[OpenBIOS] Beginners How-To for DTS and OpenFirmware?

[G 3]

On Nov 21, 2016, at 9:34 AM, Michael wrote:

> Dear list, thank you for the help with cross-compiling for ppc64 so  
> far!
> It is important but I overjumped enthusiastically the OF basics :-)
>
> I read many webpages, hints and maybe old sites etc and solved many  
> things.
> But is there a "beginners how-to" somewhere? What I would find most  
> usefull:

The website does have several pages that supply information. If you  
feel there
should be more added, I will be glad to do so.

>
> 1) Best source-code to use? There is a version-1.1.zip, a svn repo and
> a git repo.

The git repo is what we are using now. I would chose that.

>
> 2) The names are also a bit confusing when you see it first. I know  
> about
> the IEEE standard and a few things about the history (from wikipedia),
> but if you for example visit the website and click on the  
> "openfirmware"
> link, the you see a page with "OpenBIOS" heading. So even if one knows
> about history, there is confusion about actual used names.

We use OpenBIOS as the project's name. Open Firmware is a standard  
OpenBIOS follows.

>
> 3) How is the device-tree given to OF? And how does OF handle it over
> to a linux kernel?

I don't think Linux touches the OpenBIOS device tree. It likes to  
discover things for itself.

>
> 4) Minimal prerequisites on a new hardware, so that OF is able to run?
> E.g. which type of RAM does it need? Does it need a stack or .text  
> segment
> or other things to run (like c-code)? ...

Being a BIOS, I would think about anything could run OpenBIOS. I  
think any
computer made in the last 20 years should work.