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

[Hervé Poussineau]

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.

Hervé