Intel Extensible Firmware Interface - Manual (Page 731)

Protocols — Debugger Support
Version 1.10 12/01/02 16-17
EFI_DEBUGPORT_PROTOCOL.Write()
Summary
Writes data to the debugport.
Prototype
typedef
EFI_STATUS
(EFIAPI
*EFI_DEBUGPORT_WRITE) (
IN EFI_DEBUGPORT_PROTOCOL *This,
IN UINT32 Timeout,
IN OUT UINTN *BufferSize,
IN VOID *Buffer
);
Parameters
This A pointer to the EFI_DEBUGPORT_PROTOCOL instance. Type
EFI_DEBUGPORT_PROTOCOL is defined in Section 16.3.
Timeout The number of microseconds to wait before timing out a write
operation.
BufferSize On input, the requested number of bytes of data to write. On output,
the number of bytes of data actually written.
Buffer A pointer to a buffer containing the data to write.
Description
The Write() function writes the specified number of bytes to a debugport device. If a timeout
error occurs while data is being sent to the debugport, transmission of this buffer will terminate, and
EFI_TIMEOUT will be returned. In all cases the number of bytes actually written to the debugport
device is returned in BufferSize .
It is the responsibility of the caller to insure all parameters are valid. There is no provision for
parameter checking by
Write() . The implementation behavior when an invalid parameter is
passed is not defined by this specification.
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.