[U-Boot] u-boot 1.1.2 boot latest powerpc based kernel?

[Scott Wood]

On Mon, May 17, 2010 at 09:06:49AM -0500, Timur Tabi wrote:
> Shawn Jin wrote:
> 
> > However my concern is specific to the powerpc arch. If I understand
> > correctly, the powerpc arch expects a bootloader provide a DTS file.
> > I'm not sure how the current U-Boot transfers such info to the
> > kernerl. 
> 
> One of the registers (r7 maybe?) contains the address of the device tree.

r3

> > People here can shed some light on this? I'm certain the old
> > U-Boot (e.g. 1.1.2) doesn't have this kind of capability.
> 
> That's why cuImage was invented.  cuImage embeds the device tree in the
> kernel image.  The drawback is that you can't rely on U-Boot to do any fixups.

U-Boot itself can't do any fixups (because it doesn't know about the device
tree), but the cuImage bootwrapper does do some fixups (mainly memory size,
clock speed, and MAC address) based on the bd_info that U-Boot passes in. 
The drawback is that the bd_info is fragile and the information it passes is
limited.

> > The bd_info
> > is still one of data transferred to the kernel, right? 

Not in the new booting scheme.  cuImage will accept a bd_info instead of a
device tree (and will have a device tree built into the kernel).

-Scott