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Re: [Qemu-ppc] [Qemu-devel] [PATCH 0/2] m48t59: add year offset and MMIO


From: Mark Cave-Ayland
Subject: Re: [Qemu-ppc] [Qemu-devel] [PATCH 0/2] m48t59: add year offset and MMIO ISA mapping
Date: Tue, 20 Jan 2015 14:19:14 +0000
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0

On 19/01/15 21:59, Hervé Poussineau wrote:

> Le 19/01/2015 12:35, Mark Cave-Ayland a écrit :
>> This patch lays the groundwork for switching sun4u over from ioport NVRAM
>> access to MMIO NVRAM access.
>>
>> Patch 1 introduces a new year_offset property which is the offset
>> between the
>> year value stored in hardware and the actual year. In particular, Sun
>> hardware
>> has a 68 year offset used to extend the date range of the IC. While the
>> kernel sources I have viewed contain this offset within a #ifdef
>> CONFIG_SPARC
>> block, I've updated all the callers so that no change in behaviour
>> will be
>> seen across all platforms. PPC users may wish to alter the callers to
>> change
>> this behaviour as required.
>>
>> Patch 2 mimics the mem_base parameter from m48t59_init() to
>> m48t59_init_isa()
>> so that MMIO can be used for sun4u where the NVRAM is attached to the
>> ebus
>> which is essentially the same as an ISA bus.
> 
> I've a patch which QOM'ifies m48t59, that I'll send to the list.
> If you apply it, you'll be then able to create a sysbus-m48t02 device,
> and then to add it to ebus memory region.
> IMO, there is no need to add a new parameter to m48t59_init_isa device.
> 
> Tell me what do you think of it.

It took me a while to go through these patches, but yes I think that
would work (i.e. create the sysbus-m48t59 device and then map it's
MemoryRegion directly into I/O space).

If these patches can be applied then I'm happy to rebase and resubmit my
patchset for the year_offset property. Who's tree should these changes
go through? Andreas' QOM tree?


ATB,

Mark.




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