include vcomm.inc
mov ebx, hPort
mov di, Selector ;segment address of notification
shl edi, 16 ; function in high word of EDI
mov di, OFFSET CommNotifyProc ; and offset address in low word
mov cx, hwnd ;reference data (window handle)
mov dx, recvt
mov si, sendt
mov ax, VCOMM_PM_API_EnableNotify ;function number
call [_VCOMMCallAddr]
Calls the _VCOMM_EnableCommNotification service.
Because the notification function is in a VM, VCOMM does not pass its address to the port driver. Instead, it passes the address of an internal function. When the port driver calls the internal function, it schedules an event and the event handler uses the nested execution mechanism to call the notification function.
CommNotifyProc, _VCOMM_EnableCommNotification