VMware

How does windows know the VM display adapters h… |VMware Communities


If I delete the VGA.ROM file from the vmware-vmx.exe’s folder from my host’s hard drive, and try to boot up a windows VM, it displys an error message saying that it couldn’t find the VGA.ROM file as soon as I start the VM,however, it gets past the error message with seemingly no further problems and loads into windows, but everyting is in black and white and set to 640×480 resolution. If I install VM Tools, the display problems seem to entirely dissappear and it seems to have all the features of a full 1080p, with I assume 3d acceleration as well, even though the VGA.ROM file was deleted. I thought that was kind of interesting, but, that’s not even my question…

 

So here’s my question… If I DO NOT install VM Tools, and I’m in windows with no VGA.ROM, with black and white only, 640×480 resolution, and nothing but the microsoft basic display adapter… if I go to device manager and look at details on the display adapter, under hardware id, it gives me this: PCIVEN_15AD&DEV_0405&SUBSYS_040515AD&REV_00

 

That VEN_15AD is the vendor ID number for VMWare, which means that windows is seeing the virtual device’s hardware id number. That hardware ID is always the same. It’s the same if I install or don’t install VM Tools, and it’s the same if I delete or don’t delete the VGA.ROM file. It seems like no matter what, windows always knows and see’s that same hardware ID string for the display adapter: PCIVEN_15AD&DEV_0405&SUBSYS_040515AD&REV_00.

 

My question is, where is windows getting this information? I’ve deleted the VGA.ROM file, and it still somehow knows and sees this hardware id number.

 

In a physical machine, I would conclude that windows is directly accessing the physical device through the PCI port, and that the device is telling windows what it is. However, in this case, I’ve deleted the VGA.ROM file, which i assume is supposed to be the device’s bios file. Without that, I can’t see how the virtual adapter is telling windows anything AT ALL (I’m surprised it even boots, but admittingly I don’t really know how rom files work to be honest). But since this is a virtual device, I know windows is not talking to a physical device. Windows must be talking to a piece of software, and that software must be giving windows that hardware ID string. i checked the windows reigstry, and it’s not there either. So my question is… if it’s not in the registry, and not VGA.ROM or VM Tools or any driver (no drivers are installed), then what path is windows taking to get this information, and what peice of software is sitting at the end of that path, communicating this hardware ID information back to the VM?



Source link

 

To see the full content, share this page by clicking one of the buttons below

Related Articles

Leave a Reply