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VIDEO_PORT_CONFIG_INFO structure

The VIDEO_PORT_CONFIG_INFO structure contains bus-specific adapter configuration information. This structure is used to set up the video hardware and to supply the video port driver with configuration information. The video port driver can then allocate necessary system resources for the miniport driver and its adapter.

Syntax


typedef struct _VIDEO_PORT_CONFIG_INFO {
  ULONG                        Length;
  ULONG                        SystemIoBusNumber;
  INTERFACE_TYPE               AdapterInterfaceType;
  ULONG                        BusInterruptLevel;
  ULONG                        BusInterruptVector;
  KINTERRUPT_MODE              InterruptMode;
  ULONG                        NumEmulatorAccessEntries;
  PEMULATOR_ACCESS_ENTRY       EmulatorAccessEntries;
  ULONG_PTR                    EmulatorAccessEntriesContext;
  PHYSICAL_ADDRESS             VdmPhysicalVideoMemoryAddress;
  ULONG                        VdmPhysicalVideoMemoryLength;
  ULONG                        HardwareStateSize;
  ULONG                        DmaChannel;
  ULONG                        DmaPort;
  UCHAR                        DmaShareable;
  UCHAR                        InterruptShareable;
  BOOLEAN                      Master;
  DMA_WIDTH                    DmaWidth;
  DMA_SPEED                    DmaSpeed;
  BOOLEAN                      bMapBuffers;
  BOOLEAN                      NeedPhysicalAddresses;
  BOOLEAN                      DemandMode;
  ULONG                        MaximumTransferLength;
  ULONG                        NumberOfPhysicalBreaks;
  BOOLEAN                      ScatterGather;
  ULONG                        MaximumScatterGatherChunkSize;
  PVIDEO_PORT_GET_PROC_ADDRESS VideoPortGetProcAddress;
  PWSTR                        DriverRegistryPath;
  ULONGLONG                    SystemMemorySize;
} VIDEO_PORT_CONFIG_INFO, *PVIDEO_PORT_CONFIG_INFO;

Members

Length

Is the size in bytes of this structure. The video port driver always initializes the Length member. In effect, its value indicates the version of VIDEO_PORT_CONFIG_INFO being used by the system. Because this structure might grow from one version of the system to the next, a miniport driver should check this member to determine whether it is at least sizeof(VIDEO_PORT_CONFIG_INFO) that the miniport driver uses to configure its adapter.

SystemIoBusNumber

Specifies the system-assigned number of the I/O bus on which the miniport driver's adapter might be connected. The video port driver always initializes this member.

AdapterInterfaceType

Specifies the type of bus interface. The video port driver always sets this member based on the bus on which the PnP manager detected the device.

BusInterruptLevel

This member is irrelevant if the video hardware does not generate interrupts, indicated by setting the HwInterrupt member in the VIDEO_HW_INITIALIZATION_DATA structure to NULL. Otherwise, it specifies the bus-relative IRQL that corresponds to the interrupt request on Isa or MicroChannel type buses. The preset default value for this member is zero. A miniport driver must supply the correct value if it handles interrupts for a video adapter on an Isa or MicroChannel type bus, or for a video adapter configured for level-sensitive interrupts on an Eisa type bus.

If a miniport driver's HwVidFindAdapter function finds that the video adapter does not generate interrupts or that it cannot determine a valid interrupt vector/level for the adapter, HwVidFindAdapter should set both BusInterruptLevel and BusInterruptVector to zero.

BusInterruptVector

This member is irrelevant if the video hardware does not generate interrupts, indicated by setting the HwInterrupt member in the VIDEO_HW_INITIALIZATION_DATA structure to NULL. Otherwise, it specifies the bus-relative vector used by the video hardware on I/O buses that use interrupt vectors, such as PCI buses. The preset default value for this member is zero.

If a miniport driver's HwVidFindAdapter function finds that the video adapter does not generate interrupts or that it cannot determine a valid interrupt vector/level for the adapter, HwVidFindAdapter should set both BusInterruptVector and BusInterruptLevel to zero.

InterruptMode

Indicates whether the video hardware uses Latched or LevelSensitive interrupts. The video port driver initializes this member if it is relevant, but a miniport driver with an ISR should check that it contains the correct value and reset it if necessary.

NumEmulatorAccessEntries

This member and all subsequent members through HardwareStateSize are irrelevant to miniport drivers that do not declare themselves to be VGA-compatible miniport drivers on x86-based NT-based operating system platforms. For miniport drivers that do not support VGA-compatible SVGA adapters on x86-based machines, this member should be zero. Otherwise, it specifies the number of EMULATOR_ACCESS_RANGE-type elements in the following array.

EmulatorAccessEntries

Pointer to an array of emulator access ranges set up by the VGA-compatible miniport driver. Each emulator access range must be a proper subset of the miniport driver's VIDEO_ACCESS_RANGE-type array. Each element specifies a range of I/O ports to be hooked out by the V86 emulator and, possibly, monitored by a driver-supplied SvgaHwIoPortXxx function whenever an MS-DOS application, running full screen, attempts to write directly to the video adapter registers. Usually, this array describes all I/O port ranges in the corresponding access ranges array. If the miniport driver defines its array of emulator access entries statically in the driver itself, the port driver initializes this pointer to that array. If NumEmulatorAccessEntries is zero, this member is NULL.

EmulatorAccessEntriesContext

Specifies a value passed with each call to an SvgaHwIoPortXxx function described in the EmulatorAccessEntries array. Usually, a VGA-compatible miniport driver sets the value of this member to the HwDeviceExtension pointer, or to an offset within the device extension, so the miniport driver can maintain state, such as batched application-issued instructions, in its SvgaHwIoPortXxx functions.

VdmPhysicalVideoMemoryAddress

Specifies the base (mapped) logical address of a range of video memory to be mapped into a VDM's address space for x86 BIOS INT10 support. For miniport drivers that do not support VGA-compatible adapters on x86-based machines, this member should be NULL.

VdmPhysicalVideoMemoryLength

Specifies the size in bytes of the range be mapped into a VDM's address space for x86 BIOS support. For miniport drivers that do not support VGA-compatible adapters on x86-based machines, this member should be zero.

HardwareStateSize

Specifies the minimum size in bytes required to store hardware state information in response to an IOCTL_VIDEO_SAVE_HARDWARE_STATE request, which must be supported only by VGA-compatible miniport drivers on x86-based machines. The initialized value for this member is zero. A VGA-compatible miniport driver must set this member to the number of bytes it requires to hold saved adapter state.

DmaChannel

Reserved for system use.

DmaPort

Reserved for system use.

DmaShareable

Reserved for system use.

InterruptShareable

If the miniport driver's device interrupts, this member should be set to zero if the interrupt cannot be shared with another device, or set to one if the interrupt can be shared. Otherwise, a miniport driver can ignore this member.

Master

Reserved for system use.

DmaWidth

Reserved for system use.

DmaSpeed

Reserved for system use.

bMapBuffers

Reserved for system use.

NeedPhysicalAddresses

Reserved for system use.

DemandMode

Reserved for system use.

MaximumTransferLength

Reserved for system use.

NumberOfPhysicalBreaks

Reserved for system use.

ScatterGather

Reserved for system use.

MaximumScatterGatherChunkSize

Reserved for system use.

VideoPortGetProcAddress

Pointer to the VideoPortGetProcAddress callback routine. This member is used to find the address of a video port driver function that the video miniport driver can use without linking to it directly. This enables a driver binary to run on an earlier version of Windows. For details, see Using VideoPortGetProcAddress.

DriverRegistryPath

Pointer to the registry path containing the device's service. The display driver can use this information in any way it deems useful.

SystemMemorySize

Indicates to a driver the amount, in bytes, of physical memory in the system.

Requirements

Header

Video.h (include Video.h)

See also

HwVidFindAdapter
IOCTL_VIDEO_SAVE_HARDWARE_STATE
VIDEO_ACCESS_RANGE
VIDEO_HW_INITIALIZATION_DATA
VideoPortGetProcAddress
VideoPortGetAccessRanges
VideoPortGetDeviceBase
VideoPortGetDeviceData
VideoPortVerifyAccessRanges

 

 

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