Intel Extensible Firmware Interface - Manual (Page 356)

Extensible Firmware Interface Specification
10-62 12/01/02 Version 1.10
Description
The SetControl() function is used to assert or deassert the control signals on a serial device.
The following signals are set according their bit settings:
• Request to Send
• Data Terminal Ready
Only the
REQUEST_TO_SEND , DATA_TERMINAL_READY , HARDWARE_LOOPBACK_ENABLE ,
SOFTWARE_LOOPBACK_ENABLE , and HARDWARE_FLOW_CONTROL_ENABLE bits can be set
with SetControl() . All the bits can be read with GetControl() .
Status Codes Returned
EFI_SUCCESS The new control bits were set on the serial device.
EFI_UNSUPPORTED The serial device does not support this operation.
EFI_DEVICE_ERROR The serial device is not functioning correctly.