Directed_Sys_Control

include vmm.inc

mov     ecx, DDB
VMMCall Directed_Sys_Control

Jumps to the VxD's device-control procedure. Use this service instead of calling the control procedure directly.

• Return value depends on the message sent to the virtual device.

DDB

VxD's DDB that contains device control procedure. All other registers are passed unaltered to the control procedure.