Subject: Re: [PATCH] mpc7448: add alias list to DTS, clean out old chosen node

From: Paul Gortmaker <[email-masked]>
Date: Thu, 10 Jul 2008 17:42:18 -0400

Scott Wood wrote:
> Jon Loeliger wrote:
>> Scott Wood wrote:
>>> Paul Gortmaker wrote:
>>>> OK, so does that mean that the cuboot wrapper is explicitly
>>>> not supported for all the 83xx, 85xx, and 86xx boards?
>>>
>>> No (except 86xx, which doesn't have cuboot, because it never existed 
>>> in arch/ppc and thus there's no compatibility to maintain), it just 
>>> means that chosen was never added to those dts files, and thus 
>>> cuboot has no console output.
>>
>> Also note that nothing stops the causal kernel booter
>
> As opposed to the spontaneous kernel booter? :-)
>
>> from _starting_ with an arch/powerpc/boot/dts/ file,
>> adding a node to it, and using _that_.
>
> The "casual" user shouldn't need to make any changes, especially for 
> the kernel's own dts files to work with the kernel's own wrapper.
>
> The decision on whether to put the chosen node in the device tree 
> should be based on which version of u-boot it's more important to 
> maintain compatibility with (for some platforms, no chosen-duplicating 
> version of u-boot supported device trees on the platform), and what 
> the consequences of each form of incompatibility are (e.g. no console 
> output during the bootwrapper, versus no boot arguments or initrd in 
> the kernel).

Well, for the mpc7448hpc2, I can say for sure that there are
chosen-duplicating versions of u-boot 1.3.1 in use -- since
there wasn't a prebuilt, validated image newer than 1.1.3(?)
available anywhere back some 6 months ago, I'd built 1.3.1
and made it available with our 2.6.21 kernel.

If all the other boards run cuboot without console output,
then is it not consistent to have this one the same as well?
Or should we be adding chosen to the other boards instead?

Paul.

> -Scott