[OpenBIOS] [PATCH v3 3/5] Pretty-print reg property

[Andreas Färber]

Am 09.11.2010 um 11:02 schrieb Artyom Tarasenko:

> On Mon, Nov 8, 2010 at 10:53 PM, Tarl Neustaedter <tarl-b2 at tarl.net>  
> wrote:
>> On 2010-11-6 1:46 PM, Tarl Neustaedter wrote:
>>>
>>> On 2010-11-6 6:43 AM, Andreas Färber wrote:
>>>>
>>>> [...]
>>>> Hm. It's right for reg, with is one cell (0) only.
>>>> But it logically doesn't fit the MMU's available property. So it's
>>>> telling me we need to special-case that somehow for 5/5. Which in  
>>>> turn means
>>>> that we'll need to pass the #address-cells and #size-cells via  
>>>> stack in 3/5
>>>> to cover this use case.
>>>>
>>>> "The property values are as defined for the standard “reg”  
>>>> format, with
>>>> single-cell virtual
>>>> addresses. The regions of virtual address space denote the virtual
>>>> address space that is currently
>>>> unallocated by the Open Firmware and is available for use by client
>>>> programs." (IEEE 1275 3.6.5)
>>>
>>> Hmm. It's "recommended", and I believe that is incorrect for SPARC  
>>> 64.
>>> I'll check on monday - I remember recently seeing that the / 
>>> virtual-memory
>>> available property used two-cell virtual addresses. I'll check  
>>> what it does
>>> with MMUs.
>>>
>>>
>> Duhh... Sun systems haven't had an MMU node for a _long_ time. I  
>> think the
>> SS5 had one, but I literally can't find a Sun old enough to have  
>> such a
>> node. Never mind...
>
> I guess the first one which had it was Ultra-1. SS-5 didn't have it:
>
> ok .version
> Release 2.15 Version 5 created 95/03/29 14:21:55
> ok show-devs
[snip]

Just so that we don't misunderstand each other, this is not about a  
node named "MMU" that we might see in show-devs. It's about some node  
- anonymous or named - that gets referenced by the mmu property in  
the /chosen node.

On my PowerMac G3 it points to /cpus/PowerPC,750 at 0 (the CPU), for  
example.

Andreas