiled/static device tree. I don't think that this approch makes sense for a desktop platform, which uses different CPUs (750FX, 750GX, 7410, 7450, 7455, etc..), PCI/AGP cards, etc.
> 
> Any advice for me in this case?

You can also look at the rework being done currently on zImage wrappers.
Among others, they have the ability to embed a device-tree.

Ben.