Intel Extensible Firmware Interface - Manual (Page 349)

Protocols — Console Support
Version 1.10 12/01/02 10-55
10.12 Serial I/O Protocol
This section defines the Serial I/O protocol. This protocol is used to abstract byte stream devices.
SERIAL_IO_PROTOCOL
Summary
This protocol is used to communicate with any type of character-based I/O device.
GUID
#define SERIAL_IO_PROTOCOL \
{ BB25CF6F-F1D4-11D2-9A0C-0090273FC1FD }
Revision Number
#define SERIAL_IO_INTERFACE_REVISION 0x00010000
Protocol Interface Structure
typedef struct {
UINT32 Revision;
EFI_SERIAL_RESET Reset;
EFI_SERIAL_SET_ATTRIBUTES SetAttributes;
EFI_SERIAL_SET_CONTROL_BITS SetControl;
EFI_SERIAL_GET_CONTROL_BITS GetControl;
EFI_SERIAL_WRITE Write;
EFI_SERIAL_READ Read;
SERIAL_IO_MODE *Mode;
} SERIAL_IO_INTERFACE;
Parameters
Revision The revision to which the SERIAL_IO_INTERFACE adheres. All
future revisions must be backwards compatible. If a future version is
not back wards compatible, it is not the same GUID.
Reset Resets the hardware device.
SetAttributes Sets communication parameters for a serial device. These include
the baud rate, receive FIFO depth, transmit/receive time out, parity,
data bits, and stop bit attributes.
SetControl Sets the control bits on a serial device. These include Request to
Send and Data Terminal Ready.
GetControl Reads the status of the control bits on a serial device. These include
Clear to Send, Data Set Ready, Ring Indicator, and Carrier Detect.
Write Sends a buffer of characters to a serial device.
Read Receives a buffer of characters from a serial device.