internal static void SwitchToHpetClock(Hpet hpet)
{
DebugStub.WriteLine("Switching to HPET clock");
halClock.SwitchToHpetClock(
new HpetClock(hpet, (ulong)halClock.GetKernelTicks() + 1000u)
);
}
public static uint UpdateFrequency(Hpet hpet)
{
// Compute RTC clock frequency (2^n Hz) to avoid a
// wrap between clock interrupts.
ulong wrapPeriodUs =
((ulong)0xffffffffu * hpet.PeriodFs) / (1000000 * 1000);
uint wrapFrequency =
1 + (uint)((long)1000000 / (1 + wrapPeriodUs));
uint updateFrequency = 2; // Min freq of RTC
while (updateFrequency < 4 * wrapFrequency)
{
updateFrequency *= 2;
}
return(updateFrequency);
}
internal static IDevice CreateDevice(IoConfig config, string name)
{
PnpConfig pnpConfig = config as PnpConfig;
if (pnpConfig == null)
{
return(null);
}
IoMemoryRange imr = config.DynamicRanges[0] as IoMemoryRange;
if (imr == null)
{
return(null);
}
int imrBytes = (int)imr.Length.ToUInt32();
if (imrBytes < Hpet.MinRegionBytes)
{
DebugStub.Write(
"HPET failed as region too small ({0} bytes).\n",
__arglist(imrBytes));
return(null);
}
Hpet hpet = new Hpet(pnpConfig);
if (hpet.MainCounterWorks())
{
HalDevicesApic.SwitchToHpetClock(hpet);
}
else
{
DebugStub.Print("WARNING: HPET main counter does not work!\n");
}
return(hpet);
}
internal HpetClock(Hpet timer, ulong initialKernelTicks)
{
this.hpet = timer;
this.hpetLastUpdate = hpet.MainCounterValue32;
this.kernelTicksAccumulated = initialKernelTicks;
}
