IOCTL_SERENUM_GET_PORT_NAME control code
The IOCTL_SERENUM_GET_PORT_NAME request returns the value of the PortName (or Identifier) entry value for the RS-232 port -- see Registry Settings for a Plug and Play Serial Device.
The Parameters.DeviceIoControl.OutputBufferLength member is set to the size in bytes of a client-allocated output buffer.
The AssociatedIrp.SystemBuffer member points to a client-allocated buffer that Serenum uses to output the port name. The port name is a null-terminated Unicode string.
If the request is successful, the Information member is set to the size in bytes of the null-terminated Unicode string that is returned in the client's output buffer.
The Status member is set to one of the following values:
The request completed successfully.
The output buffer is too small to hold the port name string.
An error occurred when opening the registry key for the device or reading the PortName (or Identifier) entry value.