Intel Extensible Firmware Interface - Manual (Page 323)

Protocols — Console Support
Version 1.10 12/01/02 10-29
EFI_UGA_DRAW_PROTOCOL.SetMode()
Summary
Set the video device into the specified mode and clears the output display to black.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_UGA_DRAW_PROTOCOL_SET_MODE) (
IN EFI_UGA_DRAW_PROTOCOL *This,
IN UINT32 HorizontalResolution,
IN UINT32 VerticalResolution,
IN UINT32 ColorDepth,
IN UINT32 RefreshRate
);
Parameters
This The EFI_UGA_DRAW_PROTOCOL instance. Type
EFI_UGA_DRAW_PROTOCOL is defined in Section 10.5.
HorizontalResolution The size of video screen in pixels in the X dimension.
VerticalResolution The size of video screen in pixels in the Y dimension.
ColorDepth Number of bits per pixel, currently defined to be 32.
RefreshRate The refresh rate of the monitor in Hertz.
Description
This SetMode() function sets the output device to the video mode specified by
HorizontalResolution , VerticalResolution , and RefreshRate . If any of the
arguments ( HorizontalResolution , VerticalResolution , or RefreshRate ) are
not supported EFI_UNSUPPORTED is returned.
If a device error occurs while attempt to set the video mode, then EFI_DEVICE_ERROR is
returned. On success the device is in the requested geometry and the hardware frame buffer
has been cleared to black (Red = 0, Green = 0, Blue = 0) and any enabled video display device
is updated.