[OpenBIOS] Latest SPARC64 & Milax update

Igor Kovalenko igor.v.kovalenko at gmail.com
Wed Jan 6 21:44:19 CET 2010


On Wed, Jan 6, 2010 at 12:33 PM, Mark Cave-Ayland
<mark.cave-ayland at siriusit.co.uk> wrote:
> Tarl Neustaedter wrote:
>
>> On 2010-1-5 3:53 PM, Igor Kovalenko wrote:
>>>
>>> [...]
>>> On the firmware side, interesting thing is you cannot
>>> disarm alarm. What if instance is then closed?
>>>
>>
>> That's bad. "xt 0 alarm" should disarm the alarm - and close should too.
>> Why doesn't it?
>>
>> In the case of console, you won't have a problem under normal operation,
>> but other devices which use alarms might indeed cause problems.
>>
>> You'll have a problem with the console if you use the "input", "output" or
>> "io" methods to switch the input or output console devices.
>
> I'm assuming that Igor is referring to the Qemu timer model here, since the
> OpenBIOS alarm word is currently defined as "2 drop" ;)

Just looking for corner cases. Missed that disarm path is actually
documented in of1275 document in "alarm" section.

> In terms of the console, OpenBIOS currently doesn't use alarm interrupts
> there either - it just sits in a busy-wait loop checking an I/O port or
> similar to determine when a new character is incoming.

So we need i/o scheduler now (not critical at the moment) :)

-- 
Kind regards,
Igor V. Kovalenko



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