mov ax, 4002h ; Notify Foreground Switch
int 2fh
Notify Foreground Switch notifies a VM application that it has been switched to the foreground and can now access the video memory and registers without being frozen.
The virtual-display device (VDD) calls this function.
This function has no parameters.
This function has no return value.
If the VM application has called Enable VM-Assisted Save/Restore (Interrupt 2Fh Function 4000h), VDD restores the video registers to their state prior to the call to Enable VM-Assisted Save/Restore; the application is responsible for restoring video memory. If the VM application has not called Enable VM-Assisted Save/Restore (Interrupt 2Fh Function 4000h), the VDD automatically restores both video memory and registers.
Under certain error conditions, the VDD may call this function without calling a corresponding Notify Background Switch (Interrupt 2Fh Function 4001h).
Interrupt 2Fh Function 4000h Enable VM-Assisted Save/Restore,
Interrupt 2Fh Function 4001h Notify Background Switch