Skip to content

Latest commit

 

History

History
90 lines (63 loc) · 3.34 KB

nf-video-videoportgetromimage.md

File metadata and controls

90 lines (63 loc) · 3.34 KB
UID title description old-location tech.root ms.date keywords ms.keywords req.header req.include-header req.target-type req.target-min-winverclnt req.target-min-winversvr req.kmdf-ver req.umdf-ver req.ddi-compliance req.unicode-ansi req.idl req.max-support req.namespace req.assembly req.type-library req.lib req.dll req.irql targetos req.typenames f1_keywords topic_type api_type api_location api_name
NF:video.VideoPortGetRomImage
VideoPortGetRomImage function (video.h)
The VideoPortGetRomImage function (video.h) reads the device's read-only memory (ROM) and returns a pointer to a buffer containing the device's ROM (BIOS) data.
display\videoportgetromimage.htm
display
05/10/2018
VideoPortGetRomImage function
VideoPortGetRomImage, VideoPortGetRomImage function [Display Devices], VideoPort_Functions_070e50af-a33d-4dc5-9bd1-9f60367f49b2.xml, display.videoportgetromimage, video/VideoPortGetRomImage
video.h
Video.h
Desktop
Available in Windows 2000 and later versions of the Windows operating systems.
Videoprt.lib
Videoprt.sys
PASSIVE_LEVEL
Windows
VideoPortGetRomImage
video/VideoPortGetRomImage
APIRef
kbSyntax
DllExport
Videoprt.sys
VideoPortGetRomImage

VideoPortGetRomImage function

-description

Reads the device's read-only memory (ROM).

-parameters

-param HwDeviceExtension [in]

A pointer to the miniport driver's device extension.

-param Unused1 [in]

Currently ignored by the video port driver; should be set to NULL.

-param Unused2 [in]

Currently ignored by the video port driver; should be set to zero.

-param Length [in]

Either the number of bytes of ROM data that the video port driver should read and return, or zero.

-returns

VideoPortGetRomImage returns a pointer to a buffer containing the device's ROM (BIOS) data on success; otherwise, returns NULL to indicate either there was insufficient memory for the operation, or the device's ROM could not be accessed.

-remarks

VideoPortGetRomImage does not read ROM using the legacy 0xC0000 mapping. It reads ROM that can be discovered using the ACPI_METHOD_DISPLAY_ROM method or the ROM base address register.

The ACPI_METHOD_DISPLAY_ROM alias, defined in Dispmprt.h, represents the method used to obtain the BIOS ROM image. This method is required when the ROM image is stored in a proprietary format such as the system BIOS ROM. This method is not necessary if the ROM image can be read through a standard PCI interface.

The video port driver allocates a buffer of Length bytes and fills it with data read from the device's ROM. The video port driver always reads Length bytes from the beginning of the device's ROM.

If a miniport driver calls VideoPortGetRomImage multiple times, the video port driver will free the buffer from a previous call before allocating and returning a buffer in the current call. Consequently, a miniport driver must only reference the pointer returned by this call to VideoPortGetRomImage.

The miniport driver can free the buffer allocated by the video port driver by calling VideoPortGetRomImage with a Length of zero.

-see-also

VideoPortScanRom