Processor Startup

[syberarall]

Hello,

we build an virtual subsystem (RTX) which claims a cpu-core at Windows-Runtime. The startup is done by accessing the InterruptControlRegister of the LocalAPIC.
This works fine if Windows is startup in the BIOS Mode. Now with Windows 8 (10) UEFI is supported and our approach of direct accessing the local APIC doesn't work any more.
First of all, there is the idea of writing an EFI bootloader, but since windows has to run in parallel, I'm not shure if this would work.
Also I could think about Windows services (if available), which gives access back for the local APIC.
In my understanding, EFI blocks out any APIC access after PEI ? In that case, the bootloader of Windows and the virtual subsystem had to be started at PEI.
I would be glad for any hints.

syberarall

[mpack]

I see no mention of VirtualBox in that paragraph. What is your VirtualBox question?

[scottgus1]

I'm not too certain how Virtualbox fits in with this question. RTX, if I research correctly, refers to either a gaming show by someone called "Rooster Teeth" or a real-time operating system. I'm going to go with the real-time OS scenario.

Real-time and virtual machines are in two completely different leagues. Latency can be a problem in VMs, and one needs very little latency in real-time. My guess is that virtual machines should not be part of your development scheme.