Hi,
i'm developing a realtime-system (normally runnning on an embedded pc) and simulate it under windows using virtual box. I wonder if it is possible to manipulate the systemclock for the virtual machines (which are generated by software?) in order to speed up my real-time software (in detail all the sleeps and timeouts). Thanks for your help.
regards
aj
Speed up System-Clock for Realtime-Simulation
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- Posts: 1
- Joined: 26. Jul 2010, 13:40
- Primary OS: MS Windows 7
- VBox Version: PUEL
- Guest OSses: XP
Re: Speed up System-Clock for Realtime-Simulation
I'd be interested in doing this too, but for an XP box.
Any one know how to do it?
Any one know how to do it?
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- Posts: 14
- Joined: 13. Oct 2009, 16:49
- Primary OS: MS Windows Vista
- VBox Version: PUEL
- Guest OSses: lots
Re: Speed up System-Clock for Realtime-Simulation
I think that is normally a physical function of a timer on a motherboard, which usually is supplied by a battery and an oscillator. So how to swap out the virtual oscillator with a different one? If your OS has a time service like NTP, or GA is installed and set to sync your guest and host clocks, this could be thwarted. Then again, if GA can manipulate the guest clock, why not modify the GA code to factor time in its updates?
I want to accomplish this, too, btw.
Maybe get really close to a black hole. Or is it really far?
I want to accomplish this, too, btw.
Maybe get really close to a black hole. Or is it really far?
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- Site Moderator
- Posts: 39156
- Joined: 4. Sep 2008, 17:09
- Primary OS: MS Windows 10
- VBox Version: PUEL
- Guest OSses: Mostly XP
Re: Speed up System-Clock for Realtime-Simulation
You might find it useful to read section 9.11 of the user manual.
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- Posts: 14
- Joined: 13. Oct 2009, 16:49
- Primary OS: MS Windows Vista
- VBox Version: PUEL
- Guest OSses: lots
Re: Speed up System-Clock for Realtime-Simulation
Yeah section 9.11 pretty much has the answer, complete with the warning that time warping increases the risk of nausea in guest OS.
Oh well, probably a bad idea, anyway. Any interaction with the outside world that is not also warped by the same factor will probably cause the problems alluded to. Like digital signatures with timestamps on-or-in network packets, or timeouts from regular speed systems appearing too slow to the hyper-drive VM.
thanks.
Oh well, probably a bad idea, anyway. Any interaction with the outside world that is not also warped by the same factor will probably cause the problems alluded to. Like digital signatures with timestamps on-or-in network packets, or timeouts from regular speed systems appearing too slow to the hyper-drive VM.
thanks.