[Qemu-devel] Re: [Bochs-developers] [PATCH] BIOS delay_ms optimized away with?BX_QEMU enabled

[Kevin O'Connor]

On Sun, Mar 30, 2008 at 06:48:29PM +0200, Volker Ruppert wrote:
> > Do you know why QEMU uses different code for the delay?  What's wrong
> > with using inb(0x61) for both bochs and qemu?
> 
> Bochs really supports the refresh toggle bit of port 0x61, but Qemu toggles 
> on 
> every read access. I have created a patch for Qemu that implements the 15 
> usec toggle, but the Qemu developers haven't accepted it. They are not sure 
> whether the refresh toggle bit exists on modern hardware.

Ughh.  The same delay mechanism is used in the int/15/86 handler even
on qemu.  See rombios.c:int15_function32().

Is there a better way to implement a usleep function?

Thanks for the info.
-Kevin