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

[Artyom Tarasenko]

On Tue, Nov 9, 2010 at 10:49 PM, Andreas Färber <andreas.faerber at web.de> wrote:
> 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.

Yes, but there is no "/chosen" node on SPARCstations. I think it first
appeared in 64 bit (Ultra) machines.

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

-- 
Regards,
Artyom Tarasenko

solaris/sparc under qemu blog: http://tyom.blogspot.com/