Re: [Qemu-devel] Re: Question about KVM and PC speaker

["Sebastian Herbszt" <herbszt@gmx.de>]

Jan Kiszka wrote:
> Sebastian Herbszt wrote:
>> Jan Kiszka wrote:
>>> Sebastian Herbszt wrote:
>>>> Simon Bienlein wrote:
>>>>> Is a support for BIOS worked on right now?
>>>>
>>>> The vgabios (vgabios.c) has a "FIXME should beep". Volker, do you plan
>>>> to fix this?
>>>>
>>>> Which frequency should be used for the beep? Which delay?
>>>
>>> I would try 1 KHz and some hundred milliseconds.
>> 
>> I just looked at some vga bios and it uses about 896,45 Hz.
>> 
>>>> Getting a delay using "inb(0x61) & 0x10" is still a no go on qemu,
>>>> right?
>>>
>>> Looks like (should be far too inaccurate for longer delays). What about
>>> 0x40:0x6c, the BIOS' daily timer counter?
>> 
>> The bios i looked at used the refresh request port 0x61. This is
>> supported by bochs and
>> there is also a patch for qemu to replace the dummy [1]. The rombios
>> uses this to provide
>> INT 15h AH=86h functionality; this is likely broken with the dummy code
>> in qemu.
> 
> I see no problem with improving qemu's emulation accuracy this way a
> bit. But I wouldn't built new delay implementations on top of it,
> specifically if the code is in fact aware of running over a hypervisor.
> Such micro-timings are far too inaccurate for longer delays in an
> environment where you cannot be sure of running all the time during that
> period.

Volker, mind to resubmit the patch once again?
 
>> Anyway, using "timer ticks since midnight" should be possible (INT 08h
>> handler is set up
>> before vga bios is called).

I have implemented the beep for vgabios-6b and it works on bochs but fails on qemu.
With "-soundhw pcspk" i should hear it thru the hosts pc speaker, right?

- Sebastian