Intel Extensible Firmware Interface - Manual (Page 359)

Protocols — Console Support
Version 1.10 12/01/02 10-65
SERIAL_IO.Read()
Summary
Reads data from a serial device.
Prototype
EFI_STATUS
(EFIAPI *EFI_SERIAL_READ) (
IN SERIAL_IO_INTERFACE *This,
IN OUT UINTN *BufferSize,
OUT 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 returned in Buffer .
Buffer The buffer to return the data into.
Description
The Read() function reads a specified number of bytes from a serial device. If a time out error or
an overrun error is detected while data is being read from the serial device, then no more characters
will be read, and an error will be returned. In all cases the number of bytes actually read is returned
in
BufferSize .
Status Codes Returned
EFI_SUCCESS The data was read.
EFI_DEVICE_ERROR The serial device reported an error.
EFI_TIMEOUT The operation was stopped due to a timeout or overrun.