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

Andreas Färber andreas.faerber at web.de
Mon Nov 8 23:09:17 CET 2010


Am 08.11.2010 um 22:53 schrieb Tarl Neustaedter:

> 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...

Thanks for looking! It would indeed make sense for a hypothetic  
sparc64 MMU node to have a 2-4byte-cell virtual address. If this ever  
pops up, I guess we could use [IFDEF] CONFIG_SPARC64 2 [ELSE] 1  
[ENDIF] or something in 5/5.

Are there any general objections against patch 2/5?

Andreas


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