Re: [Qemu-devel] Commit 77af8a2b95b79699de650965d5228772743efe84 breaks Windows 2000 support

[Phil Dennis-Jordan]

On Fri, Jul 21, 2017 at 11:06 AM, Igor Mammedov <address@hidden> wrote:
> On Thu, 20 Jul 2017 21:29:33 +0200
> Phil Dennis-Jordan <address@hidden> wrote:
>
>> On Thu, Jul 20, 2017 at 6:40 PM, Programmingkid
>> <address@hidden> wrote:
>> > I noticed that Windows 2000 does not boot up in QEMU recently. After 
>> > bisecting the issue I found the offending commit:
> w2k is very ancient (and long time EOLed), I can't even download it from msdn 
> to test
> (oldest available is XP)
>
> do we really care about it?

I guess it'd primarily be for software archival/history purposes,
which is a reasonable use case for Qemu. (See efforts to get PPC MacOS
working, etc.)

>> Ouch. I reckon we have 2 options for fixing this:
>>
>> 1. Export two FADTs, one ACPI 1.0, one ACPI 2.0. The latter would need
>> to be pointed to by an XSDT, which Qemu currently doesn't implement at
>> all as far as I'm aware. Any ideas on how SeaBIOS or OVMF would handle
>> this? Any likely other OS regressions?
>>
>> 2. Select FADT version with an option. This one is definitely safe,
>> but adds yet another option.
> the 3rd simpler option is:
>   force rev1 on old machine types (2.9 and older),
>   using machine compat machinery and use rev3 on newer machines

That sounds good, I'd be happy to implement that.

Phil