[OpenBIOS] fdthree

[Artyom Tarasenko]

On Mon, May 14, 2012 at 10:22 PM, Blue Swirl <blauwirbel at gmail.com> wrote:
> On Mon, May 14, 2012 at 4:26 PM, Artyom Tarasenko <atar4qemu at gmail.com> wrote:
>> Since none of the current Linux/sparc64 distributions has virtio
>> drivers out of the box, it were nice to give the user ability to load
>> them from a removable media.
>> Currently Linux doesn't recognize our fdthree drive. The reason is
>> simple - in OpenBIOS
>>
>> 0 > cd /pci/ebus/fdthree  ok
>> 0 > .properties
>> name                      "fdthree"
>> reg                       00000000 00000000 00000000
>>
>> in ultra5's prtconf this property looks like this:
>>
>> reg:  00000014.003023f0.00000008.00000014.00706000.00000010.00000014.00720000.00000004
>>
>> The meaning of the first triple is clear - these are the fdc control
>> registers. But what are the two other register sets?
>>
>> It looks like qemu has a normal PC floppy, connected to EBus. Probably
>> it's not what Sun used to call fdthree?
>> If fdthree is really something else, were there any UltraSPARC
>> machines with PC floppy drives?
>
> I think the FDC was pretty standard 82077. The additional registers
> could implement a DMA controller.

It seems that in qemu the DMA controller sits on ISA, not on fdc? And
that we don't have it in EBus?
But I guess dma.c could be used directly as-is?

> At least OpenBSD only seems to use
> the 82077 registers:
> http://fxr.watson.org/fxr/source/arch/sparc64/dev/fd.c?v=OPENBSD
>
-- 
Regards,
Artyom Tarasenko

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