Intel Extensible Firmware Interface - Manual (Page 358)

Extensible Firmware Interface Specification
10-64 12/01/02 Version 1.10
SERIAL_IO.Write()
Summary
Writes data to a serial device.
Prototype
EFI_STATUS
(EFIAPI *EFI_SERIAL_WRITE) (
IN SERIAL_IO_INTERFACE *This,
IN OUT UINTN *BufferSize,
IN VOID *Buffer
);
Parameters
This A pointer to the SERIAL_IO_INTERFACE instance. Type
SERIAL_IO_INTERFACE is defined in Section 10.12.
BufferSize On input, the size of the Buffer . On output, the amount of
data actually written.
Buffer The buffer of data to write.
Description
The Write() function writes the specified number of bytes to a serial device. If a time out error
occurs while data is being sent to the serial port, transmission of this buffer will terminate, and
EFI_TIMEOUT will be returned. In all cases the number of bytes actually written to the serial
device is returned in BufferSize .
Status Codes Returned
EFI_SUCCESS The data was written.
EFI_DEVICE_ERROR The device reported an error.
EFI_TIMEOUT The data write was stopped due to a timeout.