9 uga draw protocol to uga i/o protocol mapping, 1 uga system requirements – Intel Extensible Firmware Interface User Manual

Page 337

Protocols

— Console Support

Version 1.10

12/01/02

10-43

The following

UGA_IO_REQUEST

s may not be required for specific hardware configurations:

UgaIoDeviceChannelClose

UgaIoDeviceChannelOpen

UgaIoDeviceChannelRead

UgaIoDeviceChannelWrite

UgaIoGetEdidSegment

For additional information on how implementations can be constructed please refer to the
specification found at

www.microsoft.com/hwdev/uga

10.9 UGA Draw Protocol to UGA I/O Protocol Mapping

As the

EFI_UGA_DRAW_PROTOCOL

member functions,

exist as a lightweight abstraction of the more extensive functionality abstracted by

DispatchService()

. This section describes the conceptual relationship between the protocol

member functions and I/O requests.

The

GetMode()

function can be implemented via remembering the values passed to the previous

call to

SetMode()

The

SetMode()

function can be implemented via an

UgaIoSetVideoMode

I/O request. The

actual geometry of screen can be read via an

UgaIoGetMemoryConfiguration

I/O request.

The

Blt()

function can be implemented via an

UgaIoCopyRectangle

I/O request.

10.9.1 UGA

System

Requirements

This section defines the requirements a system must meet to support an EFI 1.10 UGA driver. A
system could be defined as an EFI firmware implementation or a Virtual Machine (VM) that runs
under an OS.