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Re: [Qemu-devel] [PATCH 0/2] sparc64: Fix NVRAM access mode
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From: |
Artyom Tarasenko |
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Subject: |
Re: [Qemu-devel] [PATCH 0/2] sparc64: Fix NVRAM access mode |
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Date: |
Sat, 27 Apr 2013 16:20:13 +0200 |
On Sat, Apr 27, 2013 at 1:39 PM, Blue Swirl <address@hidden> wrote:
> On Sat, Apr 27, 2013 at 7:12 AM, Artyom Tarasenko <address@hidden> wrote:
>> The sun4u machines use a slightly different modification of the ISA Mostek
>> chip.
>> It has MMIO, 1968 as a base year and no IRQ line. Since it matches our
>> m48t08,
>> make keep PIO behavior for the 59 model and use MMIO for the 8 model.
>
> The chip is definitely m48t59 (SGS-Thompson, M48T59Y-70MH1), even if
> the IRQ is not connected and software uses 1968 as the base year.
Ops. But it's not just software afaics - think about leap years. Do you by any
chance have any docs beyond m48t59y.pdf? There is no information about base
year in there. And in the Linux kernel there is just some CONFIG_SPARC
#ifdefery.
> Please make the base year a qdev property and keep the model unchanged.
Maybe rather use something like "is_sun" property? It could be used to
decide whether the IRQ should be connected and whether a PIO or a MMIO
access should be used.
Btw can "isa_init_irq(dev, &s->IRQ, 8)" be moved from m48t59_init_isa1
to m48t59_init_isa ? Or shall the irq be silenced at the isa bridge
level?
--
Regards,
Artyom Tarasenko
linux/sparc and solaris/sparc under qemu blog:
http://tyom.blogspot.com/search/label/qemu